Potential Storm Surge Flooding Map last updated Wed, 25 Sep 2024 03:50:26 GMT

Probabilistic Storm Surge Graphics last updated Wed, 25 Sep 2024 03:30:10 GMT

5-Day Uncertainty Track last updated Wed, 25 Sep 2024 02:57:38 GMT


Wind Speed Probabilities last updated Wed, 25 Sep 2024 02:57:38 GMT

Issued at 1000 PM CDT Tue Sep 24 2024 000 WTNT44 KNHC 250256 TCDAT4 Tropical Storm Helene Discussion Number 7 NWS National Hurricane Center Miami FL AL092024 1000 PM CDT Tue Sep 24 2024 Helene continues to become better organized with increased convective banding features and an overall more symmetrical-looking cloud pattern. The convection is very deep with cloud tops to -80 deg C or colder. Doppler velocity data from a NOAA Hurricane Hunter aircraft indicate no significant vertical tilt of the vortex in the low- to mid-troposphere. This suggests that the vertical wind shear is low. Earlier flight-level wind data from the aircraft indicate the the maximum winds are near 50 kt, although this may be conservative. Although the storm has been wobbling over the past few hours, center fixes from the NOAA Hurricane Hunter aircraft indicate a generally west-northwestward motion at around 300/9 kt. Helene should turn northwestward soon as a high pressure area over Florida shifts eastward, with the tropical cyclone center passing near the northeastern Yucatan Peninsula tomorrow morning. Meanwhile, a mid-tropospheric trough is digging over the Lower Mississippi Valley. This evolution of the steering flow should cause Helene to turn northward with an increase in forward speed during the next day or so. An accelerating northward to north-northeastward motion over the eastern Gulf of Mexico should take the system to the northeastern Gulf of Mexico coast in about 48 hours. After landfall, Helene should curve cyclonically around a mid-level low over the south-central United States. The official forecast is very similar to the previous one and is on top of the latest corrected consensus track guidance. 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. Thus, significant strengthening is anticipated before landfall on the northeast Gulf coast. The NHC intensity forecast explicitly shows steady to rapid intensification (RI) of 25 kt for the next 24 hours and 30 kt for the 24- to 48-hour forecast interval. This is in general agreement with the SHIPS RI indices. Helene 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 it 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 on Wednesday, 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 complete 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 flash and urban flooding is expected across portions of Florida, the Southeast, southern Appalachians, and the 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 25/0300Z 19.9N 85.5W 50 KT 60 MPH 12H 25/1200Z 21.1N 86.3W 65 KT 75 MPH 24H 26/0000Z 22.7N 86.4W 75 KT 85 MPH 36H 26/1200Z 25.4N 85.5W 90 KT 105 MPH 48H 27/0000Z 29.5N 84.2W 105 KT 120 MPH 60H 27/1200Z 34.0N 84.5W 30 KT 35 MPH 72H 28/0000Z 36.5N 86.5W 20 KT 25 MPH...POST-TROP/INLAND 96H 29/0000Z 37.0N 89.0W 20 KT 25 MPH...POST-TROP/INLAND 120H 30/0000Z...DISSIPATED $$ Forecaster Pasch

