NHC Atlantic

Atlantic Tropical Weather Outlook

nhcwebmaster@noaa.gov (NHC Webmaster) — Fri, 10 Sep 2021 23:47:16 GMT

000
ABNT20 KNHC 102347
TWOAT

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
800 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 interacting with a surface
trough over the southwestern Gulf of Mexico. The merger of these
features is producing a large but disorganized area of showers and
thunderstorms over the western Caribbean Sea, Central America, the
Yucatan peninsula, and Gulf of Mexico. Environmental conditions are
expected to be conducive for gradual development over the weekend,
and a tropical depression is likely to form on Sunday or Monday
before the system moves near or onshore of the western Gulf of
Mexico coast. Regardless of development, this disturbance is
expected to produce heavy rain across portions of Central America
and the Yucatan Peninsula through Saturday which may lead to flash
flooding and mudslides. By late this weekend, heavy rain will likely
reach portions of the western Gulf coast, including coastal Texas
and Louisiana through the middle of next week. Localized significant
rainfall amounts will be possible, resulting in limited flash and
urban flooding.
* Formation chance through 48 hours...medium...60 percent.
* Formation chance through 5 days...high...80 percent.

A strong tropical wave located just off the west coast of Africa is
producing disorganized showers and thunderstorms. Environmental
conditions appear generally conducive for additional development
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 Papin

Summary for Hurricane Larry (AT2/AL122021)

nhcwebmaster@noaa.gov (NHC Webmaster) — Sat, 11 Sep 2021 03:55:50 GMT

...LARRY LASHING NEWFOUNDLAND WITH STRONG WINDS AND A DANGEROUS STORM SURGE... As of 2:00 AM AST Sat Sep 11 the center of Larry was located near 48.7, -53.2 with movement NNE at 47 mph. The minimum central pressure was 963 mb with maximum sustained winds of about 80 mph.

Hurricane Larry Public Advisory Number 42A

nhcwebmaster@noaa.gov (NHC Webmaster) — Sat, 11 Sep 2021 05:41:20 GMT

Issued at 200 AM AST Sat Sep 11 2021 000 WTNT32 KNHC 110541 TCPAT2 BULLETIN Hurricane Larry Intermediate Advisory Number 42A NWS National Hurricane Center Miami FL AL122021 200 AM AST Sat Sep 11 2021 ...LARRY LASHING NEWFOUNDLAND WITH STRONG WINDS AND A DANGEROUS STORM SURGE... SUMMARY OF 200 AM AST...0600 UTC...INFORMATION ---------------------------------------------- LOCATION...48.7N 53.2W ABOUT 80 MI...130 KM NNW OF ST JOHNS NEWFOUNDLAND MAXIMUM SUSTAINED WINDS...80 MPH...130 KM/H PRESENT MOVEMENT...NNE OR 30 DEGREES AT 47 MPH...76 KM/H MINIMUM CENTRAL PRESSURE...963 MB...28.44 INCHES WATCHES AND WARNINGS -------------------- CHANGES WITH THIS ADVISORY: The Tropical Storm Warning from Francois to west of Arnold's Cove has been discontinued by the Canadian Hurricane Centre. 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 north of Jones Harbor to Fogo Island A Hurricane Warning means that hurricane conditions are expected somewhere within the warning area. A Tropical Storm Warning means that tropical storm conditions are expected somewhere within the warning area. For storm information specific to your area, please monitor products issued by your national meteorological service. DISCUSSION AND OUTLOOK ---------------------- At 200 AM AST (0600 UTC), the center of Hurricane Larry was located near latitude 48.7 North, longitude 53.2 West. Larry is moving toward the north-northeast near 47 mph (76 km/h). A very rapid motion toward the north-northeast or northeast is expected through today and tonight. On the forecast track, the center of Larry will be moving quickly away from Newfoundland during the next several hours. Maximum sustained winds remain near 80 mph (130 km/h) with higher gusts. Little change in strength is forecast today, and Larry is expected to become a strong extratropical low later this morning before it merges with another low over the Labrador Sea on Sunday. 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). St. John's International Airport, Newfoundland, recently reported sustained winds of 60 mph (96 km/h) and a wind gust of 90 mph (144 km/h). The estimated minimum central pressure is 963 mb (28.44 inches) based on surface observations from Newfoundland. 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 and tropical storm conditions are expected to continue in the warned areas during the next few hours. 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 tonight. 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 500 AM AST. $$ Forecaster Blake ]]>

