National Hurricane Center (NHC) Atlantic Map

Issued at 2100 UTC SUN SEP 29 2024 000 WTNT25 KNHC 292034 TCMAT5 TROPICAL STORM ISAAC FORECAST/ADVISORY NUMBER 16 NWS NATIONAL HURRICANE CENTER MIAMI FL AL102024 2100 UTC SUN SEP 29 2024 TROPICAL STORM CENTER LOCATED NEAR 43.8N 34.7W AT 29/2100Z POSITION ACCURATE WITHIN 30 NM PRESENT MOVEMENT TOWARD THE NORTHEAST OR 50 DEGREES AT 10 KT ESTIMATED MINIMUM CENTRAL PRESSURE 973 MB MAX SUSTAINED WINDS 60 KT WITH GUSTS TO 75 KT. 50 KT....... 70NE 90SE 70SW 60NW. 34 KT.......200NE 130SE 120SW 160NW. 12 FT SEAS..270NE 540SE 420SW 390NW. 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 43.8N 34.7W AT 29/2100Z AT 29/1800Z CENTER WAS LOCATED NEAR 43.5N 35.5W FORECAST VALID 30/0600Z 44.6N 32.4W MAX WIND 55 KT...GUSTS 65 KT. 50 KT... 40NE 40SE 30SW 20NW. 34 KT...140NE 120SE 120SW 140NW. FORECAST VALID 30/1800Z 45.8N 28.6W...POST-TROP/EXTRATROP MAX WIND 50 KT...GUSTS 60 KT. 50 KT... 20NE 40SE 0SW 0NW. 34 KT...120NE 120SE 120SW 100NW. FORECAST VALID 01/0600Z 47.4N 25.8W...POST-TROP/EXTRATROP MAX WIND 45 KT...GUSTS 55 KT. 34 KT...120NE 40SE 20SW 90NW. FORECAST VALID 01/1800Z 49.3N 24.2W...POST-TROP/EXTRATROP MAX WIND 40 KT...GUSTS 50 KT. 34 KT...170NE 30SE 30SW 70NW. FORECAST VALID 02/0600Z 51.4N 23.2W...POST-TROP/EXTRATROP MAX WIND 35 KT...GUSTS 45 KT. 34 KT...160NE 30SE 30SW 30NW. FORECAST VALID 02/1800Z 53.1N 22.3W...POST-TROP/EXTRATROP MAX WIND 35 KT...GUSTS 45 KT. 34 KT...190NE 50SE 0SW 30NW. 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 03/1800Z 57.9N 17.9W...POST-TROP/EXTRATROP MAX WIND 35 KT...GUSTS 45 KT. 34 KT...110NE 35SE 0SW 0NW. OUTLOOK VALID 04/1800Z...DISSIPATED REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 43.8N 34.7W NEXT ADVISORY AT 30/0300Z $$ FORECASTER MAHONEY/BLAKE

Issued at 900 PM GMT Sun Sep 29 2024 000 WTNT35 KNHC 292034 TCPAT5 BULLETIN Tropical Storm Isaac Advisory Number 16 NWS National Hurricane Center Miami FL AL102024 900 PM GMT Sun Sep 29 2024 ...LARGE SWELLS AND DANGEROUS SURF IMPACTING THE AZORES... SUMMARY OF 900 PM GMT...2100 UTC...INFORMATION ---------------------------------------------- LOCATION...43.8N 34.7W ABOUT 565 MI...910 KM NW OF THE AZORES MAXIMUM SUSTAINED WINDS...70 MPH...110 KM/H PRESENT MOVEMENT...NE OR 50 DEGREES AT 12 MPH...19 KM/H MINIMUM CENTRAL PRESSURE...973 MB...28.74 INCHES WATCHES AND WARNINGS -------------------- There are no coastal watches or warnings in effect. DISCUSSION AND OUTLOOK ---------------------- At 900 PM GMT (2100 UTC), the center of Tropical Storm Isaac was located near latitude 43.8 North, longitude 34.7 West. Isaac is moving toward the northeast near 12 mph (19 km/h). This motion is expected to continue for the next couple of days, followed by a turn towards the north-northeast on Tuesday. Maximum sustained winds have decreased to near 70 mph (110 km/h) with higher gusts, and continued weakening is forecast over the next few days. Isaac is forecast to become an extratropical cyclone on Monday. Tropical-storm-force winds extend outward up to 230 miles (370 km) from the center. The estimated minimum central pressure is 973 mb (28.74 inches). HAZARDS AFFECTING LAND ---------------------- SURF: Swells generated by Isaac and an upstream 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 300 AM GMT. $$ Forecaster Mahoney/Blake