Storm Surge Watch/Warning Map last updated Wed, 25 Sep 2024 02:55:50 GMT

Issued at 0300 UTC WED SEP 25 2024 000 FONT14 KNHC 250255 PWSAT4 TROPICAL STORM HELENE WIND SPEED PROBABILITIES NUMBER 7 NWS NATIONAL HURRICANE CENTER MIAMI FL AL092024 0300 UTC WED SEP 25 2024 AT 0300Z THE CENTER OF TROPICAL STORM HELENE WAS LOCATED NEAR LATITUDE 19.9 NORTH...LONGITUDE 85.5 WEST WITH MAXIMUM SUSTAINED WINDS NEAR 50 KTS...60 MPH...95 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 00Z 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 00Z WED 12Z WED 00Z THU 12Z THU 00Z FRI 00Z SAT 00Z SUN PERIODS TO TO TO TO TO TO TO 12Z WED 00Z THU 12Z THU 00Z FRI 00Z SAT 00Z SUN 00Z MON FORECAST HOUR (12) (24) (36) (48) (72) (96) (120) - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - LOCATION KT COLUMBIA SC 34 X X( X) X( X) 1( 1) 2( 3) X( 3) X( 3) MYRTLE BEACH 34 X X( X) X( X) 1( 1) 2( 3) X( 3) X( 3) CHARLESTON SC 34 X X( X) X( X) 4( 4) 7(11) X(11) X(11) BEAUFORT MCAS 34 X X( X) X( X) 8( 8) 12(20) X(20) X(20) ATLANTA GA 34 X X( X) X( X) 2( 2) 14(16) X(16) X(16) AUGUSTA GA 34 X X( X) X( X) 3( 3) 8(11) X(11) X(11) SAVANNAH GA 34 X X( X) X( X) 6( 6) 5(11) X(11) X(11) KINGS BAY GA 34 X X( X) X( X) 38(38) 12(50) X(50) X(50) KINGS BAY GA 50 X X( X) X( X) 4( 4) 4( 8) X( 8) X( 8) WAYCROSS GA 34 X X( X) X( X) 23(23) 22(45) X(45) X(45) WAYCROSS GA 50 X X( X) X( X) 2( 2) 6( 8) X( 8) X( 8) MAYPORT NS FL 34 X X( X) X( X) 39(39) 10(49) X(49) X(49) MAYPORT NS FL 50 X X( X) X( X) 5( 5) 3( 8) X( 8) X( 8) JACKSONVILLE 34 X X( X) X( X) 25(25) 8(33) X(33) X(33) JACKSONVILLE 50 X X( X) X( X) 3( 3) 1( 4) X( 4) X( 4) GAINESVILLE FL 34 X X( X) 2( 2) 52(54) 4(58) X(58) X(58) GAINESVILLE FL 50 X X( X) X( X) 15(15) 3(18) X(18) X(18) GAINESVILLE FL 64 X X( X) X( X) 1( 1) 1( 2) X( 2) X( 2) DAYTONA BEACH 34 X X( X) 1( 1) 17(18) 2(20) X(20) X(20) THE VILLAGES 34 X X( X) 3( 3) 41(44) 2(46) X(46) X(46) THE VILLAGES 50 X X( X) X( X) 8( 8) 1( 9) X( 9) X( 9) THE VILLAGES 64 X X( X) X( X) 1( 1) X( 1) X( 1) X( 1) ORLANDO FL 34 X X( X) 4( 4) 17(21) 1(22) X(22) X(22) COCOA BEACH FL 34 X X( X) 4( 4) 26(30) 1(31) X(31) X(31) PATRICK AFB 34 X X( X) 4( 4) 27(31) 1(32) X(32) X(32) FT PIERCE FL 34 X X( X) 4( 4) 17(21) 1(22) X(22) X(22) W PALM BEACH 34 X X( X) 5( 5) 10(15) X(15) X(15) X(15) FT LAUDERDALE 34 X X( X) 6( 6) 7(13) X(13) X(13) X(13) MIAMI FL 34 X X( X) 4( 4) 2( 6) X( 6) X( 6) X( 6) HOMESTEAD ARB 34 X X( X) 4( 4) 2( 6) X( 6) X( 6) X( 6) MARATHON FL 34 X 2( 2) 14(16) 4(20) 1(21) X(21) X(21) KEY WEST FL 34 X 10(10) 18(28) 5(33) X(33) X(33) X(33) NAPLES FL 34 X 1( 1) 24(25) 19(44) X(44) X(44) X(44) NAPLES FL 50 X X( X) 1( 1) 4( 5) X( 5) X( 5) X( 5) FT MYERS FL 34 X X( X) 10(10) 14(24) X(24) X(24) X(24) FT MYERS FL 50 X X( X) X( X) 3( 3) X( 3) X( 3) X( 3) VENICE FL 34 X 1( 1) 27(28) 39(67) X(67) X(67) X(67) VENICE FL 50 X X( X) 2( 2) 20(22) X(22) X(22) X(22) VENICE FL 64 X X( X) X( X) 4( 4) X( 4) X( 4) X( 4) TAMPA FL 34 X X( X) 16(16) 56(72) X(72) X(72) X(72) TAMPA FL 50 X X( X) 1( 1) 30(31) 1(32) X(32) X(32) TAMPA FL 64 X X( X) X( X) 