NHC Atlantic

Atlantic Tropical Weather Outlook

nhcwebmaster@noaa.gov (NHC Webmaster) — Wed, 08 Sep 2021 11:54:34 GMT

000
ABNT20 KNHC 081154
TWOAT

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
800 AM EDT Wed Sep 8 2021

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
southeast of Bermuda.

Disorganized cloudiness and a few thunderstorms over the central
and eastern Gulf of Mexico are associated with a surface trough
and an upper-level disturbance. The system is expected to move
northeastward over the northeastern Gulf of Mexico later today.
Upper-level winds could become slightly more favorable to support
some tropical or subtropical development as the system nears the
northern Gulf coast tonight or early Thursday. The disturbance is
then expected to cross the southeastern United States, and some
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 through
Thursday, with localized flooding possible.
* Formation chance through 48 hours...medium...50 percent.
* Formation chance through 5 days...medium...50 percent.

A tropical wave is expected to emerge off of the western coast of
Africa in a few days. Some development of this system is possible
thereafter as it moves west-northwestward over the far eastern
Atlantic.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 5 days...low...20 percent.

$$
Forecaster Latto

Summary for Hurricane Larry (AT2/AL122021)

nhcwebmaster@noaa.gov (NHC Webmaster) — Wed, 08 Sep 2021 11:56:34 GMT

...LARRY CAUSING DANGEROUS SWELLS ON THE WESTERN ATLANTIC COAST THIS WEEK... As of 8:00 AM AST Wed Sep 8 the center of Larry was located near 27.0, -57.7 with movement NW at 10 mph. The minimum central pressure was 966 mb with maximum sustained winds of about 115 mph.

Hurricane Larry Public Advisory Number 31A

nhcwebmaster@noaa.gov (NHC Webmaster) — Wed, 08 Sep 2021 11:56:34 GMT

Issued at 800 AM AST Wed Sep 08 2021 000 WTNT32 KNHC 081156 TCPAT2 BULLETIN Hurricane Larry Intermediate Advisory Number 31A NWS National Hurricane Center Miami FL AL122021 800 AM AST Wed Sep 08 2021 ...LARRY CAUSING DANGEROUS SWELLS ON THE WESTERN ATLANTIC COAST THIS WEEK... SUMMARY OF 800 AM AST...1200 UTC...INFORMATION ---------------------------------------------- LOCATION...27.0N 57.7W ABOUT 560 MI...905 KM SE OF BERMUDA MAXIMUM SUSTAINED WINDS...115 MPH...185 KM/H PRESENT MOVEMENT...NW OR 325 DEGREES AT 10 MPH...17 KM/H MINIMUM CENTRAL PRESSURE...966 MB...28.53 INCHES WATCHES AND WARNINGS -------------------- CHANGES WITH THIS ADVISORY: The Bermuda Weather Service has issued a Tropical Storm Warning for Bermuda. SUMMARY OF WATCHES AND WARNINGS IN EFFECT: A Tropical Storm Warning is in effect for... * Bermuda A Tropical Storm Warning means that tropical storm conditions are expected somewhere within the warning area within 36 hours. Interests in southeastern Newfoundland should monitor the progress of this system. For storm information specific to your area, please monitor products issued by your national meteorological service. DISCUSSION AND OUTLOOK ---------------------- At 800 AM AST (1200 UTC), Hurricane Larry was located near latitude 27.0 North, longitude 57.7 West. Larry is moving toward the northwest near 10 mph (17 km/h), and this general motion is expected to continue through today. A turn toward the north-northwest and north with an increase in forward speed is forecast on Thursday. A faster northeastward motion is expected by Friday. On the forecast track, the center of Larry should pass east of Bermuda on Thursday. Maximum sustained winds are near 115 mph (185 km/h) with higher gusts. Larry is a category 3 hurricane on the Saffir-Simpson Hurricane Wind Scale. Gradual weakening is forecast during the next several days, but Larry is expected to remain a hurricane during that time. 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 an Air Force Hurricane Hunter aircraft is 966 mb (28.53 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 tonight or early Thursday. SURF: Swells generated by Larry will continue to affect the Leeward Islands, portions of the Greater Antilles, and the Bahamas through midweek, and impact Bermuda through the end of the week. Significant swells from Larry will begin reaching the east coast of the United States and Atlantic Canada today 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 complete advisory at 1100 AM AST. $$ Forecaster Pasch ]]>

