National Hurricane Center (NHC) Atlantic Map

The NHC has issued its final advisory on this system. Public Advisories from the Weather Prediction Center will provide updates as long as the system remains a flood threat. Issued at 1000 AM CDT Sat Sep 28 2024

Issued at 1100 AM AST Sat Sep 28 2024 556 WTNT41 KNHC 281441 TCDAT1 Tropical Storm Joyce Discussion Number 5 NWS National Hurricane Center Miami FL AL112024 1100 AM AST Sat Sep 28 2024 Joyce seems to be experiencing the effects of moderate-to-strong vertical wind shear. After maintaining a decent convective burst overnight, southerly wind shear appears to be pulling the thunderstorms to the north, partially exposing the low-level circulation. A new burst of convection is now growing near the center. Satellite-derived surface wind data measured a few wind speeds greater than 40 kt in the northwest quadrant, and the initial intensity is held at 45 kt for this advisory. The storm continues to move at 305/9 kt. Joyce is on the south side of a narrow and weakening subtropical ridge, and should continue generally west-northwestward to northwestward for the next day or so. As a deep-layer trough over the northern Atlantic amplifies and breaks the ridge, Joyce should slow and turn more poleward early next week. The official forecast still shows the storm not recurving to the north, as it is expected to be a shallow vortex at that time, and instead drifts north-northwestward until the system dissipates, similar to the previous prediction. Atmospheric conditions are forecast to remain marginal around Joyce in the coming days. The SHIPS model diagnostics show the deep-layer vertical wind shear staying moderate-to-strong, likely forcing dry air into Joyce's circulation. The latest intensity forecast is similar to the previous advisory and calls for little change in intensity today, followed by steady weakening through early next week. Joyce is still expected to become a remnant low by day 3, however, models are now showing the system opening into a trough and dissipating by day 4, and this is reflected in the official forecast. FORECAST POSITIONS AND MAX WINDS INIT 28/1500Z 20.0N 46.0W 45 KT 50 MPH 12H 29/0000Z 20.5N 47.3W 45 KT 50 MPH 24H 29/1200Z 21.1N 48.6W 40 KT 45 MPH 36H 30/0000Z 21.8N 49.4W 40 KT 45 MPH 48H 30/1200Z 22.2N 49.6W 35 KT 40 MPH 60H 01/0000Z 22.6N 49.7W 30 KT 35 MPH 72H 01/1200Z 23.1N 49.9W 25 KT 30 MPH...POST-TROP/REMNT LOW 96H 02/1200Z...DISSIPATED $$ Forecaster Bucci

Issued at 1500 UTC SAT SEP 28 2024 210 FONT11 KNHC 281439 PWSAT1 TROPICAL STORM JOYCE WIND SPEED PROBABILITIES NUMBER 5 NWS NATIONAL HURRICANE CENTER MIAMI FL AL112024 1500 UTC SAT SEP 28 2024 AT 1500Z THE CENTER OF TROPICAL STORM JOYCE WAS LOCATED NEAR LATITUDE 20.0 NORTH...LONGITUDE 46.0 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 12Z SAT AND THE FORECAST HOUR (CUMULATIVE PROBABILITY) PROBABILITIES ARE GIVEN IN PERCENT X INDICATES PROBABILITIES LESS THAN 1 PERCENT PROBABILITIES FOR 34 KT AND 50 KT ARE SHOWN AT A GIVEN LOCATION WHEN THE 5-DAY CUMULATIVE PROBABILITY IS AT LEAST 3 PERCENT. PROBABILITIES FOR 34...50...64 KT SHOWN WHEN THE 5-DAY 64-KT CUMULATIVE PROBABILITY IS AT LEAST 1 PERCENT. - - - - WIND SPEED PROBABILITIES FOR SELECTED LOCATIONS - - - - FROM FROM FROM FROM FROM FROM FROM TIME 12Z SAT 00Z SUN 12Z SUN 00Z MON 12Z MON 12Z TUE 12Z WED PERIODS TO TO TO TO TO TO TO 00Z SUN 12Z SUN 00Z MON 12Z MON 12Z TUE 12Z WED 12Z THU FORECAST HOUR (12) (24) (36) (48) (72) (96) (120) - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - LOCATION KT $$ FORECASTER BUCCI

...JOYCE MOVING NORTHWESTWARD OVER THE CENTRAL ATLANTIC... As of 11:00 AM AST Sat Sep 28 the center of Joyce was located near 20.0, -46.0 with movement NW at 10 mph. The minimum central pressure was 1004 mb with maximum sustained winds of about 50 mph.

