578 AXNT20 KNHC 111005 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 604 AM EDT Sat Aug 11 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 0600 UTC surface analysis and satellite imagery through 1115 UTC. ...SPECIAL FEATURE... A recent scatterometer pass provide observations of fresh to strong winds across the south-central Caribbean. High pressure north of the area will continue to support fresh to strong winds over the south central Caribbean, with strong to near gale force winds at night, particularly in the Gulf of Venezuela and near the coast of Colombia. Frequent gusts to gale force are also expected to occur tonight and Sun night. As a result, a Gale Warning has been issued. Seas are forecast to build to 12 or 13 ft over the south-central Caribbean. ...TROPICAL WAVES... A tropical wave extends across the east Atlantic with axis along 31W from 10N to 21N, moving west at 10-15 kt. This position is in line with the long-loop satellite imagery and the model diagnostics. Isolated showers are noted where the wave intersects the monsoon trough near 12N. A tropical wave extends its axis along 43W from 09N to 21N. This wave has been repositioned after analyzing 700 mb streamlines, TPW imagery and model diagnostics. Any nearby precipitation is mostly related to the monsoon trough/ITCZ proximity, mainly south of 10N. A tropical wave is moving across the Lesser Antilles, with axis along 62W and south of 21N, moving west 10-15 knots. A well- defined inverted V surface pattern is apparent in satellite imagery with this wave. A cluster of moderate convection is near the northern end of the wave axis while isolated to scattered showers are noted elsewhere near the wave axis. ...MONSOON TROUGH/ITCZ... The monsoon trough passes through the coastal sections of Mauritania near 19N16W, then across the southern Cabo Verde Islands to 07N46W. The ITCZ continues from 07N46W to the coast of Suriname near 05N55W. No significant convection is noted at this time. ...DISCUSSION... GULF OF MEXICO... Broad surface anticyclonic flow spans across the basin, with a 1018 mb high pressure center located near 27N90W. A broad surface low pressure covers the SW corner of the Gulf. In this area, a surface trough was analyzed from 25N97W to 21N96W. Scattered showers are observed south of 25N and west of 92W. A surface ridge will prevail across the area through early next week. The ridge will support moderate to fresh SE winds in the western and central Gulf of Mexico. 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 through the weekend. CARIBBEAN SEA... An upper low is centered over west Hispaniola. This feature is enhancing convection across across the Windward Passage and adjacent waters north of 18N between 72W-80W. The monsoon trough is along 08N/09N from 74W in Colombia beyond southern Costa Rica. Showers are possible from 13N southward and from 80W westward. High pressure north of the area, will support fresh to strong winds in the south central Caribbean through early next week. A tropical wave will enter the eastern Caribbean today with convection. At this time, some of this activity is reaching the Lesser Antilles. Refer to the section above for details. Wind gusts could approach gale force on Saturday night along the coast of Colombia/Venezuela as the pressure gradient tightens. ATLANTIC OCEAN... Three tropical waves are moving across the basin. Refer to the section above for details. An upper level low is centered over west Hispaniola, enhancing convection across the Windward Passage and adjacent waters near the southern Bahamas. The remainder of the basin is under the influence of a surface ridge anchored by a 1031 mb high centered near 36N28W. The surface ridge will prevail north of 28N through early next week. For additional information please visit http://www.hurricanes.gov/marine $$ Formosa