000 AXNT20 KNHC 110000 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 800 PM EDT Wed May 10 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 2345 UTC. ...TROPICAL WAVES... A tropical wave is over the central Atlc with axis extending from 01N30W to 10N29W, moving westward at 10 kt over the past 24 hours. The wave is embedded in a favorable wind shear environment with mainly shallow moderate moisture as shown by CIRA LPW imagery. Isolated showers are within 210 nm either side of the wave axis. A tropical wave is over the western tropical Atlantic with axis extending from 01N53W to 11N52W, moving westward at 15 kt over the past 24 hours. The wave is in a favorable wind shear environment S of 09N and is embedded in a moderate to high moist region as shown by both CIRA LPW and water vapor imagery. Upper level diffluent flow support scattered moderate and isolated strong convection from 03N to 10N between 50W and 56W. A tropical wave extends from the extreme southern Caribbean near 11N66W to inland Venezuela, moving west at 20 kt over the past 24 hours. Convection associated with this wave is inland Venezuela. ...ITCZ/MONSOON TROUGH... The monsoon trough crosses the western African coast near 14N17W and extends to 08N20W. The ITCZ begins near 08N20W and continues to 05N27W, then resumes west of a tropical wave near 03N33W and continues to 01N45W to 04N51W. Aside from the convection associated with the tropical waves, scattered moderate convection is from 01N to 08N between 10W and 24W, and within 120 nm either side of the ITCZ axis W of 34W. ...DISCUSSION... THE GULF OF MEXICO... Fair weather and very stable conditions prevail across most of the basin being supported by middle to upper level ridging and surface high pressure being anchored by a 1019 mb high centered in the NE basin near 29N84W. Water vapor and CIRA LPW imagery show dry air nearly basin-wide, which is allowing for clear skies E of 90W and from 24N to 26N W of 90W. Shallow moisture supports broken skies and possible isolated showers S of 24N, including the Bay of Campeche. A light to gentle breeze is across the eastern gulf while moderate return flow dominates the western basin. Locally fresh N-NE flow is over the NW Yucatan Peninsula associated with a thermal trough inland. The trough will move over the Bay of Campeche tonight enhancing winds in that region through Thursday morning. Otherwise, no significant changes are expected until Friday night when a cold front will move into NW waters. CARIBBEAN SEA... A middle to upper level trough over the W Atlc extends S to a base over the SE Caribbean. This continues to support a surface trough just NE of Puerto Rico, which is favoring scattered showers and isolated tstms across the Island as well as the Virgin Islands. Similar shower activity is over central Dominican Republic, the Lesser Antilles and from 13N to 16N between 63W and 68W. In the SW Caribbean, the eastern extension of the Pacific Ocean monsoon trough continue to support scattered showers S of 13N. Otherwise, gentle to moderate trades are basin-wide along with fair weather. Showers will continue for the northeast Caribbean through Friday. ...HISPANIOLA... Under the presence of a mid to upper level trough, scattered showers and isolated thunderstorms prevail over western Dominican Republic. Model guidance indicate rainshowers will continue to Thursday night. ATLANTIC OCEAN... A 1018 mb area of high pressure centered near 26N77W dominates the southwestern north Atlantic waters along with fair weather. A middle to upper level trough along 67W with base in the SE Caribbean supports a cold front from 30N57W to 24N64W with isolated showers within 90 nm ahead of the boundary. The trough aloft also supports a pair of surface troughs. The westernmost trough extends from 21N64W to NE Puerto Rico adjacent waters near 18N65W. The easternmost trough extends from 25N58W to 20N61W. Isolated showers and tstms are within 90 nm either side of the trough axes. The remainder central and eastern Atlc is under the influence of a surface ridge centered by a 1021 mb high near 26N45W, which will remain nearly stationary within the next 24 hours. The cold front will move to central Atlc waters where it will stall early Friday before dissipating Saturday. A new cold front will clip the northern discussion waters of the central Atlantic Friday night. For additional information please visit http://www.hurricanes.gov/marine $$ Ramos