NHC Atlantic

Atlantic Tropical Weather Outlook

nhcwebmaster@noaa.gov (NHC Webmaster) — Tue, 07 Sep 2021 17:36:09 GMT

000
ABNT20 KNHC 071735 CCA
TWOAT

Tropical Weather Outlook...Corrected
NWS National Hurricane Center Miami FL
200 PM EDT Tue Sep 7 2021

Corrected to add rainfall statement

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

The National Hurricane Center is issuing advisories on Hurricane
Larry, located over the central Atlantic several hundred miles
southwest of Bermuda.

Showers and thunderstorms have increased today over the
south-central Gulf of Mexico in association with a surface trough
and an upper-level disturbance. The system is expected to move
slowly northeastward over the central and northeastern Gulf of
Mexico during the next couple of days. Upper-level winds are
currently unfavorable for development, but they are forecast to
become more conducive for some limited tropical or subtropical
cyclone development as the system nears the northern Gulf coast on
Wednesday and Wednesday night. The disturbance is then expected to
cross the southeastern United States, and some slight additional
development will be possible after it emerges off the southeastern
United States coast late this week. Regardless of development,
areas of heavy rainfall will be possible across portions of the
Florida panhandle and southern Georgia on Wednesday and Thursday,
with localized flooding possible.
* Formation chance through 48 hours...low...30 percent.
* Formation chance through 5 days...medium...40 percent.

$$
Forecaster Latto

Summary for Hurricane Larry (AT2/AL122021)

nhcwebmaster@noaa.gov (NHC Webmaster) — Tue, 07 Sep 2021 20:52:47 GMT

...LARGE LARRY STILL A MAJOR HURRICANE... ...LIKELY TO PRODUCE DANGEROUS SWELLS OVER THE WESTERN ATLANTIC COAST THIS WEEK... As of 5:00 PM AST Tue Sep 7 the center of Larry was located near 25.1, -56.3 with movement NW at 9 mph. The minimum central pressure was 965 mb with maximum sustained winds of about 115 mph.

Hurricane Larry Public Advisory Number 29

nhcwebmaster@noaa.gov (NHC Webmaster) — Tue, 07 Sep 2021 20:52:47 GMT

Issued at 500 PM AST Tue Sep 07 2021 000 WTNT32 KNHC 072052 TCPAT2 BULLETIN Hurricane Larry Advisory Number 29 NWS National Hurricane Center Miami FL AL122021 500 PM AST Tue Sep 07 2021 ...LARGE LARRY STILL A MAJOR HURRICANE... ...LIKELY TO PRODUCE DANGEROUS SWELLS OVER THE WESTERN ATLANTIC COAST THIS WEEK... SUMMARY OF 500 PM AST...2100 UTC...INFORMATION ---------------------------------------------- LOCATION...25.1N 56.3W ABOUT 715 MI...1150 KM SE OF BERMUDA MAXIMUM SUSTAINED WINDS...115 MPH...185 KM/H PRESENT MOVEMENT...NW OR 320 DEGREES AT 9 MPH...15 KM/H MINIMUM CENTRAL PRESSURE...965 MB...28.50 INCHES WATCHES AND WARNINGS -------------------- CHANGES WITH THIS ADVISORY: None. SUMMARY OF WATCHES AND WARNINGS IN EFFECT: A Tropical Storm Watch is in effect for... * Bermuda A Tropical Storm Watch means that tropical storm conditions are possible within the watch area, generally within 48 hours. For storm information specific to your area, please monitor products issued by your national meteorological service. DISCUSSION AND OUTLOOK ---------------------- At 500 PM AST (2100 UTC), the center of Hurricane Larry was located near latitude 25.1 North, longitude 56.3 West. Larry is moving toward the northwest near 9 mph (15 km/h), and this general motion is expected to continue through Wednesday. A turn toward the north-northwest and north with an increase in forward speed is forecast on Thursday. On the forecast track, the center of Larry should pass east of Bermuda on Thursday. Maximum sustained winds remain near 115 mph (185 km/h) with higher gusts. Larry is a category 3 hurricane on the Saffir-Simpson Hurricane Wind Scale. Slow weakening is forecast during the next several days. Larry is a large hurricane. Hurricane-force winds extend outward up to 70 miles (110 km) from the center and tropical-storm-force winds extend outward up to 185 miles (295 km). The minimum central pressure reported by a NOAA Hurricane Hunter aircraft is 965 mb (28.50 inches). HAZARDS AFFECTING LAND ---------------------- Key messages for Larry can be found in the Tropical Cyclone Discussion under AWIPS header MIATCDAT2 and WMO header WTNT42 KNHC. WIND: Tropical storm conditions are possible on Bermuda beginning late Wednesday or early Thursday. SURF: Swells generated by Larry will continue to affect the Lesser Antilles, portions of the Greater Antilles, and the Bahamas through midweek, and impact Bermuda through the end of the week. Significant swells should reach the east coast of the United States and Atlantic Canada by midweek and continue affecting these shores through the end of the week. These swells are likely to cause life-threatening surf and rip current conditions. Please consult products from your local weather office. NEXT ADVISORY ------------- Next intermediate advisory at 800 PM AST. Next complete advisory at 1100 PM AST. $$ Forecaster Pasch ]]>

