000 AXNT20 KNHC 280005 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 704 PM EST Wed Nov 27 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 1800 UTC surface analysis and satellite imagery through 2330 UTC. ...SPECIAL FEATURES... ...Caribbean Sea GALE WARNING... Winds to gale force are expected this evening and overnight for portions of the waters near the coast of Colombia along with seas of 11-13 ft. Winds will then drop below gale force Thursday morning. Please refer to the Atlantic Ocean High Seas Forecast under the AWIPS header MIAHSFAT2 and under the WMO header FZNT02 KNHC for more details. ...Atlantic Ocean GALE WARNING... A cold front traversing the Atlantic waters will bring gale force winds north of 30N between 52W-60W Thursday night and Friday morning. Expect gale force SW winds prior to the frontal passage, then shifting to NW following the frontal passage. Seas will reach 12-16 ft in the area by early Friday morning. Please refer to the Atlantic Ocean High Seas Forecast under the AWIPS header MIAHSFAT2 and under the WMO header FZNT02 KNHC for more details. ...TROPICAL WAVES... A Caribbean Sea tropical wave is along 69W/70W, from 18N southward, moving W at 10 to 15 knots. Precipitation: isolated moderate within 150 nm to the east of the tropical wave, and within 60 nm to the west of the tropical wave, from 14N southward. A western Caribbean Sea tropical wave is along 87W, from 21N southward, moving W at 10-15 knots. Precipitation: Scattered moderate and isolated strong from 10N-20N between 80W-90W, including over portions of Central America. ...MONSOON TROUGH/ITCZ... The monsoon trough passes through the coastal areas of southern Sierra Leone near 07N12W, to 05N16W. The ITCZ continues from 05N16W to 03N42W. Precipitation: isolated moderate within 330 nm to the north of the ITCZ. GULF OF MEXICO... As of 27/2100 UTC, a cold front extends from the western FL panhandle near 31N85W to 29N89W to 27N94W, continuing as stationary to Brownsville TX to a 1013 mb low over NE Mexico near 25N98W. The cold front stands out well in visible satellite imagery, with a distinct line of clouds. Scattered moderate rainshowers are offshore southern TX and northeast Mexico from 24N-27.5N within 120 nm of the coast. Surface ridging extends over the Florida peninsula into the E Gulf. The ASCAT pass from earlier on Wednesday shows strong to near gale NE winds behind the front within 100 nm of the Texas and Louisiana coasts. The eastern portion of the cold front will reach the FL peninsula by Thu afternoon, while the western portion will retreat northward as a warm front back over Texas. As the front dissipates Friday, quiescent conditions will prevail Fri and Sat as weak ridging builds in north of the Gulf. On Sun and Mon a new cold front will move across the N and central Gulf, with enhanced NW to N winds building in behind the front. CARIBBEAN SEA... Gale force winds are expected tonight near the coast of Colombia. See section above for details. Two tropical waves are over the Caribbean. See section above for details. Relatively dry air and no significant precipitation are over the basin, other than that due to the tropical waves. The ASCAT pass from late Wednesday morning shows strong trades over the central Caribbean from 10N-17N between 71W-80W, with locally near gales closer to the coast of Colombia. A moderate pressure gradient south of the Bermuda high will be forcing strong to gale force winds across the S central Caribbean and to near the coast of Colombia late tonight into early Thu. From Thu afternoon through at least Mon, a large extratropical cyclone east of the mid-Atlantic states will reduce the gradient and weaken the NE tradewinds to fresh breeze or less across the Caribbean. On Sat large N swell will begin impacting the offshore Atlantic waters east of the Lesser Antilles and continue through at least Mon night. ATLANTIC OCEAN... Gale-force winds are forecast Thu night and early Fri north of 30N between 52W-60W. Please read the SPECIAL FEATURES section for more details. Surface ridging prevails from 20N-33N west of 60W. A stationary front passes through 32N48W to a 1014 mb low near 26N54W. A surface trough extends SW from the low to 21N60W. Scattered to numerous moderate convection is seen from along and within 180 nm east of the front and trough from 22N-30N. Farther E, a warm front extends from a 1018 mb low near 28N41W to 31N39W to 31N35W to 27N33W. Isolated showers are possible near this boundary. Weakening high pressure over the western Atlantic will shift eastward through early Thu in response to an approaching cold front. This cold front will quickly move across the area Thu and Fri with enhanced NW to N wind building in behind the front. Associated large NW to N swell will spread across the area late Fri and on Sat and diminish by early Mon. Significant wave heights in excess of 12 ft are expected north of a line from 31N73W to 28N68W to 25N60W to 24N50W to 31N36W Fri and Sat. Significant wave heights to 17 ft are forecast north of 29N between 50W-62W. After winds become quiescent on Sat to early Sun, another cold front will reach the far northwest waters Sun night and move across the area through Mon. Strong to possibly gale force winds are expected on either side of the front northeast of the Bahamas early next week. $$ Hagen