...LARGE SWELLS AND DANGEROUS SURF IMPACTING THE AZORES... As of 9:00 PM GMT Sun Sep 29 the center of Isaac was located near 43.8, -34.7 with movement NE at 12 mph. The minimum central pressure was 973 mb with maximum sustained winds of about 70 mph.

511
ABNT20 KNHC 291753
TWOAT

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
200 PM EDT Sun Sep 29 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 northwest of the Azores, and
on Tropical Storm Joyce, located over the central Atlantic Ocean.

Eastern and Central Tropical Atlantic (AL90):
Recent satellite imagery indicates that the circulation associated
with an area of low pressure located several hundred miles west-
southwest of the Cabo Verde Islands is becoming better defined.
Environmental conditions are favorable for continued development of
this system, and a tropical depression is likely to form early this
week, possibly as soon as tonight. The low will continue to move
westward and then northwestward across the eastern and central
tropical 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...90 percent.

Western Caribbean Sea and Gulf of Mexico:
A broad area of low pressure located over the western Caribbean Sea
is producing disorganized showers and thunderstorms. Environmental
conditions appear to be conducive for gradual development, and a
tropical depression could form around the middle part of this week
while the disturbance meanders towards the west-northwest. This
system is then expected to move northwestward into the Gulf of
Mexico during the latter portion of this week, and interests in the
northwestern Caribbean Sea and along the U.S. Gulf Coast should
monitor its progress.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 7 days...medium...50 percent.

Eastern Atlantic:
A low-latitude tropical wave located near the coast of western
Africa is currently producing limited shower and thunderstorm
activity. Upper-level winds are forecast to become more conducive
for gradual development of this system during the next several days
while it moves slowly westward or west-northwestward over the
eastern Atlantic Ocean.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 7 days...low...30 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 Blake/Mahoney

5-Day Uncertainty Track last updated Sun, 29 Sep 2024 14:41:24 GMT


Wind Speed Probabilities last updated Sun, 29 Sep 2024 15:28:44 GMT

Issued at 1100 AM AST Sun Sep 29 2024 000 WTNT41 KNHC 291439 TCDAT1 Tropical Storm Joyce Discussion Number 9 NWS National Hurricane Center Miami FL AL112024 1100 AM AST Sun Sep 29 2024 The center of Joyce is exposed on the southern side of a small area of deep convection due to continued strong south-southwesterly vertical wind shear. The most recent scatterometer data from 1230 UTC indicates at least 35 kt winds are within the circulation, and given the known low bias of the instrument, 40 kt is chosen as the initial intensity, closest to a blend of the TAFB T- and CI-numbers. The storm has been moving more slowly this morning, estimated to be northwestward at about 5 kt. Joyce should turn northward on Monday due to a deep-layer trough over the north-central Atlantic. The only notable change to some of the guidance this cycle is that they generally agree Joyce or its remnants will be less vertically deep by mid-week. This evolution should result in less northward acceleration as the circulation decays due to persistent shear and dry air aloft. Thus, the new NHC forecast is a bit to the left and slower based on the latest aids. The intensity guidance remains in good agreement, and the only slight intensity change from the last advisory is to show Joyce becoming a remnant low at 48 h. FORECAST POSITIONS AND MAX WINDS INIT 29/1500Z 21.6N 48.5W 40 KT 45 MPH 12H 30/0000Z 22.1N 49.2W 35 KT 40 MPH 24H 30/1200Z 22.6N 49.3W 30 KT 35 MPH 36H 01/0000Z 23.3N 49.3W 30 KT 35 MPH 48H 01/1200Z 24.1N 49.3W 30 KT 35 MPH...POST-TROP/REMNT LOW 60H 02/0000Z 25.2N 49.3W 25 KT 30 MPH...POST-TROP/REMNT LOW 72H 02/1200Z...DISSIPATED $$ Forecaster Blake

