...HELENE MOVING NORTHWARD AND EXPECTED TO BRING CATASTROPHIC WINDS AND STORM SURGE TO THE NORTHEASTERN GULF COAST... ...PREPARATIONS TO PROTECT LIFE AND PROPERTY SHOULD BE RUSHED TO COMPLETION... As of 1:00 AM CDT Thu Sep 26 the center of Helene was located near 23.7, -86.5 with movement N at 12 mph. The minimum central pressure was 971 mb with maximum sustained winds of about 85 mph.

Issued at 100 AM CDT Thu Sep 26 2024 000 WTNT34 KNHC 260556 TCPAT4 BULLETIN Hurricane Helene Intermediate Advisory Number 11A NWS National Hurricane Center Miami FL AL092024 100 AM CDT Thu Sep 26 2024 ...HELENE MOVING NORTHWARD AND EXPECTED TO BRING CATASTROPHIC WINDS AND STORM SURGE TO THE NORTHEASTERN GULF COAST... ...PREPARATIONS TO PROTECT LIFE AND PROPERTY SHOULD BE RUSHED TO COMPLETION... SUMMARY OF 100 AM CDT...0600 UTC...INFORMATION ---------------------------------------------- LOCATION...23.7N 86.5W ABOUT 385 MI...620 KM SW OF TAMPA FLORIDA ABOUT 425 MI...680 KM SSW OF APALACHICOLA FLORIDA MAXIMUM SUSTAINED WINDS...85 MPH...140 KM/H PRESENT MOVEMENT...N OR 5 DEGREES AT 12 MPH...19 KM/H MINIMUM CENTRAL PRESSURE...971 MB...28.67 INCHES WATCHES AND WARNINGS -------------------- CHANGES WITH THIS ADVISORY: None. SUMMARY OF WATCHES AND WARNINGS IN EFFECT: A Storm Surge Warning is in effect for... * Mexico Beach eastward and southward to Flamingo * Tampa Bay * Charlotte Harbor A Hurricane Warning is in effect for... * Anclote River to Mexico Beach A Hurricane Watch is in effect for... * 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 Little River Inlet * Lake Okeechobee * Cuban provinces of Artemisa, Pinar del Rio, and the Isle of Youth 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. 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 Hurricane Helene was located near latitude 23.7 North, longitude 86.5 West. Helene is moving toward the north near 12 mph (19 km/h). A northward or north-northeastward motion at a faster forward speed is expected during the next 36 hours. On the forecast track, Helene will move across the eastern Gulf of Mexico today and cross the Florida Big Bend coast this evening. After landfall, Helene is expected to turn northwestward and slow down over the Tennessee Valley on Friday and Saturday. Maximum sustained winds are near 85 mph (140 km/h) with higher gusts. Strengthening is forecast, and Helene is expected to be a major hurricane when it reaches the Florida Big Bend coast this 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 35 miles (55 km) from the center and tropical-storm-force winds extend outward up to 345 miles (555 km). The NOAA automated station at Sand Key, Florida recently reported sustained winds of 45 mph (72 km/h). The estimated minimum central pressure from Air Force Reserve Hurricane Hunter aircraft data is 971 mb (28.67 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 life-threatening 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 Suwannee River, FL...15-20 ft Apalachicola, FL to Carrabelle, FL...10-15 ft Suwannee River, FL to Chassahowitzka, FL...10-15 ft Chassahowitzka, FL to Anclote River, FL...8-12 ft Indian Pass, FL to Apalachicola, 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 East of Mexico Beach, FL to Indian Pass, FL...3-5 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. WIND: Hurricane conditions are expected within the U.S. hurricane warning area late today, with tropical storm conditions beginning this morning. Tropical storm conditions are expected in southern Florida this morning and will spread northward across the rest of Florida, Georgia, and South Carolina through tonight. Tropical storm conditions are expected over portions of the warning area in western Cuba during the next several hours. RAINFALL: Hurricane 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 portions of the Southeastern U.S. into the Southern Appalachians, Helene is expected to produce total rain accumulations of 6 to 12 inches with isolated totals around 18 inches. This rainfall will likely result in catastrophic and potentially life-threatening flash and urban flooding, along with significant river flooding. Numerous landslides are expected in steep terrain across the southern Appalachians. For a complete depiction of forecast rainfall associated with Hurricane 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 this morning over parts of Florida. The risk for tornadoes will increase later today, 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 today. 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

000
ABNT20 KNHC 260528
TWOAT

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
200 AM EDT Thu Sep 26 2024

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

Active Systems:
The National Hurricane Center is issuing advisories on Hurricane
Helene, located over the southeastern Gulf of Mexico and on newly
formed Tropical Storm Isaac, located over the central Subtropical
Atlantic Ocean.