5-Day Uncertainty Track last updated Sat, 28 Sep 2024 14:43:19 GMT


Wind Speed Probabilities last updated Sat, 28 Sep 2024 15:28:51 GMT

Issued at 1500 UTC SAT SEP 28 2024 000 WTNT21 KNHC 281437 TCMAT1 TROPICAL STORM JOYCE FORECAST/ADVISORY NUMBER 5 NWS NATIONAL HURRICANE CENTER MIAMI FL AL112024 1500 UTC SAT SEP 28 2024 TROPICAL STORM CENTER LOCATED NEAR 20.0N 46.0W AT 28/1500Z POSITION ACCURATE WITHIN 20 NM PRESENT MOVEMENT TOWARD THE NORTHWEST OR 305 DEGREES AT 9 KT ESTIMATED MINIMUM CENTRAL PRESSURE 1004 MB MAX SUSTAINED WINDS 45 KT WITH GUSTS TO 55 KT. 34 KT....... 40NE 20SE 20SW 90NW. 12 FT SEAS..120NE 30SE 60SW 90NW. WINDS AND SEAS VARY GREATLY IN EACH QUADRANT. RADII IN NAUTICAL MILES ARE THE LARGEST RADII EXPECTED ANYWHERE IN THAT QUADRANT. REPEAT...CENTER LOCATED NEAR 20.0N 46.0W AT 28/1500Z AT 28/1200Z CENTER WAS LOCATED NEAR 19.8N 45.6W FORECAST VALID 29/0000Z 20.5N 47.3W MAX WIND 45 KT...GUSTS 55 KT. 34 KT... 50NE 20SE 20SW 70NW. FORECAST VALID 29/1200Z 21.1N 48.6W MAX WIND 40 KT...GUSTS 50 KT. 34 KT... 50NE 20SE 0SW 40NW. FORECAST VALID 30/0000Z 21.8N 49.4W MAX WIND 40 KT...GUSTS 50 KT. 34 KT... 50NE 20SE 0SW 30NW. FORECAST VALID 30/1200Z 22.2N 49.6W MAX WIND 35 KT...GUSTS 45 KT. 34 KT... 30NE 20SE 0SW 0NW. FORECAST VALID 01/0000Z 22.6N 49.7W MAX WIND 30 KT...GUSTS 40 KT. FORECAST VALID 01/1200Z 23.1N 49.9W...POST-TROP/REMNT LOW MAX WIND 25 KT...GUSTS 35 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 02/1200Z...DISSIPATED REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 20.0N 46.0W NEXT ADVISORY AT 28/2100Z $$ FORECASTER BUCCI

