NHC Atlantic

Atlantic Tropical Weather Outlook

nhcwebmaster@noaa.gov (NHC Webmaster) — Fri, 10 Sep 2021 11:16:29 GMT

000
ABNT20 KNHC 101116
TWOAT

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
800 AM EDT Fri Sep 10 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 western Atlantic several hundred miles
southwest of Newfoundland, Canada.

The northern portion of a tropical wave is producing disorganized
showers and thunderstorms over Honduras, the western Caribbean Sea,
and portions of the Yucatan peninsula. This system is forecast to
move into the Bay of Campeche and merge with a pre-existing surface
trough located over the southwestern Gulf of Mexico by this weekend.
Environmental conditions are expected to be conducive to support
gradual development, and a tropical depression is likely to form
Sunday or Monday before the system moves onshore along the western
Gulf of Mexico coast. Regardless of development, this disturbance
is expected to produce heavy rains across portions of Central
America through Saturday.
* Formation chance through 48 hours...medium...40 percent.
* Formation chance through 5 days...high...70 percent.

A strong tropical wave is expected to emerge off of the west coast
of Africa by tonight. Environmental conditions are forecast to be
conducive for gradual development thereafter, and a tropical
depression is likely to form late this weekend or early next week as
the system moves west-northwestward over the far eastern Atlantic
near the Cabo Verde Islands. Interests in the Cabo Verde Islands
should monitor the progress of this system.
* Formation chance through 48 hours...medium...50 percent.
* Formation chance through 5 days...high...70 percent.

$$
Forecaster Cangialosi

Summary for Hurricane Larry (AT2/AL122021)

nhcwebmaster@noaa.gov (NHC Webmaster) — Fri, 10 Sep 2021 11:47:29 GMT

...LARRY MOVING QUICKLY TOWARD SOUTHEASTERN NEWFOUNDLAND... ...EXPECTED TO BRING HURRICANE-FORCE WINDS, A DANGEROUS STORM SURGE, AND HEAVY RAINFALL TO THAT AREA TONIGHT... As of 8:00 AM AST Fri Sep 10 the center of Larry was located near 39.2, -60.8 with movement NNE at 26 mph. The minimum central pressure was 968 mb with maximum sustained winds of about 85 mph.