Eastern and Central Tropical Atlantic (AL98):
Showers and thunderstorms have increased this morning in association
with a broad area of low pressure along a tropical wave located
several hundred miles west of the Cabo Verde Islands. However,
earlier satellite wind data suggested the system still lacks a
well-defined circulation. Environmental conditions appear favorable
for gradual development of this system, and a tropical depression is
likely to form during the next day or two while it moves westward to
west-northwestward at around 15 mph across the eastern and central
tropical Atlantic.
* Formation chance through 48 hours...high...70 percent.
* Formation chance through 7 days...high...80 percent.

&&
Public Advisories on Tropical Storm Isaac are issued under WMO
header WTNT35 KNHC and under AWIPS header MIATCPAT5.
Forecast/Advisories on Tropical Storm Isaac are issued under WMO
header WTNT25 KNHC and under AWIPS header MIATCMAT5.

$$
Forecaster Papin

Potential Storm Surge Flooding Map last updated Thu, 26 Sep 2024 03:44:47 GMT

Probabilistic Storm Surge Graphics last updated Thu, 26 Sep 2024 03:25:36 GMT

5-Day Uncertainty Track last updated Thu, 26 Sep 2024 03:00:32 GMT


Wind Speed Probabilities last updated Thu, 26 Sep 2024 03:29:11 GMT

Issued at 1100 PM AST Wed Sep 25 2024 000 WTNT45 KNHC 260258 TCDAT5 Tropical Storm Isaac Discussion Number 1 NWS National Hurricane Center Miami FL AL102024 1100 PM AST Wed Sep 25 2024 The non-tropical area of low pressure we have been monitoring to the northeast of Bermuda over the last day or so has become significantly better organized today, with deep central convection forming and now wrapping around a small surface circulation. While the system had previously been attached to an occluded frontal boundary to its northwest, recently received scatterometer data now shows that the circulation has fully detached form this boundary, and is producing winds of 40-45 kt in a small circular area embedded within the organizing convection. These structural changes indicate the the system has undergone and has completed tropical transition. Thus, the system is now being designated Tropical Storm Isaac this advisory, and the initial intensity is set to 45 kt based on the earlier scatterometer data. Isaac is moving just north of due east at 85/10 kt. This motion should continue with a gentle turn more east-northeastward over the next several days as the system is steered primarily by mid-level ridging present to its south. However, there does not appear to be a mid-latitude trough early on to help the storm to accelerate much over the next few days. The initial NHC track forecast is in good agreement with the simple and corrected consensus aids TCVN and HCCA. While Isaac is traversing only marginally warm waters, it is also still embedded within the base of an upper-level trough which has reduced tropospheric stability due to colder upper-level temperatures. This is partially why Isaac has been able to develop organized deep convection this evening. The shear is not anticipated to increase much over the next couple of days, which could allow for some gradual intensification. The NHC intensity forecast is in good agreement the with HCCA and ECMWF forecasts and shows a peak intensity of 60 kt in 48 h, followed by gradual weakening after 72 h as sea-surface temperatures cool further and shear begins to increase more markedly. FORECAST POSITIONS AND MAX WINDS INIT 26/0300Z 37.1N 54.1W 45 KT 50 MPH 12H 26/1200Z 37.1N 52.3W 50 KT 60 MPH 24H 27/0000Z 37.3N 49.8W 50 KT 60 MPH 36H 27/1200Z 37.9N 46.8W 55 KT 65 MPH 48H 28/0000Z 38.8N 43.2W 60 KT 70 MPH 60H 28/1200Z 40.1N 39.5W 60 KT 70 MPH 72H 29/0000Z 41.4N 35.8W 60 KT 70 MPH 96H 30/0000Z 42.7N 29.4W 55 KT 65 MPH 120H 01/0000Z 42.5N 21.0W 50 KT 60 MPH...POST-TROP/EXTRATROP $$ Forecaster Papin

...NEW TROPICAL STORM FORMS IN THE OPEN CENTRAL SUBTROPICAL ATLANTIC... As of 11:00 PM AST Wed Sep 25 the center of Isaac was located near 37.1, -54.1 with movement E at 12 mph. The minimum central pressure was 997 mb with maximum sustained winds of about 50 mph.

