Weather

Hurricane Helene Forecast Discussion Number 9

National Hurricane Center - Wed, 09/25/2024 - 9:57am
Issued at 1000 AM CDT Wed Sep 25 2024 000 WTNT44 KNHC 251457 TCDAT4 Hurricane Helene Discussion Number 9 NWS National Hurricane Center Miami FL AL092024 1000 AM CDT Wed Sep 25 2024 Air Force Reserve and NOAA Hurricane Hunter aircraft have been investigating Helene, with each plane recently measuring peak flight-level winds of 81 kt and 78 kt, respectively. Helene has therefore become a hurricane with an estimated intensity of 70 kt. Dropsonde data also indicate that the pressure has fallen to about 979 mb. Radar data from Mexico and Cuba, as well as reconnaissance reports, indicate that Helene has formed a partial, elliptical eyewall that is open on the east side. Helene has turned north-northwestward (330/9 kt) and is expected to turn northward and north-northeastward later today and tonight, bringing the center to the coast of the Florida Big Bend Thursday evening. After landfall, Helene is expected to interact with a deep-layer trough over the Lower Mississippi Valley and swing back to the northwest and stall near the Tennessee Valley late Friday into the weekend. The track guidance remains tightly clustered, and the NHC forecast is generally just an update of the previous prediction. It is still too soon at this point to be overly focused on an exact landfall location and time, since NHC track forecasts can be off by an average of 60 nm at the 36-hour forecast time. Helene is expected to move through/over an environment of relatively low shear, strong upper-level divergence, and sea surface temperatures of 29-31 degrees Celsius, all of which should foster additional strengthening. Rapid Intensification (RI) indices indicate a high chance of RI during the next 24 hours, and as a result the NHC intensity forecast shows Helene becoming a major hurricane by Thursday morning. There is still some uncertainty on exactly how strong Helene will get, and upward adjustments to the forecast intensity could be required in subsequent advisories if Helene rapidly intensifies more than forecast. Regardless, Helene is forecast to be a large major hurricane when it reaches the Big Bend coast of Florida. As a result, storm surge, wind, and rainfall impacts will likely extend well away from the center and outside the forecast cone, particularly on the east side. In addition, the fast forward speed while Helene crosses the coast will likely result in farther inland penetration of strong winds over parts of the southeastern United States after landfall, including strong gusts over higher terrain of the southern Appalachians. KEY MESSAGES: 1. Hurricane and tropical storm conditions are expected over northeastern portions of the Yucatan Peninsula of Mexico today where Tropical Storm and Hurricane Warnings are in effect. Tropical storm conditions are occurring over portions of western Cuba within the Tropical Storm Warning area, and hurricane conditions are possible today within the Hurricane Watch area. 2. Due to the large size of Helene, there is a danger of life-threatening storm surge along the entire west coast of the Florida Peninsula and Florida Big Bend. The highest inundation of greater than 10 ft is expected along the Florida Big Bend coast. Residents in those areas should follow advice given by local officials and evacuate if told to do so. 3. Devastating hurricane-force winds are expected across portions of northern Florida and southern Georgia where the core of Helene moves inland. Preparations to protect life and property should be completed by early Thursday since tropical storm conditions are expected to begin within these areas on Thursday. Because of Helene’s expected fast forward speed, damaging and life-threatening wind gusts, are expected to penetrate well inland over portions of the southeastern United States, including in the higher terrain of the southern Appalachians. 4. Helene will bring heavy rain to portions of the western Caribbean with potentially significant flooding across western Cuba and the northeastern Yucatan Peninsula into early Thursday. Considerable and potentially life-threatening flash and urban flooding is expected across portions of northwestern and northern Florida, the Southeast, southern Appalachians, and the Upper Tennessee Valley Wednesday through Friday. This includes the risk of landslides across the southern Appalachians. Widespread minor to moderate river flooding is likely, and isolated major river flooding is possible. FORECAST POSITIONS AND MAX WINDS INIT 25/1500Z 21.6N 86.3W 70 KT 80 MPH 12H 26/0000Z 23.0N 86.4W 85 KT 100 MPH 24H 26/1200Z 25.7N 85.7W 105 KT 120 MPH 36H 27/0000Z 29.7N 84.6W 110 KT 125 MPH 48H 27/1200Z 34.3N 85.0W 50 KT 60 MPH...INLAND 60H 28/0000Z 36.6N 86.9W 30 KT 35 MPH...POST-TROP/INLAND 72H 28/1200Z 36.9N 87.8W 20 KT 25 MPH...POST-TROP/INLAND 96H 29/1200Z 36.6N 87.9W 15 KT 15 MPH...POST-TROP/INLAND 120H 30/1200Z...DISSIPATED $$ Forecaster Berg
Categories: Weather

Summary for Hurricane Helene (AT4/AL092024)

National Hurricane Center - Wed, 09/25/2024 - 9:57am
...HELENE BECOMES A HURRICANE... ...EXPECTED TO BRING LIFE-THREATENING STORM SURGE, DAMAGING WINDS, AND FLOODING RAINS TO A LARGE PORTION OF FLORIDA AND THE SOUTHEASTERN UNITED STATES... As of 10:00 AM CDT Wed Sep 25 the center of Helene was located near 21.6, -86.3 with movement NNW at 10 mph. The minimum central pressure was 979 mb with maximum sustained winds of about 80 mph.
Categories: Weather

Hurricane Helene Public Advisory Number 9

National Hurricane Center - Wed, 09/25/2024 - 9:57am
Issued at 1000 AM CDT Wed Sep 25 2024 000 WTNT34 KNHC 251457 TCPAT4 BULLETIN Hurricane Helene Advisory Number 9 NWS National Hurricane Center Miami FL AL092024 1000 AM CDT Wed Sep 25 2024 ...HELENE BECOMES A HURRICANE... ...EXPECTED TO BRING LIFE-THREATENING STORM SURGE, DAMAGING WINDS, AND FLOODING RAINS TO A LARGE PORTION OF FLORIDA AND THE SOUTHEASTERN UNITED STATES... SUMMARY OF 1000 AM CDT...1500 UTC...INFORMATION ----------------------------------------------- LOCATION...21.6N 86.3W ABOUT 85 MI...135 KM NNE OF COZUMEL MEXICO ABOUT 500 MI...810 KM SSW OF TAMPA FLORIDA MAXIMUM SUSTAINED WINDS...80 MPH...130 KM/H PRESENT MOVEMENT...NNW OR 330 DEGREES AT 10 MPH...17 KM/H MINIMUM CENTRAL PRESSURE...979 MB...28.91 INCHES WATCHES AND WARNINGS -------------------- CHANGES WITH THIS ADVISORY: The Tropical Storm Warning has been extended northward along the coasts of Georgia and South Carolina to South Santee River, and westward along the Florida Gulf coast to the Okaloosa/Walton County Line. A Storm Surge Watch has been issued from Mexico Beach to Indian Pass, Florida. A Tropical Storm Watch has been issued along the coast of South Carolina north of South Santee River to Little River Inlet. SUMMARY OF WATCHES AND WARNINGS IN EFFECT: A Storm Surge Warning is in effect for... * Indian Pass southward to Flamingo * Tampa Bay * Charlotte Harbor A Hurricane Warning is in effect for... * Anclote River to Mexico Beach * Cabo Catoche to Tulum, Mexico including Cozumel A Storm Surge Watch is in effect for... * West of Indian Pass to Mexico Beach A Hurricane Watch is in effect for... * Cuban province of Pinar del Rio * Englewood to Anclote River, including Tampa Bay A Tropical Storm Warning is in effect for... * Florida Keys, including the Dry Tortugas * Flamingo to Anclote River, including Tampa Bay * West of Mexico Beach to the Okaloosa/Walton County Line * Flamingo northward to South Santee River * Lake Okeechobee * Rio Lagartos to Cabo Catoche, Mexico * Cuban provinces of Artemisa, Pinar del Rio, and the Isle of Youth A Tropical Storm Watch is in effect for... * North of South Santee River to Little River Inlet A Storm Surge Warning means there is a danger of life-threatening inundation, from rising water moving inland from the coastline, during the next 36 hours in the indicated locations. For a depiction of areas at risk, please see the National Weather Service Storm Surge Watch/Warning Graphic, available at hurricanes.gov. This is a life-threatening situation. Persons located within these areas should take all necessary actions to protect life and property from rising water and the potential for other dangerous conditions. Promptly follow evacuation and other instructions from local officials. A Hurricane Warning means that hurricane conditions are expected somewhere within the warning area. A warning is typically issued 36 hours before the anticipated first occurrence of tropical-storm-force winds, conditions that make outside preparations difficult or dangerous. Preparations to protect life and property should be rushed to completion. A Tropical Storm Warning means that tropical storm conditions are expected somewhere within the warning area within the next 36 hours. A Storm Surge Watch means there is a possibility of life- threatening inundation, from rising water moving inland from the coastline, in the indicated locations during the next 48 hours. For a depiction of areas at risk, please see the National Weather Service Storm Surge Watch/Warning Graphic, available at hurricanes.gov. A Hurricane Watch means that hurricane conditions are possible within the watch area. A watch is typically issued 48 hours before the anticipated first occurrence of tropical-storm-force winds, conditions that make outside preparations difficult or dangerous. A Tropical Storm Watch means that tropical storm conditions are possible within the watch area. Additional watches or warnings may be required later today. For storm information specific to your area in the United States, including possible inland watches and warnings, please monitor products issued by your local National Weather Service forecast office. For storm information specific to your area outside of the United States, please monitor products issued by your national meteorological service. DISCUSSION AND OUTLOOK ---------------------- At 1000 AM CDT (1500 UTC), the center of Hurricane Helene was located near latitude 21.6 North, longitude 86.3 West. Helene is moving toward the north-northwest near 10 mph (17 km/h). A turn toward the north and north-northeast with an increase in forward speed is expected later today through Thursday, bringing the center of Helene across the eastern Gulf of Mexico and to the Florida Big Bend coast by Thursday evening. After landfall, Helene is expected to slow down and turn toward the northwest over the southeastern United States Friday and Saturday. Data from NOAA and Air Force Reserve Hurricane Hunter aircraft indicate that maximum sustained winds have increased to near 80 mph (130 km/h) with higher gusts. Additional strengthening is forecast, and Helene is expected to be a major hurricane when it reaches the Florida Big Bend coast Thursday evening. Weakening is expected after landfall, but Helene's fast forward speed will allow strong, damaging winds, especially in gusts, to penetrate well inland across the southeastern United States, including over the higher terrain of the southern Appalachians. Hurricane-force winds extend outward up to 25 miles (35 km) from the center and tropical-storm-force winds extend outward up to 275 miles (445 km). The minimum central pressure based on dropsonde is 979 mb (28.91 inches). HAZARDS AFFECTING LAND ---------------------- Key Messages for Helene can be found in the Tropical Cyclone Discussion under AWIPS header MIATCDAT4 and WMO header WTNT44 KNHC and on the web at hurricanes.gov/text/MIATCDAT4.shtml STORM SURGE: The combination of a dangerous storm surge and the tide will cause normally dry areas near the coast to be flooded by rising waters moving inland from the shoreline. The water could reach the following heights above ground somewhere in the indicated areas if the peak surge occurs at the time of high tide... Carrabelle, FL to Chassahowitzka, FL...10-15 ft Chassahowitzka, FL to Anclote River, FL...6-10 ft Indian Pass, FL to Carrabelle, FL...6-10 ft Anclote River, FL to Middle of Longboat Key, FL...5-8 ft Tampa Bay...5-8 ft Middle of Longboat Key, FL to Englewood, FL...4-7 ft Englewood, FL to Flamingo, FL...3-5 ft Charlotte Harbor...3-5 ft For a complete depiction of areas at risk of storm surge inundation, please see the National Weather Service Peak Storm Surge Graphic, available at hurricanes.gov/graphics_at4.shtml?peakSurge. Storm surge could raise water levels by as much as 2 to 4 feet above normal tide levels in areas of onshore winds along the southern coast of Pinar del Rio, Cuba, including the Isle of Youth. Storm surge could raise water levels by as much as 2 to 4 feet above ground level in areas of onshore winds within the warning area along the east coast of the Yucatan Peninsula. WIND: Hurricane conditions are expected within the U.S. hurricane warning area late Thursday, with tropical storm conditions beginning Thursday morning. Tropical storm conditions are expected in southern Florida later today and will spread northward across the rest of Florida, Georgia, and South Carolina through Thursday. Tropical storm conditions are possible within the tropical storm watch area in South Carolina beginning on Thursday. Hurricane conditions, especially in gusts, are expected in the hurricane warning area in Mexico during the next several hours. Tropical storm conditions are occurring in the warning area in Cuba, and hurricane conditions are possible for the western portion of Cuba today. RAINFALL: Helene is expected to produce total rain accumulations of 4 to 8 inches over western Cuba, the Cayman Islands, and the northeast Yucatan Peninsula, with isolated totals around 12 inches. This rainfall brings a risk of considerable flooding. Over the Southeastern U.S. into the Southern Appalachians, Helene is expected to produce total rain accumulations of 5 to 10 inches with isolated totals around 15 inches. This rainfall will likely result in areas of considerable flash and urban flooding, with areas of significant river flooding. Landslides are possible in areas of steep terrain in the southern Appalachians. For a complete depiction of forecast rainfall associated with Helene, please see the National Weather Service Storm Total Rainfall Graphic, available at hurricanes.gov/graphics_at4.shtml?rainqpf and the Flash Flood Risk graphic at hurricanes.gov/graphics_at4.shtml?ero. TORNADOES: A tornado or two may occur tonight over parts of the Florida Peninsula and southern Alabama. The risk of tornadoes will increase on Thursday, expanding northward across Florida into parts of Georgia and South Carolina. SURF: Swells generated by Helene will affect the southern coast of Cuba and the Yucatan Peninsula of Mexico during the next couple of days. Swells will spread northward toward the west coast of Florida and the northeastern Gulf Coast later today and Thursday. These swells are likely to cause life-threatening surf and rip current conditions. Please consult products from your local weather office. NEXT ADVISORY ------------- Next intermediate advisory at 100 PM CDT. Next complete advisory at 400 PM CDT. $$ Forecaster Berg
Categories: Weather

