NHC Atlantic

Atlantic Tropical Weather Outlook

nhcwebmaster@noaa.gov (NHC Webmaster) — Fri, 10 Sep 2021 17:34:35 GMT

000
ABNT20 KNHC 101734
TWOAT

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
200 PM 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 part of a tropical wave is producing disorganized
showers and thunderstorms over the western Caribbean Sea, and
portions of Central America and the Yucatan peninsula. This system
is forecast to move into the Bay of Campeche and merge with a
pre-existing surface trough by Sunday. Environmental conditions are
expected to be conducive to support gradual development thereafter,
and a tropical depression is likely to form on 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 and the
Yucatan Peninsula through Saturday. Heavy rains are likely to
reach portions of the western Gulf coast late this weekend.
* Formation chance through 48 hours...medium...40 percent.
* Formation chance through 5 days...high...70 percent.

A strong tropical wave located along the west coast of Africa is
producing disorganized showers and thunderstorms. This wave will
move off the coast by this evening, and gradual development is
expected thereafter. 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 20:43:39 GMT

...LARRY NEARING SOUTHEASTERN NEWFOUNDLAND... ...EXPECTED TO BRING HURRICANE-FORCE WINDS, A DANGEROUS STORM SURGE, AND HEAVY RAINFALL TO THAT AREA TONIGHT... As of 5:00 PM AST Fri Sep 10 the center of Larry was located near 43.5, -58.2 with movement NNE at 35 mph. The minimum central pressure was 967 mb with maximum sustained winds of about 80 mph.

Hurricane Larry Public Advisory Number 41

nhcwebmaster@noaa.gov (NHC Webmaster) — Fri, 10 Sep 2021 20:43:39 GMT

Issued at 500 PM AST Fri Sep 10 2021 000 WTNT32 KNHC 102043 TCPAT2 BULLETIN Hurricane Larry Advisory Number 41 NWS National Hurricane Center Miami FL AL122021 500 PM AST Fri Sep 10 2021 ...LARRY NEARING SOUTHEASTERN NEWFOUNDLAND... ...EXPECTED TO BRING HURRICANE-FORCE WINDS, A DANGEROUS STORM SURGE, AND HEAVY RAINFALL TO THAT AREA TONIGHT... SUMMARY OF 500 PM AST...2100 UTC...INFORMATION ---------------------------------------------- LOCATION...43.5N 58.2W ABOUT 330 MI...535 KM SW OF CAPE RACE NEWFOUNDLAND MAXIMUM SUSTAINED WINDS...80 MPH...130 KM/H PRESENT MOVEMENT...NNE OR 20 DEGREES AT 35 MPH...56 KM/H MINIMUM CENTRAL PRESSURE...967 MB...28.56 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 500 PM AST (2100 UTC), the center of Hurricane Larry was located near latitude 43.5 North, longitude 58.2 West. Larry is moving quickly toward the north-northeast near 35 mph (56 km/h). An even faster north-northeast to northeast motion is expected during the next day or so. 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 remain near 80 mph (130 km/h) with higher gusts. Little change in strength is expected before landfall in Newfoundland. After landfall, Larry should weaken and become an extratropical cyclone early Saturday before it merges with another low over the Labrador Sea on Sunday. Larry is a large tropical cyclone. Hurricane-force winds extend outward up to 105 miles (165 km) from the center and tropical-storm-force winds extend outward up to 255 miles (405 km). The estimated minimum central pressure is 967 mb (28.56 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: 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 intermediate advisory at 800 PM AST. Next complete advisory at 1100 PM AST. $$ Forecaster Cangialosi ]]>

Hurricane Larry Forecast Advisory Number 41

nhcwebmaster@noaa.gov (NHC Webmaster) — Fri, 10 Sep 2021 20:43:15 GMT

Issued at 2100 UTC FRI SEP 10 2021 000 WTNT22 KNHC 102043 TCMAT2 HURRICANE LARRY FORECAST/ADVISORY NUMBER 41 NWS NATIONAL HURRICANE CENTER MIAMI FL AL122021 2100 UTC FRI SEP 10 2021 CHANGES IN WATCHES AND WARNINGS 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. HURRICANE CENTER LOCATED NEAR 43.5N 58.2W AT 10/2100Z POSITION ACCURATE WITHIN 25 NM PRESENT MOVEMENT TOWARD THE NORTH-NORTHEAST OR 20 DEGREES AT 30 KT ESTIMATED MINIMUM CENTRAL PRESSURE 967 MB MAX SUSTAINED WINDS 70 KT WITH GUSTS TO 85 KT. 64 KT....... 60NE 90SE 0SW 0NW. 50 KT.......120NE 120SE 120SW 80NW. 34 KT.......220NE 220SE 180SW 120NW. 12 FT SEAS..240NE 330SE 420SW 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 43.5N 58.2W AT 10/2100Z AT 10/1800Z CENTER WAS LOCATED NEAR 41.9N 59.5W FORECAST VALID 11/0600Z 48.6N 53.3W...POST-TROP/EXTRATROP MAX WIND 65 KT...GUSTS 80 KT. 64 KT... 60NE 80SE 0SW 0NW. 50 KT...100NE 120SE 90SW 60NW. 34 KT...210NE 230SE 210SW 120NW. FORECAST VALID 11/1800Z 54.9N 46.9W...POST-TROP/EXTRATROP MAX WIND 60 KT...GUSTS 75 KT. 50 KT...120NE 120SE 90SW 60NW. 34 KT...270NE 300SE 300SW 180NW. FORECAST VALID 12/0600Z 58.6N 42.4W...POST-TROP/EXTRATROP MAX WIND 60 KT...GUSTS 75 KT. 50 KT...120NE 120SE 100SW 90NW. 34 KT...300NE 330SE 360SW 240NW. FORECAST VALID 12/1800Z...DISSIPATED REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 43.5N 58.2W INTERMEDIATE PUBLIC ADVISORY...WTNT32 KNHC/MIATCPAT2...AT 11/0000Z NEXT ADVISORY AT 11/0300Z $$ FORECASTER CANGIALOSI ]]>