Issued at 1100 PM AST Wed Sep 25 2024 000 WTNT35 KNHC 260257 TCPAT5 BULLETIN Tropical Storm Isaac Advisory Number 1 NWS National Hurricane Center Miami FL AL102024 1100 PM AST Wed Sep 25 2024 ...NEW TROPICAL STORM FORMS IN THE OPEN CENTRAL SUBTROPICAL ATLANTIC... SUMMARY OF 1100 PM AST...0300 UTC...INFORMATION ----------------------------------------------- LOCATION...37.1N 54.1W ABOUT 1480 MI...2380 KM W OF THE AZORES ABOUT 690 MI...1115 KM ENE OF BERMUDA MAXIMUM SUSTAINED WINDS...50 MPH...85 KM/H PRESENT MOVEMENT...E OR 85 DEGREES AT 12 MPH...19 KM/H MINIMUM CENTRAL PRESSURE...997 MB...29.44 INCHES WATCHES AND WARNINGS -------------------- There are no coastal watches or warnings in effect. DISCUSSION AND OUTLOOK ---------------------- At 1100 PM AST (0300 UTC), the center of Tropical Storm Isaac was located near latitude 37.1 North, longitude 54.1 West. Isaac is moving toward the east near 12 mph (19 km/h) and a general eastward to east-northeastward motion at a slightly faster speed is anticipated over the next several days. Recent satellite wind data indicates that maximum sustained winds are near 50 mph (85 km/h) with higher gusts. Some strengthening is forecast during the next couple of days and Isaac could be near hurricane intensity by the end of the week. Tropical-storm-force winds extend outward up to 220 miles (350 km) from the center. The estimated minimum central pressure is 997 mb (29.44 inches). HAZARDS AFFECTING LAND ---------------------- SURF: Swells generated by Isaac and a large wind fetch from a deep-layer trough are affecting portions of the coast of Bermuda and could spread into the Azores by this weekend. 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 500 AM AST. $$ Forecaster Papin

Issued at 0300 UTC THU SEP 26 2024 000 FONT15 KNHC 260257 PWSAT5 TROPICAL STORM ISAAC WIND SPEED PROBABILITIES NUMBER 1 NWS NATIONAL HURRICANE CENTER MIAMI FL AL102024 0300 UTC THU SEP 26 2024 AT 0300Z THE CENTER OF TROPICAL STORM ISAAC WAS LOCATED NEAR LATITUDE 37.1 NORTH...LONGITUDE 54.1 WEST WITH MAXIMUM SUSTAINED WINDS NEAR 45 KTS...50 MPH...85 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 THU 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 THU 12Z THU 00Z FRI 12Z FRI 00Z SAT 00Z SUN 00Z MON PERIODS TO TO TO TO TO TO TO 12Z THU 00Z FRI 12Z FRI 00Z SAT 00Z SUN 00Z MON 00Z TUE FORECAST HOUR (12) (24) (36) (48) (72) (96) (120) - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - LOCATION KT SANTA CRUZ AZO 34 X X( X) X( X) X( X) 9( 9) 11(20) 1(21) SANTA CRUZ AZO 50 X X( X) X( X) X( X) X( X) 3( 3) X( 3) PONTA DELGADA 34 X X( X) X( X) X( X) X( X) 2( 2) 3( 5) $$ FORECASTER PAPIN

5-Day Uncertainty Track last updated Thu, 26 Sep 2024 02:57:21 GMT


Wind Speed Probabilities last updated Thu, 26 Sep 2024 02:57:22 GMT

Issued at 0300 UTC THU SEP 26 2024 000 WTNT25 KNHC 260257 TCMAT5 TROPICAL STORM ISAAC FORECAST/ADVISORY NUMBER 1 NWS NATIONAL HURRICANE CENTER MIAMI FL AL102024 0300 UTC THU SEP 26 2024 TROPICAL STORM CENTER LOCATED NEAR 37.1N 54.1W AT 26/0300Z POSITION ACCURATE WITHIN 30 NM PRESENT MOVEMENT TOWARD THE EAST OR 85 DEGREES AT 10 KT ESTIMATED MINIMUM CENTRAL PRESSURE 997 MB MAX SUSTAINED WINDS 45 KT WITH GUSTS TO 55 KT. 34 KT.......100NE 50SE 40SW 80NW. 12 FT SEAS.. 0NE 120SE 120SW 0NW. 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 37.1N 54.1W AT 26/0300Z AT 26/0000Z CENTER WAS LOCATED NEAR 37.0N 54.7W FORECAST VALID 26/1200Z 37.1N 52.3W MAX WIND 50 KT...GUSTS 60 KT. 50 KT... 0NE 30SE 0SW 0NW. 34 KT...100NE 50SE 50SW 80NW. FORECAST VALID 27/0000Z 37.3N 49.8W MAX WIND 50 KT...GUSTS 60 KT. 50 KT... 0NE 40SE 35SW 0NW. 34 KT... 70NE 60SE 50SW 60NW. FORECAST VALID 27/1200Z 37.9N 46.8W MAX WIND 55 KT...GUSTS 65 KT. 50 KT... 0NE 50SE 40SW 0NW. 34 KT... 80NE 90SE 60SW 60NW. FORECAST VALID 28/0000Z 38.8N 43.2W MAX WIND 60 KT...GUSTS 75 KT. 50 KT... 0NE 50SE 40SW 0NW. 34 KT... 90NE 130SE 70SW 60NW. FORECAST VALID 28/1200Z 40.1N 39.5W MAX WIND 60 KT...GUSTS 75 KT. 50 KT... 0NE 60SE 50SW 40NW. 34 KT...110NE 130SE 100SW 100NW. FORECAST VALID 29/0000Z 41.4N 35.8W MAX WIND 60 KT...GUSTS 75 KT. 50 KT... 0NE 70SE 60SW 50NW. 34 KT...160NE 110SE 90SW 140NW. 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 30/0000Z 42.7N 29.4W MAX WIND 55 KT...GUSTS 65 KT. 50 KT... 0NE 60SE 50SW 0NW. 34 KT...120NE 100SE 100SW 130NW. OUTLOOK VALID 01/0000Z 42.5N 21.0W...POST-TROP/EXTRATROP MAX WIND 50 KT...GUSTS 60 KT. 50 KT... 0NE 50SE 0SW 0NW. 34 KT...150NE 80SE 80SW 90NW. REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 37.1N 54.1W NEXT ADVISORY AT 26/0900Z $$ FORECASTER PAPIN