Hurricane Helene Wind Speed Probabilities Number 9

National Hurricane Center - Wed, 09/25/2024 - 9:57am
Issued at 1500 UTC WED SEP 25 2024 000 FONT14 KNHC 251457 PWSAT4 HURRICANE HELENE WIND SPEED PROBABILITIES NUMBER 9 NWS NATIONAL HURRICANE CENTER MIAMI FL AL092024 1500 UTC WED SEP 25 2024 AT 1500Z THE CENTER OF HURRICANE HELENE WAS LOCATED NEAR LATITUDE 21.6 NORTH...LONGITUDE 86.3 WEST WITH MAXIMUM SUSTAINED WINDS NEAR 70 KTS...80 MPH...130 KM/H. Z INDICATES COORDINATED UNIVERSAL TIME (GREENWICH) ATLANTIC STANDARD TIME (AST)...SUBTRACT 4 HOURS FROM Z TIME EASTERN DAYLIGHT TIME (EDT)...SUBTRACT 4 HOURS FROM Z TIME CENTRAL DAYLIGHT TIME (CDT)...SUBTRACT 5 HOURS FROM Z TIME WIND SPEED PROBABILITY TABLE FOR SPECIFIC LOCATIONS CHANCES OF SUSTAINED (1-MINUTE AVERAGE) WIND SPEEDS OF AT LEAST ...34 KT (39 MPH... 63 KM/H)... ...50 KT (58 MPH... 93 KM/H)... ...64 KT (74 MPH...119 KM/H)... FOR LOCATIONS AND TIME PERIODS DURING THE NEXT 5 DAYS PROBABILITIES FOR LOCATIONS ARE GIVEN AS OP(CP) WHERE OP IS THE PROBABILITY OF THE EVENT BEGINNING DURING AN INDIVIDUAL TIME PERIOD (ONSET PROBABILITY) (CP) IS THE PROBABILITY OF THE EVENT OCCURRING BETWEEN 12Z WED AND THE FORECAST HOUR (CUMULATIVE PROBABILITY) PROBABILITIES ARE GIVEN IN PERCENT X INDICATES PROBABILITIES LESS THAN 1 PERCENT PROBABILITIES FOR 34 KT AND 50 KT ARE SHOWN AT A GIVEN LOCATION WHEN THE 5-DAY CUMULATIVE PROBABILITY IS AT LEAST 3 PERCENT. PROBABILITIES FOR 34...50...64 KT SHOWN WHEN THE 5-DAY 64-KT CUMULATIVE PROBABILITY IS AT LEAST 1 PERCENT. - - - - WIND SPEED PROBABILITIES FOR SELECTED LOCATIONS - - - - FROM FROM FROM FROM FROM FROM FROM TIME 12Z WED 00Z THU 12Z THU 00Z FRI 12Z FRI 12Z SAT 12Z SUN PERIODS TO TO TO TO TO TO TO 00Z THU 12Z THU 00Z FRI 12Z FRI 12Z SAT 12Z SUN 12Z MON FORECAST HOUR (12) (24) (36) (48) (72) (96) (120) - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - LOCATION KT CHARLOTTE NC 34 X X( X) X( X) 4( 4) X( 4) X( 4) X( 4) FLORENCE SC 34 X X( X) X( X) 4( 4) X( 4) X( 4) X( 4) COLUMBIA SC 34 X X( X) 1( 1) 6( 7) X( 7) X( 7) X( 7) LITTLE RIVER 34 X X( X) X( X) 3( 3) X( 3) X( 3) X( 3) MYRTLE BEACH 34 X X( X) X( X) 5( 5) X( 5) X( 5) X( 5) GEORGETOWN SC 34 X X( X) 1( 1) 2( 3) X( 3) X( 3) X( 3) CHARLESTON SC 34 X X( X) 5( 5) 10(15) X(15) X(15) X(15) BEAUFORT MCAS 34 X X( X) 11(11) 16(27) X(27) X(27) X(27) ATLANTA GA 34 X X( X) 4( 4) 57(61) 1(62) X(62) X(62) AUGUSTA GA 34 X X( X) 5( 5) 15(20) X(20) X(20) X(20) SAVANNAH GA 34 X X( X) 8( 8) 9(17) X(17) X(17) X(17) KINGS BAY GA 34 X X( X) 43(43) 8(51) X(51) X(51) X(51) KINGS BAY GA 50 X X( X) 3( 3) 3( 6) X( 6) X( 6) X( 6) WAYCROSS GA 34 X X( X) 41(41) 16(57) X(57) X(57) X(57) WAYCROSS GA 50 X X( X) 3( 3) 5( 8) X( 8) X( 8) X( 8) MAYPORT NS FL 34 X X( X) 43(43) 7(50) X(50) X(50) X(50) MAYPORT NS FL 50 X X( X) 3( 3) 2( 5) X( 5) X( 5) X( 5) JACKSONVILLE 34 X X( X) 36(36) 6(42) X(42) X(42) X(42) JACKSONVILLE 50 X X( X) 2( 2) 2( 4) X( 4) X( 4) X( 4) GAINESVILLE FL 34 X 4( 4) 60(64) 2(66) X(66) X(66) X(66) GAINESVILLE FL 50 X X( X) 10(10) 1(11) X(11) X(11) X(11) GAINESVILLE FL 64 X X( X) 1( 1) X( 1) X( 1) X( 1) X( 1) DAYTONA BEACH 34 X 2( 2) 22(24) 1(25) X(25) X(25) X(25) THE VILLAGES 34 X 6( 6) 47(53) X(53) X(53) X(53) X(53) THE VILLAGES 50 X X( X) 6( 6) X( 6) X( 6) X( 6) X( 6) ORLANDO FL 34 X 5( 5) 21(26) 1(27) X(27) X(27) X(27) COCOA BEACH FL 34 X 4( 4) 25(29) 1(30) X(30) X(30) X(30) PATRICK AFB 34 X 4( 4) 26(30) 1(31) X(31) X(31) X(31) FT PIERCE FL 34 X 4( 4) 16(20) 1(21) X(21) X(21) X(21) W PALM BEACH 34 X 4( 4) 11(15) X(15) X(15) X(15) X(15) FT LAUDERDALE 34 X 5( 5) 7(12) X(12) X(12) X(12) X(12) MIAMI FL 34 X 4( 4) 3( 7) X( 7) X( 7) X( 7) X( 7) HOMESTEAD ARB 34 X 5( 5) 2( 7) X( 7) X( 7) X( 7) X( 7) MARATHON FL 34 2 15(17) 4(21) X(21) X(21) X(21) X(21) KEY WEST FL 34 11 20(31) 4(35) X(35) X(35) X(35) X(35) NAPLES FL 34 1 28(29) 16(45) X(45) X(45) X(45) X(45) FT MYERS FL 34 X 17(17) 17(34) X(34) X(34) X(34) X(34) VENICE FL 34 1 36(37) 31(68) X(68) X(68) X(68) X(68) VENICE FL 50 X 1( 1) 9(10) X(10) X(10) X(10) X(10) VENICE FL 64 X X( X) 1( 1) X( 1) X( 1) X( 1) X( 1) TAMPA FL 34 X 24(24) 48(72) 1(73) X(73) X(73) X(73) TAMPA FL 50 X 1( 1) 14(15) X(15) X(15) X(15) X(15) TAMPA FL 64 X X( X) 2( 2) X( 2) X( 2) X( 2) X( 2) CEDAR KEY FL 34 X 13(13) 72(85) 1(86) X(86) X(86) X(86) CEDAR KEY FL 50 X X( X) 42(42) 1(43) X(43) X(43) X(43) CEDAR KEY FL 64 X X( X) 12(12) 1(13) X(13) X(13) X(13) TALLAHASSEE FL 34 X 3( 3) 86(89) 6(95) X(95) X(95) X(95) TALLAHASSEE FL 50 X X( X) 53(53) 22(75) X(75) X(75) X(75) TALLAHASSEE FL 64 X X( X) 16(16) 21(37) X(37) X(37) X(37) ST MARKS FL 34 X 4( 4) 88(92) 4(96) X(96) X(96) X(96) ST MARKS FL 50 X X( X) 64(64) 13(77) X(77) X(77) X(77) ST MARKS FL 64 X X( X) 28(28) 15(43) X(43) X(43) X(43) APALACHICOLA 