Hurricane Larry Public Advisory Number 39A

nhcwebmaster@noaa.gov (NHC Webmaster) — Fri, 10 Sep 2021 11:47:29 GMT

Issued at 800 AM AST Fri Sep 10 2021 000 WTNT32 KNHC 101147 TCPAT2 BULLETIN Hurricane Larry Intermediate Advisory Number 39A NWS National Hurricane Center Miami FL AL122021 800 AM AST Fri Sep 10 2021 ...LARRY MOVING QUICKLY TOWARD SOUTHEASTERN NEWFOUNDLAND... ...EXPECTED TO BRING HURRICANE-FORCE WINDS, A DANGEROUS STORM SURGE, AND HEAVY RAINFALL TO THAT AREA TONIGHT... SUMMARY OF 800 AM AST...1200 UTC...INFORMATION ---------------------------------------------- LOCATION...39.2N 60.8W ABOUT 650 MI...1045 KM SW OF CAPE RACE NEWFOUNDLAND MAXIMUM SUSTAINED WINDS...85 MPH...140 KM/H PRESENT MOVEMENT...NNE OR 15 DEGREES AT 26 MPH...43 KM/H MINIMUM CENTRAL PRESSURE...968 MB...28.59 INCHES WATCHES AND WARNINGS -------------------- CHANGES WITH THIS ADVISORY: None. SUMMARY OF WATCHES AND WARNINGS IN EFFECT: A Hurricane Warning is in effect for... * Southeastern Newfoundland from Arnold's Cove to Jones Harbour A Tropical Storm Warning is in effect for... * Southeastern Newfoundland from Francois to west of Arnold's Cove * Southeastern Newfoundland from north of Jones Harbor to Fogo Island A Hurricane Warning means that hurricane conditions are expected somewhere within the warning area, in this case within the next 24 hours. 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, in this case within the next 12 hours. Interests elsewhere 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), the center of Hurricane Larry was located near latitude 39.2 North, longitude 60.8 West. Larry is moving quickly toward the north-northeast near 26 mph (43 km/h). A turn to the northeast with an increase in forward speed is expected later today. On the forecast track, the center of Larry will pass well southeast of Nova Scotia today, and move over southeastern Newfoundland tonight. Maximum sustained winds are near 85 mph (140 km/h) with higher gusts. Gradual weakening is forecast during the next day or so, but Larry is expected to remain a hurricane until it passes Newfoundland. Larry should become an extratropical cyclone on Saturday, and is now forecast to be absorbed by a larger extratropical low near Greenland by the end of the weekend. Larry is a large hurricane. Hurricane-force winds extend outward up to 90 miles (150 km) from the center and tropical-storm- force winds extend outward up to 240 miles (390 km). The estimated minimum central pressure is 968 mb (28.59 inches). HAZARDS AFFECTING LAND ---------------------- Key messages for Larry can be found in the Tropical Cyclone Discussion under AWIPS header MIATCDAT2, WMO header WTNT42 KNHC and on the web at hurricanes.gov/graphics_at2.shtml?key_messages WIND: Hurricane conditions are expected within the hurricane warning area in southeastern Newfoundland tonight, with tropical storm conditions expected to begin this afternoon or evening. Tropical storm conditions are expected to begin in the tropical storm warning area in southeastern Newfoundland later today. STORM SURGE: A dangerous storm surge is expected to produce coastal flooding within the warning areas in southeastern Newfoundland. SURF: Swells generated by Larry will continue to affect the Bahamas today. Significant swells from Larry will continue affecting Bermuda, the east coast of the United States, and Atlantic Canada through Saturday night. These swells are likely to cause life-threatening surf and rip current conditions. Please consult products from your local weather office. RAINFALL: Heavy rains from Larry will move quickly across eastern Newfoundland tonight, producing 1 to 2 inches of rain. NEXT ADVISORY ------------- Next complete advisory at 1100 AM AST. $$ Forecaster Cangialosi ]]>

