000 AXNT20 KNHC 030932 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 532 AM EDT Wed May 3 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 0600 UTC surface analysis and satellite imagery through 0930 UTC. ...SPECIAL FEATURE... A strong cold front will be entering the NW Gulf of Mexico by early morning Thursday. Gale-force winds are expected to develop along the Tamaulipas coast north of Tampico, then spread southward toward Veracruz during the afternoon hours. The cold front will continue to move southeast Thursday through early Saturday. High pressure building over eastern Mexico behind the front will weaken thereafter allowing the gale winds to subside late Thursday night. Please refer to the High Seas Forecast product under AWIPS/WMO headers HSFAT2/FZNT02 KNHC for more details. ...ITCZ/MONSOON TROUGH... The Monsoon Trough remains over the African continent. The ITCZ extends from 05N22W to 03N37W to 03N51W. Numerous heavy showers and scattered tstms are coming off Sierra Leone and Liberia, Africa from 04N to 08N between 10W and 16W. Scattered showers and isolated tstms are elsewhere from 0N to 10N W of 16W. ...DISCUSSION... GULF OF MEXICO... Weak surface ridging dominates across the Gulf waters after the passage of a weak cold front Tuesday. The ridge is anchored by a 1017 mb high over the Florida Panhandle adjacent waters near 28N85W. The high is providing east-southeast gentle to moderate winds across the basin, except for the NW waters where a tighter pressure gradient support locally fresh winds. CIRA LPW imagery show abundant shallow moisture being advected from the Caribbean, which is supporting overcast skies and fog N of 27N W of 90W. The center of high pressure will dissipate Wednesday and southeast return flow will prevail across the Gulf in advance of the next cold front, which is expected to come off the Texas coast early Thursday morning. Gale-force winds are expected to develop behind the front in the southwest Gulf. Please refer to the special features section for further information. CARIBBEAN SEA... Middle level divergent flow along Central America support scattered to isolated showers from Honduras to Panama as well as the SW Caribbean waters S of 14N W of 79W. Diffluent flow east of the base of a middle to upper level short-wave trough just east of the Bahamas continue to support broken to overcast skies across Hispaniola with scattered to isolated showers mainly concentrated in the central and eastern Dominican Republic. Moisture inflow from South America continue to support similar skies across the SE basin and the Lesser Antilles S of 17N with most of the islands reporting showers. Water vapor imagery depict dry air subsidence elsewhere, which supports fair weather conditions. Light to moderate trades are across the basin as indicated by latest scatterometer data. This pattern is expected to continue through the next 24-48 hours. ...HISPANIOLA... Diffluent flow east of the base of a middle to upper level short- wave trough just east of the Bahamas continue to support broken to overcast skies across Hispaniola with scattered to isolated showers mainly concentrated in the central and eastern Dominican Republic. The showers are expected to taper off by Thursday morning as the trough aloft weakens and drifts eastward. ATLANTIC OCEAN... A weak cold front is over SW N Atlantic waters extending from 31N76W to southern Florida near 25N80W. Scattered to isolated showers are observed within 120 nm east of the front, including the Florida seaboard and the northern Bahamas. Southeast of the front, a surface trough moves west across the central Bahamas with possible isolated showers mainly in the windward side of the islands. A second cold front enters the NE Atlc waters near 31N25W and continues SW along 25N40W to 22N50W where it starts dissipating. Isolated showers are within 90 nm either side of the front. The remainder of the basin west of the front is under the influence of a broad area of high pressure centered by a 1025 mb high near 32N55W. Expect for the cold front over the west Atlantic to stall later today while weakening. This front is expected to dissipate late tonight. The surface trough across the Bahamas will dissipate late tonight as it loses its upper-level support. For additional information please visit http://www.hurricanes.gov/marine $$ Ramos