34 X 11(11) 81(92) 3(95) X(95) X(95) X(95) APALACHICOLA 50 X X( X) 78(78) 5(83) X(83) X(83) X(83) APALACHICOLA 64 X X( X) 56(56) 8(64) X(64) X(64) X(64) GFMX 290N 850W 34 X 20(20) 77(97) X(97) X(97) X(97) X(97) GFMX 290N 850W 50 X 2( 2) 86(88) 1(89) X(89) X(89) X(89) GFMX 290N 850W 64 X X( X) 69(69) 2(71) X(71) X(71) X(71) PANAMA CITY FL 34 X 9( 9) 70(79) 4(83) X(83) X(83) X(83) PANAMA CITY FL 50 X X( X) 53(53) 7(60) X(60) X(60) X(60) PANAMA CITY FL 64 X X( X) 24(24) 9(33) X(33) X(33) X(33) DESTIN EXEC AP 34 X 3( 3) 30(33) 7(40) X(40) X(40) X(40) DESTIN EXEC AP 50 X X( X) 9( 9) 5(14) X(14) X(14) X(14) DESTIN EXEC AP 64 X X( X) 2( 2) 2( 4) X( 4) X( 4) X( 4) ALBANY GA 34 X X( X) 51(51) 39(90) X(90) X(90) X(90) ALBANY GA 50 X X( X) 8( 8) 48(56) X(56) X(56) X(56) ALBANY GA 64 X X( X) X( X) 11(11) X(11) X(11) X(11) COLUMBUS GA 34 X X( X) 12(12) 66(78) X(78) X(78) X(78) COLUMBUS GA 50 X X( X) 1( 1) 28(29) X(29) X(29) X(29) MACON GA 34 X X( X) 10(10) 60(70) X(70) X(70) X(70) MACON GA 50 X X( X) X( X) 18(18) X(18) X(18) X(18) DOTHAN AL 34 X 1( 1) 48(49) 29(78) X(78) X(78) X(78) DOTHAN AL 50 X X( X) 9( 9) 36(45) X(45) X(45) X(45) DOTHAN AL 64 X X( X) 1( 1) 10(11) X(11) X(11) X(11) BIRMINGHAM AL 34 X X( X) 3( 3) 10(13) 1(14) X(14) X(14) MONTGOMERY AL 34 X X( X) 7( 7) 23(30) X(30) X(30) X(30) MONTGOMERY AL 50 X X( X) X( X) 8( 8) X( 8) X( 8) X( 8) WHITING FLD FL 34 X 2( 2) 12(14) 7(21) X(21) X(21) X(21) WHITING FLD FL 50 X X( X) 3( 3) 2( 5) X( 5) X( 5) X( 5) PENSACOLA FL 34 X 3( 3) 10(13) 4(17) X(17) X(17) X(17) PENSACOLA FL 50 X X( X) 3( 3) 1( 4) X( 4) X( 4) X( 4) GFMX 290N 870W 34 X 12(12) 33(45) 1(46) X(46) X(46) X(46) GFMX 290N 870W 50 X 1( 1) 11(12) X(12) X(12) X(12) X(12) GFMX 290N 870W 64 X X( X) 3( 3) X( 3) X( 3) X( 3) X( 3) MOBILE AL 34 X 1( 1) 5( 6) 1( 7) X( 7) X( 7) X( 7) GULFPORT MS 34 X X( X) 4( 4) 1( 5) X( 5) X( 5) X( 5) STENNIS MS 34 X X( X) 4( 4) X( 4) X( 4) X( 4) X( 4) BURAS LA 34 X 2( 2) 3( 5) X( 5) X( 5) X( 5) X( 5) GFMX 280N 890W 34 1 8( 9) 3(12) 1(13) X(13) X(13) X(13) NEW ORLEANS LA 34 X X( X) 2( 2) 1( 3) X( 3) X( 3) X( 3) GFMX 280N 910W 34 X 1( 1) 2( 3) X( 3) X( 3) X( 3) X( 3) MERIDA MX 34 4 1( 5) X( 5) X( 5) X( 5) X( 5) X( 5) COZUMEL MX 34 83 X(83) X(83) X(83) X(83) X(83) X(83) BELIZE CITY 34 3 X( 3) X( 3) X( 3) X( 3) X( 3) X( 3) CP SAN ANTONIO 34 99 X(99) X(99) X(99) X(99) X(99) X(99) CP SAN ANTONIO 50 30 1(31) X(31) X(31) X(31) X(31) X(31) HAVANA 34 13 8(21) 1(22) X(22) X(22) X(22) X(22) ISLE OF PINES 34 40 3(43) X(43) X(43) X(43) X(43) X(43) $$ FORECASTER BERG
Categories: Weather

Hurricane Helene Forecast Advisory Number 9

National Hurricane Center - Wed, 09/25/2024 - 9:56am
Issued at 1500 UTC WED SEP 25 2024 000 WTNT24 KNHC 251456 TCMAT4 HURRICANE HELENE FORECAST/ADVISORY NUMBER 9 NWS NATIONAL HURRICANE CENTER MIAMI FL AL092024 1500 UTC WED SEP 25 2024 HURRICANE CENTER LOCATED NEAR 21.6N 86.3W AT 25/1500Z POSITION ACCURATE WITHIN 20 NM PRESENT MOVEMENT TOWARD THE NORTH-NORTHWEST OR 330 DEGREES AT 9 KT ESTIMATED MINIMUM CENTRAL PRESSURE 979 MB MAX SUSTAINED WINDS 70 KT WITH GUSTS TO 85 KT. 64 KT....... 20NE 20SE 0SW 0NW. 50 KT....... 60NE 60SE 0SW 40NW. 34 KT.......210NE 240SE 60SW 90NW. 12 FT SEAS..180NE 180SE 90SW 90NW. WINDS AND SEAS VARY GREATLY IN EACH QUADRANT. RADII IN NAUTICAL MILES ARE THE LARGEST RADII EXPECTED ANYWHERE IN THAT QUADRANT. REPEAT...CENTER LOCATED NEAR 21.6N 86.3W AT 25/1500Z AT 25/1200Z CENTER WAS LOCATED NEAR 21.1N 86.2W FORECAST VALID 26/0000Z 23.0N 86.4W MAX WIND 85 KT...GUSTS 105 KT. 64 KT... 20NE 20SE 0SW 0NW. 50 KT... 70NE 80SE 30SW 40NW. 34 KT...270NE 270SE 90SW 120NW. FORECAST VALID 26/1200Z 25.7N 85.7W MAX WIND 105 KT...GUSTS 130 KT. 64 KT... 40NE 40SE 20SW 20NW. 50 KT...100NE 100SE 50SW 60NW. 34 KT...240NE 250SE 120SW 140NW. FORECAST VALID 27/0000Z 29.7N 84.6W MAX WIND 110 KT...GUSTS 135 KT. 64 KT... 40NE 40SE 20SW 25NW. 50 KT... 80NE 90SE 40SW 50NW. 34 KT...250NE 250SE 100SW 100NW. FORECAST VALID 27/1200Z 34.3N 85.0W...INLAND MAX WIND 50 KT...GUSTS 60 KT. 50 KT... 30NE 30SE 0SW 0NW. 34 KT... 70NE 330SE 40SW 40NW. FORECAST VALID 28/0000Z 36.6N 86.9W...POST-TROP/INLAND MAX WIND 30 KT...GUSTS 40 KT. FORECAST VALID 28/1200Z 36.9N 87.8W...POST-TROP/INLAND MAX WIND 20 KT...GUSTS 30 KT. EXTENDED OUTLOOK. NOTE...ERRORS FOR TRACK HAVE AVERAGED NEAR 125 NM ON DAY 4 AND 175 NM ON DAY 5...AND FOR INTENSITY NEAR 15 KT EACH DAY OUTLOOK VALID 29/1200Z 36.6N 87.9W...POST-TROP/INLAND MAX WIND 15 KT...GUSTS 20 KT. OUTLOOK VALID 30/1200Z...DISSIPATED REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 21.6N 86.3W INTERMEDIATE PUBLIC ADVISORY...WTNT34 KNHC/MIATCPAT4...AT 25/1800Z NEXT ADVISORY AT 25/2100Z $$ FORECASTER BERG
Categories: Weather

Summary for Tropical Storm Helene (AT4/AL092024)