Storm Surge Watch/Warning Map last updated Thu, 26 Sep 2024 02:55:12 GMT

Issued at 1000 PM CDT Wed Sep 25 2024 000 WTNT44 KNHC 260255 TCDAT4 Hurricane Helene Discussion Number 11 NWS National Hurricane Center Miami FL AL092024 1000 PM CDT Wed Sep 25 2024 Satellite images show that Helene has a well-organized appearance, with numerous convective banding features. A ragged-looking eye feature is also apparent. However, reports from both Air Force and a NOAA Hurricane Hunter aircraft investigating the system suggest that the it lacks a well-defined inner core with a somewhat broad maximum wind field for now. The central pressure has dropped a little to around 972 mb. Given the slowly falling central pressure, the intensity is maintained at 75 kt for this advisory. Helene's structure and intensity will continue to be closely monitored by Hurricane Hunter aircraft tonight and Thursday. The hurricane continues moving northward with an estimated initial motion of 360/08 kt. For the next couple of days, the steering scenario for this system remains basically unchanged from the earlier advisory. The flow between a mid-tropospheric trough over the east-central United States and a ridge over the western Atlantic should result in Helene accelerating northward to north-northeastward during the next 24 to 36 hours. This motion will bring the center of Helene to the northeastern Gulf of Mexico coast in about 24 hours. The official track forecast through landfall is very similar to the previous NHC prediction and remains close to the corrected consensus guidance. After landfall, the trough to the northwest of the tropical cyclone becomes a cutoff low, and Helene should turn leftward as it rotates around the low. In 3-4 days, the system should become a shallow extratropical cyclone within weaker steering currents. Helene should be in an atmospheric and oceanic environment over the eastern Gulf of Mexico that will be very conducive for strengthening. The system is expected to traverse the Loop Current, which has especially high oceanic heat content. This, along with fairly low vertical wind shear and a moist mid- to lower- tropospheric air mass, should likely result in rapid intensification before landfall. The official forecast continues to call for the hurricane to reach category 4 status tomorrow. It should be noted that the HAFS-A and HAFS-B regional hurricane models show even more intensification than indicated here. 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 extend well away from the center and outside the forecast cone, particularly on the east side. In addition, the fast forward speed when Helene moves inland will result in a far inland penetration of strong winds over parts of the southeastern United States, including strong gusts over higher terrain of the southern Appalachians. A higher-than-normal gust factor is indicated in the official forecast while Helene is inland. KEY MESSAGES: 1. A catastrophic and deadly storm surge is likely along portions of the Florida Big Bend coast, where inundation could reach as high as 20 feet above ground level, along with destructive waves. There is also a danger of life-threatening storm surge along the remainder of the west coast of the Florida Peninsula. Residents in those areas should follow advice given by local officials and evacuate if told to do so. 2. Potentially catastrophic hurricane-force winds are expected within the eyewall of Helene when it makes landfall in the Florida Big Bend region late Thursday. Preparations to protect life and property should be completed by early Thursday before tropical storm conditions arrive. Damaging and life-threatening hurricane-force winds, especially in gusts, will penetrate well inland over portions of northern Florida and southern Georgia late Thursday and Thursday night where Hurricane Warnings are in effect. Strong wind gusts are also likely farther north across portions of northern Georgia and the Carolinas, particularly over the higher terrain of the southern Appalachians. 3. Catastrophic and life-threatening flash and urban flooding, including numerous landslides, is expected across portions of the southern Appalachians through Friday. Considerable to locally catastrophic flash and urban flooding is likely for northwestern and northern Florida and the Southeast through Friday. Widespread minor to moderate river flooding and isolated major river flooding are likely. 4. Tropical storm conditions are expected over portions of western Cuba within the Tropical Storm Warning area. Hurricane 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. FORECAST POSITIONS AND MAX WINDS INIT 26/0300Z 23.1N 86.6W 75 KT 85 MPH 12H 26/1200Z 25.4N 86.1W 95 KT 110 MPH 24H 27/0000Z 29.5N 84.5W 115 KT 130 MPH 36H 27/1200Z 34.3N 84.7W 50 KT 60 MPH...INLAND 48H 28/0000Z 36.7N 87.1W 30 KT 35 MPH...POST-TROP/EXTRATROP 60H 28/1200Z 36.8N 88.5W 25 KT 30 MPH...POST-TROP/EXTRATROP 72H 29/0000Z 36.7N 87.0W 20 KT 25 MPH...POST-TROP/EXTRATROP 96H 30/0000Z 36.7N 84.9W 15 KT 15 MPH...POST-TROP/EXTRATROP 120H 01/0000Z...DISSIPATED $$ Forecaster Pasch

