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TROPICAL WEATHER DISCUSSION
Tropical Weather DiscussionNWS National Hurricane Center Miami FL0015 UTC Thu Dec 18 2025Tropical Weather Discussion for North America, Central AmericaGulf of America, Caribbean Sea, northern sections of SouthAmerica, and Atlantic Ocean to the African coast from theEquator to 31N. The following information is based on satelliteimagery, weather observations, radar and meteorological analysis.Based on 1800 UTC surface analysis and satellite imagery through 2000 UTC
.SPECIAL FEATURES Western and Central Atlantic Gale Warning: A stationary frontextends from 31N50W to 25.5N66W then continuing as a remnant frontal trough to the SE Bahamas. A low pressure is forecast to develop along the frontal system tonight into Thu near 29N60W. Gale force winds and rough to very rough seas are expected across the W semicircle of the low center Thu through early Fri as the low moves NE and deepens, before gradually exiting the forecast area Fri night. Peak seas under the strongest winds are anticipated to be at 13 to 18 ft by late Thu afternoon and eveningand will persist through Fri evening before subsiding as well as moving north of the area. Please read the latest High Seas and Offshore Waters Forecasts issued by the National Hurricane Center at website: https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml and https://www.nhc.noaa.gov/marine/offshores.php for more informationthis event .MONSOON TROUGH/ITCZ A monsoon trough enters the Atlantic along the Liberia coast near06N10.5W, then runs west-southwestward to 06N15.5W. The ITCZ continues from 06N15.5W to 07.5N26W to 03N46.5W to the NE of thenorthern coast of Brazil. Widely scattered moderate convection is seen S of 17N to the Equator between Africa and 37W.The eastern end of the East Pacific monsoon trough is triggeringwidely scattered showers across the Caribbean waters nearNicaragua and Panama, although thunderstorms seemed to havediminished in the past few hours per recent conventional infraredsatellite imagery .GULF OF AMERICA A surface trough reaches southward from near Corpus Christi, Texas through a 1012 mb low east of Brownsville, Texas to another 1012 mb low just southeast of Tampico, Mexico. Scattered showers and isolated thunderstorms are occurring offshore from southeastern Texas and northeastern Mexico, mainly to the east ofthese features. Farther southeast, a surface trough generating scattered showers at the south-central Gulf, including the Yucatan Channel. Moderate to fresh E to SE winds and seas of 4 to 6 ft are seen across the northwestern, west-central and eastern Gulf, including the Straits of Florida. Gentle to moderate E to SE winds with 2 to 4 ft seas prevail for the rest of the Gulf.For the forecast, a ridge will dominate the Gulf region through Thu, with winds veering to the south and southwest ahead of the next cold front, forecast to move into the NW Gulf Thu evening. This front will reach from the Florida Big Bend to near Brownsville, Texas by Fri morning, and from SW Florida to NE Mexico Fri evening, then begin to lift northward and dissipate through Sat. High pressure will move into the NE Gulf Sat night and Sun. CARIBBEAN SEA The southern end of a surface trough is causing scattered showersat the northwestern basin, including the Gulf of Honduras andYucatan Channel. Refer to the Monsoon Trough/ITCZ section for additional weather in the Caribbean Sea. Otherwise, a trade-wind regime continues across much of the Caribbean Sea. Fresh to strongENE to E winds and seas of 6 to 8 ft are present at the south- central basin offshore northern Colombia. Gentle to moderate NE to E winds and 3 to 5 ft seas are noted at the far northwestern and far southwestern basin. Moderate with locally fresh easterly winds and seas at 4 to 6 ft prevail elsewhere in the Caribbean Sea, including the lee of Cuba. SEas are locally 6 to 8 ft near NEand eastern Caribbean-Atlantic passages.For the forecast, fresh to locally strong trade winds and moderate to rough seas will prevail over the south-central Caribbean through Thu as high pressure shifts eastward into the western Atlantic. Elsewhere, moderate to fresh winds are expected,with the exception of gentle to moderate winds over the NW Caribbean. Large E swell will persist over the tropical Atlantic waters, through the Atlantic passages and into the eastern part ofthe basin through Thu night. High pressure will strengthen north of the basin Thu night into the weekend to bring a return to freshto strong trades across the central and southwest Caribbean. ATLANTIC OCEAN Please see the Special Features section at the very beginning about a Gale Warning in the western and central Atlantic.A stationary front extends from 31N50W to 25.5N66W then continuingas a remnant frontal trough to the SE Bahamas. Scattered moderate convection is evident up to 120 nm along the southern side of the frontal system, s well as north of the frontal systembetween 47W and 68W. Refer to the Monsoon Trough/ITCZ section foradditional convection in the Atlantic Basin.Fresh to now near gale-force NE to ENE winds and seas at 7 to 11 ft in large N swell are found near and north of the frontal systemeast of 68W. A 1028 mb high is to the east of the front near31N23.5W. A ridge extends southwestward from the high and ahead ofthe front to near 27N55W. Gentle to moderate anticyclonic winds and 5 to 8 ft seas are present under the ridge mainly north of 26Nand east of the front to 23W. Fresh to locally strong NE to E trades prevail across the remainder of the waters southeast-south of the ridge and frontal system, as well as offshore northern Africa. Seas are 7 to 11 ft across the area of fresh to strong winds, except higher, at 9 to 13 ft northeast of the Canary Islands and offshore far northern Africa.For the forecast W of 55W, a low pressure is forecast to develop along the frontal system tonight into Thu near 29N60W. Gale force winds and rough to very rough seas are expected across the W semicircle of the low center Thu through early Fri as the low moves NE and deepens, before gradually exiting the forecast area Fri night. Peak seas under the strongest winds are anticipated to be at 13 to 18 ft by late Thu afternoon and evening and will persist through Fri evening before subsiding as well as moving north of the area. The next cold front will move into the NW waters Fri, reach from near Bermuda to the Straits of Florida Sat morning, then stall and weaken from 31N60W to the central Bahamas Sat evening. Another cold front may move off NE Florida by Sun night. |