National Hurricane Center - Wed, 09/25/2024 - 6:53am
...HELENE JUST OFFSHORE THE NORTHEASTERN COAST OF THE YUCATAN PENINSULA, CLOSE TO HURRICANE STRENGTH... As of 7:00 AM CDT Wed Sep 25 the center of Helene was located near 21.1, -86.2 with movement NW at 9 mph. The minimum central pressure was 979 mb with maximum sustained winds of about 70 mph.
Categories: Weather

Tropical Storm Helene Public Advisory Number 8A

National Hurricane Center - Wed, 09/25/2024 - 6:53am
Issued at 700 AM CDT Wed Sep 25 2024 000 WTNT34 KNHC 251153 TCPAT4 BULLETIN Tropical Storm Helene Intermediate Advisory Number 8A NWS National Hurricane Center Miami FL AL092024 700 AM CDT Wed Sep 25 2024 ...HELENE JUST OFFSHORE THE NORTHEASTERN COAST OF THE YUCATAN PENINSULA, CLOSE TO HURRICANE STRENGTH... SUMMARY OF 700 AM CDT...1200 UTC...INFORMATION ---------------------------------------------- LOCATION...21.1N 86.2W ABOUT 60 MI...100 KM ENE OF COZUMEL MEXICO ABOUT 100 MI...160 KM WSW OF THE WESTERN TIP OF CUBA MAXIMUM SUSTAINED WINDS...70 MPH...110 KM/H PRESENT MOVEMENT...NW OR 325 DEGREES AT 9 MPH...15 KM/H MINIMUM CENTRAL PRESSURE...979 MB...28.91 INCHES WATCHES AND WARNINGS -------------------- CHANGES WITH THIS ADVISORY: The Tropical Storm Warning has been extended northward to Altamaha Sound, Georgia. SUMMARY OF WATCHES AND WARNINGS IN EFFECT: A Storm Surge Warning is in effect for... * Indian Pass southward to Flamingo * Tampa Bay * Charlotte Harbor A Hurricane Warning is in effect for... * Anclote River to Mexico Beach, Florida * Cabo Catoche to Tulum, Mexico including Cozumel A Hurricane Watch is in effect for... * Cuban province of Pinar del Rio * Englewood to Anclote River, including Tampa Bay A Tropical Storm Warning is in effect for... * Dry Tortugas * All of the Florida Keys * The Florida west coast from Flamingo to Anclote River, including Tampa Bay * West of Mexico Beach to the Walton/Bay County Line * The Florida east coast from Flamingo northward to Altamaha Sound, Georgia * Lake Okeechobee * Rio Lagartos to Cabo Catoche, Mexico * Cuban provinces of Artemisa, Pinar del Rio, and the Isle of Youth A Tropical Storm Watch is in effect for... * Georgia and South Carolina coast north of Altamaha Sound to the South Santee River A Storm Surge Warning means there is a danger of life-threatening inundation, from rising water moving inland from the coastline, during the next 36 hours in the indicated locations. For a depiction of areas at risk, please see the National Weather Service Storm Surge Watch/Warning Graphic, available at hurricanes.gov. This is a life-threatening situation. Persons located within these areas should take all necessary actions to protect life and property from rising water and the potential for other dangerous conditions. Promptly follow evacuation and other instructions from local officials. A Hurricane Warning means that hurricane conditions are expected somewhere within the warning area. A warning is typically issued 36 hours before the anticipated first occurrence of tropical-storm-force winds, conditions that make outside preparations difficult or dangerous. Preparations to protect life and property should be rushed to completion. A Tropical Storm Warning means that tropical storm conditions are expected somewhere within the warning area within the next 36 hours. A Hurricane Watch means that hurricane conditions are possible within the watch area. A watch is typically issued 48 hours before the anticipated first occurrence of tropical-storm-force winds, conditions that make outside preparations difficult or dangerous. A Tropical Storm Watch means that tropical storm conditions are possible within the watch area. Additional watches or warnings may be required later today. For storm information specific to your area in the United States, including possible inland watches and warnings, please monitor products issued by your local National Weather Service forecast office. For storm information specific to your area outside of the United States, please monitor products issued by your national meteorological service. DISCUSSION AND OUTLOOK ---------------------- At 700 AM CDT (1200 UTC), the center of Tropical Storm Helene was located near latitude 21.1 North, longitude 86.2 West. Helene is moving toward the northwest near 9 mph (15 km/h). This motion should continue through this morning, followed by a general northward motion beginning later today and continuing through Friday. On the forecast track, the center of Helene will pass near the northeastern coast of the Yucatan Peninsula this morning, move across the eastern Gulf of Mexico on later today and Thursday, and reach the Big Bend coast of Florida late Thursday. Maximum sustained winds are now near 70 mph (110 km/h) with higher gusts. Additional strengthening is forecast, and Helene is expected to become a hurricane later today. The storm is forecast to rapidly strengthen over the eastern Gulf of Mexico and become a major hurricane on Thursday. Tropical-storm-force winds extend outward up to 175 miles (280 km) from the center. The minimum central pressure recently reported by an Air Force Reserve Hurricane Hunter aircraft is 979 mb (28.91 inches). HAZARDS AFFECTING LAND ---------------------- Key Messages for Helene can be found in the Tropical Cyclone Discussion under AWIPS header MIATCDAT4 and WMO header WTNT44 KNHC and on the web at hurricanes.gov/text/MIATCDAT4.shtml RAINFALL: Tropical Storm Helene is expected to produce total rain accumulations of 4 to 8 inches over western Cuba, the Cayman Islands and the northeast Yucatan Peninsula, with isolated totals around 12 inches. This rainfall brings a risk of considerable flooding. Over the Southeastern U.S., Helene is expected to produce total rain accumulations of 5 to 10 inches with isolated totals around 15 inches. This rainfall will likely result in areas of considerable flash and urban flooding, with areas of significant river flooding. Landslides are possible in areas of steep terrain in the southern Appalachians. For a complete depiction of forecast rainfall associated with Tropical Storm Helene, please see the National Weather Service Storm Total Rainfall Graphic, available at hurricanes.gov/graphics_at4.shtml?rainqpf and the Flash Flood Risk graphic at hurricanes.gov/graphics_at4.shtml?ero. STORM SURGE: The combination of a dangerous storm surge and the tide will cause normally dry areas near the coast to be flooded by rising waters moving inland from the shoreline. The water could reach the following heights above ground somewhere in the indicated areas if the peak surge occurs at the time of high tide... Ochlockonee River, FL to Chassahowitzka, FL...10-15 ft Chassahowitzka, FL to Anclote River, FL...6-10 ft Indian Pass, FL to Ochlockonee River, FL...5-10 ft Anclote River, FL to Middle of Longboat Key, FL...5-8 ft Tampa Bay...5-8 ft Middle of Longboat Key, FL to Englewood, FL...4-7 ft Englewood, FL to Flamingo, FL...3-5 ft Charlotte Harbor...3-5 ft For a complete depiction of areas at risk of storm surge inundation, please see the National Weather Service Peak Storm Surge Graphic, available at hurricanes.gov/graphics_at4.shtml?peakSurge. Storm surge could raise water levels by as much as 2 to 4 feet above normal tide levels in areas of onshore winds along the southern coast of Pinar del Rio, Cuba, including the Isle of Youth. Storm surge could raise water levels by as much as 2 to 4 feet above ground level in areas of onshore winds within the warning area along the east coast of the Yucatan Peninsula. WIND: Hurricane conditions are expected in the hurricane warning area in Mexico during the next several hours, with tropical storm conditions already ongoing. Hurricane conditions are expected within the U.S. hurricane warning area late Thursday. Hurricane conditions are possible for the western portion of Cuba later today. Tropical storm conditions are expected to begin in the warning area in Cuba during the next several hours. Tropical storm conditions are expected in southern Florida later today and spreading northward through Thursday. Tropical storm conditions are possible within the tropical storm watch area beginning Thursday and Thursday night. TORNADOES: A tornado or two may occur tonight over parts of the western Florida peninsula and southern Alabama. The risk of tornadoes will increase on Thursday, expanding across Florida and into parts of Georgia and South Carolina. SURF: Swells generated by Helene will affect the southern coast of Cuba and the Yucatan Peninsula of Mexico during the next couple of days. Swells will spread northward toward the west coast of Florida and the northeastern Gulf Coast later today and Thursday. These swells are likely to cause life-threatening surf and rip current conditions. Please consult products from your local weather office. NEXT ADVISORY ------------- Next complete advisory at 1000 AM CDT. $$ Forecaster Berg
Categories: Weather

Atlantic Tropical Weather Outlook

National Hurricane Center - Wed, 09/25/2024 - 6:52am

000
ABNT20 KNHC 251152
TWOAT

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
800 AM EDT Wed Sep 25 2024

For the North Atlantic...Caribbean Sea and the Gulf of Mexico:

Active Systems:
The National Hurricane Center is issuing advisories on Tropical
Storm Helene, located over the northwestern Caribbean Sea.

Eastern and Central Tropical Atlantic (AL98):
A broad low pressure system associated with a tropical wave located
west of the Cabo Verde Islands continues to produce disorganized
shower and thunderstorm activity. Environmental conditions appear
favorable for gradual development of this system, and a tropical
depression is likely to form in a few days while it moves westward
to west-northwestward across the eastern and central tropical
Atlantic.
* Formation chance through 48 hours...medium...50 percent.
* Formation chance through 7 days...high...80 percent.

Central Subtropical Atlantic (AL99):
A non-tropical area of low pressure is currently located several
hundred miles to the northeast of Bermuda. The system is currently
producing winds up to storm force, and environmental conditions
could support some subtropical or tropical development over the next
several days as the system moves generally eastward, remaining over
the open waters of central Subtropical Atlantic. Additional
information on this system, including storm warnings, can be found
in High Seas Forecasts issued by the National Weather Service.
* Formation chance through 48 hours...low...10 percent.
* Formation chance through 7 days...low...20 percent.

