000 AXNT20 KNHC 100605 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0605 UTC Fri Sep 10 2021 Tropical Weather Discussion for North America, Central America Gulf of Mexico, Caribbean Sea, northern sections of South America, and Atlantic Ocean to the African coast from the Equator to 31N. The following information is based on satellite imagery, weather observations, radar and meteorological analysis. Based on 0000 UTC surface analysis and satellite imagery through 0605 UTC. ...SPECIAL FEATURES... Hurricane Larry is centered near 36.5N 62.2W at 10/0600 UTC or 735 nm SW of Cape Race, Newfoundland. Larry is moving N at 22 kt. Estimated minimum central pressure is 966 mb. Maximum sustained wind speed is 80 kt with gusts to 100 kt. Numerous moderate to strong convection is noted in the northern semicircle up to 200 nm and scattered moderate convection is seen in the southern semicircle up to 115 nm. On the forecast track, the center of Larry will continue to move away from Bermuda tonight, and move near or over southeastern Newfoundland Friday night or early Saturday morning. Gradual weakening is forecast to begin on Friday, 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. Please read the latest High Seas Forecast issued by the National Hurricane Center at website https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml and the latest NHC Forecast/Advisory and Public Advisory at www.hurricanes.gov for more details. A robust tropical wave is producing scattered moderate to strong convection over W Africa. The tropical wave is expected to move into the far eastern Atlantic later today or tonight. Environmental conditions are forecast to be conducive for development thereafter, and a tropical depression is likely to form by early next week as the system moves west-northwestward over the far eastern Atlantic near the Cabo Verde Islands. The disturbance has a medium chance of development over the next 48 hours and a high chance of development over the next 5 days. Please see the latest Tropical Weather Outlook from the National Hurricane Center. ...TROPICAL WAVES... An Atlantic tropical wave has its axis along 33W, south of 21N, and it is moving W near 15 kt. No deep convection is noted with this tropical wave. Another Atlantic tropical wave has its axis along 47W, south of 21N, and it is moving W at 10-15 kt. No deep convection is noted with this tropical wave. A Caribbean tropical wave has its axis along 71W, extending from Hispaniola to W Venezuela and SE Colombia, and it is moving W near 15 kt. The wave is mainly monitored through the 700 mb trough diagnostics and the 700 mb rawindsonde observations. No deep convection is noted with this tropical wave. However, it is enhancing the development of showers and thunderstorms over SE Colombia. A Caribbean tropical wave has been introduced along 87W, extending from the Gulf of Honduras, across Honduras and E Nicaragua, and into the E Pacific. Scattered moderate convection is noted east of the wave axis to 80W and from 17N to 22N. 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 some gradual development, and a tropical depression could form by early next week before the system moves inland over mainland Mexico. For more details, please read the latest Tropical Weather Outlook from the National Hurricane Center. ...MONSOON TROUGH/ITCZ... A monsoon trough passes through the Guinea-Bissau coast near 11N16W to 08N28W and to 12N40W. No ITCZ segment is analyzed based on recent scatterometer satellite data. Scattered moderate convection is noted south of monsoon trough from the coast of Africa to 29W. ...GULF OF MEXICO... A cold front extends from the Florida panhandle near 31N86W to south of Louisiana near 29N93W, and then continues as a stationary front to the coast of SE Texas near 29N95W. A surface trough is located over the W Gulf of Mexico from 19N92W to 28N95W. The combination of these features and a mid to upper-level trough in the vicinity is causing a large area of scattered showers and thunderstorms, especially from 22N to 28N and between 87W and 94W. A recent scatterometer satellite pass show gentle to moderate anticyclonic winds dominating the Gulf. Seas of 1-3 ft are found across the basin. For the forecast, the northern portion of a tropical wave is producing disorganized showers and thunderstorms across the western Caribbean Sea. 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 some gradual development, and a tropical depression could form by early next week before the system moves inland over mainland Mexico. This system has a low chance of development in 48 hours and medium chance in the next 5 days. Regardless of development, this system could bring an increase in winds and seas across the Gulf waters during the upcoming weekend. ...CARIBBEAN SEA... Please see the Tropical Waves section for details on the tropical waves moving across the area. Most of the Caribbean Sea is dominated by dry weather conditions that are inhibiting the development of showers and thunderstorms. A recent scatterometer satellite pass depict strong to locally near gale-force trades in the south-central Caribbean, especially within 150 nm of the NW coast of Colombia. Moderate to fresh trades are found in the north-central Caribbean, E Caribbean and NW Caribbean, while gentle to moderate trades are noted in the SW Caribbean. Seas of 6-9 ft are prevalent in the south-central Caribbean and 3-6 ft elsewhere in the basin. For the forecast, as Larry continues to move farther north, the Atlantic ridge will build westward N of the Caribbean Sea. This will bring an increase in the trade wind flow tonight into the weekend. Fresh to strong winds are possible offshore Colombia and in the Gulf of Venezuela, mainly during the nights. Fresh to locally strong winds are also likely in the late evening in the Gulf of Honduras Friday and Saturday. ...ATLANTIC OCEAN... Please see the Special Features section above for details on Hurricane Larry over the NW Atlantic. The 1024 mb subtropical ridge is beginning to re-assert dominance over the tropical Atlantic as Hurricane Larry continues to move away. Recent scatterometer satellite data and satellite imagery indicate that a weak 1014 mb low pressure is located near 12N44W. It is producing disorganized showers and thunderstorms, especially over the northern semicircle, from 13N to 17N and between 39W to 45W. Moderate to fresh E winds are found within 120 nm north of the center, between 42W and 46W. Fairly tranquil weather conditions prevail across the basin. Fresh to strong cyclonic winds associated with the circulations of Hurricane Larry and Post-Tropical Cyclone Mindy are noted north of 29N between 56W and 64W, and between 74W and 79W. Seas in these areas are 8-11 ft. Larger swells traveling farther away from Larry are generating seas of 5-8 ft N of 23N between 69W and the Florida-Georgia coast, including the Bahamas. Similar seas are also found from 21N to 25N between 56W and 69W, and N of 24N between 48W and 53W. A tight pressure gradient over the NE Atlantic results in fresh to strong NE winds within 180 nm of the coasts of Morocco and Western Sahara, and the waters surrounding the Canary Islands. Seas in this region are 7-10 ft. Gentle to moderate easterlies prevail across the basin with seas of 4-7 ft. For the forecast, Post-Tropical Cyclone Mindy is centered near 32.5N 75.0W at 10/0300 UTC. Mindy is bring a brief period of fresh to strong SW to W winds N of 29N and W of 78W through early Friday morning. Swells from Mindy will also continue through Fri afternoon. Meanwhile, swells generated by Hurricane Larry will continue to propagate across the waters N of 27N and E of 73W through Fri afternoon. Seas are expected to subside into the weekend. $$ DELGADO