000 AXNT20 KNHC 291009 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1205 UTC Tue Sep 29 2020 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 32N. The following information is based on satellite imagery, weather observations, radar and meteorological analysis. Based on 0600 UTC surface analysis and satellite imagery through 1000 UTC. ...SPECIAL FEATURES... ...GULF OF MEXICO GALE WARNING... A strong cold front has entered the Gulf waters and now extends from 30N86W to 21N97W. Scattered moderate to isolated strong convection is within 120 nm of the front. The front will reach the SE Gulf waters Wed and the Straits of Florida by Wed evening. In the wake of the front, strong northerly winds are forecast in the western half of the basin, with gale force winds expected west of 95W starting at 29/12 UTC. Seas are forecast to build to 18 ft over the SW Gulf by this afternoon/evening. These conditions will dissipate by Wed morning. Please see the latest High Seas Forecast at https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml for more details. ...TROPICAL WAVES... A tropical wave has been introduced to the analysis, with axis along 21W from 02N-15N. The wave is moving west at about 10-15 kt. Scattered showers are noted in the vicinity of this wave. A tropical wave axis is along 41W from 01N-15N, moving W at 10-15 kt. Scattered moderate convection is from 08N-14N between 40W- 48W. A tropical wave axis is along 60W from 04N-20N, moving W at 10-15 kt. Scattered moderate to isolated strong convection is from 14N- 19N between 53W-62W. A tropical wave moving across the central Caribbean is currently located along 73W, moving W at 10 kt. Scattered moderate convection noted behind the wave's axis affecting Puerto Rico, Hispaniola, and adjacent waters. This wave will continue moving westward across the basin through the period accompanied by active weather and enhanced winds along with building seas. This feature is expected to become part of a broad low pressure area over the western Caribbean in a few days. ...MONSOON TROUGH/ITCZ... The monsoon trough extends from the coast of Africa near 10N14W to 06N28W. The ITCZ extends from 06N28W to 08N39W. The ITCZ resumes W of a tropical wave near 08N43W to 04N51W. Besides the convection mentioned in the tropical wave section, no significant convection is noted near these boundaries at this time. Gulf of Mexico... Refer to the section above for details on the Gale Warning currently in effect for the SW Gulf. A surface ridge from the Atlantic extends across Florida into the eastern Gulf. The most recent scatterometer data depict light to gentle winds over the eastern Gulf, and gentle to moderate southerly winds ahead of the front. Fresh to strong northerly winds follow the front. Looking ahead, in the wake of the current front, strong northerly winds are expected in the western half of the basin, with gale force winds expected west of 95W this morning. A secondary frontal boundary will drop southward to the northern Gulf early on Fri and reach the far southwestern Gulf by Fri evening. Strong high pressure will build in behind this front. The pressure gradient between the front and broad low pressure that is expected to form over the western Caribbean by the end of the week is expected to freshen the northeast winds over most of the southeastern Gulf by the end of the week. These winds may reach strong speeds on Sat along with building seas. CARIBBEAN SEA... A tropical wave is moving over the central Caribbean, while another one is approaching the Lesser Antilles. Please refer to the Tropical Waves section above for details. Presently, scattered moderate convection is noted overt eh south- central Caribbean south of 12N between 78W-82W. Scatterometer data depicts light to moderate trade winds across most of the basin except between 60W-70W, where moderate to fresh winds prevail. Moderate to fresh trade winds over the central Caribbean will increase to fresh to strong speeds by mid-week. Moderate winds will continue elsewhere, except for gentle winds over the northwestern Caribbean. ATLANTIC OCEAN... Refer to the section above for details on the tropical waves moving across the tropical Atlantic. Surface ridging prevails across the basin, anchored by a 1031 mb high is centered over the central Atlantic near 39N45W. Weak high pressure over the western Atlantic is maintaining gentle to moderate winds across the area. The high pressure will begin retreat eastward through Wed in response to a cold front that will be moving across the southeastern U.S. This front will reach the southeastern U.S. coast tonight and move over the northwest part of the area through Wed. The front will weaken through the end of the week. Scattered showers and thunderstorms are expected ahead of the cold front. $$ ERA