817 AXNT20 KNHC 270524 TWDAT 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 31N. The following information is based on satellite imagery, weather observations, radar and meteorological analysis. Based on 0000 UTC surface analysis and satellite imagery through 0500 UTC. ...SPECIAL FEATURES... Gale Warning E of 35W: A gale-force 995 mb low pressure system centered near 34N25W, or about 500 nm northwest of the Canary Islands, is forecast to move toward the south-southeast to near 30N23W over the next 24 hours while weakening some. Gale-force winds will occur in its western semicircle this morning from 30N-31N between 25W-30W, in the marine zone Irving. Winds will diminish below gale force by this afternoon, as the low pressure system weakens. Wave heights of 15-20 ft are expected today where the gales occur. Please read the latest High Seas Forecast issued by Meteo-France at website http://weather.gmdss.org/II.html for details. ...MONSOON TROUGH/ITCZ... The monsoon trough extends from the coast of Guinea near 09N13W to 03N19W. The ITCZ continues from 03N19W to 00N36W to the coast of Brazil near 02S44.5W. Numerous moderate and scattered strong convection is noted from 03S-08N between 13W-17W. Scattered moderate convection is from 04S-03N between 24W-32W. Isolated moderate convection is occurring from 03S-01N west of 36W to the coast of South America. GULF OF MEXICO... Surface ridging prevails across most of the basin, anchored by a 1020 mb high pressure centered near 27N92W. Recent ASCAT satellite wind data show gentle wind speeds across much of the Gulf. However, fresh W winds are occurring in the NE Gulf. These winds are likely being induced by an east-west oriented cold front, currently situated across the Florida Panhandle. Seas are 2-4 ft in the eastern Gulf and 1-3 ft in the western Gulf. The highest seas are found in the Yucatan Channel, currently estimated at 4 to 5 ft. For the forecast, the cold front over the Florida Panhandle will sink southward across N Florida early this morning. It is expected to cause moderate to fresh winds across the E Gulf through this morning. In its wake, the 1020 mb high currently over the western Gulf will move eastward across the northern Gulf today, allowing for moderate to fresh return flow to become established over the western and S central Gulf by this evening. Toward mid-week, strong with locally near-gale southerly flow and rough seas will develop across much of the Gulf ahead of another cold front that will approach the Texas coast. CARIBBEAN SEA... A cold front extends from eastern Cuba near 20N77W to 20N79W, where the front becomes stationary, passing through the Cayman Islands and ending near 17.5N85W. Scattered clouds with possible isolated showers are near the front. A secondary front, mentioned in the previous discussion, has now dissipated. Mainly moderate, with possible localized fresh north to northeast winds are located to the northwest of the front, according to the latest ASCAT and buoy data. Seas are likely 5 to 6 ft in this area, highest in the Gulf of Honduras. As for the remainder of the basin, the latest ASCAT data shows fresh trades across the south-central Caribbean, mainly south of 15N between 63W-77W, where seas are likely 5-7 ft. Gentle to moderate winds prevail elsewhere with 4-5 ft seas. For the forecast, the stationary front will sustain moderate to fresh northerly winds across the region, including in the Gulf of Honduras through early this morning. The front will gradually dissipate over the NW Caribbean today. High pressure over the central Atlantic will promote fresh to strong trades in the S central Caribbean, N of Colombia through midweek, and in the lee of Cuba and the Windward Passage from this evening through Tue night. Trades across the N central and NE basin will become moderate to fresh by Tue morning. ATLANTIC OCEAN... Please read the Special Features section above for more information on the Gale Warning in the eastern Atlantic. Three cold fronts are over the western Atlantic. The westernmost front extends from 31N80W to Jacksonville, Florida. Recent ASCAT data show strong to near gale force W winds associated with this front, to the east of northern Florida. West of 70W, seas increase from 6 ft near 27N to 10 ft near 31N. A second cold front extends from 31N69W to 25N75W, dissipating to 23N78W. Fresh winds are behind this front, north of 29N, with weaker winds farther south. A third cold front extends from 31N64W to 25N70W to eastern Cuba near 21N76W. Broken to overcast clouds with isolated showers are associated with this front. Moderate to fresh SW winds are within 180 nm east of this front, north of 25N. Weaker winds are elsewhere with this front. Seas of 6-8 ft are near the front north of 25N. Farther east, a 1022 mb high pressure is centered near 29N46W. Gentle winds cover the area from 20N-31N between 40W-55W. A cold front extends from the 995 mb low pressure, mentioned above in the special features section, to 30N18W to 25N20W to 21N25W to 19N32W. Scattered showers are north of 27N near the front. Fresh to strong winds are north of 25N between 15W-35W, associated with this system, with near-gale force winds now moving south of 31N between 25W-30W. Seas are 12 to 18 ft in the fresh to strong wind area. For the forecast, the westernmost cold front that just moved off northern Florida will steadily move eastward through Mon morning, with strong winds progressing into the W central Atlantic waters. The fresh SW winds that are east of the cold front extending from 31N64W to 25N70W are anticipated to shift eastward across the central Atlantic through Mon. By Mon night, a high pressure building eastward from Florida should bring improving conditions to the western Atlantic. $$ Hagen