Hurricane Larry Forecast Advisory Number 29

nhcwebmaster@noaa.gov (NHC Webmaster) — Tue, 07 Sep 2021 20:52:47 GMT

Issued at 2100 UTC TUE SEP 07 2021 000 WTNT22 KNHC 072052 TCMAT2 HURRICANE LARRY FORECAST/ADVISORY NUMBER 29 NWS NATIONAL HURRICANE CENTER MIAMI FL AL122021 2100 UTC TUE SEP 07 2021 CHANGES IN WATCHES AND WARNINGS WITH THIS ADVISORY... NONE. SUMMARY OF WATCHES AND WARNINGS IN EFFECT... A TROPICAL STORM WATCH IS IN EFFECT FOR... * BERMUDA A TROPICAL STORM WATCH MEANS THAT TROPICAL STORM CONDITIONS ARE POSSIBLE WITHIN THE WATCH AREA...GENERALLY WITHIN 48 HOURS. HURRICANE CENTER LOCATED NEAR 25.1N 56.3W AT 07/2100Z POSITION ACCURATE WITHIN 20 NM PRESENT MOVEMENT TOWARD THE NORTHWEST OR 320 DEGREES AT 8 KT ESTIMATED MINIMUM CENTRAL PRESSURE 965 MB MAX SUSTAINED WINDS 100 KT WITH GUSTS TO 120 KT. 64 KT....... 60NE 50SE 40SW 50NW. 50 KT.......100NE 90SE 70SW 80NW. 34 KT.......160NE 160SE 120SW 140NW. 12 FT SEAS..300NE 270SE 240SW 300NW. 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 25.1N 56.3W AT 07/2100Z AT 07/1800Z CENTER WAS LOCATED NEAR 24.7N 55.8W FORECAST VALID 08/0600Z 26.5N 57.4W MAX WIND 95 KT...GUSTS 115 KT. 64 KT... 70NE 60SE 40SW 50NW. 50 KT...100NE 90SE 70SW 80NW. 34 KT...160NE 160SE 120SW 140NW. FORECAST VALID 08/1800Z 28.3N 58.8W MAX WIND 95 KT...GUSTS 115 KT. 64 KT... 70NE 60SE 40SW 50NW. 50 KT...100NE 100SE 70SW 90NW. 34 KT...170NE 170SE 120SW 140NW. FORECAST VALID 09/0600Z 30.5N 60.5W MAX WIND 90 KT...GUSTS 110 KT. 64 KT... 70NE 60SE 40SW 50NW. 50 KT...110NE 100SE 80SW 90NW. 34 KT...180NE 170SE 120SW 140NW. FORECAST VALID 09/1800Z 33.3N 61.7W MAX WIND 90 KT...GUSTS 110 KT. 64 KT... 60NE 50SE 40SW 50NW. 50 KT...110NE 100SE 80SW 90NW. 34 KT...180NE 180SE 130SW 140NW. FORECAST VALID 10/0600Z 36.8N 61.2W MAX WIND 85 KT...GUSTS 105 KT. 50 KT...110NE 110SE 80SW 80NW. 34 KT...190NE 180SE 130SW 140NW. FORECAST VALID 10/1800Z 41.7N 58.2W MAX WIND 80 KT...GUSTS 100 KT. 50 KT...110NE 110SE 80SW 60NW. 34 KT...190NE 200SE 180SW 120NW. EXTENDED OUTLOOK. NOTE...ERRORS FOR TRACK HAVE AVERAGED NEAR 150 NM ON DAY 4 AND 175 NM ON DAY 5...AND FOR INTENSITY NEAR 15 KT EACH DAY OUTLOOK VALID 11/1800Z 53.0N 48.0W...POST-TROP/EXTRATROP MAX WIND 65 KT...GUSTS 80 KT. OUTLOOK VALID 12/1800Z 60.0N 38.0W...POST-TROP/EXTRATROP MAX WIND 50 KT...GUSTS 60 KT. REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 25.1N 56.3W INTERMEDIATE PUBLIC ADVISORY...WTNT32 KNHC/MIATCPAT2...AT 08/0000Z NEXT ADVISORY AT 08/0300Z $$ FORECASTER PASCH ]]>