5-Day Uncertainty Track last updated Sat, 28 Sep 2024 14:34:18 GMT


Wind Speed Probabilities last updated Sat, 28 Sep 2024 15:22:59 GMT

Issued at 300 PM GMT Sat Sep 28 2024 000 WTNT45 KNHC 281431 TCDAT5 Hurricane Isaac Discussion Number 11 NWS National Hurricane Center Miami FL AL102024 300 PM GMT Sat Sep 28 2024 Isaac's strengthening trend from the past day or so appears to have leveled off. Isaac still has a clear eye and a relatively symmetric appearance, although some dry air entrainment is evident coming in from the southwest. Intensity estimates range from 77 to 93 kt, and initial intensity has been held at 90 kt, in agreement with TAFB's Dvorak classification of 5.0. The wind radii have been modified to reflect values from 1245 UTC ASCAT-B pass. Isaac is already over relatively cool water and will reach progressively lower SSTs in the coming day or two, all while encountering increasingly hostile shear. Thus, Isaac's intensity has most likely peaked, and gradual weakening today is forecast to accelerate through the weekend. This weakening will coincide with an extratropical transition, which based on global models, will complete in about 48 hours. The NHC intensity forecast remains unchanged from the previous forecast and is in close agreement with consensus aids through the forecast period. Isaac is moving east-northeastward, 060/17 kt. Steering flow should decrease as Isaac passes in the vicinity of a mid- to upper- level ridge over the next day or so, which should lead to slower forward motion through the remainder of its warm-core existence. As Isaac becomes extratropical, it should turn more northerly as a shortwave trough digs to the west of the cyclone. The official track forecast remains unchanged through 48 hours but has again trended to the right of the previous forecast beyond 48 hours to adjust closer to consensus models. FORECAST POSITIONS AND MAX WINDS INIT 28/1500Z 40.2N 39.7W 90 KT 105 MPH 12H 29/0000Z 41.4N 37.8W 85 KT 100 MPH 24H 29/1200Z 42.9N 36.1W 75 KT 85 MPH 36H 30/0000Z 44.0N 33.9W 65 KT 75 MPH 48H 30/1200Z 45.4N 31.5W 55 KT 65 MPH...POST-TROPICAL 60H 01/0000Z 47.1N 29.4W 45 KT 50 MPH...POST-TROPICAL 72H 01/1200Z 49.6N 28.7W 45 KT 50 MPH...POST-TROP/EXTRATROP 96H 02/1200Z 53.5N 28.1W 40 KT 45 MPH...POST-TROP/EXTRATROP 120H 03/1200Z 56.6N 25.0W 35 KT 40 MPH...POST-TROP/EXTRATROP $$ Forecaster Konarik/Cangialosi

Issued at 1500 UTC SAT SEP 28 2024 000 FONT15 KNHC 281431 PWSAT5 HURRICANE ISAAC WIND SPEED PROBABILITIES NUMBER 11 NWS NATIONAL HURRICANE CENTER MIAMI FL AL102024 1500 UTC SAT SEP 28 2024 AT 1500Z THE CENTER OF HURRICANE ISAAC WAS LOCATED NEAR LATITUDE 40.2 NORTH...LONGITUDE 39.7 WEST WITH MAXIMUM SUSTAINED WINDS NEAR 90 KTS...105 MPH...165 KM/H. Z INDICATES COORDINATED UNIVERSAL TIME (GREENWICH) ATLANTIC STANDARD TIME (AST)...SUBTRACT 4 HOURS FROM Z TIME EASTERN DAYLIGHT TIME (EDT)...SUBTRACT 4 HOURS FROM Z TIME CENTRAL DAYLIGHT TIME (CDT)...SUBTRACT 5 HOURS FROM Z TIME WIND SPEED PROBABILITY TABLE FOR SPECIFIC LOCATIONS CHANCES OF SUSTAINED (1-MINUTE AVERAGE) WIND SPEEDS OF AT LEAST ...34 KT (39 MPH... 63 KM/H)... ...50 KT (58 MPH... 93 KM/H)... ...64 KT (74 MPH...119 KM/H)... FOR LOCATIONS AND TIME PERIODS DURING THE NEXT 5 DAYS PROBABILITIES FOR LOCATIONS ARE GIVEN AS OP(CP) WHERE OP IS THE PROBABILITY OF THE EVENT BEGINNING DURING AN INDIVIDUAL TIME PERIOD (ONSET PROBABILITY) (CP) IS THE PROBABILITY OF THE EVENT OCCURRING BETWEEN 12Z SAT AND THE FORECAST HOUR (CUMULATIVE PROBABILITY) PROBABILITIES ARE GIVEN IN PERCENT X INDICATES PROBABILITIES LESS THAN 1 PERCENT PROBABILITIES FOR 34 KT AND 50 KT ARE SHOWN AT A GIVEN LOCATION WHEN THE 5-DAY CUMULATIVE PROBABILITY IS AT LEAST 3 PERCENT. PROBABILITIES FOR 34...50...64 KT SHOWN WHEN THE 5-DAY 64-KT CUMULATIVE PROBABILITY IS AT LEAST 1 PERCENT. - - - - WIND SPEED PROBABILITIES FOR SELECTED LOCATIONS - - - - FROM FROM FROM FROM FROM FROM FROM TIME 12Z SAT 00Z SUN 12Z SUN 00Z MON 12Z MON 12Z TUE 12Z WED PERIODS TO TO TO TO TO TO TO 00Z SUN 12Z SUN 00Z MON 12Z MON 12Z TUE 12Z WED 12Z THU FORECAST HOUR (12) (24) (36) (48) (72) (96) (120) - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - LOCATION KT SANTA CRUZ AZO 34 X 2( 2) 2( 4) 1( 5) X( 5) X( 5) X( 5) $$ FORECASTER CANGIALOSI