&&
High Seas Forecasts issued by the National Weather Service
can be found under AWIPS header NFDHSFAT1, WMO header FZNT01
KWBC, and online at ocean.weather.gov/shtml/NFDHSFAT1.php

$$
Forecaster Kelly
Categories: Weather

Hurricane Helene Potential Storm Surge Flooding Map

National Hurricane Center - Wed, 09/25/2024 - 5:00am

Potential Storm Surge Flooding Map last updated Wed, 25 Sep 2024 10:00:41 GMT
Categories: Weather

Hurricane Helene Probabilistic Storm Surge Graphics

National Hurricane Center - Wed, 09/25/2024 - 4:43am

Probabilistic Storm Surge Graphics last updated Wed, 25 Sep 2024 09:43:38 GMT
Categories: Weather

Tropical Storm Helene Forecast Discussion Number 8

National Hurricane Center - Wed, 09/25/2024 - 4:13am
Issued at 400 AM CDT Wed Sep 25 2024 000 WTNT44 KNHC 250913 CCA TCDAT4 Tropical Storm Helene Discussion Number 8...Corrected NWS National Hurricane Center Miami FL AL092024 400 AM CDT Wed Sep 25 2024 Corrected Helen to Helene Helene has strengthened some since the last advisory. Reports from an Air Force Reserve Hurricane Hunter aircraft indicate that the central pressure has fallen to 985 mb, and that the maximum 850 mb flight-level were 58 kt in the northeastern quadrant. A dropsonde in the northwest quadrant reported a splash wind of 59 kt, but the boundary-layer average suggested sustained winds closer to 45 kt. Based on these data and increasing satellite intensity estimates, the initial intensity is increased to 55 kt. Despite the increased intensity, the aircraft data, along with radar data from Mexico and Cuba, show that Helene has not yet formed a well-defined inner core. The initial motion is 325/8 kt. Helene should turn northward during the next 12 h or so on the western side of a mid-level ridge, and then it should accelerate northward to north-northeastward as it become embedded in the deep-layer flow between the ridge and a mid-latitude trough/developing cut-off low over the Mississippi valley. This motion should bring the center near the northeastern coast of the Yucatan Peninsula this morning, then across the eastern Gulf of Mexico tonight and Thursday to a landfall along the northeast coast of the Gulf of Mexico late Thursday or Thursday night. After landfall, Helene should curve cyclonically around the cut-off low until it dissipates. The new forecast track is little changed from the previous track. Over the next couple of days, Helene will be moving through an environment of low vertical wind shear, ample environmental moisture, and over waters of high oceanic heat content. All guidance forecasts steady to rapid intensification, including the RI indices associated with the SHIPS model. The latest forecast calls for a 105 kt intensity by 36 h, and this could be conservative as some of the guidance is stronger. After landfall, Helene is forecast to weaken and become post-tropical as it gets tangled up in the baroclinic system over the southeastern United States. Helene's wind field is predicted to grow to a very large size in the NHC forecast. Therefore storm surge, wind, and rainfall impacts will likely extend well away from the center and outside the forecast cone, particularly on the east side. In addition, the fast forward speed while Helene crosses the coast will likely result in farther inland penetration of strong winds over parts of the southeastern United States after landfall. KEY MESSAGES: 1. Helene is forecast to intensify and be near hurricane strength when it passes near the northeastern coast of the Yucatan Peninsula during the next several hours, where a Hurricane Warning is in effect. 2. Helene is expected to rapidly intensify and grow in size over the eastern Gulf of Mexico. There is a danger of life-threatening storm surge along the entire west coast of the Florida Peninsula and Florida Big Bend. The highest inundation levels are expected along the coast of the Florida Big Bend. Residents in those areas should follow advice given by local officials and evacuate if told to do so. 3. Damaging hurricane-force winds are expected along portions of coast of the Florida Big Bend, where a Hurricane Warning is now in effect. Preparations to protect life and property should be completed by early Thursday since tropical storm conditions are expected to begin within this area on Thursday. 4. Tropical Storm Helene will bring heavy rain to portions of the western Caribbean with potentially significant flooding across western Cuba and the northeastern Yucatan Peninsula. Considerable and potentially life-threatening flash and urban flooding is expected across portions of Florida, the Southeast, the Southern Appalachians, and the Tennessee Valley beginning today through Friday. This includes the risk of landslides across the southern Appalachians. Widespread minor to moderate river flooding is likely, and isolated major river flooding is possible. FORECAST POSITIONS AND MAX WINDS INIT 25/0900Z 20.7N 86.2W 55 KT 65 MPH 12H 25/1800Z 21.9N 86.5W 70 KT 80 MPH 24H 26/0600Z 24.1N 86.2W 90 KT 105 MPH 36H 26/1800Z 27.4N 85.0W 105 KT 120 MPH 48H 27/0600Z 32.0N 84.2W 65 KT 75 MPH...INLAND 60H 27/1800Z 35.9N 85.4W 30 KT 35 MPH...POST-TROP/INLAND 72H 28/0600Z 37.0N 87.8W 20 KT 25 MPH...POST-TROP/INLAND 96H 29/0600Z 36.5N 88.0W 20 KT 25 MPH...POST-TROP/INLAND 120H 30/0600Z...DISSIPATED $$ Forecaster Beven
Categories: Weather

Tropical Storm Helene Graphics

National Hurricane Center - Wed, 09/25/2024 - 3:55am

5-Day Uncertainty Track last updated Wed, 25 Sep 2024 08:55:56 GMT


Wind Speed Probabilities last updated Wed, 25 Sep 2024 08:55:56 GMT
Categories: Weather

Tropical Storm Helene Storm Surge Watch/Warning Map

National Hurricane Center - Wed, 09/25/2024 - 3:54am

Storm Surge Watch/Warning Map last updated Wed, 25 Sep 2024 08:54:19 GMT
Categories: Weather

Summary for Tropical Storm Helene (AT4/AL092024)

National Hurricane Center - Wed, 09/25/2024 - 3:53am
...HELENE STRENGTHENING AS THE CENTER APPROACHES THE NORTHEASTERN COAST OF THE YUCATAN PENINSULA... ...NEW TROPICAL STORM WATCHES AND WARNINGS FOR PORTIONS OF THE UNITED STATES... As of 4:00 AM CDT Wed Sep 25 the center of Helene was located near 20.7, -86.2 with movement NW at 9 mph. The minimum central pressure was 985 mb with maximum sustained winds of about 65 mph.
Categories: Weather