7( 7) X( 7) X( 7) X( 7) CEDAR KEY FL 34 X X( X) 9( 9) 73(82) 2(84) X(84) X(84) CEDAR KEY FL 50 X X( X) X( X) 56(56) 3(59) X(59) X(59) CEDAR KEY FL 64 X X( X) X( X) 24(24) 2(26) X(26) X(26) TALLAHASSEE FL 34 X X( X) 1( 1) 56(57) 17(74) X(74) X(74) TALLAHASSEE FL 50 X X( X) X( X) 22(22) 19(41) X(41) X(41) TALLAHASSEE FL 64 X X( X) X( X) 3( 3) 8(11) X(11) X(11) ST MARKS FL 34 X X( X) 2( 2) 64(66) 11(77) X(77) X(77) ST MARKS FL 50 X X( X) X( X) 32(32) 16(48) X(48) X(48) ST MARKS FL 64 X X( X) X( X) 8( 8) 8(16) X(16) X(16) APALACHICOLA 34 X X( X) 6( 6) 65(71) 5(76) X(76) X(76) APALACHICOLA 50 X X( X) X( X) 49(49) 9(58) X(58) X(58) APALACHICOLA 64 X X( X) X( X) 24(24) 8(32) X(32) X(32) GFMX 290N 850W 34 X X( X) 11(11) 68(79) 2(81) X(81) X(81) GFMX 290N 850W 50 X X( X) 1( 1) 64(65) 2(67) X(67) X(67) GFMX 290N 850W 64 X X( X) X( X) 38(38) 4(42) X(42) X(42) PANAMA CITY FL 34 X X( X) 5( 5) 44(49) 9(58) X(58) X(58) PANAMA CITY FL 50 X X( X) X( X) 27(27) 7(34) X(34) X(34) PANAMA CITY FL 64 X X( X) X( X) 10(10) 7(17) X(17) X(17) DESTIN EXEC AP 34 X X( X) 1( 1) 12(13) 5(18) X(18) X(18) DESTIN EXEC AP 50 X X( X) X( X) 4( 4) 2( 6) X( 6) X( 6) DESTIN EXEC AP 64 X X( X) X( X) X( X) 1( 1) X( 1) X( 1) ALBANY GA 34 X X( X) X( X) 22(22) 37(59) X(59) X(59) ALBANY GA 50 X X( X) X( X) 2( 2) 19(21) X(21) X(21) ALBANY GA 64 X X( X) X( X) X( X) 3( 3) X( 3) X( 3) COLUMBUS GA 34 X X( X) X( X) 5( 5) 24(29) X(29) X(29) COLUMBUS GA 50 X X( X) X( X) X( X) 4( 4) X( 4) X( 4) MACON GA 34 X X( X) X( X) 5( 5) 29(34) X(34) X(34) MACON GA 50 X X( X) X( X) X( X) 4( 4) X( 4) X( 4) DOTHAN AL 34 X X( X) X( X) 17(17) 22(39) X(39) X(39) DOTHAN AL 50 X X( X) X( X) 3( 3) 10(13) X(13) X(13) DOTHAN AL 64 X X( X) X( X) X( X) 3( 3) X( 3) X( 3) BIRMINGHAM AL 34 X X( X) X( X) 1( 1) 2( 3) X( 3) X( 3) MONTGOMERY AL 34 X X( X) X( X) 4( 4) 6(10) X(10) X(10) WHITING FLD FL 34 X X( X) X( X) 8( 8) 2(10) X(10) X(10) WHITING FLD FL 50 X X( X) X( X) 2( 2) 1( 3) X( 3) X( 3) PENSACOLA FL 34 X X( X) 1( 1) 7( 8) 2(10) X(10) X(10) GFMX 290N 870W 34 X X( X) 7( 7) 19(26) 1(27) X(27) X(27) GFMX 290N 870W 50 X X( X) X( X) 9( 9) X( 9) X( 9) X( 9) GFMX 290N 870W 64 X X( X) X( X) 3( 3) X( 3) X( 3) X( 3) MOBILE AL 34 X X( X) X( X) 4( 4) X( 4) X( 4) X( 4) GFMX 280N 890W 34 X X( X) 5( 5) 3( 8) 1( 9) X( 9) X( 9) MERIDA MX 34 1 3( 4) 1( 5) X( 5) X( 5) X( 5) X( 5) COZUMEL MX 34 54 11(65) 1(66) X(66) X(66) X(66) X(66) COZUMEL MX 50 26 4(30) X(30) X(30) X(30) X(30) X(30) COZUMEL MX 64 2 X( 2) X( 2) X( 2) X( 2) X( 2) X( 2) BELIZE CITY 34 2 3( 5) X( 5) X( 5) X( 5) X( 5) X( 5) GUANAJA 34 2 1( 3) X( 3) X( 3) X( 3) X( 3) X( 3) GRAND BAHAMA 34 X X( X) X( X) 3( 3) X( 3) X( 3) X( 3) CP SAN ANTONIO 34 80 10(90) 1(91) X(91) X(91) X(91) X(91) CP SAN ANTONIO 50 35 29(64) 1(65) X(65) X(65) X(65) X(65) CP SAN ANTONIO 64 1 7( 8) 1( 9) X( 9) X( 9) X( 9) X( 9) HAVANA 34 3 5( 8) 4(12) 1(13) X(13) X(13) X(13) ISLE OF PINES 34 15 10(25) 5(30) X(30) X(30) X(30) X(30) CIENFUEGOS 34 X 1( 1) 1( 2) 1( 3) X( 3) X( 3) X( 3) GRAND CAYMAN 34 4 1( 5) X( 5) X( 5) X( 5) X( 5) X( 5) $$ FORECASTER PASCH