Issued at 300 PM GMT Sat Sep 28 2024 000 WTNT35 KNHC 281431 TCPAT5 BULLETIN Hurricane Isaac Advisory Number 11 NWS National Hurricane Center Miami FL AL102024 300 PM GMT Sat Sep 28 2024 ...ISAAC REMAINS A CATEGORY TWO HURRICANE OVER THE CENTRAL ATLANTIC... SUMMARY OF 300 PM GMT...1500 UTC...INFORMATION ---------------------------------------------- LOCATION...40.2N 39.7W ABOUT 695 MI...1120 KM WNW OF THE AZORES MAXIMUM SUSTAINED WINDS...105 MPH...165 KM/H PRESENT MOVEMENT...ENE OR 60 DEGREES AT 20 MPH...31 KM/H MINIMUM CENTRAL PRESSURE...968 MB...28.59 INCHES WATCHES AND WARNINGS -------------------- There are no coastal watches or warnings in effect. DISCUSSION AND OUTLOOK ---------------------- At 300 PM GMT (1500 UTC), the eye of Hurricane Isaac was located near latitude 40.2 North, longitude 39.7 West. Isaac is moving toward the east-northeast near 20 mph (31 km/h) and a decrease in forward speed and a turn to the northeast is expected during the next couple of days. Maximum sustained winds are near 105 mph (165 km/h) with higher gusts. Gradual weakening is expected, and Isaac is expected to be a post-tropical cyclone on Monday. Hurricane-force winds extend outward up to 45 miles (75 km) from the center and tropical-storm-force winds extend outward up to 195 miles (315 km). The estimated minimum central pressure is 968 mb (28.59 inches). HAZARDS AFFECTING LAND ---------------------- SURF: Swells generated by Isaac and a large wind fetch from a deep-layer trough will affect the Azores over the next few days. 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 900 PM GMT. $$ Forecaster Konarik/Cangialosi

...ISAAC REMAINS A CATEGORY TWO HURRICANE OVER THE CENTRAL ATLANTIC... As of 3:00 PM GMT Sat Sep 28 the center of Isaac was located near 40.2, -39.7 with movement ENE at 20 mph. The minimum central pressure was 968 mb with maximum sustained winds of about 105 mph.