Issued at 1500 UTC SUN SEP 29 2024 000 WTNT21 KNHC 291438 TCMAT1 TROPICAL STORM JOYCE FORECAST/ADVISORY NUMBER 9 NWS NATIONAL HURRICANE CENTER MIAMI FL AL112024 1500 UTC SUN SEP 29 2024 TROPICAL STORM CENTER LOCATED NEAR 21.6N 48.5W AT 29/1500Z POSITION ACCURATE WITHIN 20 NM PRESENT MOVEMENT TOWARD THE NORTHWEST OR 315 DEGREES AT 5 KT ESTIMATED MINIMUM CENTRAL PRESSURE 1005 MB MAX SUSTAINED WINDS 40 KT WITH GUSTS TO 50 KT. 34 KT....... 90NE 30SE 0SW 50NW. 12 FT SEAS..105NE 0SE 0SW 75NW. WINDS AND SEAS VARY GREATLY IN EACH QUADRANT. RADII IN NAUTICAL MILES ARE THE LARGEST RADII EXPECTED ANYWHERE IN THAT QUADRANT. REPEAT...CENTER LOCATED NEAR 21.6N 48.5W AT 29/1500Z AT 29/1200Z CENTER WAS LOCATED NEAR 21.3N 48.3W FORECAST VALID 30/0000Z 22.1N 49.2W MAX WIND 35 KT...GUSTS 45 KT. 34 KT... 80NE 0SE 0SW 50NW. FORECAST VALID 30/1200Z 22.6N 49.3W MAX WIND 30 KT...GUSTS 40 KT. FORECAST VALID 01/0000Z 23.3N 49.3W MAX WIND 30 KT...GUSTS 40 KT. FORECAST VALID 01/1200Z 24.1N 49.3W...POST-TROP/REMNT LOW MAX WIND 30 KT...GUSTS 40 KT. FORECAST VALID 02/0000Z 25.2N 49.3W...POST-TROP/REMNT LOW MAX WIND 25 KT...GUSTS 35 KT. FORECAST VALID 02/1200Z...DISSIPATED REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 21.6N 48.5W NEXT ADVISORY AT 29/2100Z $$ FORECASTER BLAKE

...JOYCE FORECAST TO BECOME A TROPICAL DEPRESSION ON MONDAY... As of 11:00 AM AST Sun Sep 29 the center of Joyce was located near 21.6, -48.5 with movement NW at 6 mph. The minimum central pressure was 1005 mb with maximum sustained winds of about 45 mph.

Issued at 1500 UTC SUN SEP 29 2024 000 FONT11 KNHC 291438 PWSAT1 TROPICAL STORM JOYCE WIND SPEED PROBABILITIES NUMBER 9 NWS NATIONAL HURRICANE CENTER MIAMI FL AL112024 1500 UTC SUN SEP 29 2024 AT 1500Z THE CENTER OF TROPICAL STORM JOYCE WAS LOCATED NEAR LATITUDE 21.6 NORTH...LONGITUDE 48.5 WEST WITH MAXIMUM SUSTAINED WINDS NEAR 40 KTS...45 MPH...75 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 SUN 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 SUN 00Z MON 12Z MON 00Z TUE 12Z TUE 12Z WED 12Z THU PERIODS TO TO TO TO TO TO TO 00Z MON 12Z MON 00Z TUE 12Z TUE 12Z WED 12Z THU 12Z FRI FORECAST HOUR (12) (24) (36) (48) (72) (96) (120) - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - LOCATION KT $$ FORECASTER BLAKE

