000 AXNT20 KNHC 180505 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 105 AM 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 0000 UTC surface analysis and satellite imagery through 0400 UTC. ...TROPICAL WAVES... A central Atlantic tropical wave has an axis that extends from 11N45W to 01S46W, moving W at 10 to 15 kt. This wave appears as a poleward surge in low level moisture and troughing at 700 mb. Isolated moderate convection and showers are S of 07N between 40W and the wave axis. ...MONSOON TROUGH/ITCZ... The monsoon trough passes through the coastal sections of Guinea near 10N14W to 04N21W. The ITCZ continues from 04N21W to 01N30W to 01N43W. Besides the convection associated with the tropical wave, scattered moderate to isolated strong convection is from 01N to 08N between 03W and 22W. Isolated moderate convection is from 02N to 06N between 22W and 40W. ...DISCUSSION GULF OF MEXICO... A weak surface trough extends from the western Florida panhandle near 31N86W to 30N89W supporting a line of thunderstorms along the trough axis. An upper trough is over the eastern Gulf along 87W and is interacting with a deep plume of tropical moisture E of the its axis to produce numerous showers and embedded thunderstorms east of 87W including Florida, the Florida Straits, and western Cuba. A weak ridge axis extends from central Florida to a 1014 mb high center over the western Gulf near 27N93W. This ridge supports gentle to moderate flow over the majority of the Gulf basin this morning, except for fresh SE winds near the SE Texas coast, where a tighter pressure gradient exists between the high center and lower pressures inland. The surface trough over the NE Gulf will dissipate this morning. A new surface trough will develop just east of S Florida this weekend and move into the eastern Gulf by Sunday. The upper 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 be present. CARIBBEAN SEA... An upper trough extends over the Yucatan Peninsula and the NW Caribbean. Upper level diffluence on the eastern side of this trough is supporting scattered moderate convection N of 18N W of 75W and S of 16N W of 80W. Broad high pressure over the subtropical Atlantic supports moderate to fresh tradewinds over the NW and E Caribbean, and fresh to strong winds over the central Caribbean. Light winds are occurring over the SW Caribbean near the eastern Pacific monsoon trough. Wave heights of 8 to 10 ft are occurring over the S central Caribbean as confirmed by an recent satellite altimeter pass and current buoy data. Over the next couple of days the upper trough will remain in place with an enhancement of 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 Caribbean into the upcoming weekend. ATLANTIC OCEAN... An upper trough and surface trough over the eastern Gulf of Mexico is supporting scattered showers and thunderstorms over the W Atlantic W of 76W, including the N Bahamas. A 1029 mb high is centered over the central Atlantic near 33N54W. A 1031 mb high is centered over the E Atlantic near 35N35W. These high pressure centers anchor a very broad ridge that spans the Atlantic waters E of Florida to the NW Africa 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 E to SE winds along the northern coast of Hispaniola, and fresh SW winds off the north Florida coast. Moderate to fresh tradewinds are occurring across the central and western Atlantic S 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 W 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 $$ Latto