Issued at 300 PM GMT Sat Sep 28 2024 ZCZC MIATCDAT5 ALL TTAA00 KNHC DDHHMM Hurricane Isaac Discussion Number 11 NWS National Hurricane Center Miami FL AL102024 300 PM GMT Sat Sep 28 2024 Isaac's strengthening trend from the past day or so appears to have leveled off. Isaac still has a clear eye and a relatively symmetric appearance, although some dry air entrainment is evident coming in from the southwest. Intensity estimates range from 77 to 93 kt, and initial intensity has been held at 90 kt, in agreement with TAFB's Dvorak classification of 5.0. The wind radii have been modified to reflect values from 1245 UTC ASCAT-B pass. Isaac is already over relatively cool water and will reach progressively lower SSTs in the coming day or two, all while encountering increasingly hostile shear. Thus, Isaac's intensity has most likely peaked, and gradual weakening today is forecast to accelerate through the weekend. This weakening will coincide with an extratropical transition, which based on global models, will complete in about 48 hours. The NHC intensity forecast remains unchanged from the previous forecast and is in close agreement with consensus aids through the forecast period. Isaac is moving east-northeastward, 060/17 kt. Steering flow should decrease as Isaac passes in the vicinity of a mid- to upper- level ridge over the next day or so, which should lead to slower forward motion through the remainder of its warm-core existence. As Isaac becomes extratropical, it should turn more northerly as a shortwave trough digs to the west of the cyclone. The official track forecast remains unchanged through 48 hours but has again trended to the right of the previous forecast beyond 48 hours to adjust closer to consensus models. FORECAST POSITIONS AND MAX WINDS INIT 28/1500Z 40.2N 39.7W 90 KT 105 MPH 12H 29/0000Z 41.4N 37.8W 85 KT 100 MPH 24H 29/1200Z 42.9N 36.1W 75 KT 85 MPH 36H 30/0000Z 44.0N 33.9W 65 KT 75 MPH 48H 30/1200Z 45.4N 31.5W 55 KT 65 MPH...POST-TROPICAL 60H 01/0000Z 47.1N 29.4W 45 KT 50 MPH...POST-TROPICAL 72H 01/1200Z 49.6N 28.7W 45 KT 50 MPH...POST-TROP/EXTRATROP 96H 02/1200Z 53.5N 28.1W 40 KT 45 MPH...POST-TROP/EXTRATROP 120H 03/1200Z 56.6N 25.0W 35 KT 40 MPH...POST-TROP/EXTRATROP $$ Forecaster Konarik/Cangialosi NNNN

Issued at 1500 UTC SAT SEP 28 2024 000 WTNT25 KNHC 281430 TCMAT5 HURRICANE ISAAC FORECAST/ADVISORY NUMBER 11 NWS NATIONAL HURRICANE CENTER MIAMI FL AL102024 1500 UTC SAT SEP 28 2024 HURRICANE CENTER LOCATED NEAR 40.2N 39.7W AT 28/1500Z POSITION ACCURATE WITHIN 20 NM PRESENT MOVEMENT TOWARD THE EAST-NORTHEAST OR 60 DEGREES AT 17 KT ESTIMATED MINIMUM CENTRAL PRESSURE 968 MB MAX SUSTAINED WINDS 90 KT WITH GUSTS TO 110 KT. 64 KT....... 25NE 40SE 40SW 20NW. 50 KT....... 50NE 70SE 80SW 40NW. 34 KT.......170NE 130SE 130SW 70NW. 12 FT SEAS..180NE 330SE 330SW 270NW. 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 40.2N 39.7W AT 28/1500Z AT 28/1200Z CENTER WAS LOCATED NEAR 39.7N 40.4W FORECAST VALID 29/0000Z 41.4N 37.8W MAX WIND 85 KT...GUSTS 105 KT. 64 KT... 25NE 40SE 30SW 20NW. 50 KT... 50NE 70SE 70SW 40NW. 34 KT...170NE 130SE 130SW 100NW. FORECAST VALID 29/1200Z 42.9N 36.1W MAX WIND 75 KT...GUSTS 90 KT. 64 KT... 25NE 25SE 0SW 0NW. 50 KT... 50NE 60SE 60SW 50NW. 34 KT...170NE 130SE 130SW 130NW. FORECAST VALID 30/0000Z 44.0N 33.9W MAX WIND 65 KT...GUSTS 80 KT. 64 KT... 0NE 20SE 0SW 0NW. 50 KT... 35NE 50SE 35SW 35NW. 34 KT...150NE 120SE 110SW 140NW. FORECAST VALID 30/1200Z 45.4N 31.5W...POST-TROPICAL MAX WIND 55 KT...GUSTS 65 KT. 50 KT... 0NE 40SE 0SW 0NW. 34 KT...140NE 130SE 110SW 130NW. FORECAST VALID 01/0000Z 47.1N 29.4W...POST-TROPICAL MAX WIND 45 KT...GUSTS 55 KT. 34 KT...150NE 120SE 75SW 110NW. FORECAST VALID 01/1200Z 49.6N 28.7W...POST-TROP/EXTRATROP MAX WIND 45 KT...GUSTS 55 KT. 34 KT...150NE 90SE 90SW 110NW. 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 02/1200Z 53.5N 28.1W...POST-TROP/EXTRATROP MAX WIND 40 KT...GUSTS 50 KT. 34 KT...140NE 90SE 40SW 70NW. OUTLOOK VALID 03/1200Z 56.6N 25.0W...POST-TROP/EXTRATROP MAX WIND 35 KT...GUSTS 45 KT. 34 KT... 0NE 0SE 0SW 90NW. REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 40.2N 39.7W NEXT ADVISORY AT 28/2100Z $$ FORECASTER KONARIK/CANGIALOSI

