000 AXNT20 KNHC 030959 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1205 UTC Fri Sep 3 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 0600 UTC surface analysis and satellite imagery through 0930 UTC. ...SPECIAL FEATURES... Hurricane Larry is centered near 14.6N 38.9W at 03/0900 UTC or 840 nm W of the southernmost Cabo Verde Islands moving WNW at 17 kt. Estimated minimum central pressure is 982 mb. Maximum sustained wind speed has increased to 80 kt with gusts to 100 kt. Numerous moderate to strong convection is noted within 180 nm of the center, except 360 nm of the SW quadrant. Larry is forecast continue WNW for the next couple of days, followed by a turn to the northwest on Sunday. Additional strengthening is forecast during the next few days, and Larry is likely to become a major hurricane tonight. 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. ...TROPICAL WAVES... An eastern Atlantic tropical wave has its axis along 25W, from 04N to 19N, moving W around 15 kt. The weak low pressure that had been associated with this wave has diminished early this morning and related showers and thunderstorms have also continued to decrease. In addition, recent satellite derived wind data indicate that the system does not have a closed circulation. This disturbance is expected to move westward into an environment less conducive for development during the next couple of days, and the chances of formation appear to be decreasing. This system could bring showers and gusty winds to portions of the southernmost Cabo Verde Islands during the next several hours. The disturbance has a low chance of tropical cyclone formation during the next 48 hr. A tropical wave has its axis along 61W, crossing the Lesser Antilles and into eastern Venezuela, moving W at around 15 kt. Scattered moderate to isolated strong convection is noted from 08N to 13N between 53W and 63W, and fresh E winds are occurring behind the wave axis, eastward to about 55W. A Caribbean tropical wave has its axis along 80W, S of 14N, moving W around 15 kt. No convection is currently occurring with this weak tropical wave. ...MONSOON TROUGH/ITCZ... The monsoon trough axis passes through the coast of Senegal near 15N17W to near 13N22W to 12N32W. It then resumes, W of Hurricane Larry, at 11N41W and continues to 09N50W. The ITCZ extends from 09N50W to 08N59W. Aside from convection associated with Hurricane Larry and that mentioned in the Tropical Waves section above, scattered moderate convection is noted from 05N to 12N between 42W and 55W. GULF OF MEXICO... A cold front extends from near the Florida Big Bend to the mouth of the Mississippi River. No significant convection is occurring along this boundary, although isolated thunderstorms are present in the northern Gulf. A 1015 mb high pressure is centered over the Dry Tortugas. Generally gentle and variable winds prevail over the basin, although fresh ESE winds are occurring to the west of the Yucatan Peninsula. Seas range from 2 to 4 ft, highest W of the Yucatan Peninsula. For the forecast, a surface trough currently over the Gulf of Honduras and portions of Central America is expected to move WNW across the Yucatan Peninsula, bringing heavy rainfall. The trough may move over the SW Gulf of Mexico late this weekend, but unfavorable upper level winds are likely to limit significant development while the system moves NW or N over the western Gulf of Mexico early next week. There is a low chance of tropical formation with this trough in the next 5 days. Otherwise, a cold front over the far NE Gulf will stall, then gradually dissipate over the weekend, while weak high pressure dominates much of the remainder of the basin. CARIBBEAN SEA... See the tropical waves section above for details on a tropical wave that could bring gusty showers today to the southeastern Caribbean. Thunderstorms that had been over and near Haiti overnight have diminished. Fresh to locally strong trades are occurring in the south-central Caribbean, with fresh trades also ongoing in the Gulf of Honduras. Elsewhere, gentle to moderate mainly east winds prevail. Seas are 4 to 6 ft in the areas of fresh winds, and 2 to 4 ft elsewhere. A surface trough over the Gulf of Honduras and portions of Central America is producing disorganized scattered moderate convection over northern Nicaragua and Honduras, and over water from 16N-19N between 81W-85W. This system is expected to move west-northwestward across Central America and the Yucatan Peninsula, bringing heavy rains to that area during the next couple of days. The disturbance could then move over the southwestern Gulf of Mexico late this weekend. Although Hurricane Larry is forecast to stay well N and E of the basin, swell from Larry may get through NE Caribbean passages early next week. ATLANTIC OCEAN... Please see the Special Features section for details on Hurricane Larry. A cold front extends from 32N75W to just south of Jacksonville, Florida. Moderate N winds are occurring behind this weakening boundary, with moderate SW winds ahead of it, N of 26N. Scattered moderate convection is occurring ahead of this front, all the way E to 65W, aided by a mid to upper level low pressure south of Bermuda. To the east, high pressure prevails, with the center of a 1021 mb high pressure near 31N45W. Over the eastern Atlantic, a surface trough stretches from 31N22W to 25N31W. Convection associated with this trough is N of 31N. N of 25N, gentle to moderate wind prevails, with areas to the south in a regime of moderate to fresh trades. Outside of swells from Hurricane Larry, seas are currently 4 to 6 feet across most of the Atlantic. For the forecast, Hurricane Larry will move to 15.2N 41.1W this afternoon, 16.2N 43.8W Sat morning, 17.3N 46.2W Sat afternoon, 18.6N 48.5W Sun morning, 19.8N 50.5W Sun afternoon, and 21.1N 52.5W Mon morning. Larry will change little in intensity as it moves well northeast of the Leeward Islands early Tue. At a minimum, large swells generated by Hurricane Larry are expected to propagate across the waters east of the Leeward Islands on Sun, likely spreading beyond 65W Mon and Mon night. $$ KONARIK