000 AXNT20 KNHC 282314 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0005 UTC Mon Sep 28 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 0000 UTC surface analysis and satellite imagery through 2300 UTC. ...SPECIAL FEATURES... ...GULF OF MEXICO GALE WARNING... A strong cold front has entered the Gulf waters and now extends from southwestern Louisiana to inland Texas near Brownsville. A large area of scattered showers and thunderstorms are noted ahead of the frontal boundary, covering mainly the waters from 23N-28N W of 85W. 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 on Tue. Seas are forecast to build to 18 or 19 ft over the SW Gulf by Tue afternoon and evening. A secondary front 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 SE Gulf by the end of the week. These winds may reach strong speeds on Sat and Sat night along with building seas. Please see the latest High Seas Forecast at https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml for more details. ...TROPICAL WAVES... A tropical wave is approaching the west coast of Africa, and will likely be added to the 0000 UTC surface map. The Hovmoller Diagram indicates the westward propagation of the wave, and satellite imagery shows a cluster of moderate convection from 10N-13N between 12W-16W. A tropical wave axis is along 37W from 03N-18N, moving W at 10-15 kt. Scattered moderate convection is from 08N-11N between 35W-41W. A tropical wave axis is along 57W from 03N-18N, moving W at 10-15 kt. Scattered moderate convection is from 10N-16N between 50W-60W. A tropical wave moving across the eastern Caribbean is currently located along 70W, moving W at 10 kt. Scattered to numerous moderate convection is noted behind the wave from 11N-18N between the Lesser Antilles and the wave axis. The wave is helping to induce convection over Puerto Rico and regional waters as well as over Dominican Republic. 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 12N16W to 09N30W. The ITCZ extends from 08N41W to 11N50W. Besides the convection mentioned in the tropical wave section, scattered moderate convection is noted from 08N-10N between 41W-46W. Gulf of Mexico... A strong cold front is moving across the Gulf of Mexico. This front is forecast to produce gale-force winds. Refer to the Special Features section for more details. A 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. CARIBBEAN SEA... A tropical wave is moving over the E Caribbean. Please refer to the Tropical Waves section above for details. 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. Looking ahead, a broad area of low pressure is expected to form over the western Caribbean Sea in a few days. Environmental conditions are expected to be conducive for some gradual development thereafter, and a tropical depression could form late this week or this weekend while the system moves slowly west- northwestward over the northwestern Caribbean Sea. The latest Tropical Weather Outlook states that this system has a medium chance of tropical cyclone formation through 5 days. Refer to the latest Tropical Weather Outlook at www.hurricanes.gov for more details. ATLANTIC OCEAN... Refer to the section above for details on the tropical waves moving across the tropical Atlantic. Convection continues to flare-up over Florida due to abundant moisture and a diffluent pattern aloft. The cold front now over the Gulf of Mexico is forecast to reach South Florida on Wed. High pressure of 1031 mb located W of the Azores dominates the area. This system is maintaining generally 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 cold front will reach the southeastern U.S. coast Tue night and move over the northwest part of the area through Wed. The front will begin to weaken as it reaches from near 31N74W to South Florida by Wed night and become stationary from 31N73W to the Straits of Florida by late Thu through Fri night, then diffuse Sat. Scattered showers and thunderstorms are expected ahead of the cold front. $$ GR