000 AXNT20 KNHC 181720 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 120 PM EDT Fri May 18 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 1200 UTC surface analysis and satellite imagery through 1715 UTC. ...TROPICAL WAVES... A central Atlantic tropical wave has an axis that extends from 12N47W to 00N49W, moving W at 10 to 15 kt. This wave appears as a poleward surge in low-level moisture and troughing at 700 mb. Scattered showers are S of 10N between 42W-46W. ...MONSOON TROUGH/ITCZ... The monsoon trough passes through the coastal sections of Guinea near 09N13W to 03N30W. The ITCZ continues from 03N30W to 05N44W. Besides the convection associated with the tropical wave, scattered to numerous moderate convection is from 02N-11N between 10W-22W. ...DISCUSSION GULF OF MEXICO... A weak surface trough extends south of the western Florida panhandle near 30N84W to 29N87W supporting scattered convection across that area. An upper-level trough with axis along 87W is interacting with a deep plume of tropical moisture moving from the east producing scattered to numerous showers and embedded thunderstorms mainly east of 85W affecting the Florida peninsula, Florida Straits and the majority of Cuba. A weak ridge axis extends across the remainder of the basin along 25N. The surface trough over the northeast Gulf will dissipate later today. A new surface trough will develop just east of South Florida this weekend and move into the eastern Gulf by Sunday. The upper-level trough over the eastern Gulf will remain for several days, and will continue to be the focus for shower and thunderstorm activity mainly over the far eastern Gulf, where deeper moisture and better lift will prevail. CARIBBEAN SEA... An upper-level trough extends over the Yucatan Channel and the northwest Caribbean. Upper-level diffluence on the eastern side of this trough is supporting scattered to numerous moderate convection between 76W-84W, with stronger activity south of 14N and north of 18N. Broad high pressure over the subtropical Atlantic supports moderate to fresh tradewinds over the western half of the basin, while fresh to strong winds prevail over the central and east Caribbean mainly east of 74W. Wave heights of 8 to 10 ft are occurring over the S central Caribbean as confirmed by an recent satellite altimeter pass and buoy data. Over the next couple of days, the upper-level trough will remain in place enhancing shower and thunderstorm activity over the western Caribbean. The surface ridging pattern over the Atlantic will persist, keeping a similar wind profile in place across the basin into the upcoming weekend. ATLANTIC OCEAN... A diffluent flow to the east of an upper-level trough currently over the eastern Gulf of Mexico is supporting scattered moderate convection across the west Atlantic mainly west of 74W affecting the Bahamas and Florida Peninsula. To the east, a 1028 mb high is centered over the central Atlantic near 34N55W. A 1030 mb high is also over the central Atlantic near 34N35W. These centers anchor a very broad ridge that spans the Atlantic waters east of Florida to the northwest African coast. The pressure gradient between the central Atlantic high and lower pressures in the Caribbean and eastern Gulf of Mexico support fresh to locally strong easterly winds along the northern coast of Hispaniola, and fresh westerly winds off the north Florida coast. Moderate to fresh tradewinds are occurring across the central and western Atlantic south of 27N. Gentle to moderate winds cover the central Atlantic N of 27N. Moderate to occasionally fresh NE winds are occurring over the eastern Atlantic. The overall pattern will change little over the next few days, with ongoing convection possible west of 75W and strong winds expected to continue along the northern coast of Hispaniola, and at times eastern Cuba. For additional information please visit http://www.hurricanes.gov/marine $$ ERA