Issued at 0300 UTC THU SEP 26 2024 000 FONT14 KNHC 260254 PWSAT4 HURRICANE HELENE WIND SPEED PROBABILITIES NUMBER 11 NWS NATIONAL HURRICANE CENTER MIAMI FL AL092024 0300 UTC THU SEP 26 2024 AT 0300Z THE CENTER OF HURRICANE HELENE WAS LOCATED NEAR LATITUDE 23.1 NORTH...LONGITUDE 86.6 WEST WITH MAXIMUM SUSTAINED WINDS NEAR 75 KTS...85 MPH...140 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 THU 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 THU 12Z THU 00Z FRI 12Z FRI 00Z SAT 00Z SUN 00Z MON PERIODS TO TO TO TO TO TO TO 12Z THU 00Z FRI 12Z FRI 00Z SAT 00Z SUN 00Z MON 00Z TUE FORECAST HOUR (12) (24) (36) (48) (72) (96) (120) - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - LOCATION KT CHARLOTTE NC 34 X X( X) 6( 6) X( 6) X( 6) X( 6) X( 6) FLORENCE SC 34 X X( X) 5( 5) X( 5) X( 5) X( 5) X( 5) COLUMBIA SC 34 X 1( 1) 8( 9) X( 9) X( 9) X( 9) X( 9) LITTLE RIVER 34 X X( X) 4( 4) X( 4) X( 4) X( 4) X( 4) MYRTLE BEACH 34 X X( X) 7( 7) X( 7) X( 7) X( 7) X( 7) GEORGETOWN SC 34 X X( X) 5( 5) X( 5) X( 5) X( 5) X( 5) CHARLESTON SC 34 X 5( 5) 17(22) X(22) X(22) X(22) X(22) BEAUFORT MCAS 34 X 11(11) 24(35) X(35) X(35) X(35) X(35) ATLANTA GA 34 X 5( 5) 71(76) 2(78) X(78) X(78) X(78) AUGUSTA GA 34 X 5( 5) 27(32) X(32) X(32) X(32) X(32) SAVANNAH GA 34 X 9( 9) 19(28) X(28) X(28) X(28) X(28) KINGS BAY GA 34 X 50(50) 15(65) X(65) X(65) X(65) X(65) KINGS BAY GA 50 X 3( 3) 2( 5) X( 5) X( 5) X( 5) X( 5) WAYCROSS GA 34 X 47(47) 30(77) X(77) X(77) X(77) X(77) WAYCROSS GA 50 X 2( 2) 4( 6) X( 6) X( 6) X( 6) X( 6) MAYPORT NS FL 34 X 53(53) 11(64) X(64) X(64) X(64) X(64) MAYPORT NS FL 50 X 3( 3) 1( 4) X( 4) X( 4) X( 4) X( 4) JACKSONVILLE 34 X 51(51) 12(63) X(63) X(63) X(63) X(63) JACKSONVILLE 50 X 2( 2) 1( 3) X( 3) X( 3) X( 3) X( 3) GAINESVILLE FL 34 1 84(85) 2(87) X(87) X(87) X(87) X(87) GAINESVILLE FL 50 X 7( 7) 1( 8) X( 8) X( 8) X( 8) X( 8) DAYTONA BEACH 34 X 44(44) 1(45) X(45) X(45) X(45) X(45) THE VILLAGES 34 2 76(78) X(78) X(78) X(78) X(78) X(78) THE VILLAGES 50 X 4( 4) 1( 5) X( 5) X( 5) X( 5) X( 5) ORLANDO FL 34 1 49(50) X(50) X(50) X(50) X(50) X(50) COCOA BEACH FL 34 X 41(41) 1(42) X(42) X(42) X(42) X(42) PATRICK AFB 34 X 41(41) 1(42) X(42) X(42) X(42) X(42) FT PIERCE FL 34 X 29(29) 1(30) X(30) X(30) X(30) X(30) W PALM BEACH 34 X 16(16) 1(17) X(17) X(17) X(17) X(17) FT LAUDERDALE 34 X 11(11) X(11) X(11) X(11) X(11) X(11) MIAMI FL 34 1 5( 6) X( 6) X( 6) X( 6) X( 6) X( 6) HOMESTEAD ARB 34 1 5( 6) X( 6) X( 6) X( 6) X( 6) X( 6) MARATHON FL 34 11 10(21) X(21) X(21) X(21) X(21) X(21) KEY WEST FL 34 27 16(43) X(43) X(43) X(43) X(43) X(43) NAPLES FL 34 21 37(58) X(58) X(58) X(58) X(58) X(58) FT MYERS FL 34 8 47(55) X(55) X(55) X(55) X(55) X(55) VENICE FL 34 26 56(82) X(82) X(82) X(82) X(82) X(82) VENICE FL 50 X 7( 7) X( 7) X( 7) X( 7) X( 7) X( 7) TAMPA