Hurricane Larry Forecast Advisory Number 31

nhcwebmaster@noaa.gov (NHC Webmaster) — Wed, 08 Sep 2021 08:48:34 GMT

Issued at 0900 UTC WED SEP 08 2021 859 WTNT22 KNHC 080848 TCMAT2 HURRICANE LARRY FORECAST/ADVISORY NUMBER 31 NWS NATIONAL HURRICANE CENTER MIAMI FL AL122021 0900 UTC WED SEP 08 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...IN THIS CASE WITHIN THE NEXT 36 HOURS. INTERESTS IN SOUTHEASTERN NEWFOUNDLAND SHOULD MONITOR THE PROGRESS OF THIS SYSTEM. HURRICANE CENTER LOCATED NEAR 26.5N 57.3W AT 08/0900Z POSITION ACCURATE WITHIN 20 NM PRESENT MOVEMENT TOWARD THE NORTHWEST OR 325 DEGREES AT 9 KT ESTIMATED MINIMUM CENTRAL PRESSURE 967 MB MAX SUSTAINED WINDS 100 KT WITH GUSTS TO 120 KT. 64 KT....... 60NE 50SE 40SW 50NW. 50 KT.......100NE 90SE 70SW 90NW. 34 KT.......160NE 160SE 120SW 150NW. 12 FT SEAS..360NE 300SE 330SW 330NW. 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 26.5N 57.3W AT 08/0900Z AT 08/0600Z CENTER WAS LOCATED NEAR 26.2N 57.1W FORECAST VALID 08/1800Z 28.0N 58.7W MAX WIND 95 KT...GUSTS 115 KT. 64 KT... 60NE 50SE 40SW 50NW. 50 KT...100NE 90SE 70SW 90NW. 34 KT...160NE 160SE 120SW 150NW. FORECAST VALID 09/0600Z 30.1N 60.6W 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 09/1800Z 32.9N 61.9W 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 10/0600Z 36.7N 61.6W MAX WIND 85 KT...GUSTS 105 KT. 64 KT... 60NE 50SE 40SW 50NW. 50 KT...110NE 100SE 80SW 90NW. 34 KT...180NE 180SE 140SW 140NW. FORECAST VALID 10/1800Z 41.7N 58.3W MAX WIND 80 KT...GUSTS 100 KT. 50 KT...110NE 110SE 80SW 80NW. 34 KT...200NE 200SE 160SW 130NW. FORECAST VALID 11/0600Z 47.3N 52.4W MAX WIND 75 KT...GUSTS 90 KT. 50 KT...110NE 110SE 80SW 60NW. 34 KT...200NE 200SE 190SW 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 12/0600Z 58.8N 40.0W...POST-TROP/EXTRATROP MAX WIND 60 KT...GUSTS 75 KT. OUTLOOK VALID 13/0600Z 65.0N 33.0W...POST-TROP/EXTRATROP MAX WIND 45 KT...GUSTS 55 KT. REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 26.5N 57.3W INTERMEDIATE PUBLIC ADVISORY...WTNT32 KNHC/MIATCPAT2...AT 08/1200Z NEXT ADVISORY AT 08/1500Z $$ FORECASTER BROWN ]]>

Hurricane Larry Forecast Discussion Number 31

nhcwebmaster@noaa.gov (NHC Webmaster) — Wed, 08 Sep 2021 08:50:28 GMT

Issued at 500 AM AST Wed Sep 08 2021 000 WTNT42 KNHC 080850 TCDAT2 Hurricane Larry Discussion Number 31 NWS National Hurricane Center Miami FL AL122021 500 AM AST Wed Sep 08 2021 Larry's overall satellite presentation has not changed appreciably overnight, however there has been some recent cooling of the cloud tops in the surrounding ring of convection. A fairly recent AMSR2 microwave overpass has revealed a fragmented inner eye with a band or ring of convection at a fairly large radius from the center. Subjective Dvorak Current Intensity (CI) numbers from TAFB and SAB are T5.0 (90 kt) while objective UW/CIMSS ADT T-numbers are around T5.8 (110 kt). A consensus of these estimates, and the latest SATCON estimate of 100 kt, is used as the initial intensity for this advisory. The next Air Force Reserve Hurricane Hunter aircraft is scheduled to investigate Larry this morning and should provide in situ data to help better ascertain the intensity and structure of the hurricane. Larry continues to move northwestward or 325/9 kt. The track forecast reasoning is once again unchanged from before. Larry is expected to move northwestward and then northward around the western portion of a deep-layer ridge during the next 36 to 48 hours, with the center of the hurricane passing east of Bermuda on Thursday. After that time, Larry should begin to accelerate northeastward ahead of a deep-layer trough that will be moving across the northeastern United States, and this will bring the cyclone near or over southeastern Newfoundland in about 72 hours. The track guidance continues to be in excellent agreement, and only slight modifications were made to the previous official forecast. The updated NHC track is near the various consensus aids and the latest GFS ensemble mean. The hurricane is forecast to remain within an area of low vertical wind shear for the next day or two, but the upper-ocean heat content will be gradually decreasing along the forecast path. This, along with some upwelling beneath the relatively slow-moving hurricane, is likely to result in gradual weakening over the next couple of days. After that time, increasing southwesterly shear and much colder SSTs along the forecast track should result in additional weakening. The global models indicate that Larry will merge with a frontal zone and complete its extratropical transition in a little more than 3 days. The NHC intensity forecast is once again similar to the previous advisory and is in best agreement with the IVCN consensus aid. Key Messages: 1. Large swells generated by Larry will continue to affect the Leeward Islands, portions of the Greater Antilles, and the Bahamas today. Significant swells will begin to reach the east coast of the United States and Atlantic Canada later today 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 08/0900Z 26.5N 57.3W 100 KT 115 MPH 12H 08/1800Z 28.0N 58.7W 95 KT 110 MPH 24H 09/0600Z 30.1N 60.6W 95 KT 110 MPH 36H 09/1800Z 32.9N 61.9W 90 KT 105 MPH 48H 10/0600Z 36.7N 61.6W 85 KT 100 MPH 60H 10/1800Z 41.7N 58.3W 80 KT 90 MPH 72H 11/0600Z 47.3N 52.4W 75 KT 85 MPH 96H 12/0600Z 58.8N 40.0W 60 KT 70 MPH...POST-TROP/EXTRATROP 120H 13/0600Z 65.0N 33.0W 45 KT 50 MPH...POST-TROP/EXTRATROP $$ Forecaster Brown ]]>