...HELENE EXPECTED TO STRENGTHEN RAPIDLY OVER THE GULF OF MEXICO... As of 10:00 PM CDT Tue Sep 24 the center of Helene was located near 19.9, -85.5 with movement WNW at 10 mph. The minimum central pressure was 991 mb with maximum sustained winds of about 60 mph.

Issued at 1000 PM CDT Tue Sep 24 2024 000 WTNT34 KNHC 250255 TCPAT4 BULLETIN Tropical Storm Helene Advisory Number 7 NWS National Hurricane Center Miami FL AL092024 1000 PM CDT Tue Sep 24 2024 ...HELENE EXPECTED TO STRENGTHEN RAPIDLY OVER THE GULF OF MEXICO... SUMMARY OF 1000 PM CDT...0300 UTC...INFORMATION ----------------------------------------------- LOCATION...19.9N 85.5W ABOUT 100 MI...160 KM ESE OF COZUMEL MEXICO ABOUT 145 MI...230 KM SSW OF THE WESTERN TIP OF CUBA MAXIMUM SUSTAINED WINDS...60 MPH...95 KM/H PRESENT MOVEMENT...WNW OR 300 DEGREES AT 10 MPH...17 KM/H MINIMUM CENTRAL PRESSURE...991 MB...29.27 INCHES WATCHES AND WARNINGS -------------------- CHANGES WITH THIS ADVISORY: A Tropical Storm Warning has been issued for Lake Okeechobee. A Tropical Storm Warning has been issued from the Palm Beach/Martin County Line northward to the Flagler/Volusia County Line. 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 on Wednesday. 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 PM CDT (0300 UTC), the center of Tropical Storm Helene was located near latitude 19.9 North, longitude 85.5 West. Helene is moving toward the west-northwest near 10 mph (17 km/h). A turn toward the northwest is expected later tonight, followed by a general northward motion beginning on Wednesday and continuing through Friday. On the forecast track, the center of Helene will pass near the northeastern coast of the Yucatan Peninsula later tonight or early Wednesday, move across the eastern Gulf of Mexico on Wednesday 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 tonight or early Wednesday. 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 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 on Wednesday. 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 on Wednesday 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 Wednesday night 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 on Wednesday 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 AM CDT. Next complete advisory at 400 AM CDT. $$ Forecaster Pasch

