000 AXNT20 KNHC 171940 CCA TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 240 PM EST Tue Dec 17 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. ...Corrected third paragraph of Gulf of Mexico section... Based on 1200 UTC surface analysis and satellite imagery through 1720 UTC. ...SPECIAL FEATURES... A cold front is along 30N87W 19N95W. Expect NW-to-N gale-force winds, and sea heights ranging from 8 feet to 10 feet, within 22N96W to 19N96W to 23N98W to 24N98W to 24N95W to 22N96W. The gale-force wind conditions are forecast to continue until at least Thursday morning, for the next 48 hours or so. Please read the latest HIGH SEAS FORECAST: MIAHSFAT2/FZNT02 KNHC, the latest OFFSHORE FORECAST: MIAOFFNT4/FZNT24 KNHC, or go to the website https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml, everything from the NWS National Hurricane Center, for more details. ...MONSOON TROUGH/ITCZ... The monsoon trough passes through the coastal sections of Sierra Leone near 09N13W to 06N15W and 01N17W, westward, to the Equator along 35W, to 01S37W. Precipitation: widely scattered moderate to isolated strong from 05N southward between 10W and 30W. More precipitation: Widely scattered moderate to isolated strong also is within 120 nm of the coast of Brazil and French Guiana, between 49W and 55W. Isolated moderate is within 600 nm to the ENE of the coast of French Guiana. GULF OF MEXICO... A cold front passes through the Florida Panhandle, into the north central Gulf of Mexico, into the west central sections of the Gulf, to the coast of Mexico near 18.5N96W, and inland northwestward into Mexico. Precipitation: scattered moderate to isolated strong within 135 nm to the southeast of the cold front from 25N northward. Isolated moderate is elsewhere within 120 nm to the SE of the cold front from 20N to 25N. The current strong cold front will move southeastward across the Gulf of Mexico. The front will extend from Tampa Bay Florida to the central Yucatan Peninsula tonight, before moving southeast of the area on Wednesday. Northerly gale-force winds and very large seas will prevail behind the front, mainly W of 90W, through late Wednesday. The wind speeds and the sea heights will diminish in the central and western Gulf of Mexico on Thursday and Thursday night. Strong NE to E winds will continue in the Straits of Florida after the frontal passage, from Thursday through Friday night. It is possible that low pressure may develop in the eastern Gulf of Mexico on Friday night, and move across Florida during the upcoming weekend. Strong northerly winds, today and on Wednesday, behind the front, will result in heavy rainfall amounts between the Mexican States of Veracruz and Tabasco/Campeche, from today into Wednesday. The maximum rainfall amounts may range from 4 inches to 6 inches. Additional rainfall amounts may range from 1 inch to 3 inches on Wednesday and Thursday. The most intense rainfall is expected on Wednesday and on Thursday, from NW Honduras to central Guatemala (Puerto Barrios), where a maximum of 6 inches to 8 inches is likely. It is possible that localized maxima may range from 10 inches to 12 inches, due to strong topographical forcing. CARIBBEAN SEA... The GFS model for 500 mb and for 700 mb shows broad cyclonic wind flow, with an inverted trough, from the SW corner of the Caribbean Sea within 300 nm of the coast of Colombia, and within 150 nm to the north of Honduras. Precipitation: warming cloud top temperatures and dissipating/weakening precipitation, covers the SW corner of the area from 12N southward from 76W westward. Widely scattered moderate to isolated strong from 16N to 23N in the Yucatan Channel, between 80W and 87W. High pressure, to the northeast of the region, will maintain fresh to strong trade winds and building seas, from the tropical north Atlantic Ocean from 55W westward, to the south central Caribbean Sea through Saturday. A strong cold front will move through the Yucatan Channel late on Wednesday. The front will move across the far NW Caribbean Sea, before stalling and weakening from central Cuba to central Honduras by late Thursday. Fresh to strong northerly winds will accompany the front. It is possible that a second cold front may move across the southern Gulf of Mexico, and approach the NW Caribbean Sea by late Saturday. The precise timing remains uncertain at this time. ATLANTIC OCEAN... A stationary front passes through 32N50W to 30N40W to 28N60W. The front becomes dissipating stationary from 28N60W to 28N63W and 26N74W. Precipitation: isolated moderate within 30 nm on either side of the line from 31N40W to 33N36W to 34N33W. Broken to overcast multilayered clouds and possible rainshowers are from 27N to 30N between 40W and 60W. Broad upper level cyclonic wind flow and comparatively drier air in subsidence cover the area that is from 10N to 20N between 40W and 60W. High level clouds are curving anticyclonically, from 10N40W to 20N30W to 23N25W, and into the southern sections of the Western Sahara. The current dissipating stationary front will continue to become weaker with time. A strong cold front will move off the southeast U.S.A. coast late tonight. The strong cold front will extend from 31N70W to western Cuba on Wednesday night, and then from 27N65W across the central Bahamas to central Cuba on Thursday night. Strong N to NE winds and building seas are expected across much of the forecast waters following the frontal passage. The front will stall gradually, in the central waters on Friday and Friday night. It is possible that fresh to strong easterly winds may persist on Saturday, from the northern Bahamas to northeast Florida, as low pressure develops in the Gulf of Mexico. The exact timing and location are still uncertain. $$ MT/Hagen