000 AXNT20 KNHC 131706 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 106 PM EDT Thu Apr 13 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 1200 UTC surface analysis and satellite imagery through 1645 UTC. ...ITCZ/MONSOON TROUGH... The Monsoon Trough passes through the coastal sections of Liberia near 07N11W, to 05N14W 05N17W and 03N28W. The ITCZ continues from 03N28W, to Equator along 39W. Convective precipitation: isolated moderate from 06N southward. ...DISCUSSION... ...THE GULF OF MEXICO... An upper level ridge is along 92W/93W. Upper level anticyclonic wind flow covers the entire area. A surface trough is along 30N85W 26N84W. The trough has been weakening with time. An upper level trough, that was in the NE part of the Gulf of Mexico 24 hours ago, has been moving eastward with time. The trough now extends from a 31N79W Atlantic Ocean cyclonic circulation center, to 28N79W, to the Florida coast near 26N80W, to the Florida Keys and the Straits of Florida. Convective precipitation: rainshowers are possible in scattered to broken low level clouds, from 29N southward from 88W eastward. Broad surface anticyclonic wind flow spans the Gulf of Mexico. ...LOW LEVEL CLOUD CEILINGS AND WEATHER FOR THE OFFSHORE OIL PLATFORM SITES THAT ARE IN THE AREA WHOSE BOUNDARIES ARE FROM 27N NORTHWARD AND FROM 88W WESTWARD... LIFR: none. IFR: none. MVFR: KVOA. LOW LEVEL CLOUD CEILINGS AND WEATHER...FOR THE COASTAL PLAINS OF THE U.S.A. FROM THE DEEP SOUTH OF TEXAS TO FLORIDA... FLORIDA: MVFR at the NAS in Key West. elsewhere from TEXAS to the rest of FLORIDA: VFR. ...THE CARIBBEAN SEA... Upper level SW wind flow covers the area that is to the east of the line that runs from the Gulf of Honduras beyond SE Cuba. Middle level to upper level W-to-SW wind flow covers the rest of the Caribbean Sea. Rainshowers are possible, in the Caribbean Sea, in scattered to broken low level clouds, from 18N southward, and from 18N to 21N between 79W and 84W. 24-hour rainfall totals that are listed for the period that ended at 13/1200 UTC...according to the PAN AMERICAN TEMPERATURE AND PRECIPITATION TABLES...MIATPTPAN/SXCA01 KNHC...3.41 for Freeport in the Bahamas, 1.64 in San Juan in Puerto Rico, and 0.18 in St. Thomas in the Virgin Islands. ...HISPANIOLA... W wind flow from 350 mb to 800 mb is moving across the area. Upper level SW wind flow is moving from the SW corner of the Caribbean Sea toward the southern coastal waters of Hispaniola. SURFACE OBSERVATIONS...for Port-au-Prince in Haiti: VFR. for the DOMINICAN REPUBLIC: Santo Domingo: VFR. La Romana: VFR. Punta Cana: VFR. Santiago: VFR. Puerto Plata: VFR. The GFS MODEL forecast for 250 mb shows that broad SW wind flow will cover the area for the entire time. The GFS MODEL forecast for 500 mb shows that generally W-to-NW wind flow will be moving across the area during the next 48 hours. Hispaniola will be on the southern side of an Atlantic Ocean trough/area of cyclonic wind flow. It is possible that SW wind flow will cover the area at the end of the 48-hour forecast period, with an approaching trough. The GFS MODEL forecast for 700 mb shows that the area will be under the influence of cyclonic wind flow with a trough that will be to the NW of the area, and SW wind flow with an approaching ridge from the SE. ...THE ATLANTIC OCEAN... A mean upper level cyclonic circulation center is near 25N65W. Cyclonic wind flow covers parts of the Caribbean Sea and the Atlantic Ocean from 18N northward between 60W and 80W. An upper level trough extends from 36N36W, through 32N38W, to 29N44W. Cyclonic wind flow covers the Atlantic Ocean from 20N northward between 20W and 50W. A 1011 mb low pressure center is near 25N69W. A surface trough extends from the 1011 mb low center to 25N65W 22N64W 18N65W near the eastern part of Puerto Rico. An occluded front curves away from the low center, to 28N65W. A stationary front continues from 28N65W to 27N48W. A cold front passes through 32N34W to 28N40W to 27N48W. Convective precipitation: isolated moderate to locally strong from 17N northward, in the Atlantic Ocean, between 57W and 75W. Widely scattered moderate to isolated strong from 29N to 32N between 28W and 32W. A surface ridge extends from a 1022 mb high pressure center that is near 33N14W, to 28N22W, 23N41W, and 17N57W. For additional information please visit http://www.hurricanes.gov/marine $$ MT