Tropical Storm Helene Public Advisory Number 8

National Hurricane Center - Wed, 09/25/2024 - 3:53am
Issued at 400 AM CDT Wed Sep 25 2024 000 WTNT34 KNHC 250853 TCPAT4 BULLETIN Tropical Storm Helene Advisory Number 8 NWS National Hurricane Center Miami FL AL092024 400 AM CDT Wed Sep 25 2024 ...HELENE STRENGTHENING AS THE CENTER APPROACHES THE NORTHEASTERN COAST OF THE YUCATAN PENINSULA... ...NEW TROPICAL STORM WATCHES AND WARNINGS FOR PORTIONS OF THE UNITED STATES... SUMMARY OF 400 AM CDT...0900 UTC...INFORMATION ---------------------------------------------- LOCATION...20.7N 86.2W ABOUT 45 MI...75 KM ENE OF COZUMEL MEXICO ABOUT 120 MI...190 KM SW OF THE WESTERN TIP OF CUBA MAXIMUM SUSTAINED WINDS...65 MPH...100 KM/H PRESENT MOVEMENT...NW OR 325 DEGREES AT 9 MPH...15 KM/H MINIMUM CENTRAL PRESSURE...985 MB...29.09 INCHES WATCHES AND WARNINGS -------------------- CHANGES WITH THIS ADVISORY: A Tropical Storm Warning is now in effect for the Upper Florida Keys from the Channel 5 Bridge to Ocean Reef and for the southern Florida Peninsula east of Flamingo to the Palm Beach/Martin County line. A Tropical Storm Warning is now in effect for the northeast coast of Florida north of the Flagler/Volusia line to the mouth of the St. Mary's River. A Tropical Storm Watch is now in effect for the South Carolina coast north of the Savannah River to the South Santee River. SUMMARY OF WATCHES AND WARNINGS IN EFFECT: A Storm Surge Warning is in effect for... * Indian Pass southward to Flamingo * Tampa Bay * Charlotte Harbor A Hurricane Warning is in effect for... * Anclote River to Mexico Beach, Florida * Cabo Catoche to Tulum, Mexico including Cozumel A Hurricane Watch is in effect for... * Cuban province of Pinar del Rio * Englewood to Anclote River, including Tampa Bay A Tropical Storm Warning is in effect for... * Dry Tortugas * All of the Florida Keys * The Florida west coast from Flamingo to Anclote River, including Tampa Bay * West of Mexico Beach to the Walton/Bay County Line * The Florida east coast from Flamingo northward to the mouth of the St. Mary's River * Lake Okeechobee * Rio Lagartos to Cabo Catoche, Mexico * Cuban provinces of Artemisa, Pinar del Rio, and the Isle of Youth A Tropical Storm Watch is in effect for... * The Georgia and South Carolina coast north of the mouth of the St. Mary's River to the South Santee River A Storm Surge Warning means there is a danger of life-threatening inundation, from rising water moving inland from the coastline, during the next 36 hours in the indicated locations. For a depiction of areas at risk, please see the National Weather Service Storm Surge Watch/Warning Graphic, available at hurricanes.gov. This is a life-threatening situation. Persons located within these areas should take all necessary actions to protect life and property from rising water and the potential for other dangerous conditions. Promptly follow evacuation and other instructions from local officials. A Hurricane Warning means that hurricane conditions are expected somewhere within the warning area. A warning is typically issued 36 hours before the anticipated first occurrence of tropical-storm-force winds, conditions that make outside preparations difficult or dangerous. Preparations to protect life and property should be rushed to completion. A Tropical Storm Warning means that tropical storm conditions are expected somewhere within the warning area within the next 36 hours. A Hurricane Watch means that hurricane conditions are possible within the watch area. A watch is typically issued 48 hours before the anticipated first occurrence of tropical-storm-force winds, conditions that make outside preparations difficult or dangerous. A Tropical Storm Watch means that tropical storm conditions are possible within the watch area. Additional watches or warnings may be required for portions of Florida and the southeastern United States later today. For storm information specific to your area in the United States, including possible inland watches and warnings, please monitor products issued by your local National Weather Service forecast office. For storm information specific to your area outside of the United States, please monitor products issued by your national meteorological service. DISCUSSION AND OUTLOOK ---------------------- At 400 AM CDT (0900 UTC), the center of Tropical Storm Helene was located near latitude 20.7 North, longitude 86.2 West. Helene is moving toward the northwest near 9 mph (15 km/h). This motion should continue through this morning, followed by a general northward motion beginning later today and continuing through Friday. On the forecast track, the center of Helene will pass near the northeastern coast of the Yucatan Peninsula this morning, move across the eastern Gulf of Mexico on later today and Thursday, and reach the Big Bend coast of Florida late Thursday. Maximum sustained winds are now near 65 mph (100 km/h) with higher gusts. Strengthening is forecast, and Helene is expected to become a hurricane later today. The storm is forecast to rapidly strengthen over the eastern Gulf of Mexico and become a major hurricane on Thursday. Tropical-storm-force winds extend outward up to 175 miles (280 km) from the center. A Mexican Navy weather station at Isla Contoy recently reported sustained winds of 38 mph (61 km/h) and a wind gust of 48 mph (78 km/h). The minimum central pressure recently reported by an Air Force Reserve Hurricane Hunter aircraft is 985 mb (29.09 inches). HAZARDS AFFECTING LAND ---------------------- Key Messages for Helene can be found in the Tropical Cyclone Discussion under AWIPS header MIATCDAT4 and WMO header WTNT44 KNHC and on the web at hurricanes.gov/text/MIATCDAT4.shtml RAINFALL: Tropical Storm Helene is expected to produce total rain accumulations of 4 to 8 inches over western Cuba, the Cayman Islands and the northeast Yucatan Peninsula, with isolated totals around 12 inches. This rainfall brings a risk of considerable flooding. Over the Southeastern U.S., Helene is expected to produce total rain accumulations of 5 to 10 inches with isolated totals around 15 inches. This rainfall will likely result in areas of considerable flash and urban flooding, with areas of significant river flooding. Landslides are possible in areas of steep terrain in the southern Appalachians. For a complete depiction of forecast rainfall associated with Tropical Storm Helene, please see the National Weather Service Storm Total Rainfall Graphic, available at hurricanes.gov/graphics_at4.shtml?rainqpf and the Flash Flood Risk graphic at hurricanes.gov/graphics_at4.shtml?ero. STORM SURGE: The combination of a dangerous storm surge and the tide will cause normally dry areas near the coast to be flooded by rising waters moving inland from the shoreline. The water could reach the following heights above ground somewhere in the indicated areas if the peak surge occurs at the time of high tide... Ochlockonee River, FL to Chassahowitzka, FL...10-15 ft Chassahowitzka, FL to Anclote River, FL...6-10 ft Indian Pass, FL to Ochlockonee River, FL...5-10 ft Anclote River, FL to Middle of Longboat Key, FL...5-8 ft Tampa Bay...5-8 ft Middle of Longboat Key, FL to Englewood, FL...4-7 ft Englewood, FL to Flamingo, FL...3-5 ft Charlotte Harbor...3-5 ft For a complete depiction of areas at risk of storm surge inundation, please see the National Weather Service Peak Storm Surge Graphic, available at hurricanes.gov/graphics_at4.shtml?peakSurge. Storm surge could raise water levels by as much as 2 to 4 feet above normal tide levels in areas of onshore winds along the southern coast of Pinar del Rio, Cuba, including the Isle of Youth. Storm surge could raise water levels by as much as 2 to 4 feet above ground level in areas of onshore winds within the warning area along the east coast of the Yucatan Peninsula. WIND: Hurricane conditions are expected in the hurricane warning area in Mexico during the next several hours, with tropical storm conditions already ongoing. Hurricane conditions are expected within the U.S. hurricane warning area late Thursday. Hurricane conditions are possible for the western portion of Cuba later today. Tropical storm conditions are expected to begin in the warning area in Cuba during the next several hours. Tropical storm conditions are expected in southern Florida later today and spreading northward through Thursday. Tropical storm conditions are possible within the tropical storm watch area beginning Thursday and Thursday night. TORNADOES: A tornado or two may occur tonight over parts of the western Florida peninsula and southern Alabama. The risk of tornadoes will increase on Thursday, expanding across Florida and into parts of Georgia and South Carolina. SURF: Swells generated by Helene will affect the southern coast of Cuba and the Yucatan Peninsula of Mexico during the next couple of days. Swells will spread northward toward the west coast of Florida and the northeastern Gulf Coast later today and Thursday. These swells are likely to cause life-threatening surf and rip current conditions. Please consult products from your local weather office. NEXT ADVISORY ------------- Next intermediate advisory at 700 AM CDT. Next complete advisory at 1000 AM CDT. $$ Forecaster Beven
Categories: Weather

Tropical Storm Helene Forecast Advisory Number 8

National Hurricane Center - Wed, 09/25/2024 - 3:53am
Issued at 0900 UTC WED SEP 25 2024 000 WTNT24 KNHC 250853 TCMAT4 TROPICAL STORM HELENE FORECAST/ADVISORY NUMBER 8 NWS NATIONAL HURRICANE CENTER MIAMI FL AL092024 0900 UTC WED SEP 25 2024 TROPICAL STORM CENTER LOCATED NEAR 20.7N 86.2W AT 25/0900Z POSITION ACCURATE WITHIN 25 NM PRESENT MOVEMENT TOWARD THE NORTHWEST OR 325 DEGREES AT 8 KT ESTIMATED MINIMUM CENTRAL PRESSURE 985 MB MAX SUSTAINED WINDS 55 KT WITH GUSTS TO 65 KT. 50 KT....... 60NE 60SE 0SW 0NW. 34 KT.......150NE 150SE 50SW 80NW. 12 FT SEAS..180NE 180SE 60SW 60NW. WINDS AND SEAS VARY GREATLY IN EACH QUADRANT. RADII IN NAUTICAL MILES ARE THE LARGEST RADII EXPECTED ANYWHERE IN THAT QUADRANT. REPEAT...CENTER LOCATED NEAR 20.7N 86.2W AT 25/0900Z AT 25/0600Z CENTER WAS LOCATED NEAR 20.3N 85.9W FORECAST VALID 25/1800Z 21.9N 86.5W MAX WIND 70 KT...GUSTS 85 KT. 64 KT... 20NE 20SE 0SW 0NW. 50 KT... 60NE 60SE 0SW 20NW. 34 KT...210NE 210SE 60SW 80NW. FORECAST VALID 26/0600Z 24.1N 86.2W MAX WIND 90 KT...GUSTS 110 KT. 64 KT... 25NE 20SE 0SW 0NW. 50 KT... 60NE 60SE 20SW 30NW. 34 KT...240NE 250SE 80SW 100NW. FORECAST VALID 26/1800Z 27.4N 85.0W MAX WIND 105 KT...GUSTS 130 KT. 64 KT... 35NE 45SE 20SW 30NW. 50 KT... 70NE 80SE 30SW 40NW. 34 KT...250NE 250SE 120SW 120NW. FORECAST VALID 27/0600Z 32.0N 84.2W...INLAND MAX WIND 65 KT...GUSTS 80 KT. 64 KT... 0NE 25SE 0SW 0NW. 50 KT... 40NE 50SE 30SW 30NW. 34 KT...210NE 240SE 100SW 70NW. FORECAST VALID 27/1800Z 35.9N 85.4W...POST-TROP/INLAND MAX WIND 30 KT...GUSTS 40 KT. FORECAST VALID 28/0600Z 37.0N 87.8W...POST-TROP/INLAND MAX WIND 20 KT...GUSTS 30 KT. EXTENDED OUTLOOK. NOTE...ERRORS FOR TRACK HAVE AVERAGED NEAR 125 NM ON DAY 4 AND 175 NM ON DAY 5...AND FOR INTENSITY NEAR 15 KT EACH DAY OUTLOOK VALID 29/0600Z 36.5N 88.0W...POST-TROP/INLAND MAX WIND 20 KT...GUSTS 30 KT. OUTLOOK VALID 30/0600Z...DISSIPATED REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 20.7N 86.2W INTERMEDIATE PUBLIC ADVISORY...WTNT34 KNHC/MIATCPAT4...AT 25/1200Z NEXT ADVISORY AT 25/1500Z $$ FORECASTER BEVEN
Categories: Weather