Issued at 1100 AM AST Sun Sep 29 2024 000 WTNT31 KNHC 291438 TCPAT1 BULLETIN Tropical Storm Joyce Advisory Number 9 NWS National Hurricane Center Miami FL AL112024 1100 AM AST Sun Sep 29 2024 ...JOYCE FORECAST TO BECOME A TROPICAL DEPRESSION ON MONDAY... SUMMARY OF 1100 AM AST...1500 UTC...INFORMATION ----------------------------------------------- LOCATION...21.6N 48.5W ABOUT 975 MI...1570 KM ENE OF THE NORTHERN LEEWARD ISLANDS MAXIMUM SUSTAINED WINDS...45 MPH...75 KM/H PRESENT MOVEMENT...NW OR 315 DEGREES AT 6 MPH...9 KM/H MINIMUM CENTRAL PRESSURE...1005 MB...29.68 INCHES WATCHES AND WARNINGS -------------------- There are no coastal watches or warnings in effect. DISCUSSION AND OUTLOOK ---------------------- At 1100 AM AST (1500 UTC), the center of Tropical Storm Joyce was located near latitude 21.6 North, longitude 48.5 West. Joyce is moving toward the northwest near 6 mph (9 km/h), and this general motion is expected to continue today with a turn toward the north anticipated on Monday and Tuesday. Maximum sustained winds are near 45 mph (75 km/h) with higher gusts. Joyce is likely to start weakening later today and could become a tropical depression on Monday and a remnant low on Tuesday. Tropical-storm-force winds extend outward up to 105 miles (165 km) from the center. The estimated minimum central pressure is 1005 mb (29.68 inches). HAZARDS AFFECTING LAND ---------------------- None NEXT ADVISORY ------------- Next complete advisory at 500 PM AST. $$ Forecaster Blake

5-Day Uncertainty Track last updated Sun, 29 Sep 2024 14:38:24 GMT


Wind Speed Probabilities last updated Sun, 29 Sep 2024 15:22:58 GMT

Issued at 300 PM GMT Sun Sep 29 2024 000 WTNT45 KNHC 291436 TCDAT5 Hurricane Isaac Discussion Number 15 NWS National Hurricane Center Miami FL AL102024 300 PM GMT Sun Sep 29 2024 Hurricane Isaac continues to maintain a small inner-core, which has proved resilient in an increasingly unfavorable environment characterized by strong deep-layer vertical wind shear near 30 kt and sea surface temperatures (SSTs) around 23C. The satellite appearance of the hurricane has been relatively steady this morning, with consistent bursts of deep convection near the center. The initial intensity is set to a possibly generous 65 kt, which is on the higher end of the subjective and objective intensity estimates. The tropical cyclone is forecast to track over cooler SSTs and into increasing west-southwesterly vertical wind shear, which will induce steady weakening through the forecast period. The intensity forecast is similar to the previous forecast. There is evidence on visible satellite this morning that Isaac has begun to interact with a baroclinic zone to its north and east, in addition to wrapping dry air from the northwest around the southern side of the circulation. These factors are likely to result in Isaac becoming an extratropical cyclone by Monday. Isaac's forward motion continues to be northeastward (045/10 kt) as it is steered by deep-layer southwesterly flow. This general motion should continue for the next day or so, with a turn toward the north-northeast expected by the middle part of this week in response to a mid- to upper-level trough approaching from the west. The cyclone is then forecast to turn back towards the northeast beyond 72 hr as it tracks along the southeastern periphery of an upper-level trough. Once again, the track forecast is adjusted eastward from the previous advisory beyond the 24 hr period, in agreement with the latest consensus guidance. FORECAST POSITIONS AND MAX WINDS INIT 29/1500Z 43.2N 35.6W 65 KT 75 MPH 12H 30/0000Z 44.0N 33.6W 55 KT 65 MPH 24H 30/1200Z 45.1N 30.3W 50 KT 60 MPH...POST-TROP/EXTRATROP 36H 01/0000Z 46.6N 26.8W 45 KT 50 MPH...POST-TROP/EXTRATROP 48H 01/1200Z 48.5N 25.0W 40 KT 45 MPH...POST-TROP/EXTRATROP 60H 02/0000Z 50.6N 24.3W 35 KT 40 MPH...POST-TROP/EXTRATROP 72H 02/1200Z 52.8N 23.1W 35 KT 40 MPH...POST-TROP/EXTRATROP 96H 03/1200Z 57.1N 18.6W 35 KT 40 MPH...POST-TROP/EXTRATROP 120H 04/1200Z 61.2N 14.2W 35 KT 40 MPH...POST-TROP/EXTRATROP $$ Forecaster Mahoney/Papin

