000 AXNT20 KNHC 302302 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 702 PM EDT Sun Jul 30 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 2300 UTC. ...TROPICAL WAVES... A tropical wave off the west coast of Africa near 23W extends from about 07N to 18N, moving W at 10 kt. The wave is robustly depicted in the 700 mb GFS analyses and the SUNY-Albany Tropical Wave Diagnostics. METEOSAT10 infrared imagery shows a mid-level circulation, though it is likely that only a trough exists at the surface. No deep convection is currently associated with this wave, though scattered showers are occurring within 120 nm of the wave axis south of about 13N. A tropical wave in the central Atlantic near 40W extends from near 07N to 17N, moving W around 15 kt. The wave is evident both from the broad surface circulation as well as a maximum of Total Precipitable Water east of the wave axis. No deep convection is currently associated with this wave, though scattered showers are occurring 120 nm east of the wave axis south of about 15N. A large Saharan Air Layer is located just north and west of the tropical wave. A tropical wave in the central Atlantic near 50W extends from near 06N to 16N, moving W at 15 kt. This wave is very indistinct with little signs evident in the GFS or ECMWF-based Tropical Wave Diagnostics, TPW, or surface observation. No deep convection or showers are likely associated with this wave. A tropical wave over the E Caribbean near 62W extends from near 09N to 18N, moving W at 15 kt. The wave is readily apparent in the 12Z rawindsondes in the Lesser Antilles as well as the TPW, which shows a maximum just east of the wave axis. Only a slight trough is noted at the surface from station observations. Scattered moderate convection is observed south of 12N within 120 nm east of the wave axis. A tropical wave in the W Caribbean near 84W extends from near 07N to 20N, moving W at 20 kt. The wave is difficult to identify and is only identifiable as a maximum in the TPW east of the wave axis. Numerous moderate and scattered strong convection is noted south of 16N west of 80W including portions of Honduras, Nicaragua, Costa Rica, and Panama due to interaction with the eastern North Pacific monsoon trough and diurnal heating over land. ...ITCZ/MONSOON TROUGH... The monsoon trough extends from the west African coast near 16N17W to 11N32W to 08N48W. The ITCZ extends from 09N52W to 10N60W. Scattered moderate convection is occurring within 120 nm of the trough axis east of 19W, from 07N to 11N between 25W and 32W, and within 60 nm of the trough axis between 43W and 46W. ...DISCUSSION... GULF OF MEXICO... As of 2100 UTC, a cold front extends from northern Florida near 29N83W to an embedded 1011 mb low over the northeastern Gulf near 28N85W. The front continues from the low to the eastern Texas coast as a stationary front. Scattered moderate and isolated deep convection is occurring within 240 nm south of the front boundary, including south Florida. Winds are 20 kt or less across the Gulf. Expect in 24 hours for the cold front to dip to central Florida and then become stationary on Tuesday. Scattered moderate and isolated deep convection is likely to continue as substantial moisture is being advected toward the front from southerlies in the western Caribbean. CARIBBEAN SEA... Two tropical waves are moving across the Caribbean; see above. Numerous moderate and scattered strong convection is noted south of 16N west of 80W including portions of Honduras, Nicaragua, Costa Rica, and Panama due to interaction with the eastern North Pacific monsoon trough and diurnal heating over land. While most of the Caribbean has light winds, scatterometer data and buoy 42058 shows 20-25 kt tradewinds over the central Caribbean. Expect the southwestern Caribbean to continue to produce convection over the next couple of days as well in association with the wave currently over 62W as it moves westward. ...HISPANIOLA... Presently scattered moderate convection is occurring over northern Haiti and scattered showers elsewhere. Expect more moderate convection and showers Monday and Tuesday afternoon/evening due to diurnal heating. ATLANTIC OCEAN... Three tropical waves are moving across the tropical North Atlantic; see above. A cold front extends from northeastern Florida to 32N75W. Scattered moderate and isolated strong convection is occurring within 240 nm south of the front. Expect continued convection over the next two days as the front stalls by Monday. A large 1029 mb high is centered over the central Atlantic near 35N42W producing fair weather and winds are 20 kt or less across the tropical North Atlantic. For additional information please visit http://www.hurricanes.gov/marine $$ Landsea