Hurricane Larry Forecast Discussion Number 41

nhcwebmaster@noaa.gov (NHC Webmaster) — Fri, 10 Sep 2021 20:44:09 GMT

Issued at 500 PM AST Fri Sep 10 2021 691 WTNT42 KNHC 102044 TCDAT2 Hurricane Larry Discussion Number 41 NWS National Hurricane Center Miami FL AL122021 500 PM AST Fri Sep 10 2021 Even though Larry is crossing the north wall of the Gulf Stream Current, the hurricane remains well organized and has changed little during the past several hours. Satellite images and radar data indicate that Larry still has an inner core, though the southern side has eroded some. Large curved bands surround the inner core region, with dry slots noted between the core and bands. The initial intensity is held at 70 kt based mostly on the ASCAT data from earlier today, which showed peak winds of around 65 kt to the east of the center. It should be noted that this intensity value is above the Dvorak estimates, which are often not as reliable for high latitude storms like Larry. The earlier ASCAT data confirmed that Larry is a large cyclone with hurricane-force and tropical-storm-force winds extending outward up to 90 n mi and 220 n mi from the center, respectively. Larry is rapidly approaching southeastern Newfoundland, and weather conditions are expected to begin to deteriorate there in a few hours. The hurricane continues to accelerate to the north-northeast, and the latest initial motion estimate is 020/30 kt. An even faster north-northeast to northeast motion is expected during the next day or so as the hurricane moves in the fast flow between a mid- to upper-level trough over the northeastern U.S./eastern Canada and a mid-level ridge over the central Atlantic. This motion should take Larry across southeastern Newfoundland tonight. Larry is then expected to merge with a large extratropical low over the Labrador Sea on Sunday. The NHC track forecast is largely an update of the previous one and near the middle of the tightly clustered models. Larry is expected to maintain its intensity through landfall in Newfoundland tonight. However, a combination of land interaction, much cooler SSTs, and an increase in shear are expected to promote weakening shortly after landfall. Larry should be fully extratropical early Saturday morning when it is forecast to be exiting Newfoundland and moving over the cold waters of the Labrador Sea. The NHC intensity forecast remains close to the GFS model, which often performs well for hurricanes that transition to extratropical cyclones. 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 night. 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 10/2100Z 43.5N 58.2W 70 KT 80 MPH 12H 11/0600Z 48.6N 53.3W 65 KT 75 MPH...POST-TROP/EXTRATROP 24H 11/1800Z 54.9N 46.9W 60 KT 70 MPH...POST-TROP/EXTRATROP 36H 12/0600Z 58.6N 42.4W 60 KT 70 MPH...POST-TROP/EXTRATROP 48H 12/1800Z...DISSIPATED $$ Forecaster Cangialosi ]]>

Hurricane Larry Wind Speed Probabilities Number 41

nhcwebmaster@noaa.gov (NHC Webmaster) — Fri, 10 Sep 2021 20:43:39 GMT

Issued at 2100 UTC FRI SEP 10 2021 000 FONT12 KNHC 102043 PWSAT2 HURRICANE LARRY WIND SPEED PROBABILITIES NUMBER 41 NWS NATIONAL HURRICANE CENTER MIAMI FL AL122021 2100 UTC FRI SEP 10 2021 AT 2100Z THE CENTER OF HURRICANE LARRY WAS LOCATED NEAR LATITUDE 43.5 NORTH...LONGITUDE 58.2 WEST WITH MAXIMUM SUSTAINED WINDS NEAR 70 KTS...80 MPH...130 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 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 18Z FRI 06Z SAT 18Z SAT 06Z SUN 18Z SUN 18Z MON 18Z TUE PERIODS TO TO TO TO TO TO TO 06Z SAT 18Z SAT 06Z SUN 18Z SUN 18Z MON 18Z TUE 18Z WED FORECAST HOUR (12) (24) (36) (48) (72) (96) (120) - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - LOCATION KT HIBERNIA OILFD 34 34 7(41) X(41) X(41) X(41) X(41) X(41) CAPE RACE NFLD 34 99 X(99) X(99) X(99) X(99) X(99) X(99) CAPE RACE NFLD 50 85 X(85) X(85) X(85) X(85) X(85) X(85) CAPE RACE NFLD 64 24 X(24) X(24) X(24) X(24) X(24) X(24) ILE ST PIERRE 34 99 X(99) X(99) X(99) X(99) X(99) X(99) ILE ST PIERRE 50 90 X(90) X(90) X(90) X(90) X(90) X(90) BURGEO NFLD 34 53 X(53) X(53) X(53) X(53) X(53) X(53) PTX BASQUES 34 6 X( 6) X( 6) X( 6) X( 6) X( 6) X( 6) SYDNEY NS 34 5 X( 5) X( 5) X( 5) X( 5) X( 5) X( 5) SABLE ISLAND 34 99 X(99) X(99) X(99) X(99) X(99) X(99) $$ FORECASTER CANGIALOSI ]]>

Hurricane Larry Graphics

nhcwebmaster@noaa.gov (NHC Webmaster) — Fri, 10 Sep 2021 20:45:10 GMT

5-Day Uncertainty Track last updated Fri, 10 Sep 2021 20:45:10 GMT

Wind Speed Probabilities last updated Fri, 10 Sep 2021 20:45:10 GMT