Hurricane Larry Forecast Discussion Number 29

nhcwebmaster@noaa.gov (NHC Webmaster) — Tue, 07 Sep 2021 20:54:19 GMT

Issued at 500 PM AST Tue Sep 07 2021 000 WTNT42 KNHC 072054 TCDAT2 Hurricane Larry Discussion Number 29 NWS National Hurricane Center Miami FL AL122021 500 PM AST Tue Sep 07 2021 After becoming rather ragged-looking in earlier satellite images, Larry's eye has become a little better defined recently, and the surrounding deep convection is more or less maintaining its strength. Observations from a NOAA Hurricane Hunter aircraft show that the central pressure has fallen slightly, to 965 mb. Peak flight-level winds from the aircraft were 110 kt so the advisory intensity is kept at 100 kt. This is also consistent with a Dvorak Current Intensity number from TAFB. Larry continues its northwestward motion at about 320/8 kt. The hurricane should move around the western side of a deep-layer subtropical anticyclone during the next 48-60 hours. After passing Bermuda, the system is likely to accelerate northeastward while moving into the mid-latitude westerlies ahead of a trough moving from the northeastern United States to Atlantic Canada, and move into the far north Atlantic by day 5. The official track forecast stays close to the previous NHC prediction, and remains in good agreement the various model consensus solutions. The hurricane continues to exhibit well-defined upper-level outflow, indicative of weak vertical shear. Over the next couple of days, Larry will be traversing waters of gradually decreasing oceanic heat content. This, combined with some dry mid-level air in the environment, should lead to a gradual decrease in intensity through 48-60 hours. Later in the forecast period, colder waters and strong shear should cause more rapid weakening. By day 4, the global models show Larry merging with a frontal zone. Therefore, the NHC forecast calls for extratropical transition by that time. The official intensity forecast is generally below the statistical-dynamical guidance and above the coupled dynamical hurricane models through 72 hours, but in good agreement with the model consensus aids. Key Messages: 1. Large swells generated by Larry will continue to affect the Lesser Antilles, portions of the Greater Antilles, and the Bahamas through midweek. Significant swells should reach the east coast of the United States and Atlantic Canada by midweek and continue affecting these shores through the end of the week. These swells will likely cause life-threatening surf and rip current conditions, and beachgoers and other interests along these coasts are urged to follow the guidance of lifeguards and local officials this week. 2. The center of Larry is forecast to pass east of Bermuda on Thursday, but given Larry's large size, tropical storm conditions are possible there Thursday, along with a risk of heavy rainfall and coastal flooding. A Tropical Storm Watch is in effect for Bermuda and interests there should closely monitor the latest forecast updates. 3. Larry is forecast to move near or over portions of southeastern Newfoundland late Friday and Friday night as it transitions to a hurricane-force post-tropical cyclone. There is a risk of impacts from high winds, rainfall, and storm surge in portions of Newfoundland, and interests there should monitor the progress of Larry and updates to the forecast. FORECAST POSITIONS AND MAX WINDS INIT 07/2100Z 25.1N 56.3W 100 KT 115 MPH 12H 08/0600Z 26.5N 57.4W 95 KT 110 MPH 24H 08/1800Z 28.3N 58.8W 95 KT 110 MPH 36H 09/0600Z 30.5N 60.5W 90 KT 105 MPH 48H 09/1800Z 33.3N 61.7W 90 KT 105 MPH 60H 10/0600Z 36.8N 61.2W 85 KT 100 MPH 72H 10/1800Z 41.7N 58.2W 80 KT 90 MPH 96H 11/1800Z 53.0N 48.0W 65 KT 75 MPH...POST-TROP/EXTRATROP 120H 12/1800Z 60.0N 38.0W 50 KT 60 MPH...POST-TROP/EXTRATROP $$ Forecaster Pasch ]]>