Hurricane Larry Forecast Advisory Number 42

nhcwebmaster@noaa.gov (NHC Webmaster) — Sat, 11 Sep 2021 02:47:44 GMT

Issued at 0300 UTC SAT SEP 11 2021 000 WTNT22 KNHC 110247 TCMAT2 HURRICANE LARRY FORECAST/ADVISORY NUMBER 42 NWS NATIONAL HURRICANE CENTER MIAMI FL AL122021 0300 UTC SAT SEP 11 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 12 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 46.8N 54.9W AT 11/0300Z POSITION ACCURATE WITHIN 30 NM PRESENT MOVEMENT TOWARD THE NORTH-NORTHEAST OR 30 DEGREES AT 41 KT ESTIMATED MINIMUM CENTRAL PRESSURE 958 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..150NE 380SE 500SW 150NW. 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 46.8N 54.9W AT 11/0300Z AT 11/0000Z CENTER WAS LOCATED NEAR 45.0N 56.4W FORECAST VALID 11/1200Z 51.9N 49.5W...POST-TROP/EXTRATROP MAX WIND 65 KT...GUSTS 80 KT. 64 KT... 60NE 80SE 0SW 0NW. 50 KT...120NE 120SE 90SW 60NW. 34 KT...230NE 250SE 210SW 120NW. FORECAST VALID 12/0000Z 56.8N 44.7W...POST-TROP/EXTRATROP MAX WIND 60 KT...GUSTS 75 KT. 50 KT...120NE 120SE 90SW 60NW. 34 KT...270NE 300SE 300SW 180NW. FORECAST VALID 12/1200Z...DISSIPATED REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 46.8N 54.9W INTERMEDIATE PUBLIC ADVISORY...WTNT32 KNHC/MIATCPAT2...AT 11/0600Z NEXT ADVISORY AT 11/0900Z $$ FORECASTER BEVEN ]]>

Hurricane Larry Forecast Discussion Number 42

nhcwebmaster@noaa.gov (NHC Webmaster) — Sat, 11 Sep 2021 02:48:46 GMT

Issued at 1100 PM AST Fri Sep 10 2021 000 WTNT42 KNHC 110248 TCDAT2 Hurricane Larry Discussion Number 42 NWS National Hurricane Center Miami FL AL122021 1100 PM AST Fri Sep 10 2021 Satellite imagery and data from Canadian radars indicate that Larry is maintaining good central convective banding in the northeastern semicircle, and based on this it is still a tropical cyclone at this time. The maximum intensity is held at 70 kt based mainly on recently-received scattterometer data showing 64-67 kt winds to the east and southeast of the center. Surface observations indicate that tropical storm conditions are spreading into southeastern Newfoundland, and hurricane condition should move onshore during the next few hours as the center makes landfall. After landfall, Larry is expected to quickly lose its tropical cyclone characteristics and become a strong extratropical low over the Labrador Sea. The cyclone is forecast to dissipate after 24 h as it merges with a developing mid-latitude low currently to its northwest. Larry is moving rapidly toward the north-northeast with an initial motion of 030/41. This general motion should continue until Larry merges with the other low pressure area. The new official forecast track is little changed from the previous track and is in the middle of the tightly clustered guidance models. Key Messages: 1. Larry will move over portions of southeastern Newfoundland during the next several hours 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 11/0300Z 46.8N 54.9W 70 KT 80 MPH 12H 11/1200Z 51.9N 49.5W 65 KT 75 MPH...POST-TROP/EXTRATROP 24H 12/0000Z 56.8N 44.7W 60 KT 70 MPH...POST-TROP/EXTRATROP 36H 12/1200Z...DISSIPATED $$ Forecaster Beven ]]>

Hurricane Larry Wind Speed Probabilities Number 42

nhcwebmaster@noaa.gov (NHC Webmaster) — Sat, 11 Sep 2021 02:48:22 GMT

Issued at 0300 UTC SAT SEP 11 2021 510 FONT12 KNHC 110248 PWSAT2 HURRICANE LARRY WIND SPEED PROBABILITIES NUMBER 42 NWS NATIONAL HURRICANE CENTER MIAMI FL AL122021 0300 UTC SAT SEP 11 2021 AT 0300Z THE CENTER OF HURRICANE LARRY WAS LOCATED NEAR LATITUDE 46.8 NORTH...LONGITUDE 54.9 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 00Z SAT 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 00Z SAT 12Z SAT 00Z SUN 12Z SUN 00Z MON 00Z TUE 00Z WED PERIODS TO TO TO TO TO TO TO 12Z SAT 00Z SUN 12Z SUN 00Z MON 00Z TUE 00Z WED 00Z THU FORECAST HOUR (12) (24) (36) (48) (72) (96) (120) - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - LOCATION KT HIBERNIA OILFD 34 45 X(45) X(45) X(45) X(45) X(45) X(45) CAPE RACE NFLD 34 99 X(99) X(99) X(99) X(99) X(99) X(99) CAPE RACE NFLD 50 99 X(99) X(99) X(99) X(99) X(99) X(99) CAPE RACE NFLD 64 86 X(86) X(86) X(86) X(86) X(86) X(86) ILE ST PIERRE 34 99 X(99) X(99) X(99) X(99) X(99) X(99) ILE ST PIERRE 50 99 X(99) X(99) X(99) X(99) X(99) X(99) BURGEO NFLD 34 10 X(10) X(10) X(10) X(10) X(10) X(10) $$ FORECASTER BEVEN ]]>

Hurricane Larry Graphics

nhcwebmaster@noaa.gov (NHC Webmaster) — Sat, 11 Sep 2021 05:41:33 GMT

5-Day Uncertainty Track last updated Sat, 11 Sep 2021 05:41:33 GMT

Wind Speed Probabilities last updated Sat, 11 Sep 2021 03:22:41 GMT