000 AXNT20 KNHC 091713 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 112 PM EDT Tue May 9 2017 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 tropical wave is over the tropical Atlantic with axis extending from 10N41W to 03S42W, moving westward at 15 kt. Cyclonic curvature is noted in infrared satellite imagery and model fields between 38W-48W. SSMI total precipitable water imagery depicts the wave well. Scattered showers are within 180 nm of the axis. A tropical wave is over the tropical Atlantic with axis extending from 11N56W to 01S57W, moving westward at 10 kt. This wave has become less well defined over the past 24 hours. However, some signature remains in infrared satellite imagery and in model fields. Scattered showers are within 180 nm of the axis. ...ITCZ/MONSOON TROUGH... The monsoon trough crosses the western African coast near 12N16W and extends to 07N17W. The ITCZ begins near 07N17W and continues to 01N30W to 02N41W, then resumes west of a tropical wave near 02N44W and extends to the South American coast near 00N48W. Aside from showers associated with the tropical wave, scattered moderate to isolated strong convection is from 01N-06N between 15W-27W. Scattered moderate convection is from 00N-05N between 34W-38W, and from 1S-3N between 45W-50W. ...DISCUSSION... THE GULF OF MEXICO... A 1021 mb surface high is centered over S Mississippi near 31N90W, supporting 10-15 kt anticyclonic flow over the NE Gulf of Mexico. 10-20 kt SE flow is over the W Gulf with strongest winds along the Texas coast. Fair weather dominates the E Gulf. In the upper levels, an upper level ridge is over the Gulf with axis along 92W. Broken upper level high clouds are over Texas and the NW Gulf. Over the next 24 hours, the surface high will drift E to S Alabama. Expect scattered showers to be along the S Texas and the NE Mexico coasts, due to onshore return flow. CARIBBEAN SEA... The tail end of a stationary front extends from the Turks and Caicos Islands to Haiti near 20N72W. The tail end of a prefrontal trough extends from the Atlantic to Puerto Rico near 18N67W. Scattered showers are over the NE Caribbean N of 15N between 60W- 70W. The monsoon trough traverses the SW Caribbean along 10N. Widely scattered moderate convection is from 08N-12N between 75W- 84W. Elsewhere, scattered moderate convection is inland over NW Venezuela, and N Colombia. In the upper levels, an upper level ridge is over the W Caribbean with axis along 92W. An upper level trough is over the E Caribbean with axis along 70W. Upper level diffluence is E of the trough axis enhancing the showers over the NE Caribbean. Expect over the next 24 hours for continued showers over the NE Caribbean, and convection over the SW Caribbean. ...HISPANIOLA... Scattered showers are presently over E Hispaniola due to frontal activity, and upper level diffluence. Expect a lessening of precipitation in 24 hours. ATLANTIC OCEAN... A slow moving cold front is over the W Atlantic from 31N63W to Haiti near 20N72W. A prefrontal trough extends from 26N64W to Puerto Rico near 18N67W. Isolated moderate convection is E of trough to 55W. A 1021 mb high is over the central Atlantic near 30N50W. A surface trough is over the Cape Verde Islands from 31N14W to 27N18W. Scattered showers are within 90 nm of the trough. Expect over the next 24 hours for the Atlantic front to move slowly E with convection. For additional information please visit http://www.hurricanes.gov/marine $$ Formosa