Issued at 0300 UTC WED SEP 25 2024 000 WTNT24 KNHC 250254 TCMAT4 TROPICAL STORM HELENE FORECAST/ADVISORY NUMBER 7 NWS NATIONAL HURRICANE CENTER MIAMI FL AL092024 0300 UTC WED SEP 25 2024 TROPICAL STORM CENTER LOCATED NEAR 19.9N 85.5W AT 25/0300Z POSITION ACCURATE WITHIN 25 NM PRESENT MOVEMENT TOWARD THE WEST-NORTHWEST OR 300 DEGREES AT 9 KT ESTIMATED MINIMUM CENTRAL PRESSURE 991 MB MAX SUSTAINED WINDS 50 KT WITH GUSTS TO 60 KT. 50 KT....... 90NE 90SE 0SW 0NW. 34 KT.......150NE 150SE 0SW 0NW. 12 FT SEAS..120NE 150SE 30SW 30NW. 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 19.9N 85.5W AT 25/0300Z AT 25/0000Z CENTER WAS LOCATED NEAR 19.7N 85.2W FORECAST VALID 25/1200Z 21.1N 86.3W MAX WIND 65 KT...GUSTS 80 KT. 64 KT... 20NE 20SE 0SW 0NW. 50 KT... 60NE 60SE 0SW 0NW. 34 KT...210NE 210SE 40SW 80NW. FORECAST VALID 26/0000Z 22.7N 86.4W MAX WIND 75 KT...GUSTS 90 KT. 64 KT... 25NE 20SE 0SW 0NW. 50 KT... 60NE 60SE 20SW 30NW. 34 KT...240NE 250SE 80SW 100NW. FORECAST VALID 26/1200Z 25.4N 85.5W MAX WIND 90 KT...GUSTS 110 KT. 64 KT... 30NE 40SE 15SW 20NW. 50 KT... 70NE 80SE 30SW 40NW. 34 KT...250NE 250SE 120SW 120NW. FORECAST VALID 27/0000Z 29.5N 84.2W MAX WIND 105 KT...GUSTS 130 KT. 64 KT... 45NE 55SE 20SW 20NW. 50 KT... 70NE 90SE 40SW 40NW. 34 KT...210NE 240SE 140SW 100NW. FORECAST VALID 27/1200Z 34.0N 84.5W MAX WIND 30 KT...GUSTS 40 KT. FORECAST VALID 28/0000Z 36.5N 86.5W...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 29/0000Z 37.0N 89.0W...POST-TROP/INLAND MAX WIND 20 KT...GUSTS 30 KT. OUTLOOK VALID 30/0000Z...DISSIPATED REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 19.9N 85.5W INTERMEDIATE PUBLIC ADVISORY...WTNT34 KNHC/MIATCPAT4...AT 25/0600Z NEXT ADVISORY AT 25/0900Z $$ FORECASTER PASCH

...HELENE STRENGTHENING... As of 8:00 PM EDT Tue Sep 24 the center of Helene was located near 19.8, -85.3 with movement WNW at 12 mph. The minimum central pressure was 991 mb with maximum sustained winds of about 60 mph.

Issued at 800 PM EDT Tue Sep 24 2024 479 WTNT34 KNHC 242351 TCPAT4 BULLETIN Tropical Storm Helene Intermediate Advisory Number 6A NWS National Hurricane Center Miami FL AL092024 800 PM EDT Tue Sep 24 2024 ...HELENE STRENGTHENING... SUMMARY OF 800 PM EDT...0000 UTC...INFORMATION ---------------------------------------------- LOCATION...19.8N 85.3W ABOUT 115 MI...185 KM ESE OF COZUMEL MEXICO ABOUT 145 MI...235 KM S OF THE WESTERN TIP OF CUBA MAXIMUM SUSTAINED WINDS...60 MPH...95 KM/H PRESENT MOVEMENT...WNW OR 300 DEGREES AT 12 MPH...19 KM/H MINIMUM CENTRAL PRESSURE...991 MB...29.26 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 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 * 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... * Lake Okeechobee * Palm Beach/Martin 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 tonight or on Wednesday. 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 800 PM EDT (0000 UTC), the center of Tropical Storm Helene was located near latitude 19.8 North, longitude 85.3 West. Helene is moving toward the west-northwest near 12 mph (19 km/h). A turn toward the northwest is expected later tonight, followed by a general northward motion beginning on Wednesday and continuing through Friday. On the forecast track, the center of Helene will pass near the northeastern coast of the Yucatan Peninsula on Wednesday, move across the eastern Gulf of Mexico on Wednesday and Thursday, and reach the Big Bend coast of Florida late Thursday. Maximum sustained winds have increased to near 60 mph (95 km/h) with higher gusts. Additional strengthening is forecast, and Helene is expected to become a hurricane on Wednesday. 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) to the east of the center. The minimum central pressure based on Hurricane Hunter aircraft observations is 991 mb (29.26 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: Helene is expected to produce total rain accumulations of 4 to 8 inches over western Cuba and the Cayman Islands with isolated totals around 12 inches. Over the eastern Yucatan Peninsula, 4 to 6 inches of rain are expected with isolated totals over 8 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 likely, including the risk of landslides 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. 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 on Wednesday. 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 on Wednesday and spread northward through Thursday. Tropical storm conditions are possible within the tropical storm watch area beginning Thursday. 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 on Wednesday 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 1100 PM EDT. $$ Forecaster Pasch