Hurricane Larry Wind Speed Probabilities Number 31

nhcwebmaster@noaa.gov (NHC Webmaster) — Wed, 08 Sep 2021 08:49:33 GMT

Issued at 0900 UTC WED SEP 08 2021 000 FONT12 KNHC 080849 PWSAT2 HURRICANE LARRY WIND SPEED PROBABILITIES NUMBER 31 NWS NATIONAL HURRICANE CENTER MIAMI FL AL122021 0900 UTC WED SEP 08 2021 AT 0900Z THE CENTER OF HURRICANE LARRY WAS LOCATED NEAR LATITUDE 26.5 NORTH...LONGITUDE 57.3 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 06Z WED AND THE FORECAST HOUR (CUMULATIVE PROBABILITY) PROBABILITIES ARE GIVEN IN PERCENT X INDICATES PROBABILITIES LESS THAN 1 PERCENT PROBABILITIES FOR 34 KT AND 50 KT ARE SHOWN AT A GIVEN LOCATION WHEN THE 5-DAY CUMULATIVE PROBABILITY IS AT LEAST 3 PERCENT. PROBABILITIES FOR 34...50...64 KT SHOWN WHEN THE 5-DAY 64-KT CUMULATIVE PROBABILITY IS AT LEAST 1 PERCENT. - - - - WIND SPEED PROBABILITIES FOR SELECTED LOCATIONS - - - - FROM FROM FROM FROM FROM FROM FROM TIME 06Z WED 18Z WED 06Z THU 18Z THU 06Z FRI 06Z SAT 06Z SUN PERIODS TO TO TO TO TO TO TO 18Z WED 06Z THU 18Z THU 06Z FRI 06Z SAT 06Z SUN 06Z MON FORECAST HOUR (12) (24) (36) (48) (72) (96) (120) - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - LOCATION KT HIBERNIA OILFD 34 X X( X) X( X) X( X) 39(39) 17(56) X(56) HIBERNIA OILFD 50 X X( X) X( X) X( X) 9( 9) 10(19) X(19) HIBERNIA OILFD 64 X X( X) X( X) X( X) 2( 2) 3( 5) X( 5) CAPE RACE NFLD 34 X X( X) X( X) X( X) 72(72) 4(76) X(76) CAPE RACE NFLD 50 X X( X) X( X) X( X) 40(40) 4(44) X(44) CAPE RACE NFLD 64 X X( X) X( X) X( X) 16(16) 1(17) X(17) ILE ST PIERRE 34 X X( X) X( X) X( X) 44(44) 1(45) X(45) ILE ST PIERRE 50 X X( X) X( X) X( X) 17(17) X(17) X(17) ILE ST PIERRE 64 X X( X) X( X) X( X) 5( 5) X( 5) X( 5) BURGEO NFLD 34 X X( X) X( X) X( X) 18(18) 1(19) X(19) BURGEO NFLD 50 X X( X) X( X) X( X) 3( 3) X( 3) X( 3) PTX BASQUES 34 X X( X) X( X) X( X) 9( 9) X( 9) X( 9) EDDY POINT NS 34 X X( X) X( X) X( X) 4( 4) X( 4) X( 4) SYDNEY NS 34 X X( X) X( X) X( X) 11(11) X(11) X(11) SABLE ISLAND 34 X X( X) X( X) X( X) 34(34) X(34) X(34) SABLE ISLAND 50 X X( X) X( X) X( X) 10(10) X(10) X(10) SABLE ISLAND 64 X X( X) X( X) X( X) 2( 2) X( 2) X( 2) HALIFAX NS 34 X X( X) X( X) X( X) 4( 4) X( 4) X( 4) BERMUDA 34 X 5( 5) 23(28) 3(31) X(31) X(31) X(31) BERMUDA 50 X X( X) 4( 4) X( 4) X( 4) X( 4) X( 4) $$ FORECASTER BROWN ]]>

Hurricane Larry Graphics

nhcwebmaster@noaa.gov (NHC Webmaster) — Wed, 08 Sep 2021 08:54:11 GMT

5-Day Uncertainty Track last updated Wed, 08 Sep 2021 08:54:11 GMT

Wind Speed Probabilities last updated Wed, 08 Sep 2021 09:23:05 GMT