FL 34 13 72(85) X(85) X(85) X(85) X(85) X(85) TAMPA FL 50 X 12(12) X(12) X(12) X(12) X(12) X(12) TAMPA FL 64 X 2( 2) X( 2) X( 2) X( 2) X( 2) X( 2) CEDAR KEY FL 34 7 88(95) 1(96) X(96) X(96) X(96) X(96) CEDAR KEY FL 50 X 41(41) 1(42) X(42) X(42) X(42) X(42) CEDAR KEY FL 64 X 9( 9) 1(10) X(10) X(10) X(10) X(10) TALLAHASSEE FL 34 1 93(94) 5(99) X(99) X(99) X(99) X(99) TALLAHASSEE FL 50 X 43(43) 41(84) X(84) X(84) X(84) X(84) TALLAHASSEE FL 64 X 9( 9) 44(53) X(53) X(53) X(53) X(53) ST MARKS FL 34 2 95(97) 2(99) X(99) X(99) X(99) X(99) ST MARKS FL 50 X 62(62) 22(84) X(84) X(84) X(84) X(84) ST MARKS FL 64 X 25(25) 31(56) X(56) X(56) X(56) X(56) APALACHICOLA 34 7 90(97) 1(98) X(98) X(98) X(98) X(98) APALACHICOLA 50 X 81(81) 5(86) X(86) X(86) X(86) X(86) APALACHICOLA 64 X 44(44) 10(54) X(54) X(54) X(54) X(54) GFMX 290N 850W 34 11 88(99) X(99) X(99) X(99) X(99) X(99) GFMX 290N 850W 50 X 92(92) 1(93) X(93) X(93) X(93) X(93) GFMX 290N 850W 64 X 67(67) 1(68) X(68) X(68) X(68) X(68) PANAMA CITY FL 34 5 80(85) 3(88) X(88) X(88) X(88) X(88) PANAMA CITY FL 50 X 40(40) 12(52) X(52) X(52) X(52) X(52) PANAMA CITY FL 64 X 8( 8) 9(17) X(17) X(17) X(17) X(17) DESTIN EXEC AP 34 2 30(32) 7(39) X(39) X(39) X(39) X(39) DESTIN EXEC AP 50 X 3( 3) 2( 5) X( 5) X( 5) X( 5) X( 5) ALBANY GA 34 X 54(54) 42(96) X(96) X(96) X(96) X(96) ALBANY GA 50 X 3( 3) 62(65) X(65) X(65) X(65) X(65) ALBANY GA 64 X X( X) 25(25) X(25) X(25) X(25) X(25) COLUMBUS GA 34 X 9( 9) 77(86) X(86) X(86) X(86) X(86) COLUMBUS GA 50 X X( X) 29(29) X(29) X(29) X(29) X(29) MACON GA 34 X 8( 8) 80(88) X(88) X(88) X(88) X(88) MACON GA 50 X X( X) 21(21) X(21) X(21) X(21) X(21) DOTHAN AL 34 X 48(48) 36(84) X(84) X(84) X(84) X(84) DOTHAN AL 50 X 3( 3) 36(39) X(39) X(39) X(39) X(39) DOTHAN AL 64 X X( X) 10(10) X(10) X(10) X(10) X(10) BIRMINGHAM AL 34 X 3( 3) 6( 9) X( 9) X( 9) X( 9) X( 9) MONTGOMERY AL 34 X 6( 6) 22(28) X(28) X(28) X(28) X(28) WHITING FLD FL 34 1 10(11) 7(18) X(18) X(18) X(18) X(18) PENSACOLA FL 34 1 10(11) 3(14) X(14) X(14) X(14) X(14) GFMX 290N 870W 34 8 37(45) 1(46) X(46) X(46) X(46) X(46) GFMX 290N 870W 50 X 8( 8) X( 8) X( 8) X( 8) X( 8) X( 8) MOBILE AL 34 X 6( 6) 1( 7) X( 7) X( 7) X( 7) X( 7) GULFPORT MS 34 X 6( 6) X( 6) X( 6) X( 6) X( 6) X( 6) STENNIS MS 34 X 5( 5) X( 5) X( 5) X( 5) X( 5) X( 5) BURAS LA 34 2 4( 6) X( 6) X( 6) X( 6) X( 6) X( 6) GFMX 280N 890W 34 6 4(10) X(10) X(10) X(10) X(10) X(10) NEW ORLEANS LA 34 X 3( 3) X( 3) X( 3) X( 3) X( 3) X( 3) GFMX 280N 910W 34 2 1( 3) X( 3) X( 3) X( 3) X( 3) X( 3) MERIDA MX 34 3 X( 3) X( 3) X( 3) X( 3) X( 3) X( 3) COZUMEL MX 34 99 X(99) X(99) X(99) X(99) X(99) X(99) CP SAN ANTONIO 34 99 X(99) X(99) X(99) X(99) X(99) X(99) HAVANA 34 20 1(21) X(21) X(21) X(21) X(21) X(21) ISLE OF PINES 34 24 X(24) X(24) X(24) X(24) X(24) X(24) $$ FORECASTER PASCH

