000 AXNT20 KNHC 162328 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 728 PM EDT Tue May 16 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 central tropical Atlantic with axis extending from 07N31W to 01N32W, moving westward at 15 kt. The wave has a subtle signal in satellite imagery, but still appears in model diagnostics. Saharan dry air and dust in the wave environment limits convection to isolated showers within 90 nm either side of its axis. A tropical wave is over the western tropical Atlantic with axis extending from 09N52W to 00N51W, moving westward at 15 kt. The wave continue to be difficult to locate in satellite imagery, but still appears in model diagnostics. Unfavorable wind shear, dry air and dust in the wave environment inhibits convection at this time. A tropical wave extends from the south-central Caribbean near 13N70W to inland Venezuela and eastern Colombia near 03N71W. Unfavorable wind shear across this region of the Caribbean limits convection to isolated showers S of 12N between 66W and 72W. ...ITCZ/MONSOON TROUGH... The monsoon trough crosses the western African coast near 08N13W to 06N21W. The ITCZ begins near 06N21W and extends to 03N29W, then resumes west of a tropical wave near 03N34W to the Souith American coast near 00N49W. Aside from the convection related to the tropical waves, scattered showers are within 120 nm of the ITCZ between 21W-30W. ...DISCUSSION... GULF OF MEXICO... As of 16/2100 UTC, a 1022 mb high is centered off the coast of South Carolina near 33N72W. 10-15 kt E winds are over the E Gulf of Mexico, while 20-25 kt SE winds are over the Gulf. Radar imagery shows scattered showers over the SE Gulf, S Florida, and W Cuba. The remainder of the Gulf has fair weather. In the upper levels, an upper level ridge is over the W Gulf with axis extending from Baton Rouge Louisiana to Tampico Mexico. An upper level trough is over the E Gulf with axis from Fort Pierce Florida to Roatan Honduras. Strong subsidence is over the entire Gulf. Expect over the next 24 hours for scattered showers to persist over the S Florida, the Straits of Florida, and W Cuba. CARIBBEAN SEA... As of 16/2100 UTC, a 1009 mb low is centered near the Cayman Islands at 20N82W. A surface trough extends S from the low to the SW Caribbean near 13N80W. Scattered showers are 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. Upper level diffluence E of the trough axis is producing scattered moderate to isolated strong convection over the central Caribbean between 71W- 77W. A tropical wave is over W Venezuela and N Colombia producing showers. See above. Expect the surface trough to remain over the W Caribbean for the next 24 hours with showers. Also expect the upper level trough to remain quasi-stationary over the next three days. This will lead to the continuation of showers for the north-central Caribbean. Hispaniola, E Cuba and Jamaica will receive numerous showers with the potential for flooding and mud slides. 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. The upper level diffluent flow aloft will remain nearly stationary for the next three days, thus there is a risk for flooding and mud slides. ATLANTIC OCEAN... A 1022 mb high is centered over the W Atlantic near 33N72W. A cold front is over the W Atlantic from 31N59W to 26N70W. Widely scattered moderate convection is within 240 nm SE of the front. A 1030 mb high is over the central Atlantic near 37N35W. A dissipating cold front is over the E Atlantic from 31N25W to 26N33W. 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, upper level diffluence is over the W and Central Atlantic enhancing convection from the S Bahamas to the Central Atlantic. 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