000 AXNT20 KNHC 251701 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1201 PM EST Wed Dec 25 2019 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 1200 UTC surface analysis and satellite imagery through 1640 UTC. ...SPECIAL FEATURES... ...CENTRAL ATLANTIC GALE WARNING... A 1007 mb low is near 31N54W, with a developing cold front extending SW from the low to 27N59W. Gale force winds are currently occurring in the eastern semicircle of the low, north of 29N. Gales will continue in the eastern and southern quadrants of the low, and east of the cold front, north of 28N, as the system moves eastward and then east-northeastward during the next 24 hours. Gales are forecast for the area north of 28N between 40W- 53W this afternoon and evening. Thursday morning, gales are expected north of 29N between 35W-43W. Winds will decrease to below gale force, south of 32N, by late Thursday afternoon. Seas of 10-14 ft will develop this afternoon, with 12-16 ft expected by this evening. Please refer to the latest NWS High Seas Forecast issued by the National Hurricane Center under AWIPS/WMO headers MIAHSFAT2/FZNT02 KNHC for further details. ...MONSOON TROUGH/ITCZ... The monsoon trough extends from the west coast of Africa near the Sierra Leone/Liberia border near 07N11W to 05N15W. The ITCZ extends from 05N15W to 04N38W to the coast of NE Brazil near 00N50W. Scattered moderate with embedded isolated strong convection is seen within 75 nm either side of the ITCZ between 25W-36W. Isolated moderate convection is within 75 nm of the ITCZ between 36W-46W. GULF OF MEXICO... A 1016 mb surface high is over the western Gulf near 25N93W. Mid- upper level ridging covers the eastern and central Gulf of Mexico. A surface trough is analyzed from 23N86W to 27N89W, with little to no precipitation noted. The latest ASCAT pass shows moderate E winds east of the surface trough. Gentle anticyclonic winds prevail west of the surface trough. The weak surface trough that is currently from 23N86W to 27N89W will drift westward across the central and western Gulf today through Fri, with fresh to locally strong E to SE winds east of the trough. A cold front is forecast to enter the NW Gulf Sat night into Sun followed by fresh to strong northerly winds and building seas. CARIBBEAN SEA... A cold front extends from Haiti near 20N72W to 17N76W. A stationary front extends from 17N76W to 13N79W, dissipating to 12N80W. Isolated showers are along the front. Isolated tstorms are seen over the Dominican Republic. In the far SW Caribbean, the east Pacific monsoon trough is inducing numerous moderate with embedded isolated strong convection from 8.5N-11N between 79W-83W, including over western Panama and far SE Costa Rica. The latest ASCAT pass shows strong SE winds in the SE Caribbean from 12N-14N between 65W-68W, but these winds should decrease to fresh this afternoon. Gentle winds currently prevail across the central Caribbean between 70W and the front. Fresh to strong N winds are seen between the front and the coasts of Nicaragua and Costa Rica. The front extending from western Haiti to 13N79W will dissipate by tonight. Fresh to strong N winds are expected west of the front to the coast of Nicaragua today. Winds and seas will diminish across the central Caribbean on Thu, then increase again on Fri as high pressure builds N of area. ATLANTIC OCEAN... Refer to the section above for details on the Gale Warning currently in effect for the central Atlantic. A 1003 mb surface low is centered near 29N69W. A surface trough extends westward from the low to Stuart Florida, with little to no shower activity noted along the trough. An occluded front extends from the low to a triple point near 30N65W. A cold front extends from 30N65W to 25N66W to 21N71W to Haiti near 20N72W. A warm front extends from 30N65W to 27N59W. The surface low and front are being supported by a strong mid-upper level low near 27N69W. Ahead of the cold front, numerous moderate with embedded scattered strong convection is seen within 60 nm either side of a line from 27N60W to 24.5N63W to 21.5N66.5W, as of 25/1600 UTC. These strong thunderstorms are likely producing wind gusts to gale force. Scattered moderate convection is elsewhere within the area bounded by 32N65W to 21N68W to 32N49W to 32N65W. The latest ASCAT pass shows 25-30 kt NE winds, north of a line from 31N66W to 30N69W to 28N75W. An altimeter pass from 25/1026 UTC shows wave heights of 10-12 ft from 30N-32N near 72W-73W. Farther E, a 1024 mb surface high is near 30N31W, with a surface ridge axis extending west-southwestward from the high to the Lesser Antilles. An east Atlantic cold front extends from 32N16W to 25N24W. Scattered showers are seen over water from 24N-32N between 10W-22W. The low pressure system centered near 29N69W will continue to affect the forecast waters through Thu, then shift eastward. The pressure gradient between the low pres and high pres building across the US eastern seaboard will support fresh to strong NE to E winds, from 25N-30N on Thu, and from 21N-27N on Fri, between 60W and the NW Bahamas. $$ Hagen