Tropical Storm Helene Wind Speed Probabilities Number 8

National Hurricane Center - Wed, 09/25/2024 - 3:53am
Issued at 0900 UTC WED SEP 25 2024 000 FONT14 KNHC 250853 PWSAT4 TROPICAL STORM HELENE WIND SPEED PROBABILITIES NUMBER 8 NWS NATIONAL HURRICANE CENTER MIAMI FL AL092024 0900 UTC WED SEP 25 2024 AT 0900Z THE CENTER OF TROPICAL STORM HELENE WAS LOCATED NEAR LATITUDE 20.7 NORTH...LONGITUDE 86.2 WEST WITH MAXIMUM SUSTAINED WINDS NEAR 55 KTS...65 MPH...100 KM/H. Z INDICATES COORDINATED UNIVERSAL TIME (GREENWICH) ATLANTIC STANDARD TIME (AST)...SUBTRACT 4 HOURS FROM Z TIME EASTERN DAYLIGHT TIME (EDT)...SUBTRACT 4 HOURS FROM Z TIME CENTRAL DAYLIGHT TIME (CDT)...SUBTRACT 5 HOURS FROM Z TIME WIND SPEED PROBABILITY TABLE FOR SPECIFIC LOCATIONS CHANCES OF SUSTAINED (1-MINUTE AVERAGE) WIND SPEEDS OF AT LEAST ...34 KT (39 MPH... 63 KM/H)... ...50 KT (58 MPH... 93 KM/H)... ...64 KT (74 MPH...119 KM/H)... FOR LOCATIONS AND TIME PERIODS DURING THE NEXT 5 DAYS PROBABILITIES FOR LOCATIONS ARE GIVEN AS OP(CP) WHERE OP IS THE PROBABILITY OF THE EVENT BEGINNING DURING AN INDIVIDUAL TIME PERIOD (ONSET PROBABILITY) (CP) IS THE PROBABILITY OF THE EVENT OCCURRING BETWEEN 06Z WED AND THE FORECAST HOUR (CUMULATIVE PROBABILITY) PROBABILITIES ARE GIVEN IN PERCENT X INDICATES PROBABILITIES LESS THAN 1 PERCENT PROBABILITIES FOR 34 KT AND 50 KT ARE SHOWN AT A GIVEN LOCATION WHEN THE 5-DAY CUMULATIVE PROBABILITY IS AT LEAST 3 PERCENT. PROBABILITIES FOR 34...50...64 KT SHOWN WHEN THE 5-DAY 64-KT CUMULATIVE PROBABILITY IS AT LEAST 1 PERCENT. - - - - WIND SPEED PROBABILITIES FOR SELECTED LOCATIONS - - - - FROM FROM FROM FROM FROM FROM FROM TIME 06Z WED 18Z WED 06Z THU 18Z THU 06Z FRI 06Z SAT 06Z SUN PERIODS TO TO TO TO TO TO TO 18Z WED 06Z THU 18Z THU 06Z FRI 06Z SAT 06Z SUN 06Z MON FORECAST HOUR (12) (24) (36) (48) (72) (96) (120) - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - LOCATION KT CHARLOTTE NC 34 X X( X) X( X) 2( 2) 1( 3) X( 3) X( 3) COLUMBIA SC 34 X X( X) X( X) 5( 5) 1( 6) X( 6) X( 6) LITTLE RIVER 34 X X( X) X( X) 3( 3) 2( 5) X( 5) X( 5) MYRTLE BEACH 34 X X( X) X( X) 5( 5) 1( 6) X( 6) X( 6) CHARLESTON SC 34 X X( X) X( X) 14(14) 1(15) X(15) X(15) BEAUFORT MCAS 34 X X( X) X( X) 24(24) 2(26) X(26) X(26) ATLANTA GA 34 X X( X) X( X) 19(19) 23(42) X(42) X(42) AUGUSTA GA 34 X X( X) X( X) 15(15) 5(20) X(20) X(20) SAVANNAH GA 34 X X( X) 1( 1) 13(14) X(14) X(14) X(14) KINGS BAY GA 34 X X( X) 8( 8) 39(47) X(47) X(47) X(47) KINGS BAY GA 50 X X( X) X( X) 6( 6) X( 6) X( 6) X( 6) KINGS BAY GA 64 X X( X) X( X) 1( 1) X( 1) X( 1) X( 1) WAYCROSS GA 34 X X( X) 4( 4) 40(44) 1(45) X(45) X(45) WAYCROSS GA 50 X X( X) X( X) 9( 9) X( 9) X( 9) X( 9) WAYCROSS GA 64 X X( X) X( X) 2( 2) X( 2) X( 2) X( 2) MAYPORT NS FL 34 X X( X) 10(10) 34(44) X(44) X(44) X(44) MAYPORT NS FL 50 X X( X) X( X) 5( 5) X( 5) X( 5) X( 5) JACKSONVILLE 34 X X( X) 5( 5) 24(29) X(29) X(29) X(29) JACKSONVILLE 50 X X( X) X( X) 3( 3) X( 3) X( 3) X( 3) GAINESVILLE FL 34 X X( X) 14(14) 34(48) X(48) X(48) X(48) GAINESVILLE FL 50 X X( X) 1( 1) 8( 9) X( 9) X( 9) X( 9) GAINESVILLE FL 64 X X( X) X( X) 1( 1) X( 1) X( 1) X( 1) DAYTONA BEACH 34 X X( X) 8( 8) 7(15) X(15) X(15) X(15) THE VILLAGES 34 X X( X) 18(18) 19(37) X(37) X(37) X(37) THE VILLAGES 50 X X( X) 1( 1) 4( 5) X( 5) X( 5) X( 5) ORLANDO FL 34 X X( X) 11(11) 7(18) X(18) X(18) X(18) COCOA BEACH FL 34 X X( X) 15(15) 11(26) X(26) X(26) X(26) PATRICK AFB 34 X X( X) 16(16) 11(27) X(27) X(27) X(27) FT PIERCE FL 34 X X( X) 14(14) 5(19) X(19) X(19) X(19) W PALM BEACH 34 X X( X) 11(11) 3(14) X(14) X(14) X(14) FT LAUDERDALE 34 X 1( 1) 9(10) 2(12) X(12) X(12) X(12) MIAMI FL 34 X X( X) 6( 6) 1( 7) X( 7) X( 7) X( 7) HOMESTEAD ARB 34 X 1( 1) 5( 6) X( 6) X( 6) X( 6) X( 6) MARATHON FL 34 X 8( 8) 10(18) X(18) X(18) X(18) X(18) KEY WEST FL 34 2 13(15) 11(26) 1(27) X(27) X(27) X(27) NAPLES FL 34 X 10(10) 29(39) 1(40) X(40) X(40) X(40) NAPLES FL 50 X X( X) 3( 3) X( 3) X( 3) X( 3) X( 3) FT MYERS FL 34 X 5( 5) 17(22) 2(24) X(24) X(24) X(24) VENICE FL 34 X 9( 9) 52(61) 4(65) X(65) X(65) X(65) VENICE FL 50 X X( X) 12(12) 2(14) X(14) X(14) X(14) VENICE FL 64 X X( X) 2( 2) 1( 3) X( 3) X( 3) X( 3) TAMPA FL 34 X 5( 5) 54(59) 10(69) X(69) X(69) X(69) TAMPA FL 50 X X( X) 12(12) 8(20) X(20) X(20) X(20) TAMPA FL 64 X X( X) 2( 2) 2( 4) X( 4) X( 4) X( 4) CEDAR KEY FL 34 X X( X) 52(52) 29(81) X(81) X(81) X(81) CEDAR KEY FL 50 X X( X) 12(12) 29(41) X(41) X(41) X(41) CEDAR KEY FL 64 X X( X) 2( 2) 13(15) X(15) X(15) X(15) TALLAHASSEE FL 34 X X( X) 12(12) 73(85) 1(86) X(86) X(86) TALLAHASSEE FL 50 X X( X) 1( 1) 51(52) 1(53) X(53) X(53) TALLAHASSEE FL 64 X X( X) X( X) 11(11) X(11) X(11) X(11) ST MARKS FL 34 X X( X) 16(16) 72(88) X(88) X(88) X(88) ST MARKS FL 50 X X( X) 2( 2) 55(57) X(57) X(57) X(57) ST MARKS FL 64 X X( X) X( X) 17(17) X(17) X(17) X(17) APALACHICOLA 34 X 1( 1) 44(45) 46(91) X(91) X(91) X(91) APALACHICOLA 50 X X( X) 10(10) 61(71) X(71) X(71) X(71) APALACHICOLA 64 X X( X) 2( 2) 43(45) X(45) X(45) X(45) GFMX 290N 850W 34 X 4( 4) 64(68) 26(94) X(94) X(94) X(94) GFMX 290N 850W 50 X X( X) 28(28) 50(78) X(78) X(78) X(78) GFMX 290N 850W 64 X X( X) 11(11) 44(55) X(55) X(55) X(55) PANAMA CITY FL 34 X X( X) 30(30) 45(75) X(75) X(75) X(75) PANAMA CITY FL 50 X X( X) 4( 4) 39(43) 1(44) X(44) X(44) PANAMA CITY FL 64 X X( X) X( X) 21(21) 1(22) X(22) X(22) DESTIN EXEC AP 34 X X( X) 7( 7) 21(28) X(28) X(28) X(28) DESTIN EXEC AP 50 X X( X) X( X) 6( 6) X( 6) X( 6) X( 6) ALBANY GA 34 X X( X) 4( 4) 69(73) 3(76) X(76) X(76) ALBANY GA 50 X X( X) X( X) 32(32) 1(33) X(33) X(33) ALBANY GA 64 X X( X) X( X) 2( 2) X( 2) X( 2) X( 2) COLUMBUS GA 34 X X( X) 1( 1) 40(41) 9(50) X(50) X(50) COLUMBUS GA 50 X X( X) X( X) 5( 5) 2( 7) X( 7) X( 7) MACON GA 34 X X( X) 1( 1) 47(48) 12(60) X(60) X(60) MACON GA 50 X X( X) X( X) 8( 8) 4(12) X(12) X(12) DOTHAN AL 34 X X( X) 5( 5) 49(54) 1(55) X(55) X(55) DOTHAN AL 50 X X( X) X( X) 17(17) X(17) X(17) X(17) DOTHAN AL 64 X X( X) X( X) 1( 1) X( 1) X( 1) X( 1) BIRMINGHAM AL 34 X X( X) X( X) 4( 4) 3( 7) X( 7) X( 7) MONTGOMERY AL 34 X X( X) 1( 1) 12(13) 3(16) X(16) X(16) WHITING FLD FL 34 X X( X) 4( 4) 9(13) X(13) X(13) X(13) PENSACOLA FL 34 X X( X) 4( 4) 7(11) X(11) X(11) X(11) GFMX 290N 870W 34 X 4( 4) 26(30) 11(41) X(41) X(41) X(41) GFMX 290N 870W 50 X X( X) 5( 5) 5(10) X(10) X(10) X(10) GFMX 290N 870W 64 X X( X) 1( 1) 2( 3) X( 3) X( 3) X( 3) MOBILE AL 34 X X( X) 3( 3) 3( 6) X( 6) X( 6) X( 6) GULFPORT MS 34 X X( X) 3( 3) 1( 4) X( 4) X( 4) X( 4) STENNIS MS 34 X X( X) 2( 2) 1( 3) X( 3) X( 3) X( 3) BURAS LA 34 X X( X) 3( 3) 1( 4) X( 4) X( 4) X( 4) GFMX 280N 890W 34 X 5( 5) 6(11) 1(12) X(12) X(12) X(12) MERIDA MX 34 2 4( 6) X( 6) X( 6) X( 6) X( 6) X( 6) COZUMEL MX 34 99 X(99) X(99) X(99) X(99) X(99) X(99) COZUMEL MX 50 4 1( 5) X( 5) X( 5) X( 5) X( 5) X( 5) BELIZE CITY 34 3 X( 3) X( 3) X( 3) X( 3) X( 3) X( 3) CP SAN ANTONIO 34 99 X(99) X(99) X(99) X(99) X(99) X(99) CP SAN ANTONIO 50 16 9(25) X(25) X(25) X(25) X(25) X(25) CP SAN ANTONIO 64 1 1( 2) X( 2) X( 2) X( 2) X( 2) X( 2) HAVANA 34 4 6(10) 3(13) X(13) X(13) X(13) X(13) ISLE OF PINES 34 11 10(21) 2(23) X(23) X(23) X(23) X(23) GRAND CAYMAN 34 4 X( 4) X( 4) X( 4) X( 4) X( 4) X( 4) $$ FORECASTER BEVEN
Categories: Weather

Atlantic Tropical Weather Outlook

National Hurricane Center - Wed, 09/25/2024 - 12:53am

238
ABNT20 KNHC 250553
TWOAT

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
200 AM EDT Wed Sep 25 2024

For the North Atlantic...Caribbean Sea and the Gulf of Mexico:

Active Systems:
The National Hurricane Center is issuing advisories on Tropical
Storm Helene, located over the northwestern Caribbean Sea.