220
ABNT20 KNHC 242333
TWOAT

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
800 PM EDT Tue Sep 24 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 is producing disorganized showers and
thunderstorms.. 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.

$$
Forecaster Kelly

...STORM SURGE AND HURRICANE WARNINGS ISSUED FOR THE GULF COAST OF FLORIDA... ...HELENE'S LARGE SIZE WILL LIKELY CAUSE AN EXTENSIVE AREA TO BE AFFECTED BY THE STORM'S HAZARDS... As of 5:00 PM EDT Tue Sep 24 the center of Helene was located near 19.7, -84.7 with movement WNW at 12 mph. The minimum central pressure was 995 mb with maximum sustained winds of about 50 mph.

Issued at 500 PM EDT Tue Sep 24 2024 000 WTNT34 KNHC 242226 CCB TCPAT4 BULLETIN Tropical Storm Helene Advisory Number 6...Corrected NWS National Hurricane Center Miami FL AL092024 500 PM EDT Tue Sep 24 2024 Corrected summary of watches and warnings in effect ...STORM SURGE AND HURRICANE WARNINGS ISSUED FOR THE GULF COAST OF FLORIDA... ...HELENE'S LARGE SIZE WILL LIKELY CAUSE AN EXTENSIVE AREA TO BE AFFECTED BY THE STORM'S HAZARDS... SUMMARY OF 500 PM EDT...2100 UTC...INFORMATION ---------------------------------------------- LOCATION...19.7N 84.7W ABOUT 155 MI...245 KM ESE OF COZUMEL MEXICO ABOUT 150 MI...245 KM S OF THE WESTERN TIP OF CUBA MAXIMUM SUSTAINED WINDS...50 MPH...85 KM/H PRESENT MOVEMENT...WNW OR 300 DEGREES AT 12 MPH...19 KM/H MINIMUM CENTRAL PRESSURE...995 MB...29.39 INCHES WATCHES AND WARNINGS -------------------- CHANGES WITH THIS ADVISORY: A Storm Surge Warning has been issued from Flamingo to Indian Pass, Florida, including Tampa Bay and Charlotte Harbor. A Hurricane Warning has been issued from Anclote River to Mexico Beach, Florida. The government of Mexico has issued a Hurricane Warning from Cabo Catoche to Tulum. A Tropical Storm Warning has been issued for the Middle Florida Keys from the Seven Mile Bridge to the Channel 5 Bridge. A Tropical Storm Warning has been issued for the Gulf coast of Florida from Flamingo northward to Anclote River, including Tampa Bay, and west of Mexico Beach to the Walton/Bay County Line. A Tropical Storm Watch has been issued for the east coasts of Florida and Georgia from the Palm Beach/Martin County Line northward to the Savannah River, and for Lake Okeechobee. 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 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 * 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... * Lake Okeechobee * Palm Beach/Martin 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 tonight or on Wednesday. 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 500 PM EDT (2100 UTC), the center of Tropical Storm Helene was located near latitude 19.7 North, longitude 84.7 West. Helene is moving toward the west-northwest near 12 mph (19 km/h). A turn toward the northwest is expected tonight, followed by a general northward motion beginning on Wednesday and continuing through Friday. On the forecast track, the center of Helene will pass near the northeastern coast of the Yucatan Peninsula on Wednesday, move across the eastern Gulf of Mexico on Wednesday and Thursday, and reach the Big Bend coast of Florida late Thursday. Maximum sustained winds have increased to near 50 mph (85 km/h) with higher gusts. Additional strengthening is forecast, and Helene is expected to become a hurricane on Wednesday. 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) to the east of the center. Data from NOAA buoy 42056 indicate that the minimum central pressure is 995 mb (29.39 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: Helene is expected to produce total rain accumulations of 4 to 8 inches over western Cuba and the Cayman Islands with isolated totals around 12 inches. Over the eastern Yucatan Peninsula, 4 to 6 inches of rain are expected with isolated totals over 8 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 likely, including the risk of landslides 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. 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 on Wednesday. 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 Florida on Wednesday and spread northward through Thursday. Tropical storm conditions are possible within the tropical storm watch area beginning Thursday. 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 on Wednesday 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 800 PM EDT. Next complete advisory at 1100 PM EDT. $$ Forecaster Berg