Issued at 300 PM GMT Sun Sep 29 2024 333 WTNT35 KNHC 291435 TCPAT5 BULLETIN Hurricane Isaac Advisory Number 15 NWS National Hurricane Center Miami FL AL102024 300 PM GMT Sun Sep 29 2024 ...ISAAC CONTINUES MOVING TOWARDS THE NORTHEAST OVER THE OPEN ATLANTIC... ...LARGE AREA OF DANGEROUS HIGH SEAS SURROUND THE HURRICANE... SUMMARY OF 300 PM GMT...1500 UTC...INFORMATION ---------------------------------------------- LOCATION...43.2N 35.6W ABOUT 575 MI...925 KM NW OF THE AZORES MAXIMUM SUSTAINED WINDS...75 MPH...120 KM/H PRESENT MOVEMENT...NE OR 45 DEGREES AT 12 MPH...19 KM/H MINIMUM CENTRAL PRESSURE...971 MB...28.68 INCHES WATCHES AND WARNINGS -------------------- There are no coastal watches or warnings in effect. DISCUSSION AND OUTLOOK ---------------------- At 300 PM GMT (1500 UTC), the center of Hurricane Isaac was located near latitude 43.2 North, longitude 35.6 West. Isaac is moving toward the northeast near 12 mph (19 km/h) and this motion is expected to continue during the next couple of days, followed by a turn toward the north-northeast on Tuesday. Maximum sustained winds have decreased to near 75 mph (120 km/h) with higher gusts, and continued weakening is forecast over the next few days. Isaac is forecast to become 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 205 miles (335 km). The estimated minimum central pressure is 971 mb (28.68 inches). HAZARDS AFFECTING LAND ---------------------- SURF: Swells generated by Isaac and an upstream 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 Mahoney/Papin

...ISAAC CONTINUES MOVING TOWARDS THE NORTHEAST OVER THE OPEN ATLANTIC... ...LARGE AREA OF DANGEROUS HIGH SEAS SURROUND THE HURRICANE... As of 3:00 PM GMT Sun Sep 29 the center of Isaac was located near 43.2, -35.6 with movement NE at 12 mph. The minimum central pressure was 971 mb with maximum sustained winds of about 75 mph.

Issued at 1500 UTC SUN SEP 29 2024 000 FONT15 KNHC 291435 PWSAT5 HURRICANE ISAAC WIND SPEED PROBABILITIES NUMBER 15 NWS NATIONAL HURRICANE CENTER MIAMI FL AL102024 1500 UTC SUN SEP 29 2024 AT 1500Z THE CENTER OF HURRICANE ISAAC WAS LOCATED NEAR LATITUDE 43.2 NORTH...LONGITUDE 35.6 WEST WITH MAXIMUM SUSTAINED WINDS NEAR 65 KTS...75 MPH...120 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 SUN 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 SUN 00Z MON 12Z MON 00Z TUE 12Z TUE 12Z WED 12Z THU PERIODS TO TO TO TO TO TO TO 00Z MON 12Z MON 00Z TUE 12Z TUE 12Z WED 12Z THU 12Z FRI FORECAST HOUR (12) (24) (36) (48) (72) (96) (120) - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - LOCATION KT $$ FORECASTER MAHONEY/PAPIN

