050 AXNT20 KNHC 050003 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 803 PM EDT Sat Aug 4 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 1800 UTC surface analysis and satellite imagery through 2345 UTC. ...TROPICAL WAVES... A tropical wave is in the E Atlc with axis extending from 04N- 17N along 22W, moving W at 10 kt. The wave continue to be affected by intrusion of Saharan dry air and dust as indicated by GOES-16 RGB imagery and by CIRA LPW imagery. Shallow moisture and diffluent flow aloft support scattered moderate convection from 09N-14N between 20W- 26W. A tropical wave is in the E Atlc with axis extending from 04N-17N along 30W, moving W at 10-15 kt. The wave continue to be affected by intrusion of Saharan dry air and dust as indicated by GOES-16 RGB imagery and by CIRA LPW imagery. No convection is associated with this wave at this time. A tropical wave is just E of the Lesser Antilles with axis extending from 07N-18N along 57W, moving W at 10-15 kt. The wave is in a very moist environment that is supporting scattered showers and tstms from 12N-16N W of the wave axis...including the Windward Islands and southern Leeward Islands. A tropical wave is in the central Caribbean with axis S of 20N along 72W, moving W at 15-20 kt. The southern half of the wave environment is in a strong deep layer shear environment that hinder convection development at the time. A tropical wave is in the W Caribbean with axis S of 20N along 87W, moving W at 15 kt. Abundant low level moisture and upper level divergence support scattered showers and tstms from 12N- 18N W of 81W. ...MONSOON TROUGH/ITCZ... The monsoon trough extends from 14N17W to 11N24W to 09N33W. The ITCZ begins near 09N33W and continues to 12N54W. Please refer to the TROPICAL WAVES section for information about precipitation. ...DISCUSSION... GULF OF MEXICO... An upper level trough passes through the Texas coastal plains, into Mexico near 20N103W. Upper level cyclonic wind flow covers the areas from the Texas coastal plains and coastal waters, into central Mexico. Widely scattered moderate to isolated strong rainshowers cover the Gulf of Mexico from 90W westward. A surface trough is along 28N85W 25N85W 22N86W. Widely scattered moderate to isolated strong rainshowers cover the Gulf of Mexico from 90W eastward. The current 28N85W 22N86W surface trough will move westward across the southern and central waters through Sunday night, accompanied by scattered rainshowers with thunder. Surface troughs moving offshore the Yucatan Peninsula will produce fresh to locally strong wind speeds in the eastern waters of the Bay of Campeche from the evenings to late at night during the next few days. Surface high pressure will prevail. CARIBBEAN SEA... Upper level cyclonic wind flow covers the NW corner of the Caribbean Sea, remaining for the upper level trough of the last few days. Middle level cyclonic wind flow is in the coastal areas and inland areas of Honduras and Nicaragua. scattered strong rainshowers cover the areas that are from 14N to 18N between 82W and 86W, in the coastal waters and the coastal plains of Honduras and Nicaragua. An upper level trough extends from an Atlantic Ocean 21N63W cyclonic circulation center, into the eastern Caribbean Sea, to the coast of Venezuela along 67W/68W. Isolated moderate to locally strong rainshowers cover the waters from 17N southward between 55W and 72W. A tropical wave is along 55W/56W, moving into the area of the upper level cyclonic wind flow. Isolated moderate to locally strong rainshowers are between Cuba, Haiti, and Jamaica. The monsoon trough is along 09N74W to 09N79W, beyond 10N86W. Widely scattered moderate to isolated strong rainshowers are elsewhere in the SW corner of the Caribbean Sea, away from the Honduras-Nicaragua precipitation, from 12N southward from 75W westward. Fresh to locally strong trade winds are expected in the central Caribbean Sea and in the Gulf of Honduras through Wednesday night. The strongest wind speeds will pulse to 30 knots near 12N74W during the overnight hours, and the sea heights may reach 10 to 12 feet. It is possible that the wind speeds may approach minimal gale force near the coast of Colombia late on Wednesday night. ATLANTIC OCEAN... Upper level cyclonic wind flow and comparatively drier air in subsidence cover the Atlantic Ocean from the Bahamas northward between 71W and 76W. An upper level cyclonic circulation center is near 33N44W. Large- scale cyclonic wind flow covers the Atlantic Ocean from 20N northward between 20W and 60W. A stationary front is along 33N37W 31N40W, to a 1014 mb low pressure center that is near 32N45W. The stationary front continues to a 1015 mb low pressure center that is near 32N51W. A cold front continues from the 1015 mb low pressure center, to 28N56W, 28N60W, to 32N70W. Widely scattered moderate to isolated strong rainshowers cover the Atlantic Ocean from 25N northward between 39W and 52W. isolated moderate rainshowers accompany the cold front from 26N northward between 50W and 70W. The wind speeds will pulse to strong speeds near the northern coast of Hispaniola each night through Wednesday night. The trade trade winds, elsewhere across the region, will diminish gradually through early next week. An Atlantic Ocean ridge will weaken, with a backdoor cold front moving southward. The front will weaken into a trough by Sunday evening. It is possible that weak low pressure may develop along the trough through early next week. A surface ridge will re-develop by the middle of the next week as the trough dissipates. For additional information please visit http://www.hurricanes.gov/marine $$ MT/NR