000 AXNT20 KNHC 240009 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 809 PM EDT Wed May 23 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 1800 UTC surface analysis and satellite imagery through 2315 UTC. ...SPECIAL FEATURES... A broad surface low centered over the southeastern Yucatan Peninsula has become better defined since yesterday, and it continues to produce a large area of cloudiness and showers extending from the northwestern Caribbean Sea across Cuba into the Florida Straits. Continued slow development of this system is possible during the next couple of days as it drifts northward near the Yucatan Peninsula. Thereafter, environmental conditions are forecast to become more conducive for development, and a subtropical or tropical depression is likely to form this weekend over the eastern or central Gulf of Mexico. Regardless of development, locally heavy rainfall is possible across western Cuba and the Cayman Islands during the next few days, and over much of Florida and the northern Gulf Coast during the weekend. For more information on the heavy rain threat, please see products issued by your local weather office. The chance for tropical cyclone formation during the next 48 hours is low. The chance for tropical cyclone formation during the next 5 days, on the other hand, is high. ...TROPICAL WAVES... A tropical wave is along 45W S of 10N moving westward at 10 to 15 knots. This wave is embedded in a sharp 700 mb trough. Scattered showers are within 120 nm of the wave axis. ...MONSOON TROUGH/ITCZ... The monsoon trough passes through the coastal sections of Guinea near 10N13W to 05N17W. The ITCZ continues from 05N17W to 00N28W to 01N44W. The ITCZ continues W of the tropical wave from 01N46W to the coast of Brazil near 00N50W. Isolated moderate convection is from 01N-06N between 08W-25W. Widely scattered moderate convection is from 05S-04N between 25W-35W. ...DISCUSSION GULF OF MEXICO... A surface ridge extends from an Atlantic Ocean high centered near 32N42W to the NE Gulf of Mexico. 10-15 knot E to SE winds are over the Gulf. An upper level trough is over the Gulf of Mexico with axis along 90W. Upper level moisture is over the Gulf except over the SW Gulf where strong subidence is noted. Isolated moderate convection is over the central Gulf from 24N-27N between 85W-91W. More isolated moderate convection is over the NW Gulf from 25N-31N berween 91W-95W. The surface ridge is forecast to shift eastward through early Thursday. Broad surface low pressure, that is just to the north of Belize, is expected to develop and move to the northern coast of the Yucatan Peninsula on Friday morning. The low pressure center will then move northward, slowly, to the eastern Gulf of Mexico this weekend. Expect near gale-force winds and associated seas to the east of the low pressure center. CARIBBEAN SEA... Please read the Special Features section above. Scattered moderate convection is over the NW Caribbean Sea from 18N-22N between 82W-88W. Scattered moderate convection is inland over Central America from the Yucatan Peninsula to Panama. Elsewhere, 15-20 knot tradewinds are over the central and E Caribbean. An upper level trough extends from an Atlantic Ocean 23N55W cyclonic circulation center, through 17N58W, to the coast of Venezuela near 11N63W. Comparatively drier air in subsidence is apparent in water vapor imagery from 11N to 20N between 52W and 70W, in the Caribbean Sea and in the Atlantic Ocean. Upper level cyclonic wind flow covers the Caribbean Sea from 70W eastward. No significant deep convective precipitation is apparent in satellite imagery. ATLANTIC OCEAN... Scattered showers are over the Bahamas. A 1028 mb high is centered over the central Atlantic near 32N42W producing fair weather. An upper level trough extends from a 23N55W cyclonic circulation center, through 17N58W, to the coast of Venezuela near 11N63W. Comparatively drier air in subsidence is apparent in water vapor imagery from 11N to 20N between 52W and 70W, in the Caribbean Sea and in the Atlantic Ocean. Expect moderate to fresh trade winds south of 27N this week, with winds pulsing to strong N of Hispaniola at night on Wednesday and on Thursday. The winds will diminish slightly on Friday, as the ridge shifts eastward. A developing area of low pressure in the Gulf of Mexico for this weekend will increase SE winds west of 77W from Friday through Sunday. For additional information please visit http://www.hurricanes.gov/marine $$ Formosa