Hurricane Larry Forecast Advisory Number 39

nhcwebmaster@noaa.gov (NHC Webmaster) — Fri, 10 Sep 2021 08:43:24 GMT

Issued at 0900 UTC FRI SEP 10 2021 000 WTNT22 KNHC 100843 TCMAT2 HURRICANE LARRY FORECAST/ADVISORY NUMBER 39 NWS NATIONAL HURRICANE CENTER MIAMI FL AL122021 0900 UTC FRI SEP 10 2021 CHANGES IN WATCHES AND WARNINGS WITH THIS ADVISORY... THE CANADIAN HURRICANE CENTRE HAS EXTENDED THE TROPICAL STORM WARNING ALONG THE SOUTHERN COAST OF SOUTHEASTERN NEWFOUNDLAND WESTWARD TO FRANCOIS AND ALONG THE NORTHERN COAST OF SOUTHEASTERN NEWFOUNDLAND TO FOGO ISLAND. SUMMARY OF WATCHES AND WARNINGS IN EFFECT... A HURRICANE WARNING IS IN EFFECT FOR... * SOUTHEASTERN NEWFOUNDLAND FROM ARNOLD'S COVE TO JONES HARBOUR A TROPICAL STORM WARNING IS IN EFFECT FOR... * SOUTHEASTERN NEWFOUNDLAND FROM FRANCOIS TO WEST OF ARNOLD'S COVE * SOUTHEASTERN NEWFOUNDLAND FROM NORTH OF JONES HARBOR TO FOGO ISLAND A HURRICANE WARNING MEANS THAT HURRICANE CONDITIONS ARE EXPECTED SOMEWHERE WITHIN THE WARNING AREA...IN THIS CASE WITHIN THE NEXT 24 HOURS. 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...IN THIS CASE WITHIN THE NEXT 12 TO 24 HOURS. INTERESTS ELSEWHERE IN SOUTHEASTERN NEWFOUNDLAND SHOULD MONITOR THE PROGRESS OF THIS SYSTEM. HURRICANE CENTER LOCATED NEAR 37.7N 61.8W AT 10/0900Z POSITION ACCURATE WITHIN 25 NM PRESENT MOVEMENT TOWARD THE NORTH-NORTHEAST OR 15 DEGREES AT 23 KT ESTIMATED MINIMUM CENTRAL PRESSURE 968 MB MAX SUSTAINED WINDS 75 KT WITH GUSTS TO 90 KT. 64 KT....... 80NE 60SE 30SW 50NW. 50 KT.......120NE 120SE 70SW 90NW. 34 KT.......210NE 210SE 140SW 140NW. 12 FT SEAS..380NE 350SE 280SW 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 37.7N 61.8W AT 10/0900Z AT 10/0600Z CENTER WAS LOCATED NEAR 36.5N 62.2W FORECAST VALID 10/1800Z 41.9N 59.2W MAX WIND 75 KT...GUSTS 90 KT. 64 KT... 80NE 80SE 50SW 40NW. 50 KT...120NE 140SE 100SW 70NW. 34 KT...210NE 230SE 180SW 120NW. FORECAST VALID 11/0600Z 48.6N 53.0W MAX WIND 70 KT...GUSTS 85 KT. 64 KT... 70NE 70SE 50SW 30NW. 50 KT...120NE 140SE 100SW 70NW. 34 KT...210NE 250SE 210SW 120NW. FORECAST VALID 11/1800Z 55.0N 46.8W...POST-TROP/EXTRATROP MAX WIND 60 KT...GUSTS 75 KT. 50 KT...120NE 140SE 100SW 60NW. 34 KT...300NE 330SE 330SW 150NW. FORECAST VALID 12/0600Z 60.0N 42.0W...POST-TROP/EXTRATROP MAX WIND 60 KT...GUSTS 75 KT. 50 KT...200NE 200SE 120SW 0NW. 34 KT...420NE 420SE 480SW 180NW. FORECAST VALID 12/1800Z...DISSIPATED REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 37.7N 61.8W INTERMEDIATE PUBLIC ADVISORY...WTNT32 KNHC/MIATCPAT2...AT 10/1200Z NEXT ADVISORY AT 10/1500Z $$ FORECASTER BROWN ]]>

Hurricane Larry Forecast Discussion Number 39

nhcwebmaster@noaa.gov (NHC Webmaster) — Fri, 10 Sep 2021 08:44:31 GMT

Issued at 500 AM AST Fri Sep 10 2021 000 WTNT42 KNHC 100844 TCDAT2 Hurricane Larry Discussion Number 39 NWS National Hurricane Center Miami FL AL122021 500 AM AST Fri Sep 10 2021 Larry's satellite presentation has remained largely unchanged overnight. Deep convection continues to persist over and to the northeast of the center, with a larger outer band around the eastern portion of the circulation. Subjective Dvorak intensity estimates from TAFB and SAB have lowered slightly, and the initial intensity has been adjusted downward to 75 kt. This lies between the lower subjective satellite estimates and the higher UW/CIMSS ADT and SATCON values. Larry is forecast to remain over warm waters and in low vertical wind shear conditions this morning, therefore little overall change in intensity is expected in the short term. The hurricane will cross the north wall of the Gulf Stream over much cooler SSTs this afternoon, but the increasingly fast forward speed of the system and baroclinic forcing from a mid-latitude trough approaching from the west is likely to help Larry maintain hurricane strength as is passes over southeastern Newfoundland tonight. Larry is forecast to become extratropical shortly thereafter, and some slight weakening should occur before the post-tropical cyclone is absorbed by a larger extratropical low near southern Greenland in a couple of days. The NHC intensity forecast is similar to the HCCA and IVCN consensus aids and also follows the trends of the latest global model guidance. Larry has turned north-northeastward or 015/23 kt. The track guidance is once again in excellent agreement that Larry should turn northeastward today and continue to accelerate ahead of the aforementioned trough. The center of Larry should pass over southeastern Newfoundland tonight, but users are reminded to not focus on the exact details of the track forecast as strong winds, heavy rainfall, and a dangerous storm surge will extend far from the center of the cyclone. The updated official forecast lies near the center of the track guidance envelope, but is slightly faster than the previous forecast during the first 36 hours. Key Messages: 1. Larry is forecast to move over portions of southeastern Newfoundland tonight as it undergoes transition to a hurricane-force post-tropical cyclone. Hurricane conditions, a dangerous storm surge, and heavy rainfall are expected in portions of southeastern Newfoundland where a Hurricane Warning in effect. 2. Large swells generated by Larry will continue to affect the Bahamas, Bermuda, and the east coast of the United States and Atlantic Canada through Saturday. These swells will 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. FORECAST POSITIONS AND MAX WINDS INIT 10/0900Z 37.7N 61.8W 75 KT 85 MPH 12H 10/1800Z 41.9N 59.2W 75 KT 85 MPH 24H 11/0600Z 48.6N 53.0W 70 KT 80 MPH 36H 11/1800Z 55.0N 46.8W 60 KT 70 MPH...POST-TROP/EXTRATROP 48H 12/0600Z 60.0N 42.0W 60 KT 70 MPH...POST-TROP/EXTRATROP 60H 12/1800Z...DISSIPATED $$ Forecaster Brown ]]>

