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 17:52:01 GMT

...LARRY APPROACHING SOUTHEASTERN NEWFOUNDLAND... ...EXPECTED TO BRING HURRICANE-FORCE WINDS, A DANGEROUS STORM SURGE, AND HEAVY RAINFALL TO THAT AREA TONIGHT... As of 2:00 PM AST Fri Sep 10 the center of Larry was located near 41.8, -59.5 with movement NNE at 29 mph. The minimum central pressure was 971 mb with maximum sustained winds of about 80 mph.

Hurricane Larry Public Advisory Number 40A

nhcwebmaster@noaa.gov (NHC Webmaster) — Fri, 10 Sep 2021 17:52:01 GMT

Issued at 200 PM AST Fri Sep 10 2021 000 WTNT32 KNHC 101751 TCPAT2 BULLETIN Hurricane Larry Intermediate Advisory Number 40A NWS National Hurricane Center Miami FL AL122021 200 PM AST Fri Sep 10 2021 ...LARRY APPROACHING SOUTHEASTERN NEWFOUNDLAND... ...EXPECTED TO BRING HURRICANE-FORCE WINDS, A DANGEROUS STORM SURGE, AND HEAVY RAINFALL TO THAT AREA TONIGHT... SUMMARY OF 200 PM AST...1800 UTC...INFORMATION ---------------------------------------------- LOCATION...41.8N 59.5W ABOUT 465 MI...745 KM SW OF CAPE RACE NEWFOUNDLAND MAXIMUM SUSTAINED WINDS...80 MPH...130 KM/H PRESENT MOVEMENT...NNE OR 15 DEGREES AT 29 MPH...46 KM/H MINIMUM CENTRAL PRESSURE...971 MB...28.68 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 200 PM AST (1800 UTC), the center of Hurricane Larry was located near latitude 41.8 North, longitude 59.5 West. Larry is moving quickly toward the north-northeast near 29 mph (46 km/h). An even faster north-northeast to northeast motion is expected during the next day or two. 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 on 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 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 971 mb (28.68 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 500 PM AST. $$ Forecaster Cangialosi ]]>

Hurricane Larry Forecast Advisory Number 40

nhcwebmaster@noaa.gov (NHC Webmaster) — Fri, 10 Sep 2021 14:47:29 GMT

Issued at 1500 UTC FRI SEP 10 2021 000 WTNT22 KNHC 101447 TCMAT2 HURRICANE LARRY FORECAST/ADVISORY NUMBER 40 NWS NATIONAL HURRICANE CENTER MIAMI FL AL122021 1500 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 40.0N 60.5W AT 10/1500Z POSITION ACCURATE WITHIN 25 NM PRESENT MOVEMENT TOWARD THE NORTH-NORTHEAST OR 15 DEGREES AT 25 KT ESTIMATED MINIMUM CENTRAL PRESSURE 971 MB MAX SUSTAINED WINDS 70 KT WITH GUSTS TO 85 KT. 64 KT....... 80NE 60SE 50SW 50NW. 50 KT.......120NE 120SE 90SW 90NW. 34 KT.......210NE 210SE 180SW 140NW. 12 FT SEAS..300NE 350SE 280SW 340NW. 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 40.0N 60.5W AT 10/1500Z AT 10/1200Z CENTER WAS LOCATED NEAR 39.0N 61.0W FORECAST VALID 11/0000Z 45.1N 56.4W MAX WIND 70 KT...GUSTS 85 KT. 64 KT... 80NE 80SE 50SW 40NW. 50 KT...120NE 140SE 100SW 70NW. 34 KT...210NE 230SE 210SW 120NW. FORECAST VALID 11/1200Z 52.0N 49.4W...POST-TROP/EXTRATROP MAX WIND 60 KT...GUSTS 75 KT. 50 KT...120NE 140SE 100SW 70NW. 34 KT...210NE 250SE 240SW 120NW. FORECAST VALID 12/0000Z 57.5N 44.0W...POST-TROP/EXTRATROP MAX WIND 60 KT...GUSTS 75 KT. 50 KT...120NE 140SE 100SW 60NW. 34 KT...300NE 330SE 330SW 150NW. FORECAST VALID 12/1200Z 61.1N 38.7W...POST-TROP/EXTRATROP MAX WIND 55 KT...GUSTS 65 KT. 50 KT...200NE 200SE 120SW 0NW. 34 KT...420NE 420SE 480SW 180NW. FORECAST VALID 13/0000Z...DISSIPATED REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 40.0N 60.5W INTERMEDIATE PUBLIC ADVISORY...WTNT32 KNHC/MIATCPAT2...AT 10/1800Z NEXT ADVISORY AT 10/2100Z $$ FORECASTER CANGIALOSI ]]>

