000 AXNT20 KNHC 020531 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0605 UTC Thu Sep 2 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 0500 UTC. ...SPECIAL FEATURES... Tropical Storm Larry is centered near 12.8N 30.9W at 02/0300 UTC or 395 nm WSW of the southernmost Cabo Verde Islands moving W at 18 kt. Estimated minimum central pressure is 991 mb. Maximum sustained wind speed is 60 kt with gusts to 75 kt. Scattered moderate to strong convection is within 150 nm of the center in the E semicircle and 270 nm W semicircle. Larry is expected to continue moving west today, followed by a turn toward the west-northwest on Friday. Conditions appear favorable for Larry to strengthen to a hurricane today and to a major hurricane by Friday night. Please read the latest NHC Public Advisory at https://www.nhc.noaa.gov/text/MIATCPAT2.shtml and Forecast/ Advisory at https://www.nhc.noaa.gov/text/MIATCMAT2.shtml for more details. ...TROPICAL WAVES... A tropical wave has been added to the analysis along 16.5W, or along the west coast of Africa, from 04N-19N, moving W at around 15 kt. Scattered moderate to strong convection is seen from 10N-15N between 16W-19W. The axis of a tropical wave is near 51W from 20N southward, moving westward at about 20 kt. Scattered moderate and isolated strong convection is from 05N to 08N between 49W and 54W. The tropical wave that was previously analyzed to be near 76W at 01/1800 UTC was moved back east to about 72W, south of 14N, based on recent satellite data and model data. However, this position is low confidence since the wave is quite weak and difficult to track. The wave is estimated to be moving westward at about 10 kt. Scattered moderate convection is noted over northern Colombia. ...MONSOON TROUGH/ITCZ... The monsoon trough extends from the coast of northern Senegal near 16N17W to 15N23W, then resumes west of Larry near 10N35W to 08N49W. The ITCZ extends from 08N53W to 08N59W. Aside from convection noted above, scattered moderate to strong convection is seen within 240 nm north of the monsoon trough between 40W-46W. GULF OF MEXICO... A 1015 mb surface high pressure is analyzed over the southeast Gulf near 25N87W. The latest ASCAT data shows fresh west winds in the NE Gulf to the north of the high pressure. Mainly moderate E to SE winds are in the SW Gulf. Light to gentle anticyclonic wind speeds are noted in the SE to central Gulf of Mexico, near the surface high pressure. Seas are 2 to 4 ft across most of the basin, except 4 to 6 ft in the NE Gulf. To the NW of the Yucatan Peninsula, it is possible that fresh NE to E winds with 3 to 5 ft seas are occurring. A few showers and tstorms are noted along the Gulf Coast between Destin FL and Mobile AL. Additional showers and tstorms are noted near the coast of Mexico near Tuxpan and near Coatzacoalcos. Fresh to strong southwest to west winds over the NE Gulf will persist through early this morning ahead of a frontal trough. Then, light and variable winds will prevail over the NE Gulf during the upcoming weekend. Elsewhere, a ridge will dominate the Gulf region producing mainly gentle to moderate southerly winds through Fri. Pulsing fresh winds are expected northwest of the Yucatan Peninsula at night through Fri. Looking ahead, an area of low pressure that is currently located just off the coast of Nicaragua could move over the southwestern Gulf of Mexico during the weekend and early next week, but by then strong upper-level winds would likely limit significant development. CARIBBEAN SEA... Low pressure is centered along the coast of Nicaragua near 13.5N83W. Scattered moderate showers are noted near and within 90 nm north of the low. The low is moving inland over Nicaragua now, but a portion of the low's circulation could move over the Gulf of Honduras later today and Friday, where development, if any, is expected to be slow to occur. Regardless of development, heavy rains are possible across portions of Central America and the Yucatan Peninsula through the weekend. There is a low chance for tropical cyclone development over the next 48 hours. Please see the latest Atlantic Tropical Weather Outlook for more on this feature. The latest ASCAT data show gentle to moderate trade winds across the Caribbean Sea, except for fresh to strong in the Gulf of Honduras. Seas are 2 to 4 ft, except 4 to 6 ft in the Gulf of Honduras. Aside from the convection already mentioned, there are no other major areas of precipitation in the Caribbean Sea at the moment. For the forecast, the pressure gradient between a ridge east of Florida and lower pressure over northern Colombia will support moderate to fresh trade winds over the south-central and northwest Caribbean through Fri night. Similar wind speeds are expected in the Gulf of Honduras at night through the weekend. Looking ahead, swells generated by tropical cyclone Larry are expected to reach the waters NE and E of the Leeward Islands on Sun. ATLANTIC OCEAN... A surface trough extends over the W Atlantic from 31N77W to 25N80W. Isolated showers and tstorms are along and just east of the trough. Fresh to locally strong SW to W winds are noted north of 29N between the trough and northern Florida, where seas are likely 5 to 7 ft. An upper-level cyclonic low-pressure area extends from 23N-31N between 70W-76W. Scattered showers and isolated tstorms are associated with it, from 22N-29N between 67W-73W. A 1019 mb surface high pressure is near 33N59W. A surface trough, the remnants of Kate, extends from 31N53W to 27N54W with isolated moderate convection in the vicinity. Fresh S winds are noted on the east side of the trough, where seas are likely 5 to 8 ft. Gentle wind speeds are noted across most of the remainder of the subtropical Atlantic, from 20N-30N between 55W-70W, and from 25N-30N between 15W-50W. Fresh trades prevail south of 24N and east of 47W. For the forecast west of 65W, fresh to strong southwest winds over the northwest part of the region will shift northeast of the area by late today. These winds are ahead of a frontal trough forecast to weaken as it moves across the northern waters W of 70W Sat through Sun night. Looking ahead, swells generated by tropical cyclone Larry are expected to propagate across the waters NE and E of the Leeward Islands Sun, likely reaching 65W Mon and Mon night. For the forecast east of 65W, Larry is forecast to strengthen to a major hurricane Fri night near 15N42W, with seas up to 38 ft. Larry is forecast to reach near 17N47W Sat night, near 20N51W Sun night, and near 23N55W Mon night. By Mon, expect large swells from 16N-30N between 45W-65W. $$ Hagen