273 AXNT20 KNHC 130505 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 105 AM EDT Mon Aug 13 2018 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 0000 UTC surface analysis and satellite imagery through 0515 UTC. ...SPECIAL FEATURE... Caribbean Gale Warning... Gale-force winds are expected again tonight near the coast of Colombia and in the Gulf of Venezuela from 11N to 13N between 70W and 76W. Expect sea heights to range from 9 feet to 13 ft in this area. Please read the High Seas Forecast, that is listed under the WMO/AFOS headers FZNT02 KNHC/MIAHSFAT2 for more details. ...TROPICAL WAVES... An Atlantic tropical wave extends its axis along 21W, from 20N southward, moving west at 10-15 kt. Scattered moderate convection is noted over the southern portion of the wave south of 10N. An Atlantic tropical wave extends its axis along 42W from 21N southward, moving west at 10-15 kt. This wave is depicted in model diagnostics and 700 mb streamline analysis, and TPW imagery shows moderate moisture in its vicinity. Isolated showers are observed along the wave's axis south of 13N. An Atlantic tropical wave extends its axis along 54W, from 21N southward, moving west at 15-20 kt. This wave is also depicted in model diagnostics. Isolated showers are noted south of 10N, possibly related to the monsoon trough's proximity. A Caribbean tropical wave extends its axis along 72W from 21N southward, moving west at 15-20 kt. Despite the fact that TPW imagery shows abundant moisture in the wave's environment, no significant convection is observed at this time. ...MONSOON TROUGH/ITCZ... The monsoon trough passes through the coastal sections of Africa near 19N17W, then resumes west of a tropical wave from 09N22W to 11N40W. The ITCZ is along 10N43W to 10N51W. Scattered moderate convection is within 75 nm south of the monsoon trough between 20W-40W. ...DISCUSSION... GULF OF MEXICO... A surface ridge prevails across the basin, anchored by a 1018 mb high centered near 28N88W. With this, a gentle to moderate anticyclonic flow prevails across the area. To the southwest, a surface trough extends over the Bay of Campeche from 23N93W to 19N92W. The surface ridge will prevail across the area through early next week. The ridge will support moderate to fresh easterly winds in the west-central and NW Gulf. A nocturnal trough moving off the Yucatan peninsula will induce a surge of fresh to strong NE to E winds in the Bay of Campeche each night. CARIBBEAN SEA... Please refer to the Special Feature section for more details about the Gale Warning currently in effect. An upper-level low is centered near 21N80W. This feature is enhancing convection across the northwest Caribbean waters mainly north of 18W and west of 79W, including western Cuba. A tropical wave extends its axis along 72W. For more information, refer to the section above. The monsoon trough extends along 10N between 76W-82W. Scattered showers are noted across Panama and Costa Rica due to this. Little change is expected through early next week. The next tropical wave will enter the eastern Caribbean by late Monday. ATLANTIC OCEAN... An upper level low is centered over the northwest Caribbean near 21N80W. This feature is also enhancing convection across the west Atlantic, mainly over the Bahamas. Three tropical waves are moving across the basin. Refer to the section above for details. The remainder of the basin is under the influence of a surface ridge, anchored by a 1026 mb high centered near 31N61W and another 1026 mb high near 34N35W. The surface ridge will remain in place during the next several days. This ridge will help to maintain fresh to locally strong winds along the northern coast of Hispaniola and in the approaches to the Windward Passage, during the evening and nighttime hours. Gentle to moderate anticyclonic wind flow will continue N of 23N, while mainly moderate easterly wind flow will prevail S of 23N. For additional information please visit http://www.hurricanes.gov/marine $$ ERA