Hurricane Larry Forecast Discussion Number 40

nhcwebmaster@noaa.gov (NHC Webmaster) — Fri, 10 Sep 2021 14:48:30 GMT

Issued at 1100 AM AST Fri Sep 10 2021 000 WTNT42 KNHC 101448 TCDAT2 Hurricane Larry Discussion Number 40 NWS National Hurricane Center Miami FL AL122021 1100 AM AST Fri Sep 10 2021 Larry remains a well organized hurricane at a high latitude, and it is quickly approaching southeastern Newfoundland. Satellite images show a fairly tight inner core and large curved bands surrounding that feature. However, there are some notable dry slots between the core and bands that have developed during the past several hours. The latest Dvorak numbers have nudged downward, with the CI values ranging between 65 kt and 72 kt. Based on these estimates, and a very recent ASCAT pass that showed peak winds near 65 kt, the initial intensity is set at 70 kt for this advisory. The cyclone remains quite large, with hurricane-force winds and tropical-storm-force winds estimated to extend outward up to 80 and 210 n mi from the center, respectively. The hurricane is in the process of turning to the right, with the latest initial motion estimated to be a fairly quick 015/25 kt. An even faster north-northeast to northeast motion is expected during the next day or two 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 similar to the previous one and near the middle of the guidance envelope. Although Larry will be moving over cooler waters north of the Gulf Stream Current later today, the hurricane will likely hold its strength or weaken just a little before landfall. After landfall, the models show the inner core dissipating, and the combination of land interaction, cooler waters, and an increase in shear should cause weakening and lead to extratropical transition by early Saturday. The NHC intensity forecast is 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 10/1500Z 40.0N 60.5W 70 KT 80 MPH 12H 11/0000Z 45.1N 56.4W 70 KT 80 MPH 24H 11/1200Z 52.0N 49.4W 60 KT 70 MPH...POST-TROP/EXTRATROP 36H 12/0000Z 57.5N 44.0W 60 KT 70 MPH...POST-TROP/EXTRATROP 48H 12/1200Z 61.1N 38.7W 55 KT 65 MPH...POST-TROP/EXTRATROP 60H 13/0000Z...DISSIPATED $$ Forecaster Cangialosi ]]>

Hurricane Larry Wind Speed Probabilities Number 40

nhcwebmaster@noaa.gov (NHC Webmaster) — Fri, 10 Sep 2021 14:48:02 GMT

Issued at 1500 UTC FRI SEP 10 2021 287 FONT12 KNHC 101447 PWSAT2 HURRICANE LARRY WIND SPEED PROBABILITIES NUMBER 40 NWS NATIONAL HURRICANE CENTER MIAMI FL AL122021 1500 UTC FRI SEP 10 2021 AT 1500Z THE CENTER OF HURRICANE LARRY WAS LOCATED NEAR LATITUDE 40.0 NORTH...LONGITUDE 60.5 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 12Z 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 12Z FRI 00Z SAT 12Z SAT 00Z SUN 12Z SUN 12Z MON 12Z TUE PERIODS TO TO TO TO TO TO TO 00Z SAT 12Z SAT 00Z SUN 12Z SUN 12Z MON 12Z TUE 12Z WED FORECAST HOUR (12) (24) (36) (48) (72) (96) (120) - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - LOCATION KT HIBERNIA OILFD 34 X 36(36) X(36) X(36) X(36) X(36) X(36) CAPE RACE NFLD 34 58 37(95) X(95) X(95) X(95) X(95) X(95) CAPE RACE NFLD 50 1 85(86) X(86) X(86) X(86) X(86) X(86) CAPE RACE NFLD 64 X 26(26) X(26) X(26) X(26) X(26) X(26) ILE ST PIERRE 34 83 15(98) X(98) X(98) X(98) X(98) X(98) ILE ST PIERRE 50 21 53(74) X(74) X(74) X(74) X(74) X(74) ILE ST PIERRE 64 3 17(20) X(20) X(20) X(20) X(20) X(20) BURGEO NFLD 34 32 19(51) X(51) X(51) X(51) X(51) X(51) PTX BASQUES 34 8 6(14) X(14) X(14) X(14) X(14) X(14) EDDY POINT NS 34 3 X( 3) X( 3) X( 3) X( 3) X( 3) X( 3) SYDNEY NS 34 18 2(20) X(20) X(20) X(20) X(20) X(20) SABLE ISLAND 34 78 X(78) X(78) X(78) X(78) X(78) X(78) SABLE ISLAND 50 4 X( 4) X( 4) X( 4) X( 4) X( 4) X( 4) HALIFAX NS 34 3 X( 3) X( 3) X( 3) X( 3) X( 3) X( 3) $$ FORECASTER CANGIALOSI ]]>

Hurricane Larry Graphics

nhcwebmaster@noaa.gov (NHC Webmaster) — Fri, 10 Sep 2021 17:52:12 GMT

5-Day Uncertainty Track last updated Fri, 10 Sep 2021 17:52:12 GMT

Wind Speed Probabilities last updated Fri, 10 Sep 2021 15:22:52 GMT