...ISAAC REMAINS A CATEGORY TWO HURRICANE OVER THE CENTRAL ATLANTIC... As of 3:00 PM GMT Sat Sep 28 the center of Isaac was located near 40.2, -39.7 with movement ENE at 20 mph. The minimum central pressure was 968 mb with maximum sustained winds of about 105 mph.

Issued at 300 PM GMT Sat Sep 28 2024 ZCZC MIATCPAT5 ALL TTAA00 KNHC DDHHMM BULLETIN Hurricane Isaac Advisory Number 11 NWS National Hurricane Center Miami FL AL102024 300 PM GMT Sat Sep 28 2024 ...ISAAC REMAINS A CATEGORY TWO HURRICANE OVER THE CENTRAL ATLANTIC... SUMMARY OF 300 PM GMT...1500 UTC...INFORMATION ---------------------------------------------- LOCATION...40.2N 39.7W ABOUT 695 MI...1120 KM WNW OF THE AZORES MAXIMUM SUSTAINED WINDS...105 MPH...165 KM/H PRESENT MOVEMENT...ENE OR 60 DEGREES AT 20 MPH...31 KM/H MINIMUM CENTRAL PRESSURE...968 MB...28.59 INCHES WATCHES AND WARNINGS -------------------- There are no coastal watches or warnings in effect. DISCUSSION AND OUTLOOK ---------------------- At 300 PM GMT (1500 UTC), the eye of Hurricane Isaac was located near latitude 40.2 North, longitude 39.7 West. Isaac is moving toward the east-northeast near 20 mph (31 km/h) and a decrease in forward speed and a turn to the northeast is expected during the next couple of days. Maximum sustained winds are near 105 mph (165 km/h) with higher gusts. Gradual weakening is expected, and Isaac is expected to be a post-tropical cyclone on Monday. Hurricane-force winds extend outward up to 45 miles (75 km) from the center and tropical-storm-force winds extend outward up to 195 miles (315 km). The estimated minimum central pressure is 968 mb (28.59 inches). HAZARDS AFFECTING LAND ---------------------- SURF: Swells generated by Isaac and a large wind fetch from a deep-layer trough will affect the Azores over the next few days. 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 900 PM GMT. $$ Forecaster Konarik/Cangialosi NNNN

000
ABNT20 KNHC 281138
TWOAT

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
800 AM EDT Sat Sep 28 2024

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

Active Systems:
The National Hurricane Center is issuing advisories on Hurricane
Isaac, located several hundred miles east of the Azores, and on
Tropical Storm Joyce, located over the central tropical Atlantic
Ocean. The Weather Prediction Center is issuing advisories on
Post-Tropical Cyclone Helene, located inland over the Ohio River
Valley.

Eastern and Central Tropical Atlantic:
A broad and elongated area of low pressure, associated with a
tropical wave, is producing disorganized showers and thunderstorms
near and to the west of the Cabo Verde Islands. Environmental
conditions appear conducive for gradual development of this system,
and a tropical depression could form during the early or middle
part of next week while the system moves toward the west and then
northwest across the eastern and central tropical Atlantic.
* Formation chance through 48 hours...low...20 percent.
* Formation chance through 7 days...medium...60 percent.