Hurricane Larry Wind Speed Probabilities Number 29

nhcwebmaster@noaa.gov (NHC Webmaster) — Tue, 07 Sep 2021 20:52:47 GMT

Issued at 2100 UTC TUE SEP 07 2021 000 FONT12 KNHC 072052 PWSAT2 HURRICANE LARRY WIND SPEED PROBABILITIES NUMBER 29 NWS NATIONAL HURRICANE CENTER MIAMI FL AL122021 2100 UTC TUE SEP 07 2021 AT 2100Z THE CENTER OF HURRICANE LARRY WAS LOCATED NEAR LATITUDE 25.1 NORTH...LONGITUDE 56.3 WEST WITH MAXIMUM SUSTAINED WINDS NEAR 100 KTS...115 MPH...185 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 18Z TUE 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 18Z TUE 06Z WED 18Z WED 06Z THU 18Z THU 18Z FRI 18Z SAT PERIODS TO TO TO TO TO TO TO 06Z WED 18Z WED 06Z THU 18Z THU 18Z FRI 18Z SAT 18Z SUN FORECAST HOUR (12) (24) (36) (48) (72) (96) (120) - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - LOCATION KT HIBERNIA OILFD 34 X X( X) X( X) X( X) X( X) 39(39) X(39) HIBERNIA OILFD 50 X X( X) X( X) X( X) X( X) 10(10) X(10) HIBERNIA OILFD 64 X X( X) X( X) X( X) X( X) 3( 3) X( 3) CAPE RACE NFLD 34 X X( X) X( X) X( X) 3( 3) 72(75) X(75) CAPE RACE NFLD 50 X X( X) X( X) X( X) 1( 1) 41(42) X(42) CAPE RACE NFLD 64 X X( X) X( X) X( X) X( X) 17(17) X(17) ILE ST PIERRE 34 X X( X) X( X) X( X) 5( 5) 54(59) X(59) ILE ST PIERRE 50 X X( X) X( X) X( X) 1( 1) 28(29) X(29) ILE ST PIERRE 64 X X( X) X( X) X( X) X( X) 12(12) X(12) BURGEO NFLD 34 X X( X) X( X) X( X) 2( 2) 31(33) X(33) BURGEO NFLD 50 X X( X) X( X) X( X) X( X) 12(12) X(12) BURGEO NFLD 64 X X( X) X( X) X( X) X( X) 4( 4) X( 4) PTX BASQUES 34 X X( X) X( X) X( X) 1( 1) 15(16) X(16) PTX BASQUES 50 X X( X) X( X) X( X) X( X) 4( 4) X( 4) PTX BASQUES 64 X X( X) X( X) X( X) X( X) 1( 1) X( 1) EDDY POINT NS 34 X X( X) X( X) X( X) 2( 2) 4( 6) X( 6) SYDNEY NS 34 X X( X) X( X) X( X) 5( 5) 11(16) X(16) SYDNEY NS 50 X X( X) X( X) X( X) X( X) 4( 4) X( 4) SYDNEY NS 64 X X( X) X( X) X( X) X( X) 1( 1) X( 1) SABLE ISLAND 34 X X( X) X( X) X( X) 26(26) 11(37) X(37) SABLE ISLAND 50 X X( X) X( X) X( X) 7( 7) 6(13) X(13) SABLE ISLAND 64 X X( X) X( X) X( X) 2( 2) 3( 5) X( 5) HALIFAX NS 34 X X( X) X( X) X( X) 3( 3) 2( 5) X( 5) BERMUDA 34 X X( X) 8( 8) 18(26) 2(28) X(28) X(28) BERMUDA 50 X X( X) X( X) 3( 3) 1( 4) X( 4) X( 4) $$ FORECASTER PASCH ]]>

Hurricane Larry Graphics

nhcwebmaster@noaa.gov (NHC Webmaster) — Tue, 07 Sep 2021 17:49:37 GMT

5-Day Uncertainty Track last updated Tue, 07 Sep 2021 17:49:37 GMT

Wind Speed Probabilities last updated Tue, 07 Sep 2021 15:23:04 GMT