000 AXNT20 KNHC 041613 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1113 AM EST Mon Dec 4 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 1200 UTC surface analysis and satellite imagery through 1515 UTC. ...SPECIAL FEATURES... A 1010 mb low centered N of the discussion area near 37N60W is forecast to deepen through Tuesday while moving E-SE with a cold front expected to bring near gale to gale force W to NW winds late tonight into Tuesday generally N of 28N W of the front to 59W. Winds are forecast to diminish below gale force by late Tuesday night. See the latest NWS High Seas Forecast under AWIPS/WMO headers MIAHSFAT2/FZNT02 for more details. ...ITCZ/MONSOON TROUGH... The monsoon trough extends from the African coast near 09N13W to 08N18W. The Intertropical Convergence Zone axis extends from 08N18W to 04N34W to 02N50W. Widely scattered moderate convection is from 01N-03N between the Prime Meridian and 05W...and from 04N-08N between 09W-19W. Scattered moderate convection is from 03N-07N between 20W-47W. ...DISCUSSION... GULF OF MEXICO... West-northwesterly flow aloft prevails over the Gulf basin this afternoon with water vapor imagery indicating a weak mid-level shortwave trough over the NW Gulf in the vicinity of 29N94W. The mid-level energy is generating a few isolated showers across the NW Gulf waters and portions of interior Louisiana within moderate to fresh S-SE return flow across the western Gulf. Otherwise... conditions across the remainder of the basin are relatively tranquil as a surface ridge anchored by a 1029 mb high centered across the Mid-Atlc coast extends across the central and eastern waters...as well as the Florida peninsula. Gentle to moderate E-SE winds prevail elsewhere within the southwestern periphery of the ridge and are expected to persist through Tuesday night. The next cold front is forecast to emerge off the Texas and Louisiana coasts Tuesday night introducing strong to near gale N-NE winds to the western and north-central waters as the front moves S-SE into Wednesday. CARIBBEAN SEA... Generally westerly upper level flow continues over the Caribbean basin this afternoon with only slightly divergent flow noted on water vapor imagery over the southwestern waters. A broad area of low pressure focused in the vicinity of coastal Colombia and Panama along with the divergence aloft is generating scattered showers and widely scattered tstms S of 12N between 74W-84W. This area of low pressure troughing extends NE across the central and eastern portion of the basin highlighted by a surface trough extending from 12N71W to 17N68W. Embedded within fresh trades across the central Caribbean...low-level moisture convergence in the vicinity of the trough is generating widely scattered showers and isolated tstms from 13N-17N between 68W-77W. Farther east... another surface trough lies to the E of the Lesser Antilles from 11N60W to 17N57W. Increased cloudiness accompanies this surface trough as it continues to move westward with isolated showers occurring S of 17N E of 65W. Fresh to strong trades are forecast across a large portion of the basin between 64W-82W for much of next week. High pressure will anchor across the SW North Atlc region through the week ahead and the associated pressure gradient is expected to impact the basin with these enhanced trades. ...HISPANIOLA... Generally clear skies and fair weather conditions prevail across the island as dry westerly flow aloft remains in place over the area. A stationary front boundary lies to the NE in the adjacent coastal waters from 20N71W to beyond 23N60W. Isolated showers and possible isolated tstms are expected to remain N of 19N this afternoon into the evening. Winds across the island are expected to increase Monday night into Tuesday as high pressure builds in across the SW North Atlc. ATLANTIC OCEAN... Westerly flow aloft prevails over much of the SW North Atlc with a pair of middle to upper level troughs noted on water vapor imagery N of the discussion area in the vicinity of 36N62W and 39N39W. While these two areas of middle to upper level energy support a broad area of lower pressure and complex low centers N of the area...the primary cold front extends into the area near 32N35W SW to 24N50W then becomes stationary to 23N60W to the northern coast of Hispaniola near 20N71W. Scattered showers and isolated tstms are occurring N of 29N between 30W and the front...and from 22N-25N between 52W-68W mostly along and N of the stationary front. A secondary dissipating cold front extends from 32N44W W-SW to 27N60W. Otherwise...the remainder of the SW North Atlc is under the influence of a a surface ridge anchored by a 1029 mb high centered across Virginia. Mostly gentle to moderate NE to E winds prevail W of 65W. Lastly...the remainder of the eastern Atlc is under the influence of a surface ridge with axis extending from W of the Iberian peninsula near 39N13W SW to 20N40W. For additional information please visit http://www.hurricanes.gov/marine $$ HUFFMAN