000 AXNT20 KNHC 181125 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 725 AM EDT Sun Jun 18 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 1045 UTC. ...SPECIAL FEATURE... A tropical wave is along 45W/46W from 11N southward. The wave is moving westward 10 to 15 knots. A 1007 mb low pressure is along the tropical wave near 06N. Widely scattered moderate to isolated strong rainshowers are from 04N to 10N between 43W and 50W. The chance of formation into a tropical cyclone during the next two days is medium. Please read the latest NHC Tropical Weather Outlook under AWIPS/WMO headers MIATWOAT/ABNT20 KNHC for more details. A 1007 mb low pressure center is about 45 nm to the east of the northern part of the coast of Belize, near 17.5N87W. Numerous strong rainshowers cover the area that is from 13N to 20N between 81W and 85W, in the coastal waters of Nicaragua and Honduras. Widely scattered moderate to isolated strong rainshowers also cover the area from 15N to the southern coast of Cuba between 77W and 82W. This low pressure center is forecast to move slowly northwestward across the Yucatan Peninsula on Sunday, and into the southern or central Gulf of Mexico early next week. It is likely that a subtropical or tropical cyclone may form. Heavy rains are expected in parts of Central America, the Yucatan Peninsula, Jamaica, the Cayman Islands, and western Cuba during the next several days. An Air Force Reserve Hurricane Hunter aircraft is scheduled to investigate this system on Sunday, if necessary. The chance of formation into a tropical cyclone during the next two days is medium. Please read the latest NHC Tropical Weather Outlook under AWIPS/WMO headers MIATWOAT/ABNT20 KNHC for more details. ...TROPICAL WAVES... An Atlantic Ocean tropical wave is along 22W/23W from 12N southward. Isolated moderate to locally strong rainshowers are from 04N to 12N between 10W and 30W. An Atlantic Ocean tropical wave is along 33W/34W from 11N southward, moving westward 10 to 15 knots. Isolated moderate from 10N southward between 30W and 40W. An Atlantic Ocean tropical wave is along 53W/54W from 18N southward moving westward 10 knots. Widely scattered moderate to isolated strong rainshowers are from 12N southward between 50W and 60W. A Caribbean Sea tropical wave is along 81W/82W, from 20N southward. This wave is moving into the area of weather that is being influenced by the 1007 mb low pressure center that is just to the east of Belize, from the Special Features section. ...MONSOON TROUGH/ITCZ... The Monsoon Trough passes through the coastal border sections of Senegal and Mauritania near 16N16W, to 08N23W, 06N40W, and 06N43W. The ITCZ continues from 06N43W to 07N52W, to the border of Guyana and Suriname near 06N57W. Convective precipitation: Isolated moderate to locally strong elsewhere from 10N southward from 60W eastward. ...DISCUSSION... ...THE GULF OF MEXICO... A NE-to-SW oriented upper level trough cuts through the Florida Panhandle, to 19N98W in southern Mexico, just to the west of the Isthmus of Tehuantepec. A surface ridge passes through 27N/28N in Florida, into the central Gulf of Mexico, to the coast of Mexico near 20N97W. Comparatively drier air in subsidence is apparent in water vapor imagery, within 120 nm to 180 nm on either side of the line that passes through the Florida Big Bend, into the central Gulf of Mexico, to the Mexico coast near 21N97W. ...CURRENT CONDITIONS AND WEATHER, FOR THE OFFSHORE OIL PLATFORM SITES, FROM 27N NORTHWARD AND FROM 88W WESTWARD... LIFR: none. IFR: none. MVFR: KGHB. CURRENT CONDITIONS AND WEATHER, FOR THE COASTAL PLAINS OF THE U.S.A., FROM THE DEEP SOUTH OF TEXAS TO FLORIDA... Texas: MVFR, from interior sections of the Lower Valley to Victoria. Some occasional MVFR ceilings have been reported during the last few observations in the Houston metropolitan area and surrounding smaller communities. LOUISIANA: MVFR in Baton Rouge. Occasional IFR-to-MVFR ceilings around the northern side of Lake Pontchartrain during the last few observations. MISSISSIPPI: LIFR in Natchez. FLORIDA: rain and thunder and occasional MVFR ceilings have ended for the moment from Pensacola to Milton. MVFR in Perry, and at the Tampa Executive Airport. ...THE REST OF THE CARIBBEAN SEA... Upper level anticyclonic wind flow covers the area from 66W westward. The rest of the Caribbean Sea is just to the west of the Atlantic Ocean 26N55W-to-08N60W trough. The Monsoon Trough is along 09N74W in Colombia, through 10N80W in the SW corner of the Caribbean Sea, into El Salvador. Widely scattered moderate to isolated strong rainshowers from 10N to 13N between 75W and 78W, in the coastal waters of Colombia. 24-hour rainfall totals that are listed for the period that ended at 18/0000 UTC...according to the PAN AMERICAN TEMPERATURE AND PRECIPITATION TABLES...MIATPTPAN/SXCA01 KNHC...are 0.04 in Guadeloupe, and a trace in Tegucigalpa in Honduras. ...HISPANIOLA... Upper level NW wind flow is moving across Hispaniola. SURFACE OBSERVATIONS...for Port-au-Prince in Haiti: VFR. for the DOMINICAN REPUBLIC: Santo Domingo: VFR. earlier rain and MVFR ceilings have ended for the moment. Punta Cana: VFR. Santiago: light rain. MVFR. ceiling 1600 feet. Puerto Plata: VFR. The GFS MODEL forecast for 250 mb shows that NW wind flow will move across the area during the first 24 hours of the 48-hour forecast. N wind flow will continue for the next 24 hours. A N-to-S oriented trough develops directly on top of Hispaniola at the end of the forecast period, and for the start of day three. The GFS MODEL forecast for 500 mb shows that anticyclonic wind flow, with a N-to-S oriented ridge, will move across Hispaniola during much of the first 24 hours of the forecast. The ridge will be followed by an inverted trough at the end of day one. The inverted trough remains across Hispaniola during the first two- thirds of day two. The ridge slides westward during the rest of the time of the day two forecast period. The GFS MODEL forecast for 700 mb shows that SE wind flow will move across the area during the next 48 hours, with Hispaniola being on the southern side of an E-to-W oriented Atlantic Ocean ridge. ...THE ATLANTIC OCEAN... An upper level central Atlantic Ocean trough is anchored by a cyclonic circulation center that is about 760 nm to the NE of Puerto Rico, and that ends near NE coastal Venezuela and northern sections of Guyana near 08N60W. Scattered to numerous strong rainshowers are from 08N to 10N between 59W and 61W, near Venezuela and Guyana. A cold front/stationary front is along 32N/33N between 38W and 54W. Broken to overcast multilayered clouds and possible rainshowers cover the area from 30N northward between 33W and 70W. A surface trough is along 30N55W 29N58W 26N61W. Isolated moderate rainshowers cover the Atlantic Ocean from 10N northward between 45W and 70W. A NE-to-SW oriented upper level trough, from 20N northeastward, is within 300 nm to 600 nm to the west of Africa. No significant deep convective precipitation is apparent in satellite imagery. Surface anticyclonic wind flow covers the Atlantic Ocean from 20N northward from 53W eastward. A 1024 mb high pressure center is near 30N42W. For additional information please visit http://www.hurricanes.gov/marine $$ MT