000 AXNT20 KNHC 152356 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 756 PM EDT Mon May 15 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 1800 UTC surface analysis and satellite imagery through 2315 UTC. ...TROPICAL WAVES... A tropical wave is over the eastern tropical Atlantic with an axis extending from 09N26W to 01N26W, moving westward at about 15 kt. This wave continues to appear in satellite imagery and in model diagnostics. Isolated moderate convection is within 180 nm of either side of the wave axis S of 07N. A tropical wave is over the central Atlantic with an axis extending from 09N46W to 00N47W, moving westward at around 15 kt. This wave continues to be difficult to locate in satellite imagery. There is a 700 mb subtle reflection of the wave. Low to mid level moisture is S of 07N. No convection is currently occurring with this wave. A tropical wave is over Venezuela with an axis extending along 66W, south of 11N, moving westward at 15 to 20 kt. This wave coincides with a surge of deep moisture. Scattered moderate to isolated strong convection is inland within 180 nm of the axis. A tropical wave extends from the southwest Caribbean near 12N75W to SW Colombia near 03N76W, moving westward at 10 to 15 kt. This wave shows up well in 850 mb model streamlines. Scattered thunderstorms are within 180 nm of the wave axis. ...ITCZ/MONSOON TROUGH... The monsoon trough crosses the western African coast near 08N13W to 03N17W. The ITCZ begins near 03N17W and extends to 04N25W, then resumes east of a tropical wave near 03N27W to 04N45W. Aside from the convection related to the tropical waves, isolated moderate convection is within 180 nm of the monsoon trough axis. ...DISCUSSION... GULF OF MEXICO... As of 15/2100 UTC, a 1016 mb high is centered over the north central Gulf of Mexico near 28N89W. 5-15 kt anticyclonic winds are going around the high. Residual scattered showers are over the SE Gulf from 23N-25N between 84W-87W. More showers are inland over W Cuba. In the upper levels, an upper level trough is over the E Gulf with axis extending from N Florida to N Guatemala. Strong subsidence is over the Gulf. Expect over the next 24 hours for the surface pressure gradient to tighten up over the W Gulf and produce 15-20 kt SE flow. Also expect scattered showers to be over the Straits of Florida. CARIBBEAN SEA... A surface trough over the W Caribbean extends from 21N81W to 18N82W to 12N82W. Scattered moderate convection is within 210 nm E of the trough axis. Further S, the monsoon trough is over Panama and Costa Rica with scattered moderate convection. 15 kt tradewind flow is over the central and eastern Caribbean E of 78W. In the upper levels, an upper level trough is over the W Caribbean with upper level diffluence E of the trough axis between 75W-83W, enhancing convection. Two tropical waves are primarily over South America with convection. See above. Expect the surface trough to remain over the W Caribbean for the next 24 hours with convection. Also expect the upper level trough to move E over the next 24 hours shifting convection to the central Caribbean. HISPANIOLA... Scattered showers are over most of Hispaniola mostly due to upper level diffluence. Expect thunderstorms to form again during max heating Tuesday afternoon and evening. ATLANTIC OCEAN... A 1017 mb high is centered over the W Atlantic near 31N78W. A cold front is over the W Atlantic from 31N64W to 27N74W. A stationary front continues to W Cuba near 23N80W. Widely scattered moderate convection is within 240 nm SE of the fronts. A 1022 mb high is over the central Atlantic near 28N49W. A dissipating cold front is over the E Atlantic from 31N29W to 25N40W to 22N50W. Scattered showers are within 60 nm of the front. In the tropics two tropical waves are noted. See above. Of note in the upper levels, an upper level diffluence is over the W Atlantic enhancing the convection over the Bahamas. Likewise upper level diffluence is over the E Atlantic producing scattered showers over the Canary Islands. Expect over the next 24 hours for the W Atlantic front to move E with continued convection. Also expect the W Atlantic front to fully dissipate. For additional information please visit http://www.hurricanes.gov/marine $$ Formosa