...HELENE EXPECTED TO BRING CATASTROPHIC WINDS AND STORM SURGES TO THE NORTHEASTERN GULF COAST... ...PREPARATIONS TO PROTECT LIFE AND PROPERTY SHOULD BE RUSHED TO COMPLETION... As of 10:00 PM CDT Wed Sep 25 the center of Helene was located near 23.1, -86.6 with movement N at 9 mph. The minimum central pressure was 972 mb with maximum sustained winds of about 85 mph.

Issued at 1000 PM CDT Wed Sep 25 2024 000 WTNT34 KNHC 260254 TCPAT4 BULLETIN Hurricane Helene Advisory Number 11 NWS National Hurricane Center Miami FL AL092024 1000 PM CDT Wed Sep 25 2024 ...HELENE EXPECTED TO BRING CATASTROPHIC WINDS AND STORM SURGES TO THE NORTHEASTERN GULF COAST... ...PREPARATIONS TO PROTECT LIFE AND PROPERTY SHOULD BE RUSHED TO COMPLETION... SUMMARY OF 1000 PM CDT...0300 UTC...INFORMATION ----------------------------------------------- LOCATION...23.1N 86.6W ABOUT 425 MI...680 KM SW OF TAMPA FLORIDA ABOUT 465 MI...750 KM SSW OF APALACHICOLA FLORIDA MAXIMUM SUSTAINED WINDS...85 MPH...140 KM/H PRESENT MOVEMENT...N OR 360 DEGREES AT 9 MPH...15 KM/H MINIMUM CENTRAL PRESSURE...972 MB...28.71 INCHES WATCHES AND WARNINGS -------------------- CHANGES WITH THIS ADVISORY: The government of Mexico has discontinued the Hurricane and Tropical Storm Warnings for the Yucatan Peninsula of Mexico. The government of Cuba has discontinued the Hurricane Watch for the Cuban province of Pinar del Rio. SUMMARY OF WATCHES AND WARNINGS IN EFFECT: A Storm Surge Warning is in effect for... * Mexico Beach eastward and southward to Flamingo * Tampa Bay * Charlotte Harbor A Hurricane Warning is in effect for... * Anclote River to Mexico Beach A Hurricane Watch is in effect for... * 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 Little River Inlet * Lake Okeechobee * Cuban provinces of Artemisa, Pinar del Rio, and the Isle of Youth 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. 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 Hurricane Helene was located near latitude 23.1 North, longitude 86.6 West. Helene is moving toward the north near 9 mph (15 km/h). A northward or north-northeastward motion at a faster forward speed is expected during the next 36 hours. On the forecast track, Helene will move across the eastern Gulf of Mexico tonight and Thursday and cross the Florida Big Bend coast Thursday evening. After landfall, Helene is expected to turn northwestward and slow down over the Tennessee Valley on Friday and Saturday. Maximum sustained winds are near 85 mph (140 km/h) with higher gusts. 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 35 miles (55 km) from the center and tropical-storm-force winds extend outward up to 345 miles (555 km). The minimum central pressure reported by Hurricane Hunter aircraft is 972 mb (28.71 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 life-threatening 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 Suwannee River, FL...15-20 ft Apalachicola, FL to Carrabelle, FL...10-15 ft Suwannee River, FL to Chassahowitzka, FL...10-15 ft Chassahowitzka, FL to Anclote River, FL...8-12 ft Indian Pass, FL to Apalachicola, 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 East of Mexico Beach, FL to Indian Pass, FL...3-5 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 3 to 5 feet above ground level in areas of onshore winds within the warning area along the north 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 tonight and will spread northward across the rest of Florida, Georgia, and South Carolina through Thursday night. Tropical storm conditions are expected over portions of the warning area in western Cuba during the next several hours. RAINFALL: Hurricane 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 portions of the Southeastern U.S. into the Southern Appalachians, Helene is expected to produce total rain accumulations of 6 to 12 inches with isolated totals around 18 inches. This rainfall will likely result in catastrophic and potentially life-threatening flash and urban flooding, along with significant river flooding. Numerous landslides are expected in steep terrain across the southern Appalachians. For a complete depiction of forecast rainfall associated with Hurricane 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 Florida. The risk for 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 tonight 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 THU SEP 26 2024 000 WTNT24 KNHC 260253 TCMAT4 HURRICANE HELENE FORECAST/ADVISORY NUMBER 11 NWS NATIONAL HURRICANE CENTER MIAMI FL AL092024 0300 UTC THU SEP 26 2024 HURRICANE CENTER LOCATED NEAR 23.1N 86.6W AT 26/0300Z POSITION ACCURATE WITHIN 20 NM PRESENT MOVEMENT TOWARD THE NORTH OR 360 DEGREES AT 8 KT ESTIMATED MINIMUM CENTRAL PRESSURE 972 MB MAX SUSTAINED WINDS 75 KT WITH GUSTS TO 90 KT. 64 KT....... 30NE 30SE 0SW 0NW. 50 KT....... 60NE 60SE 40SW 40NW. 34 KT.......210NE 300SE 90SW 120NW. 12 FT SEAS..240NE 270SE 150SW 150NW. 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 23.1N 86.6W AT 26/0300Z AT 26/0000Z CENTER WAS LOCATED NEAR 22.8N 86.7W FORECAST VALID 26/1200Z 25.4N 86.1W MAX WIND 95 KT...GUSTS 115 KT. 64 KT... 30NE 40SE 25SW 20NW. 50 KT... 80NE 90SE 50SW 40NW. 34 KT...270NE 270SE 120SW 120NW. FORECAST VALID 27/0000Z 29.5N 84.5W MAX WIND 115 KT...GUSTS 140 KT. 64 KT... 40NE 50SE 25SW 20NW. 50 KT... 80NE 100SE 50SW 40NW. 34 KT...270NE 270SE 140SW 140NW. FORECAST VALID 27/1200Z 34.3N 84.7W...INLAND MAX WIND 50 KT...GUSTS 70 KT. 50 KT... 40NE 40SE 20SW 20NW. 34 KT...200NE 200SE 50SW 60NW. FORECAST VALID 28/0000Z 36.7N 87.1W...POST-TROP/EXTRATROP MAX WIND 30 KT...GUSTS 50 KT. FORECAST VALID 28/1200Z 36.8N 88.5W...POST-TROP/EXTRATROP MAX WIND 25 KT...GUSTS 35 KT. FORECAST VALID 29/0000Z 36.7N 87.0W...POST-TROP/EXTRATROP 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 30/0000Z 36.7N 84.9W...POST-TROP/EXTRATROP MAX WIND 15 KT...GUSTS 20 KT. OUTLOOK VALID 01/0000Z...DISSIPATED REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 23.1N 86.6W INTERMEDIATE PUBLIC ADVISORY...WTNT34 KNHC/MIATCPAT4...AT 26/0600Z NEXT ADVISORY AT 26/0900Z $$ FORECASTER PASCH