Issued at 1500 UTC SUN SEP 29 2024 000 WTNT25 KNHC 291435 TCMAT5 HURRICANE ISAAC FORECAST/ADVISORY NUMBER 15 NWS NATIONAL HURRICANE CENTER MIAMI FL AL102024 1500 UTC SUN SEP 29 2024 HURRICANE CENTER LOCATED NEAR 43.2N 35.6W AT 29/1500Z POSITION ACCURATE WITHIN 30 NM PRESENT MOVEMENT TOWARD THE NORTHEAST OR 45 DEGREES AT 10 KT ESTIMATED MINIMUM CENTRAL PRESSURE 971 MB MAX SUSTAINED WINDS 65 KT WITH GUSTS TO 80 KT. 64 KT....... 0NE 40SE 40SW 0NW. 50 KT....... 50NE 70SE 60SW 60NW. 34 KT.......180NE 150SE 120SW 160NW. 12 FT SEAS..270NE 480SE 360SW 360NW. 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 43.2N 35.6W AT 29/1500Z AT 29/1200Z CENTER WAS LOCATED NEAR 42.9N 36.2W FORECAST VALID 30/0000Z 44.0N 33.6W MAX WIND 55 KT...GUSTS 65 KT. 50 KT... 45NE 50SE 50SW 45NW. 34 KT...140NE 120SE 120SW 140NW. FORECAST VALID 30/1200Z 45.1N 30.3W...POST-TROP/EXTRATROP MAX WIND 50 KT...GUSTS 60 KT. 50 KT... 40NE 30SE 30SW 0NW. 34 KT...120NE 120SE 120SW 120NW. FORECAST VALID 01/0000Z 46.6N 26.8W...POST-TROP/EXTRATROP MAX WIND 45 KT...GUSTS 55 KT. 34 KT...120NE 80SE 80SW 120NW. FORECAST VALID 01/1200Z 48.5N 25.0W...POST-TROP/EXTRATROP MAX WIND 40 KT...GUSTS 50 KT. 34 KT...170NE 30SE 30SW 100NW. FORECAST VALID 02/0000Z 50.6N 24.3W...POST-TROP/EXTRATROP MAX WIND 35 KT...GUSTS 45 KT. 34 KT...200NE 70SE 20SW 90NW. FORECAST VALID 02/1200Z 52.8N 23.1W...POST-TROP/EXTRATROP MAX WIND 35 KT...GUSTS 45 KT. 34 KT...190NE 60SE 0SW 30NW. 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 03/1200Z 57.1N 18.6W...POST-TROP/EXTRATROP MAX WIND 35 KT...GUSTS 45 KT. 34 KT...100NE 50SE 0SW 0NW. OUTLOOK VALID 04/1200Z 61.2N 14.2W...POST-TROP/EXTRATROP MAX WIND 35 KT...GUSTS 45 KT. 34 KT...190NE 105SE 0SW 0NW. REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 43.2N 35.6W NEXT ADVISORY AT 29/2100Z $$ FORECASTER MAHONEY/PAPIN

000
ABNT20 KNHC 291153
TWOAT

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
800 AM EDT Sun Sep 29 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 northwest of the Azores, and
on Tropical Storm Joyce, located over the central Atlantic Ocean.

Eastern and Central Tropical Atlantic (AL90):
Showers and thunderstorms associated with an elongated area of low
pressure located a few hundred miles west-southwest of the Cabo
Verde Islands have become better organized since yesterday.
Environmental conditions are conducive for gradual development of
this system, and a tropical depression is likely to form during the
early or middle part of this week while the system initially moves
westward and then northwestward across the eastern and central
tropical Atlantic.
* Formation chance through 48 hours...medium...60 percent.
* Formation chance through 7 days...high...80 percent.

