000 AXNT20 KNHC 042319 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0005 UTC Fri Dec 4 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 1800 UTC surface analysis and satellite imagery through 2300 UTC. ...MONSOON TROUGH/ITCZ... The monsoon trough enters the Atlantic Ocean through Sierra Leone and continues westward to near 07N15W. The ITCZ extends from 07N15W to 06N34W to near the coast of French Guiana. A trough is analyzed within the ITCZ and extends along 39W from 04N-12N. Scattered moderate convection is from 07N-10N between 20W-30W, from 04N-12N between 30W-40W, and from 03N-06.5N between 40W- 45W. GULF OF MEXICO... A cold front extends from a 1015 mb low pressure over eastern Alabama to near 23N92W where it becomes stationary. Abundant low- level clouds with some shower activity are noted behind the front, and are banked up along the eastern slopes of the Sierra Madre Mountains in Mexico. An area of showers with embedded thunderstorms is observed ahead of the frontal boundary over the east-central Gulf reaching the Florida peninsula. Fresh northerly winds are behind the front per recent scatterometer data, with seas of 8-11 ft. These winds will persist through this evening. The northern half of the cold front will move slowly across the Gulf. By Sat afternoon, the front will extend from the SW Florida peninsula to the Bay of Campeche. South of 25N, the front will remain stationary. The cold front will weaken by Sat night. A new, stronger cold front will develop near the Mexican coast late Sat. This new front will extend from Alabama to the Bay of Campeche by Sun afternoon, and exit the SE Gulf Mon afternoon. Near gale-force NW to N winds are expected west of the new cold front on Sun. Winds and seas will diminish across the Gulf by Tue. CARIBBEAN SEA... A large area of showers and scattered thunderstorms is noted over the western Caribbean and western Cuba, including the Isle of Youth. A diffluent pattern aloft is helping to induce this convective activity that roughly covers the area N of 15N W of 80W. Abundant moisture will persist in this region, in a SE wind flow, tonight and Sat. The pressure gradient between a high pressure located W of Bermuda and low pressure over N South America is causing strong trades across the central Caribbean. The most recent satellite-derived wind data confirmed the presence of these winds. As the Bermuda High retreats northeastward well north of these waters, a reduced pressure gradient will weaken the trade winds across the Caribbean through Mon, with peak winds of primarily fresh E trades just north of Colombia. A cold front should reach the Yucatan Channel on Mon afternoon, extend from Cuba to Honduras Tue afternoon, and perhaps move to the SW Caribbean on Wed afternoon. Increasing winds and seas are expected in the wake of the front over the NW Caribbean, including the Yucatan Channel and the Gulf of Honduras Mon night into Tue. ATLANTIC OCEAN... A cold front extends from a 1017 mb low pressure center near 31N57W to 26N61W, then continues as a stationary front across the SE Bahamas into to eastern Cuba. This front will dissipate by Sat. Patches of low level clouds are noted along the frontal boundary. Fresh NE winds are still seen behind the front over the SE Bahamas. A 1028 mb surface high located W of Bermuda follows the front and dominates most of the SW N Atlantic, including Florida and the Bahamas. The high pressure will move northeastward ahead of another cold front moving off the NE coast of Florida. Strong S to SW winds will develop east of N Florida tonight ahead of the front. This system will extend from 31N74W to central Florida on Sat afternoon, then weaken from 29N65W to the central Bahamas on Sun afternoon. A developing low pressure system will sweep a new, strong cold front across the W Atlantic Mon and Tue. Strong to near gale SW winds are expected ahead of the new front with fresh to strong NW winds behind it. Farther E, and area of showers and thunderstorms persists over the Central Atlantic, extending from 18N-25N between 42W-48W. This convective activity is the result of an upper level low spinning near 24N46W. An upper-level trough extends from the low to near 04N48W. Upper diffluence ahead of this trough is helping to support convection near the ITCZ and the aforementioned trough along 39W. At the surface, another trough, likely reflection of this low, is analyzed from 30N52W to 20N48W. Fresh to strong winds are on the E side of the trough axis due to the pressure gradient between the trough and strong high pressure located well N of the area. A ridge dominates the eastern Atlantic. $$ GR