000 AXNT20 KNHC 240003 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 703 PM EST Thu Nov 23 2017 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 2315 UTC. ...SPECIAL FEATURES... A 998 mb low is N of the area over the E Atlantic near 35N34W. A cold front extends from 31N28W to beyond 36N40W. Gale force winds are N of 29.5N between 28W-39W. Seas are 10-18 ft. Gale force winds are to diminish to 30 kt on 24/1200 UTC. See the latest NWS High Seas Forecast under AWIPS/WMO headers MIAHSFAT2/FZNT02 KNHC for more details. A 1007 mb low is N of the area over the W Atlantic near 33N62W with the associated cold front extending SW to near 27N67W. The existing pressure gradient remains strong within the NE and E quadrants of the low generating near gale to gale force S-SW winds N of 30N between 59W-62W. Seas are 9-12 ft. These conditions will persist for the next six hours. See the latest NWS High Seas Forecast under AWIPS/WMO headers MIAHSFAT2/FZNT02 KNHC for more details. ...ITCZ/MONSOON TROUGH... The monsoon trough extends from the African coast near 10N14W to 07N20W. The Intertropical Convergence Zone extends from 07N20W to 07N40W to 08N52W. A surface trough is analyzed W of the ITCZ from 13N54W to 06N58W. Scattered moderate to isolated strong convection is from 04N-10N between 20W-35W. ...DISCUSSION... GULF OF MEXICO... As of 2100 UTC, a 1008 mb low is centered N of Tampa Florida near 28N82W. A cold front extends SW from the low to the Yucatan Peninsula near 19N91W. A warm front extends NE from the low to beyond 31N79W. Isolated moderate convection is within 180 nm of the fronts, to include a large portion of the Florida Peninsula. A 1020 mb high is centered over S Texas near 28N99W producing mostly fair weather over the W Gulf of Mexico W of 90W. In the upper levels a large trough is over the Gulf of Mexico with axis extending from the Florida Panhandle to the Bay of Campeche. The trough is supporting the frontal system over the E Gulf. Strong subsidence is W of the upper level trough axis, while upper level moisture is E of the trough. Expect in 24 hours for the cold front to extend from S Florida to W Cuba with convection. CARIBBEAN SEA... Isolated moderate convection and scattered showers are over the NW Caribbean and W Cuba due to prefrontal activity from the E Gulf of Mexico front. Further S, a surface trough is over the SW Caribbean from 16N80W to N Colombia near 10N75W. Isolated moderate convection is within 180 nm of the trough. In addition, the eastern extent of the Eastern Pacific monsoon trough extends over Costa rica and Panama producing scattered moderate convection. In the upper levels, upper level diffluence is over the NW Caribbean enhancing convection. A small upper level high is centered over the E Caribbean near 13N66W with strong subsidence E of 70W. Expect showers and convection to persist over the Caribbean between 75W-85W for the next 24 hours. ...HISPANIOLA... Clear skies and fair weather is over the Island. These conditions will deteriorate Friday as a weak surface trough currently over the NE Caribbean moves west across the Island producing isolated to scattered showers. ATLANTIC OCEAN... A warm front extends from 31N79W SW to a 1008 mb low N of Tampa Florida. Scattered moderate convection is within 120 nm of the front. Further E, an W Atlantic low is centered near 33N62W with associated cold front and Gale. See above. Scattered showers are within 120 nm E of the front. Over the E Atlantic, a cold front slices across northern portions of the discussion area from 31N28W W-SW to 26N40W to 26N49W. Scattered showers are within 90 nm of the front. A E Atlantic gale is associated with this front. See above. Lastly, a weak 1014 mb low is centered near 19N45W. Scattered showers are within 180 nm of the N semicircle. For additional information please visit http://www.hurricanes.gov/marine $$ Formosa