099
ABNT20 KNHC 260243
TWOAT

Special Tropical Weather Outlook
NWS National Hurricane Center Miami FL
1045 PM EDT Wed Sep 25 2024

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

Special outlook issued to update information about AL99, the
system located over the Central Subtropical Atlantic.

Active Systems:
The National Hurricane Center is issuing advisories on Hurricane
Helene, located over the southeastern Gulf of Mexico.

Eastern and Central Tropical Atlantic (AL98):
Showers and thunderstorms have become slightly better organized over
the past 24 hours in association with a broad low pressure system
along a tropical wave located several hundred miles west of the Cabo
Verde Islands. Environmental conditions appear favorable for
gradual development of this system, and a tropical depression is
likely to form during the next couple of days while it moves
westward to west-northwestward across the eastern and central
tropical Atlantic.
* Formation chance through 48 hours...high...70 percent.
* Formation chance through 7 days...high...80 percent.

Central Subtropical Atlantic (AL99):
Updated: Showers and thunderstorms continue to become better
organized with a gale-force area of low pressure located several
hundred miles to the east-northeast of Bermuda. Recently-received
satellite wind data has revealed that the low is no longer attached
to a frontal boundary and is producing a concentrated area of
tropical-storm-force winds near the center. If these trends
continue, this system is likely to become a tropical storm shortly.
The system should continue moving generally east-northeastward,
remaining over the central and eastern subtropical Atlantic.
Additional information on this system, including gale warnings, can
be found in High Seas Forecasts issued by the National Weather
Service.
* Formation chance through 48 hours...high...80 percent.
* Formation chance through 7 days...high...80 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/Beven

...HELENE LIKELY TO BECOME A MAJOR HURRICANE TOMORROW... ...PREPARATIONS TO PROTECT LIFE AND PROPERTY ALONG THE FLORIDA BIG BEND COAST SHOULD BE RUSHED TO COMPLETION... As of 7:00 PM CDT Wed Sep 25 the center of Helene was located near 23.0, -86.6 with movement N at 12 mph. The minimum central pressure was 974 mb with maximum sustained winds of about 85 mph.