000 AXNT20 KNHC 251120 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 720 AM EDT Sat Mar 25 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 0600 UTC surface analysis and satellite imagery through 1115 UTC. ...SPECIAL FEATURES... The 12-hour forecast, starting at 25/0600 UTC, consists of: a cold front along 31N41W 26N51W, and then stationary to 24N69W. A 1014 mb low pressure center will be near 21N68W, with a surface trough extending from the low center to 19N70W. Expect gale-force winds, and sea heights ranging from 11 feet to 15 feet, between 180 nm and 270 nm in the NE quadrant of the low pressure center. Please read the latest High Seas Forecast product under AWIPS/WMO headers HSFAT2/FZNT02 KNHC for more details. ...ITCZ/MONSOON TROUGH... The Monsoon Trough passes through the coastal sections of Guinea near 09N13W, curving to the Equator along 21W. The ITCZ continues from the Equator along 21W, to 01S30W, and to 03S39W off the coast of Brazil. Convective precipitation: scattered to numerous strong from 05N to 07N between 13W and 16W, in the coastal waters of Sierra Leone. Scattered strong from 02N to 03N between 23W and 27W. Isolated moderate elsewhere from 08N southward from 47W eastward. ...DISCUSSION... ...THE GULF OF MEXICO... A deep layer trough is digging through the central sections of the U.S.A. A north-to-south oriented cold front cuts through Texas. Middle level-to-upper level anticyclonic wind flow spans the Gulf of Mexico. Comparatively drier air in subsidence is apparent in water vapor imagery, in the NW corner of the Gulf of Mexico. Convective precipitation: scattered moderate to strong has been moving through east Texas into Louisiana. A surface ridge passes through the Florida Panhandle, into the north central Gulf of Mexico, to 27N94W to 23N98W along the coast of Mexico. Rainshowers are possible, in areas of scattered to broken low level clouds in SE return flow, from 90W eastward. ...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: KBBF. MVFR: KMZG, KBQX, KXIH, KVBS, KHHV, KEHC, KVQT, KEIR, KSPR, KGRY, KMDJ, KIKT, KMIS, and KDLP. LOW LEVEL CLOUD CEILINGS AND WEATHER...FOR THE COASTAL PLAINS OF THE U.S.A. FROM THE DEEP SOUTH OF TEXAS TO FLORIDA... TEXAS: Mostly MVFR/some IFR from the Lower Valley northward to the Houston metropolitan area and smaller surrounding communities and to Conroe, to Beaumont/Port Arthur and Jasper. rainshowers and thunder in Tomball and Conroe. LOUISIANA: rainshowers and thunder in Lafayette and New Iberia. MVFR from Lafayette and New Iberia eastward, from Baton Rouge southward and southeastward. MISSISSIPPI: rain and MVFR ceilings are moving eastward with time, from Natchez eastward and southeastward. ALABAMA and FLORIDA: VFR. ...FROM THE CENTRAL ATLANTIC OCEAN, ACROSS THE BAHAMAS AND CUBA, AND INTO THE SW CORNER OF THE CARIBBEAN SEA, INCLUDING THE REST OF THE CARIBBEAN SEA... An upper level trough passes through 32N47W to 30N52W, along a shear axis to 29N70W, to 27N74W. The trough continues from 27N74W, across SE Cuba, into the Windward Passage, to 14N79W, and to the border of Nicaragua and Costa Rica. A cold front passes through 32N44W to 27N50W and 25N56W. A shear line is along 26N55W 24N60W 22N66W 21N72W 21N76W with comparatively faster surface winds to the north of it. Convective precipitation: broken to overcast multilayered clouds and possible rainshowers are within 240 nm to 360 nm on either side of 32N38W, 27N42W, 25N55W, 25N65W, and 19N66W. ...FROM THE ATLANTIC OCEAN INTO THE CARIBBEAN SEA... A cold front passes through 32N44W to 27N50W and 25N56W. A shear line is along 26N55W 24N60W 22N66W 21N72W 21N76W with comparatively faster surface winds to the north of it. The surface trough continues from 21N63W, through the Mona Passage, into the Caribbean Sea near 13N70W. Convective precipitation: broken to overcast multilayered clouds and possible rainshowers are within 240 nm to 360 nm on either side of 32N38W, 27N42W, 25N55W, 25N65W, and 11N69W at the coast of Venezuela. Upper level SW wind flow is moving on top of the area of clouds and possible precipitation in the Caribbean Sea. Upper level anticyclonic wind flow is moving on top of the area of clouds and possible precipitation in the Atlantic Ocean. ...THE REST OF THE CARIBBEAN SEA... The dividing line of wind flow regimes extends from the southern border of Haiti and the Dominican Republic to the coast of Costa Rica near 10N83W. The upper level wind flow that is to the west of that line is cyclonic. The upper level wind flow that is to the east of that line is from the SW. Rainshowers are comparatively more possible to the east of the dividing line of upper level cyclonic wind flow and upper level SW wind flow. Comparatively drier air in subsidence is evident in water vapor imagery to the west of the dividing line. The 24-hour rainfall total in inches for the period ending at 25/0000 UTC...according to the PAN AMERICAN TEMPERATURE AND PRECIPITATION TABLES...MIATPTPAN/SXCA01 KNHC...is 0.16 in Curacao. ...HISPANIOLA... SW wind flow at all levels is moving across the island. Rainshowers are possible inland, and in the coastal waters. SURFACE OBSERVATIONS...for the DOMINICAN REPUBLIC: Santo Domingo/La Romana: VFR. Punta Cana: MVFR. ceiling 1600 feet. Santiago: MVFR. ceiling 1400 feet. earlier rain has ended for the moment. Puerto Plata: heavy rain 4 to 5 hours ago. IFR. ceiling 1200 feet. The GFS MODEL forecasts, for 250 mb and for 500 mb, show that SW wind flow will move across the area during the next 48 hours. A trough will remain to the west of Hispaniola during the next 48 hours. The GFS MODEL forecast for 700 mb shows that cyclonic wind flow with a trough will cover the area for the first 30 hours. Expect SW and W wind flow during the rest of the 48-hour forecast period. THE REST OF THE ATLANTIC OCEAN... An upper level trough passes through Morocco, across the Canary Islands, to 24N19W, to 15N26W and to 09N30W. No significant deep convective precipitation is apparent in satellite imagery. Surface anticyclonic wind flow is to the east, and to the northwest of, the 32N44W-to-25N56W cold front. A surface ridge passes through 32N33W 23N45W to 17N55W to 11N60W, on the eastern side of the surface trough. A 1034 mb high pressure center is near 35N61W, to the northwest of the front. A surface ridge extends from the 1034 mb high pressure center to South Carolina and Georgia. For additional information please visit http://www.hurricanes.gov/marine $$ MT