Potential Storm Surge Flooding Map last updated Tue, 24 Sep 2024 21:58:28 GMT

Probabilistic Storm Surge Graphics last updated Tue, 24 Sep 2024 21:37:45 GMT

...STORM SURGE AND HURRICANE WARNINGS ISSUED FOR THE GULF COAST OF FLORIDA... ...HELENE'S LARGE SIZE WILL LIKELY CAUSE AN EXTENSIVE AREA TO BE AFFECTED BY THE STORM'S HAZARDS... As of 5:00 PM EDT Tue Sep 24 the center of Helene was located near 19.7, -84.7 with movement WNW at 12 mph. The minimum central pressure was 995 mb with maximum sustained winds of about 50 mph.

Issued at 500 PM EDT Tue Sep 24 2024 000 WTNT34 KNHC 242125 CCA TCPAT4 BULLETIN Tropical Storm Helene Advisory Number 6...Corrected NWS National Hurricane Center Miami FL AL092024 500 PM EDT Tue Sep 24 2024 Corrected summary of watches and warnings in effect ...STORM SURGE AND HURRICANE WARNINGS ISSUED FOR THE GULF COAST OF FLORIDA... ...HELENE'S LARGE SIZE WILL LIKELY CAUSE AN EXTENSIVE AREA TO BE AFFECTED BY THE STORM'S HAZARDS... SUMMARY OF 500 PM EDT...2100 UTC...INFORMATION ---------------------------------------------- LOCATION...19.7N 84.7W ABOUT 155 MI...245 KM ESE OF COZUMEL MEXICO ABOUT 150 MI...245 KM S OF THE WESTERN TIP OF CUBA MAXIMUM SUSTAINED WINDS...50 MPH...85 KM/H PRESENT MOVEMENT...WNW OR 300 DEGREES AT 12 MPH...19 KM/H MINIMUM CENTRAL PRESSURE...995 MB...29.39 INCHES WATCHES AND WARNINGS -------------------- CHANGES WITH THIS ADVISORY: A Storm Surge Warning has been issued from Flamingo to Indian Pass, Florida, including Tampa Bay and Charlotte Harbor. A Hurricane Warning has been issued from Anclote River to Mexico Beach, Florida. The government of Mexico has issued a Hurricane Warning from Cabo Catoche to Tulum. A Tropical Storm Warning has been issued for the Middle Florida Keys from the Seven Mile Bridge to the Channel 5 Bridge. A Tropical Storm Warning has been issued for the Gulf coast of Florida from Flamingo northward to Anclote River, including Tampa Bay, and west of Mexico Beach to the Walton/Bay County Line. A Tropical Storm Watch has been issued for the east coasts of Florida and Georgia from the Palm Beach/Martin County Line northward to the Savannah River, and for Lake Okeechobee. 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 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 * Rio Lagartos to Tulum, Mexico * Cuban provinces of Artemisa, Pinar del Rio, and the Isle of Youth A Tropical Storm Watch is in effect for... * Lake Okeechobee * Palm Beach/Martin 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 tonight or on Wednesday. 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 500 PM EDT (2100 UTC), the center of Tropical Storm Helene was located near latitude 19.7 North, longitude 84.7 West. Helene is moving toward the west-northwest near 12 mph (19 km/h). A turn toward the northwest is expected tonight, followed by a general northward motion beginning on Wednesday and continuing through Friday. On the forecast track, the center of Helene will pass near the northeastern coast of the Yucatan Peninsula on Wednesday, move across the eastern Gulf of Mexico on Wednesday and Thursday, and reach the Big Bend coast of Florida late Thursday. Maximum sustained winds have increased to near 50 mph (85 km/h) with higher gusts. Additional strengthening is forecast, and Helene is expected to become a hurricane on Wednesday. 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) to the east of the center. Data from NOAA buoy 42056 indicate that the minimum central pressure is 995 mb (29.39 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: Helene is expected to produce total rain accumulations of 4 to 8 inches over western Cuba and the Cayman Islands with isolated totals around 12 inches. Over the eastern Yucatan Peninsula, 4 to 6 inches of rain are expected with isolated totals over 8 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 likely, including the risk of landslides 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. 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 on Wednesday. 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 Florida on Wednesday and spread northward through Thursday. Tropical storm conditions are possible within the tropical storm watch area beginning Thursday. 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 on Wednesday 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 800 PM EDT. Next complete advisory at 1100 PM EDT. $$ Forecaster Berg

