000 AXNT20 KNHC 121205 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 705 AM EST MON DEC 12 2016 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. ...THE ITCZ/THE MONSOON TROUGH... The Monsoon Trough reaches the coastal sections of Sierra Leone near 08N13W to 06N16W. The ITCZ continues from 06N16W to 04N28W and 01N42W. Convective precipitation: widely scattered moderate to isolated strong from 10N southward from 50W eastward, in disorganized precipitation. A surface trough is along 44W/45W from 01N to 09N. Convective precipitation: isolated moderate to locally strong from 06N to 09N between 40W and 50W. ...DISCUSSION... ...THE GULF OF MEXICO... An upper level trough passes through the southern border sections of Mississippi and Alabama, into the Gulf of Mexico near 26N93W, and to 23N97W. A cold front is in Texas now, passing through NE Texas, into the central sections of the state, and then curving northwestward into the eastern sections of New Mexico. Upper level SW wind flow spans the rest of the Gulf of Mexico, to the east of the trough. An upper level trough is moving through the central U.S.A. The 24-hour forecast consists of a stationary front to be along the U.S.A. coast of the Gulf of Mexico, from Florida to Texas. The front will be stationary at 48 hours. The 72-hour forecast consists of a cold front across the northern sections of the Gulf of Mexico. Comparatively drier air in subsidence is apparent in water vapor imagery,now, within 240 nm to 300 nm to the north of the line that passes through 27N80W 25N90W 21N98W. A surface ridge passes through the Florida Panhandle, into the north central Gulf of Mexico, to a 1019 mb high pressure center that is near 21N97W along the coast 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: KVOA. IFR: none. MVFR: KBBF and KATP. LOW LEVEL CLOUD CEILINGS AND WEATHER...FOR THE COASTAL PLAINS OF THE U.S.A. FROM THE DEEP SOUTH OF TEXAS TO FLORIDA... TEXAS: LIFR/IFR in the deep south of Texas. LIFR and heavy rain in Hebbronville. LIFR/IFR in the middle Texas coastal plains. MVFR with intermittent LIFR/IFR, from Victoria/Port Lavaca/Palacios, toward Jasper, and toward Huntsville. LOUISIANA: VFR. MISSISSIPPI: MVFR along the Gulf of Mexico coast, except for LIFR in Pascagoula. ALABAMA: LIFR from the immediate coastal plains to Evergreen. IFR in Fort Rucker and Dothan. FLORIDA: LIFR from Marianna westward. IFR from Apalachicola to Tallahassee and Perry and Cross City. LIFR in the Tampa/St. Petersburg metropolitan area, and from Naples to Sarasota. ...THE CARIBBEAN SEA... Upper level cyclonic wind flow is to the west of the line that runs from 11N75W at the coast of Colombia, to 17N81W, to the Gulf of Honduras. Upper level anticyclonic wind flow is curving away from the area of cyclonic wind flow, toward Cuba and Hispaniola. A 1008 mb low pressure center is near 11N83W, along the SE coast of Nicaragua. Convective precipitation: widely scattered moderate to isolated strong from 11N to 18N between 80W and 87W,covering parts of Nicaragua and Honduras, and the coastal waters of each country. Upper level SE wind flow is moving through the Caribbean Sea, to the south of Hispaniola, crossing 70W, moving toward Jamaica. Upper level NE wind flow covers the area that is between 60W and 65W. Upper level SE wind flow covers the area also that is between 65W and 70W. Comparatively drier air in subsidence is apparent in water vapor imagery between 60W and 70W. The 24-HOUR rainfall total in inches for the period ending at 12/0000 UTC...according to the PAN AMERICAN TEMPERATURE AND PRECIPITATION TABLES...MIATPTPAN/SXCA01 KNHC...is 0.02 in Guadeloupe. ...HISPANIOLA... A surface trough is along 72W/73W from 18N to 22N, from Haiti to the SE Bahamas. Upper level anticyclonic wind flow is moving around Hispaniola. Convective precipitation: Rainshowers are possible across Hispaniola, and in the coastal waters and coastal plains, in areas of broken low level to middle level clouds. Isolated moderate from 20N to 27N between 70W and 77W, in the waters that are around the Bahamas, and to the north of Hispaniola. SURFACE OBSERVATIONS...for Port-au-Prince in Haiti: VFR/no ceiling. for the DOMINICAN REPUBLIC: Santo Domingo/La Romana/Punta Cana: VFR/no ceiling. Santiago: MVFR. ceiling at 1200 feet. Puerto Plata: VFR/no ceiling. The GFS MODEL forecast for 250 MB shows that an anticyclonic circulation center will be the south of Hispaniola for the first 30 hours or so, of the 48-hour forecast period. The anticyclonic center is forecast to dissipate and move eastward, pushing SW-to- W wind flow across the area for the rest of the forecast period. The GFS MODEL forecast for 500 MB shows that an Atlantic Ocean E- to-W oriented ridge will push E and SE wind flow across the area. The anticyclonic circulation center that is associated with the ridge eventually is forecast to reach the northern coast of Hispaniola during the last 12 hours or so of the forecast period. It is possible that broad anticyclonic wind flow also will be spread across the area, depending on the exact position of the anticyclonic circulation center. The GFS MODEL forecast for 700 mb shows that an E-to-W oriented Atlantic Ocean ridge will push E-to-SE wind flow across Hispaniola during the next 48 hours, along with a possible inverted trough during the first half of day one. ...THE ATLANTIC OCEAN... Convective precipitation: Broken to overcast multilayered clouds and scattered moderate to isolated strong from 27N to 32N between 70W and 80W. The clouds and precipitation are associated with a warm front that is to the north of 32N. An upper level trough passes through 32N42W to 30N47W, to 27N54W and 23N59W. This trough is supporting a cold front whose southernmost point is near 33N47W. A cold front passes through 32N35W to 30N42W 26N50W and to 23N62W. Convective precipitation: broken low level and middle level clouds and possible rainshowers are within 300 nm to the NW of the cold front. A surface ridge passes through 32N24W to 27N36W to 24N50W. For additional information please visit http://www.hurricanes.gov/marine $$ MT