000 AXNT20 KNHC 220535 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 135 AM EDT Tue May 22 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 0515 UTC. ...SPECIAL FEATURES... A broad surface low pressure area has formed over the northwestern Caribbean Sea a couple of hundred miles east of the coast of Belize. This low and an upper-level trough are producing widespread cloudiness and showers extending from the northwestern Caribbean Sea across Cuba and the Florida peninsula. While environmental conditions are expected to be unfavorable for development during the next couple of days, some gradual subtropical or tropical development is possible later this week while the system moves slowly northward into the central or eastern Gulf of Mexico. Regardless of development, locally heavy rainfall is possible across western Cuba and much of Florida during the next several days. For more information on the heavy rain threat, please see products issued by your local weather office. There is a very low chance for tropical storm formation within 48 hours. ...TROPICAL WAVES... A tropical wave is along 35W S of 10N, moving W at 10-15 kt. This wave is embedded in a sharp 700 mb trough. Scattered moderate convection is from 00N-03N between 31W-35W. A tropical wave is over the E Caribbean Sea along 63W S of 16N, moving W at 10-15 kt. This wave is also embedded in a 700 mb trough and has a poleward surge of moisture associated with it. This wave is expected to weaken over the next 24-36 hours and be ill defined thereafter. Scattered showers are confined to NE Venezuela. ...MONSOON TROUGH/ITCZ... The monsoon trough passes through the coastal sections of Sierra Leone near 08N12W to 04N15W. The ITCZ continues from 04N15W to 02N34W. The ITCZ continues W of the tropical wave near 01N36W and extends to the coast of Brazil near 00N50W. Besides the convection mentioned in the tropical wave section, widely scattered moderate convection is from 01N-06N between 11W-29W. ...DISCUSSION GULF OF MEXICO... A 1014 mb low is centered over the Florida Panhandle near 30N87W. A surface trough extends S from the low to the SE Gulf of Mexico near 23N85W. Radar imagery shows scattered moderate convection over S Florida, the Straits of Florida , and the SE Gulf, S of 26N and E of 85W. Elsewhere, scattered showers remain along the Louisiana and Texas coasts. In the upper levels, a sharp upper level ridge is over the NW Gulf with axis along 94W. More importantly, a sharp upper level trough is over the E Gulf with axis along 86W. Upper level diffluence E of the trough axis is enhancing the convection over the SE Gulf. A surface ridge over the NW Gulf will shift east through mid week ahead of a developing low pressure area expected to emerge off the coast of Yucatan Thu. The low pressure will continue to move northward into the north central Gulf through Sat, bringing fresh to strong winds and building seas to the eastern Gulf. CARIBBEAN SEA... Please read the Special Features section for more details about the upper level trough and related surface weather features over the NW Caribbean Sea. Scattered moderate to isolated strong convection is over the W Caribbean from 13N-22N between 76W-85W. Patches of scattered moderate convection is inland over Central America from the Yucatan Peninsula to Panama. Elsewhere, the monsoon trough is along 09N from Costa Rica to N Colombia. Scattered moderate convection is from 08N-13N between 73W-86W. In the upper levels, an upper level trough is over the NW Caribbean. An upper level ridge is over the central Caribbean. A large upper level trough is over the E Caribbean with strong subsidence over the NE Caribbean. Atlantic Ocean high pressure will maintain fresh to locally strong trades in the central Caribbean Sea through Friday night. Strong winds, and sea heights to 9 feet, will affect the NW coast of Colombia. A surface trough will linger in the NW Caribbean Sea through Thursday. It is possible that a low pressure center may form along the surface trough in the Gulf of Honduras on Tuesday, and then move northward into the Gulf of Mexico on Friday. Fresh to strong winds will develop in the central and western Caribbean Sea from Thursday through Friday night. ATLANTIC OCEAN... A 1026 mb high is centered over the central Atlantic near 31N53W producing mostly fair weather. Upper level diffluence is over the W Atlantic W of 74W to include central Cuba, the Bahamas, and the Florida coast. Scattered showers are over the area. A large upper level low is centered near 22N58W. Scattered moderate convection is from 17N-22N between 54W-58W. A surface E to W ridge along 30N will support gentle to moderate SE winds north of 22N and moderate to fresh trade winds south of 22N into mid week, with winds pulsing to strong off Haiti mainly at night. Winds and seas will diminish slightly into Fri as the ridge shifts east. SE winds may increase near Cay Sal Bank starting Fri as low pressure moves northward through the Gulf of Mexico. For additional information please visit http://www.hurricanes.gov/marine $$ Formosa