Western Caribbean Sea and Gulf of Mexico:
An area of low pressure could form over the western Caribbean Sea in
a few days. Environmental conditions are expected to be conducive
for additional development thereafter while the system moves
generally northwestward, and a tropical depression could form during
the middle to latter part of next week as the system enters the Gulf
of Mexico.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 7 days...medium...40 percent.

&&
Public Advisories on Tropical Storm Joyce are issued under WMO
header WTNT31 KNHC and under AWIPS header MIATCPAT1.
Forecast/Advisories on Tropical Storm Joyce are issued under WMO
header WTNT21 KNHC and under AWIPS header MIATCMAT1.

$$
Forecaster Cangialosi/Konarik

The NHC has issued its final advisory on this system. Public Advisories from the Weather Prediction Center will provide updates as long as the system remains a flood threat. Issued at 400 AM CDT Sat Sep 28 2024

5-Day Uncertainty Track last updated Sat, 28 Sep 2024 08:36:40 GMT

5-Day Uncertainty Track last updated Sat, 28 Sep 2024 08:43:07 GMT


Wind Speed Probabilities last updated Sat, 28 Sep 2024 09:23:15 GMT

Issued at 900 AM GMT Sat Sep 28 2024 000 WTNT45 KNHC 280840 TCDAT5 Hurricane Isaac Discussion Number 10 NWS National Hurricane Center Miami FL AL102024 900 AM GMT Sat Sep 28 2024 Isaac has continued to strengthen this morning. The satellite presentation consists of a 20 nm (WMG 8C) clear eye and an impressive curve band in the north side of the cyclone beneath the upper diffluent westerlies. The initial intensity is bumped up to 90 kt for this advisory and is based on a UW-CIMSS SATCON analysis of 93 kt and the Dvorak intensity estimates for TAFB and SAB. Some fluctuations in strength are possible during the day, after which Isaac will be traversing cooler oceanic surface temperatures and experiencing increasing deep-layer shear. Subsequently, gradual weakening is forecast, and the cyclone is expected to lose its deep core convection and become a post-tropical cyclone in 48 hrs. After that time, the global model fields and the FSU Cyclone Phase Evolution forecast show Isaac transitioning from a symmetric warm-core system to an asymmetric cold-core, more frontal thermal structure. The NHC intensity forecast is similar to the consensus aids and shows Isaac completing its extratropical cyclone transition by Tuesday. Isaac has turned toward the northeast, or 055/17 kt, in response to a mid-latitude shortwave ridge temporarily building to the north of the cyclone. By early next week, as Isaac loses its tropical characteristics and completes an extratropical transition, the cyclone should turn toward the north-northeast while a major shortwave trough approaches from the northwest over the central Atlantic. The official track forecast is adjusted a little to the right of the previous forecast beyond 48 hrs to agree more with the TVCA and HCCA consensus models. FORECAST POSITIONS AND MAX WINDS INIT 28/0900Z 39.3N 41.3W 90 KT 105 MPH 12H 28/1800Z 40.4N 39.2W 85 KT 100 MPH 24H 29/0600Z 42.1N 37.0W 75 KT 85 MPH 36H 29/1800Z 43.5N 35.2W 65 KT 75 MPH 48H 30/0600Z 44.6N 33.1W 55 KT 65 MPH...POST-TROPICAL 60H 30/1800Z 46.0N 31.5W 50 KT 60 MPH...POST-TROP/EXTRATROP 72H 01/0600Z 48.0N 30.4W 45 KT 50 MPH...POST-TROP/EXTRATROP 96H 02/0600Z 52.5N 30.0W 40 KT 45 MPH...POST-TROP/EXTRATROP 120H 03/0600Z 55.7N 28.6W 35 KT 40 MPH...POST-TROP/EXTRATROP $$ Forecaster Roberts