000 AXNT20 KNHC 101012 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 612 AM EDT Mon Jul 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 0600 UTC surface analysis and satellite imagery through 1115 UTC. ...TROPICAL WAVES... A tropical wave is in the eastern Atlantic southwest of the Cabo Verde Islands with axis extending from 13N30W to 05N30W, moving west at 15 kt. Abundant moisture prevails within this wave, as noted in TPW imagery. Model guidance shows this wave staying fairly consistently active and fast in the deep tropics over the next several days, possibly forming a weak low pressure in the next 24 to 48 hours. Scattered moderate convection is along the southern portion of the wave axis, close to where it intersects the monsoon trough, from 07N to 13N between 25W and 30W. Another tropical wave is over the far eastern Atlantic with axis extending from 15N42W to 05N42W, moving west at 10 kt. A sharp upper trough is observed just west of the tropical wave along 45W. Deep layer moisture is pooling along the tropical wave under the divergent area aloft on the east side of the upper trough, extending well north into the subtropics to 25N. A large area of Saharan dust is noted to the east of the moisture plume. The wave is slower and higher latitude than the faster and lower latitude more to the east. Model guidance suggests these feature may almost come into phase at different latitudes over the next couple of days. Scattered moderate to isolated strong convection is noted closer to the monsoon trough, from 04N to 07N between 40W and 42W. A broad area of lower to mid level cyclonic turning is noted in satellite derived winds farther west, with an axis along roughly 48W to 50W. This is likely a mid latitude trough that intruded into the tropics over the eastern Atlantic. While scatterometer and buoy data hint of a very broad trough at the surface, this feature is on the drier subsident side of the sharp upper trough, and little to no sensible weather is noted, other than a few showers along the monsoon trough. The trough will across the Leeward and Windward Islands late Tuesday, but with little impact anticipated at this time. Model guidance also suggests this feature will dampen out over the central Caribbean later in the week, but spawn a weak trough into the subtropics. A tropical wave is analyzed over the central Caribbean. The 00 UTC sounding data from St Maarten, San Juan, and Santo Domingo indicate the main wave axis was crossing Puerto Rico, the Mona Passage and into the eastern portion of Hispaniola. The tropical wave will stay on the southeast quadrant of a broad upper low currently centered over the western Caribbean as it shifts westward through late week. A tropical wave is analyzed from far western Panama through eastern Nicaragua and Honduras to near the Isle of Youth and western Cuba, moving west at 10 kt. 00Z sounding data from Grand Cayman provided evidence the axis of the wave passed through. The trough is in an area of dry subsident area on west side of an upper low. Aside from scattered to numerous moderate to strong convection off Panama and Costa Rica in the far southwest Caribbean, little sensible weather is noted with this trough. ...ITCZ/MONSOON TROUGH... The monsoon trough extends from 15N17W to 08N25W to 07N40W. The intertropical convergence zone extends from 08N43W to 06N55W. No significant convection noted other than as described in the tropical wave section. ...DISCUSSION... GULF OF MEXICO... Earlier scatterometer data indicated a weak trough emerging off the west coast of the Yucatan peninsula, supporting a few showers and thunderstorms near Ciudad del Carmen. A few showers extended farther north through the western Gulf, supported by divergence aloft related to an upper trough over south Texas. Weak ridge extended from the western Atlantic across the Florida peninsula into the eastern Gulf. Light to gentle winds and slight seas were noted across the region as a result, with the exception of moderate to fresh east winds in the Straights of Florida. CARIBBEAN SEA... Two tropical waves are moving across the Caribbean. See above. A small area of strong convection is ongoing between southwest Haiti, Jamaica and southeast Cuba, on the divergent eastern side of an upper trough centered over the western Caribbean. The pressure gradient related to ridging sandwiched between the tropical waves is supporting strong trade winds over the south central Caribbean where seas are building to 7 to 9 ft. ...HISPANIOLA... The interaction of an approaching tropical wave with an upper low over the western Caribbean will maintain scattered showers and thunderstorms across eastern Hispaniola through this morning. Daytime heating will add another impetus for convection, mainly across the mountainous interior areas. ATLANTIC OCEAN... Two tropical waves are analyzed over the tropical Atlantic. See the section above for details. A broad 1033 mb surface high is centered north of our area near 37N41W with fair weather. An extensive area of African Saharan dust is situated over the central Atlantic and is gradually shifting westward. For additional information please visit http://www.hurricanes.gov/marine $$ Christensen