000 AXNT20 KNHC 310606 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 206 AM EDT Mon Jul 31 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 0000 UTC surface analysis and satellite imagery through 0545 UTC. ...SPECIAL FEATURES... A small non-tropical low pressure area located over Tampa adjacent waters is producing scattered heavy showers and thunderstorms in the E-central and SE Gulf of Mexico. This system has some chance to acquire tropical or subtropical characteristics on Monday before it moves inland over the central Florida peninsula on Tuesday, and into the western Atlantic by Wednesday. Regardless of development, the low is expected to enhance locally heavy rainfall across portions of central and northeastern Florida during the next couple of days. There is a medium chance for this system to become a tropical cyclone. ...TROPICAL WAVES... A tropical wave is in the E Atlc with axis extending from 18N23W to 07N23W, moving W at 10 kt within the last 24 hours. The wave is in a region of low to moderate vertical wind shear N of 10N, however is being severely affected by Saharan dry air and dust, which support the lack of convection in that region of the wave. Scattered moderate convection and isolated tstms are confined to the vicinity of the monsoon trough from 07N to 13N E of 31W. A tropical wave is in the central Atlantic with axis extending from 17N41W to 06N41W, moving west at 20 kt within the last 24 hours. The wave is in a region of low vertical wind shear, but is being severely affected by Saharan dry air and dust intrusion to its environment. Moisture confined to the monsoon trough along with upper level diffluence support scattered showers from 05N to 10N between 40W and 51W. A tropical wave is in the E Caribbean with axis extending from 18N62W to 09N62W, moving west at 10 kt within the last 24 hours. The wave is in a low to moderate vertical wind shear region and continues to be affected by Saharan dry air and dust intrusion to its environment, which is limiting the convection to isolated showers mainly in the SE Caribbean. A tropical wave is in the W Caribbean with axis extending from 16N85W to 06N88W, moving W at 20-25 kt within the last 24 hours. Scattered showers associated with this wave are mainly inland Honduras, Nicaragua and Costa Rica, extending to the Gulf of Honduras. ...ITCZ/MONSOON TROUGH... The monsoon trough extends from the west African coast near 20N17W to 13N22W to 08N47W. The ITCZ extends from 08N47W to 09N60W. For convection information see the Tropical Waves section above. ...DISCUSSION... GULF OF MEXICO... As of 0300 UTC, a stationary front extends across central Florida to N of Tampa, Florida near 28N82W to an embedded 1011 mb low over the northeastern Gulf near 27N84W. A cold front continues from the low to the eastern Texas coast near 28N96W. Scattered moderate and isolated deep convection is occurring from 25N to 28N E of the low. Isolated showers are elsewhere in the SE Gulf. The latest scatterometer pass show fresh E-NE winds in the NE quadrant of the low, and gentle to light winds elsewhere across the basin. The front is forecast to stall across central Florida and the Gulf Monday before it starts dissipating 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, however none are generating deep convection in the basin. See the tropical waves section above. Heavy showers and tstms are in SW Haiti and in the Windward Passage being supported by an upper level low centered over Jamaica and middle level diffluent flow. These showers are forecast to dissipate later during Monday morning as the upper level low drifts SW. In the SW Caribbean, the eastern North Pacific monsoon trough continue to support scattered heavy showers and tstms S of 13N. While most of the Caribbean has light winds, scatterometer data shows 20-25 kt tradewinds over the central Caribbean. ...HISPANIOLA... Heavy showers and tstms are in SW Haiti and in the Windward Passage being supported by an upper level low centered over Jamaica and middle level diffluent flow. These showers are forecast to dissipate later during Monday morning as the upper level low drifts SW. ATLANTIC OCEAN... Two tropical waves are moving across the tropical North Atlantic; see above. A stationary front extends from northeastern Florida to 30N78W. Scattered heavy showers and tstms are occurring between the front and 68W. Expect continued convection over the next two days as the front remains stationary 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 $$ Ramos