Western Caribbean Sea and Gulf of Mexico:
A broad area of low pressure located over the western Caribbean Sea
is producing disorganized showers and thunderstorms. Environmental
conditions appear to be conducive for gradual development, and a
tropical depression could form around the middle part of this week
while the disturbance meanders towards the west-northwest. This
system is then expected to move northwestward into the Gulf of
Mexico during the latter portion of this week, and interests in the
northwestern Caribbean Sea and along the U.S. Gulf Coast should
monitor its progress.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 7 days...medium...50 percent.

Eastern Atlantic:
A tropical wave located near the coast of western Africa is
currently producing limited shower activity. Some gradual
development of this system is possible during the next several days
while it moves slowly westward or west-northwestward over the
eastern Atlantic Ocean.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 7 days...low...20 percent.

$$
Forecaster Blake/Mahoney

5-Day Uncertainty Track last updated Sun, 29 Sep 2024 08:41:48 GMT


Wind Speed Probabilities last updated Sun, 29 Sep 2024 09:22:54 GMT

5-Day Uncertainty Track last updated Sun, 29 Sep 2024 08:40:38 GMT


Wind Speed Probabilities last updated Sun, 29 Sep 2024 09:28:47 GMT

Issued at 900 AM GMT Sun Sep 29 2024 000 WTNT45 KNHC 290839 TCDAT5 Hurricane Isaac Discussion Number 14 NWS National Hurricane Center Miami FL AL102024 900 AM GMT Sun Sep 29 2024 The strong deep-layer shear and sub-24C sea surface temperatures continue to disrupt Isaac's cloud pattern, although recent images show a small burst of deep convection developing near the surface center. The outer convective curve bands are diminishing and have dissipated in the east semicircle of the cyclone. Based on the latest Dvorak satellite intensity estimates and a UW-CIMSS SATCON analysis, the initial intensity is set at 70 kt. Decreasing oceanic surface temperatures and a sharp increase in west-southwesterly vertical shear support further weakening as an extratropical cyclone through day 5. Isaac could lose what remains of its organized deep convection later tonight and become a post-tropical cyclone, as suggested by the global model simulated/IR forecast. In any event, extratropical transition is anticipated by Monday evening due to baroclinic forcing from a middle-latitude trough and the proximity of a frontal boundary. Isaac's initial motion is estimated to be northeastward, or 045/11 kt as it continues to be steered by the mid-latitude southwesterly flow. A turn toward the north-northeast by the middle part of this week is forecast in response to a mid- to upper-level trough approaching the cyclone from the west-northwest. Around the 72 hr period, Isaac should turn northward while moving around the eastern periphery of a larger baroclinic low-pressure system. An adjustment slightly to the right of the previous track advisory is again needed beyond the 24 hr period to conform with the latest consensus guidance. FORECAST POSITIONS AND MAX WINDS INIT 29/0900Z 42.6N 36.5W 70 KT 80 MPH 12H 29/1800Z 43.5N 34.9W 60 KT 70 MPH 24H 30/0600Z 44.5N 31.8W 50 KT 60 MPH...POST-TROPICAL 36H 30/1800Z 46.0N 28.7W 45 KT 50 MPH...POST-TROP/EXTRATROP 48H 01/0600Z 47.8N 26.3W 40 KT 45 MPH...POST-TROP/EXTRATROP 60H 01/1800Z 49.9N 25.2W 35 KT 40 MPH...POST-TROP/EXTRATROP 72H 02/0600Z 52.0N 24.6W 35 KT 40 MPH...POST-TROP/EXTRATROP 96H 03/0600Z 56.4N 20.8W 35 KT 40 MPH...POST-TROP/EXTRATROP 120H 04/0600Z 60.3N 16.8W 35 KT 40 MPH...POST-TROP/EXTRATROP $$ Forecaster Roberts