Storm Surge Watch/Warning Map last updated Tue, 24 Sep 2024 20:59:15 GMT

Issued at 500 PM EDT Tue Sep 24 2024 504 WTNT44 KNHC 242058 TCDAT4 Tropical Storm Helene Discussion Number 6 NWS National Hurricane Center Miami FL AL092024 500 PM EDT Tue Sep 24 2024 Deep convection is gradually filling in within Helene's circulation, and the well-defined center that formed earlier this morning is now obscured by cloudiness and showers. Data from NOAA buoy indicate that the central pressure has fallen to 995 mb, and the initial intensity is therefore estimated to be 45 kt. NOAA and the Air Force Reserve Hurricane Hunters will be investigating Helene this evening to provide more information about the storm's intensity and structure. With the center formation this morning, Helene has taken a short-term jog to the west-northwest (300/10 kt). The storm is expected to turn northwestward by tonight and then northward on Wednesday as high pressure over Florida shifts eastward, and a deep-layer trough digs southward over the Lower Mississippi Valley. The NHC track forecast has been shifted westward during the first 24 hours to account for the recent motion, and Helene's center could get very close to the northeastern coast of the Yucatan Peninsula Wednesday morning. After that time, however, the NHC track forecast is relatively unchanged from the previous prediction, except for being a little bit slower based on the latest guidance. Helene is expected to accelerate while it moves northward across the eastern Gulf of Mexico and approaches the Florida Gulf coast. Warm sea surface temperatures, decreasing shear, and strong upper-level divergence are likely to foster Helene's strengthening while it moves across the northwestern Caribbean Sea and eastern Gulf of Mexico. The statistical-dynamical SHIPS/LGEM models, as well as the regional hurricane models, continue to show Helene reaching major hurricane intensity while over the eastern Gulf of Mexico, and that continues to be shown in the NHC forecast. Helene could maintain that level of intensity until it reaches the Gulf coast of Florida. Of equal importance to the forecast intensity is Helene's forecast size. Helene's forecast radii are at the 90th percentile of major hurricane size at similar latitudes, and 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 it 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 on Wednesday, 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 complete by early Thursday since tropical storm conditions are expected to begin within this area on Thursday. 4. Helene will bring heavy rain to portions of the western Caribbean with potentially significant flooding and mudslides across western Cuba. Considerable flash and urban flooding is expected across portions of Florida, the Southeast, southern Appalachians, and the 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 24/2100Z 19.7N 84.7W 45 KT 50 MPH 12H 25/0600Z 20.4N 86.0W 55 KT 65 MPH 24H 25/1800Z 21.7N 86.6W 65 KT 75 MPH 36H 26/0600Z 23.7N 86.1W 80 KT 90 MPH 48H 26/1800Z 27.0N 84.9W 100 KT 115 MPH 60H 27/0600Z 31.5N 84.0W 60 KT 70 MPH...INLAND 72H 27/1800Z 35.5N 84.8W 30 KT 35 MPH...INLAND 96H 28/1800Z 38.2N 89.0W 20 KT 25 MPH...POST-TROP/INLAND 120H 29/1800Z...DISSIPATED $$ Forecaster Berg