Eastern and Central Tropical Atlantic:
A broad low pressure system associated with a tropical wave located
west of the Cabo Verde Islands continues to produce disorganized
shower and thunderstorm activity. Environmental conditions appear
favorable for gradual development of this system, and a tropical
depression is likely to form in a few days while it moves westward
to west-northwestward across the eastern and central tropical
Atlantic.
* Formation chance through 48 hours...medium...50 percent.
* Formation chance through 7 days...high...80 percent.

Central Subtropical Atlantic:
A non-tropical area of low pressure is currently located several
hundred miles to the northeast of Bermuda. Earlier satellite-wind
data indicated the system was producing winds up to storm-force, and
environmental conditions could support some subtropical or tropical
development over the next several days as the system moves generally
eastward, remaining over the open waters of central Subtropical
Atlantic. Additional information on this system, including storm
warnings, can be found in High Seas Forecasts issued by the National
Weather Service.
* Formation chance through 48 hours...low...10 percent.
* Formation chance through 7 days...low...20 percent.

&&
High Seas Forecasts issued by the National Weather Service
can be found under AWIPS header NFDHSFAT1, WMO header FZNT01
KWBC, and online at ocean.weather.gov/shtml/NFDHSFAT1.php

$$
Forecaster Papin

Categories: Weather

Summary for Tropical Storm Helene (AT4/AL092024)

National Hurricane Center - Wed, 09/25/2024 - 12:53am
...CENTER OF HELENE APPROACHING THE NORTHEASTERN COAST OF THE YUCATAN PENINSULA... As of 1:00 AM CDT Wed Sep 25 the center of Helene was located near 20.4, -85.9 with movement NW at 10 mph. The minimum central pressure was 991 mb with maximum sustained winds of about 60 mph.
Categories: Weather

Tropical Storm Helene Public Advisory Number 7A

National Hurricane Center - Wed, 09/25/2024 - 12:53am
Issued at 100 AM CDT Wed Sep 25 2024 306 WTNT34 KNHC 250553 TCPAT4 BULLETIN Tropical Storm Helene Intermediate Advisory Number 7A NWS National Hurricane Center Miami FL AL092024 100 AM CDT Wed Sep 25 2024 ...CENTER OF HELENE APPROACHING THE NORTHEASTERN COAST OF THE YUCATAN PENINSULA... SUMMARY OF 100 AM CDT...0600 UTC...INFORMATION ---------------------------------------------- LOCATION...20.4N 85.9W ABOUT 65 MI...105 KM E OF COZUMEL MEXICO ABOUT 120 MI...195 KM SW OF THE WESTERN TIP OF CUBA MAXIMUM SUSTAINED WINDS...60 MPH...95 KM/H PRESENT MOVEMENT...NW OR 305 DEGREES AT 10 MPH...17 KM/H MINIMUM CENTRAL PRESSURE...991 MB...29.27 INCHES WATCHES AND WARNINGS -------------------- CHANGES WITH THIS ADVISORY: None. SUMMARY OF WATCHES AND WARNINGS IN EFFECT: A Storm Surge Warning is in effect for... * Indian Pass southward to Flamingo * Tampa Bay * Charlotte Harbor A Hurricane Warning is in effect for... * Anclote River to Mexico Beach, Florida * Cabo Catoche to Tulum, Mexico including Cozumel A Hurricane Watch is in effect for... * Cuban province of Pinar del Rio * Englewood to Anclote River, including Tampa Bay A Tropical Storm Warning is in effect for... * Dry Tortugas * Lower and Middle Florida Keys west of the Channel 5 Bridge * Flamingo to Anclote River, including Tampa Bay * West of Mexico Beach to the Walton/Bay County Line * Palm Beach/Martin County Line northward to the Flagler/Volusia County Line * Lake Okeechobee * Rio Lagartos to Cabo Catoche, Mexico * Cuban provinces of Artemisa, Pinar del Rio, and the Isle of Youth A Tropical Storm Watch is in effect for... * Flagler/Volusia County Line northward to the Savannah River A Storm Surge Warning means there is a danger of life-threatening inundation, from rising water moving inland from the coastline, during the next 36 hours in the indicated locations. For a depiction of areas at risk, please see the National Weather Service Storm Surge Watch/Warning Graphic, available at hurricanes.gov. This is a life-threatening situation. Persons located within these areas should take all necessary actions to protect life and property from rising water and the potential for other dangerous conditions. Promptly follow evacuation and other instructions from local officials. A Hurricane Warning means that hurricane conditions are expected somewhere within the warning area. A warning is typically issued 36 hours before the anticipated first occurrence of tropical-storm-force winds, conditions that make outside preparations difficult or dangerous. Preparations to protect life and property should be rushed to completion. A Tropical Storm Warning means that tropical storm conditions are expected somewhere within the warning area within the next 36 hours. A Hurricane Watch means that hurricane conditions are possible within the watch area. A watch is typically issued 48 hours before the anticipated first occurrence of tropical-storm-force winds, conditions that make outside preparations difficult or dangerous. A Tropical Storm Watch means that tropical storm conditions are possible within the watch area. Additional watches or warnings may be required for portions of Florida and the southeastern United States later today. For storm information specific to your area in the United States, including possible inland watches and warnings, please monitor products issued by your local National Weather Service forecast office. For storm information specific to your area outside of the United States, please monitor products issued by your national meteorological service. DISCUSSION AND OUTLOOK ---------------------- At 100 AM CDT (0600 UTC), the center of Tropical Storm Helene was located near latitude 20.4 North, longitude 85.9 West. Helene is moving toward the northwest near 10 mph (17 km/h). This motion should continue through this morning, followed by a general northward motion beginning later today and continuing through Friday. On the forecast track, the center of Helene will pass near the northeastern coast of the Yucatan Peninsula this morning, move across the eastern Gulf of Mexico on later today and Thursday, and reach the Big Bend coast of Florida late Thursday. Maximum sustained winds are near 60 mph (95 km/h) with higher gusts. Strengthening is forecast, and Helene is expected to become a hurricane later today. The storm is forecast to rapidly strengthen over the eastern Gulf of Mexico and become a major hurricane on Thursday. Tropical-storm-force winds extend outward up to 175 miles (280 km) from the center. Wind gusts of 35 to 40 mph (55 to 65 km/h) are being reported from the northeastern Yucatan Peninsula near Cancun and Cozumel. The estimated minimum central pressure is 991 mb (29.27 inches). HAZARDS AFFECTING LAND ---------------------- Key Messages for Helene can be found in the Tropical Cyclone Discussion under AWIPS header MIATCDAT4 and WMO header WTNT44 KNHC and on the web at hurricanes.gov/text/MIATCDAT4.shtml RAINFALL: Tropical Storm Helene is expected to produce total rain accumulations of 4 to 8 inches over western Cuba, the Cayman Islands and the northeast Yucatan Peninsula, with isolated totals around 12 inches. This rainfall brings a risk of considerable flooding. Over the Southeastern U.S., Helene is expected to produce total rain accumulations of 4 to 8 inches with isolated totals around 12 inches. This rainfall will likely result in areas of considerable flash and urban flooding, with areas of significant river flooding. Landslides are possible in areas of steep terrain in the southern Appalachians. For a complete depiction of forecast rainfall associated with Tropical Storm Helene, please see the National Weather Service Storm Total Rainfall Graphic, available at hurricanes.gov/graphics_at4.shtml?rainqpf and the Flash Flood Risk graphic at hurricanes.gov/graphics_at4.shtml?ero. STORM SURGE: The combination of a dangerous storm surge and the tide will cause normally dry areas near the coast to be flooded by rising waters moving inland from the shoreline. The water could reach the following heights above ground somewhere in the indicated areas if the peak surge occurs at the time of high tide... Ochlockonee River, FL to Chassahowitzka, FL...10-15 ft Chassahowitzka, FL to Anclote River, FL...6-10 ft Indian Pass, FL to Ochlockonee River, FL...5-10 ft Anclote River, FL to Middle of Longboat Key, FL...5-8 ft Tampa Bay...5-8 ft Middle of Longboat Key, FL to Englewood, FL...4-7 ft Englewood, FL to Flamingo, FL...3-5 ft Charlotte Harbor...3-5 ft For a complete depiction of areas at risk of storm surge inundation, please see the National Weather Service Peak Storm Surge Graphic, available at hurricanes.gov/graphics_at4.shtml?peakSurge. Storm surge could raise water levels by as much as 2 to 4 feet above normal tide levels in areas of onshore winds along the southern coast of Pinar del Rio, Cuba, including the Isle of Youth. Storm surge could raise water levels by as much as 2 to 4 feet above ground level in areas of onshore winds within the warning area along the east coast of the Yucatan Peninsula. WIND: Hurricane conditions are expected in the hurricane warning area in Mexico later today. Hurricane conditions are expected within the U.S. hurricane warning area late Thursday. Tropical storm conditions are expected to begin in the tropical storm warning area in Florida later today and spread northward through Thursday. Tropical storm conditions are possible within the tropical storm watch area beginning Thursday. TORNADOES: A tornado or two may occur tonight over parts of the western Florida peninsula and southern Alabama. The risk of tornadoes will increase on Thursday, expanding across Florida and into parts of Georgia and South Carolina. SURF: Swells generated by Helene will affect the southern coast of Cuba and the Yucatan Peninsula of Mexico during the next couple of days. Swells will spread northward toward the west coast of Florida and the northeastern Gulf Coast today and Thursday. These swells are likely to cause life-threatening surf and rip current conditions. Please consult products from your local weather office. NEXT ADVISORY ------------- Next complete advisory at 400 AM CDT. $$ Forecaster Beven
Categories: Weather
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