000 AXNT20 KNHC 112304 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 604 PM EST Sat Nov 11 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 2115 UTC. ...ITCZ/MONSOON TROUGH... The monsoon trough extends from the African coast near 12N16W to 10N20W. The Intertropical Convergence Zone axis extends from 10N20W to 08N40W to 06N53W. Scattered moderate convection is from 05N-12N between 23W-32W. Isolated moderate convection is within 120 nm either side of a line from 08N51W to 15N34W. ...DISCUSSION... GULF OF MEXICO... Water vapor imagery indicates an upper level trough axis extends from over the SW North Atlc and central Florida peninsula into the central Gulf near 26N90W then southward to a base over southern Mexico near 17N93W. The troughing over the Gulf remains relatively tranquil...however supports a cold front across the SW North Atlc waters to the Florida peninsula near 27N80W then northwestward to the Florida panhandle near 30N84W. This backdoor cold front will bring stronger...fresh to strong...E-NE winds to the eastern Gulf overnight into Sunday. By Sunday night...the front is expected to weaken somewhat with moderate to fresh NE winds prevailing Monday and Tuesday. Otherwise...a surface trough with widely scattered showers is analyzed along the Mexico coast from 19N95W to 25N97W. The shallow shower activity remains generally W of 95W this evening. CARIBBEAN SEA... Generally broad lower pressure is noted across much of the Caribbean this evening focused on a 1007 mb low centered off the coast of Nicaragua near 13N82W in the western waters. A surface trough extends N-NE from the low to 18N81W. Water vapor imagery indicates the surface low and troughing is supported aloft by mid- level energy stretching from the Windward Passage region SW to the waters SW of Jamaica near 16N80W. In addition...a favorable divergent environment remains over the western and central Caribbean...including the Windward Passage and Hispaniola. As a result...scattered showers and widely scattered tstms are occurring primarily N of 14N between 66W-88W...however a few isolated showers and tstms are occurring S of 13N between 79W- 84W. This synoptic pattern will be slow to modify through Monday as the upper level troughing over the Gulf of Mexico and SW North Atlc will be slow to weaken into early next week. Otherwise... moderate to occasional fresh trades E of 75W will persist. ...HISPANIOLA... Scattered showers and isolated tstms continue across the island this evening as the region remains in a favorable middle to upper level divergent environment within generally west-southwesterly flow aloft. Upper level troughing is expected to persist to the NW over the SE Gulf of Mexico and SW North Atlc through Sunday night with persistent convection expected across the island...adjacent coastal waters...and much of the north-central Caribbean Sea. Potential hazards of localized flooding and life-threatening mud slides are possible...especially if stronger convection develops during peak daytime heating and instability Sunday and Monday. ATLANTIC OCEAN... A cold front extends across the SW North Atlc from 32N64W near Bermuda SW to 28N72W then to the Florida coast near 27N80W. A pre-frontal surface trough is analyzed to the E of the front from 28N67W to 31N64W. While only a few isolated showers are possible in association with the cold front...low-level moisture convergence in the vicinity of the surface trough and a favorable divergent environment aloft are generating scattered showers and isolated tstms from 19N-28N between 59W-75W...and from 28N-33N between 56W-67W. To the east...another surface trough extends from 20N34W to 28N30W supported aloft by a broad middle to upper level low centered near 30N35W. Widely scattered showers and isolated tstms are noted from 24N-33N between 26W-37W. The surface trough remains within the southern periphery of a surface ridge anchored by a 1034 mb high centered NE of the Azores near 42N21W. For additional information please visit http://www.hurricanes.gov/marine $$ HUFFMAN