000 AXNT20 KNHC 262325 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 625 PM EST Tue Dec 26 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. ...ITCZ/MONSOON TROUGH... The monsoon trough enters the Atlantic Ocean near 04N06W to 03N06W. The Intertropical Convergence Zone continues from 03N06W to 00N50W. Scattered moderate convection is from 02N-10N between 24W-46W. ...DISCUSSION... GULF OF MEXICO... A weak low pressure continues over the northwest Gulf centered near 29N96W. A warm front extends eastward from the low to near 28N91W. Isolated showers are noted in the vicinity of the low/front. A surface trough extends from the low to the northeast Mexico coast near 23N98W. Scatterometer data depicts moderate to fresh easterly winds just north of the warm front, and mainly gentle to moderate southeast winds across the remainder of the western half of the Gulf. The remainder of the basin is under the influence of a surface ridge anchored by a 1034 mb high currently centered over North Carolina. The ridge is providing gentle to moderate easterly winds across the eastern half of the Gulf. The area of weak low pressure across the northwest Gulf will drift eastward over the next couple of days. The pressure gradient between the low and high pressure north of area will bring a slightly stronger northeast winds on Tuesday night into Wednesday across the northwest Gulf eventually becoming more diffuse by Thursday as the frontal wave weakens across the north-central and northeast Gulf waters. The next strong cold front is expected to emerge off the Texas and Louisiana coasts Sunday evening followed by gale-force winds. CARIBBEAN SEA... The most recent scatterometer data show moderate to fresh winds across the south-central Caribbean near the coast of Colombia, while moderate winds prevail across the remainder of the Caribbean. Patches of low-level moisture embedded in the trade wind flow are producing isolated to scattered passing showers across the Greater and Lesser Antilles from time to time. Little change in this weather pattern is expected during the next couple of days. Strong trades will pulse over the Central and southwest Caribbean through Thursday, with near gale-force nocturnal winds near the coast of Colombia tonight. Fresh to locally strong easterly winds are expected through the Windward Passage this evening. Large east swell, in the form of 7 to 9 ft seas, will reach the east Atlantic passages this evening, and continue through Thursday evening. ...HISPANIOLA... Low-topped trade wind showers will continue to move across the island from time to time. Mostly dry and stable conditions are expected to persist during the next couple of days under the influence of a mid to upper-level ridge and associated strong subsidence. ATLANTIC OCEAN... A frontal boundary extends across the west Atlantic, analyzed as a cold front from 31N64W to 29N71W, then as a stationary front from that point to 27N76W. A surface trough extends from 27N76W to 24N77W. Isolated showers are noted along these boundaries. The cold front is expected to drift eastward through Wednesday, and begin to stall and weaken on Thursday. The remainder of central and eastern Atlantic is under the influence of a surface ridge anchored by a stationary 1032 mb high centered southwest of the Azores near 35N29W. This system will undergo occasional intensity fluctuations resulting in a rather tight pressure gradient across the waters north of the ITCZ/monsoon trough between the coast of Africa and the Lesser Antilles through at least mid-week. Recent scatterometer data indicates moderate to fresh winds around the southern periphery of the ridge east of the Lesser Antilles. Seas are in the 8-11 ft range within this area of winds based on several altimeter passes. For additional information please visit http://www.hurricanes.gov/marine $$ ERA