Hurricane Larry Wind Speed Probabilities Number 39

nhcwebmaster@noaa.gov (NHC Webmaster) — Fri, 10 Sep 2021 08:43:55 GMT

Issued at 0900 UTC FRI SEP 10 2021 000 FONT12 KNHC 100843 PWSAT2 HURRICANE LARRY WIND SPEED PROBABILITIES NUMBER 39 NWS NATIONAL HURRICANE CENTER MIAMI FL AL122021 0900 UTC FRI SEP 10 2021 AT 0900Z THE CENTER OF HURRICANE LARRY WAS LOCATED NEAR LATITUDE 37.7 NORTH...LONGITUDE 61.8 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 06Z FRI 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 FRI 18Z FRI 06Z SAT 18Z SAT 06Z SUN 06Z MON 06Z TUE PERIODS TO TO TO TO TO TO TO 18Z FRI 06Z SAT 18Z SAT 06Z SUN 06Z MON 06Z TUE 06Z WED FORECAST HOUR (12) (24) (36) (48) (72) (96) (120) - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - LOCATION KT HIBERNIA OILFD 34 X 46(46) 4(50) X(50) X(50) X(50) X(50) CAPE RACE NFLD 34 X 98(98) X(98) X(98) X(98) X(98) X(98) CAPE RACE NFLD 50 X 87(87) X(87) X(87) X(87) X(87) X(87) CAPE RACE NFLD 64 X 33(33) X(33) X(33) X(33) X(33) X(33) ILE ST PIERRE 34 X 97(97) X(97) X(97) X(97) X(97) X(97) ILE ST PIERRE 50 X 71(71) X(71) X(71) X(71) X(71) X(71) ILE ST PIERRE 64 X 23(23) X(23) X(23) X(23) X(23) X(23) BURGEO NFLD 34 X 48(48) X(48) X(48) X(48) X(48) X(48) BURGEO NFLD 50 X 3( 3) X( 3) X( 3) X( 3) X( 3) X( 3) PTX BASQUES 34 X 13(13) X(13) X(13) X(13) X(13) X(13) EDDY POINT NS 34 2 2( 4) X( 4) X( 4) X( 4) X( 4) X( 4) SYDNEY NS 34 4 11(15) X(15) X(15) X(15) X(15) X(15) SABLE ISLAND 34 67 12(79) X(79) X(79) X(79) X(79) X(79) SABLE ISLAND 50 4 8(12) X(12) X(12) X(12) X(12) X(12) SABLE ISLAND 64 X 1( 1) X( 1) X( 1) X( 1) X( 1) X( 1) HALIFAX NS 34 4 1( 5) X( 5) X( 5) X( 5) X( 5) X( 5) $$ FORECASTER BROWN ]]>

Hurricane Larry Graphics

nhcwebmaster@noaa.gov (NHC Webmaster) — Fri, 10 Sep 2021 11:47:47 GMT

5-Day Uncertainty Track last updated Fri, 10 Sep 2021 11:47:47 GMT

Wind Speed Probabilities last updated Fri, 10 Sep 2021 09:23:08 GMT