000 AXNT20 KNHC 070525 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 125 AM EDT Mon May 7 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 0000 UTC surface analysis and satellite imagery through 0500 UTC. ...SPECIAL FEATURES... A broad area of upper level cyclonic wind flow spans the area that runs from 12N in the Caribbean Sea to 27N in the Atlantic Ocean between 69W and 80W. A few individual cyclonic circulation centers are in the larger area of broad cyclonic wind flow. The cyclonic wind flow covers Cuba, Jamaica, Hispaniola, and the Bahamas, and the nearby waters. A surface trough is along 28N81W in Florida, through 22N81W in Cuba, to 16N80W and 12N80W in the Caribbean Sea. Precipitation: scattered moderate to strong rainshowers from 15N to Jamaica between 75W and 78W. rainshowers are possible elsewhere from 27N in the Atlantic Ocean into the Caribbean Sea between the Mona Passage along 67W/68W and 84W. This feature was forecast by the computer models at the beginning of the week that just ended. The GFS model forecast for 250 mb shows that the current area of cyclonic wind flow will span the area that is between 70W and 80W, weaken into a trough, and then move eastward. An upper level trough will move across the Gulf of Mexico to Florida. The GFS model fforecast for 500 mb shows that cyclonic wind flow will remain in the area that is from 17N southward between 70W and 80W. The area that is from 17N to the central Bahamas between 70W and 80W will consist of anticyclonic wind flo. The GFS model, for 700 mb, shows that the trough will be pushed westward, into the area that extends from the Yucatan Peninsula to the eastern Gulf of Mexico, by a westward-moving ridge. The GFS model for the surface shows that a broad trough will remain in the area from Hispaniola northward between 70W in the Atlantic Ocean and 80W in the Gulf of Mexico, including Florida and the Greater Antilles, and the Bahamas. ...MONSOON TROUGH/ITCZ... The monsoon trough passes through the coastal sections of Sierra Leone near 08N13W to 03N18W and 03N27W. The ITCZ continues from 03N27W, crossing the Equator along 32W, to 02S37W and 02S44W along the coast of Brazil. Precipitation: scattered moderate to strong rainshowers are from 01N to 05N between 16W and 20W, from 01N to 02N between 34W and 36W. isolated moderate to locally strong rainshowers are from 05N southward between 20W and 52W. ...DISCUSSION... GULF OF MEXICO... A stationary front passes through the NE sections of Florida, to the Tampa metropolitan area, into the central sections of the Gulf of Mexico, to the west central Gulf and the coast of Mexico near 24N98W. Precipitation: rainshowers are possible from 26N southward. rainshowers are possible in Florida from 26N to 29N. A surface trough extends from NE Florida, through the Florida Big Bend, through SE Louisiana, into the upper Texas Gulf coast, to south Texas. The current frontal boundary will weaken as it moves slowly toward the SE Gulf of Mexico through Monday night. Building high pressure in the Gulf of Mexico, in the wake of the front, will support gentle to moderate N to NE winds through Tuesday night. Winds in the basin gradually will veer to SE by Thursday night. The high pressure center will enter the western Atlantic Ocean on Friday, but ridge W across the northern Gulf waters, and maintain moderate E to SE winds in the basin. A weak thermal trough will move across the eastern Bay of Campeche from the Yucatan Peninsula during the morning hours, then dissipate during the afternoon each day beginning on Wednesday. CARIBBEAN SEA... Please read the SPECIAL FEATURES section for more infomation about the upper level cyclonic circulation and surface trough near Cuba and the Bahamas and Florida. The current surface trough, that is part of the SPECIAL FEATURES section, will dissipate by Thursday. An upper level trough, that stretches from eastern Cuba to Nicaragua, gradually will shift ESE, weaken into a trough, and reach eastern Caribbean by Tuesday night. Expect scattered rainshowers and isolated thunderstorms on the SE side of the trough. ATLANTIC OCEAN... Please read the SPECIAL FEATURES section for more infomation about the upper level cyclonic circulation and surface trough near Cuba and the Bahamas and Florida. A stationary front passes through SE South Carolina and SE Georgia beyond the NE part of Florida, into the central Gulf of Mexico. Precipitation: widely scattered moderate to isolated strong rainshowers cover the area that is from 27N northward from 75W westward. An upper level trough extends from a 31N10W Morocco cyclonic circulation center, to 27N26W, through 27N36W, to a 20N46W and 15N52W. Precipitation: no significant deep convective precipitation is apparent in satellite imagery. The current frontal boundary from South Carolina to Florida will move slowly SE, and reach from near 31N77W to western Cuba by early Monday afternoon, then from near 31N74W to the central Bahamas to west- central Cuba early Tuesday. Fresh to strong southerly winds will precede the front N of 27N through late Monday afternoon. The front will weaken on Wednesday and Thursday, and then dissipate on Friday. A high pressure center will move SE from the U.S.A. to 31N75W on Thursday night, then to near 31N70W on Friday, but ridge W to near 30N80W. For additional information please visit http://www.hurricanes.gov/marine $$ MT