000 AXNT20 KNHC 101746 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 146 PM 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 1200 UTC surface analysis and satellite imagery through 1715 UTC. ...TROPICAL WAVES... A tropical wave is in the eastern Atlantic southwest of the Cabo Verde Islands with axis extending from 14N31W to 06N31W, moving west at 15 kt. Abundant moisture prevails within this wave, as noted in TPW imagery. Satellite imagery shows an area of moderate convection along the wave axis from 10N to 12.5N between 30W and 33W. Some gradual development of this system is possible through the week while it moves westward across the tropical Atlantic Ocean. Another tropical wave extends from 15N42W to 05N42W, moving west at 10 kt. Scattered showers are on either side of the wave axis. A large area of moisture is noted on the TPW animation to the NE of the wave, and on the east side of an upper-level 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 forecast to reach 55W by Tuesday night. A broad area of lower to mid level cyclonic turning is noted in satellite derived winds farther west, with an axis roughly along 50W. Scatterometer and buoy data hint a very broad trough at the surface. This feature is on the drier subsident side of the above mentioned upper-level trough, and little to no sensible weather is noted, other than a few showers. Moisture associated with this trough will reach the Leeward and Windward Islands Tuesday night into Wednesday. A tropical wave is analyzed over the eastern Caribbean with axis extending from Dominican Republic to western Venezuela. The wave will enter the central Caribbean this afternoon and continue to move westward across this area on Tuesday enhancing convection over Hispaniola. Another tropical wave extends from the westernmost tip of Cuba to the Gulf of Honduras, and then across Honduras and Nicaragua moving west at 10 kt. The wave is on the west and dry side of an upper level low spinning over the Cayman Islands. Clusters of moderate to isolated strong convection are over the SW Caribbean, and just behind the wave axis covering the area S of 13N and W of 80W. This wave will be over the Yucatan Peninsula early Tuesday morning. ...ITCZ/MONSOON TROUGH... The monsoon trough extends from 15N17W to 10N26W to 08N31W to 09N40W. The intertropical convergence zone extends from 09N44W to the coast of Guyana at 07N59W. Outside of the convection associated with the tropical waves, an area of moderate to isolated strong convection is noted along the west coast of Africa from 07N to 10N E of 16W. ...DISCUSSION... GULF OF MEXICO... The combination of a tropical wave, with axis near the westernmost tip of Cuba and the northern periphery of an upper-level low located over the Cayman Islands is producing scattered showers and thunderstorms across south Florida and the Florida Keys since early this morning. Mosaic Doppler Radar from the SE U.S. confirmed the presence of this convective activity affecting also parts of the Straits of Florida. Isolated showers are noted over the NE Gulf. Weak ridge extended from the western Atlantic across the Florida peninsula into the eastern Gulf where a 1018 mb high pressure is analyzed. Light to gentle winds and slight seas are noted across the region as a result, with the exception of moderate to fresh east winds in the Straits of Florida. Earlier scatterometer data indicated the wind shift related to the thermal trough emerging off the west coast of the Yucatan Peninsula. Fresh to locally strong winds were associated with this trough forecast to develop each evening over the Yucatan peninsula, then move across the SW Gulf each night and dissipate each morning. CARIBBEAN SEA... Two tropical waves are moving across the Caribbean. See Tropical Waves section for details. As perviously mentioned, an upper-level low is spinning over the Cayman Islands generating some shower activity. Clusters of moderate to isolated strong convection are over the SW Caribean likely associated with the Monsoon Trough and a tropical wave with axis over Central America. Shallow moisture embedded in the trade wind flow is noted elsewhere. A ridge, with axis north of the area, combined with the Colombian/Panamanian low will continue to support fresh to strong winds across the south- central Caribbean through midweek, with moderate to locally fresh trades prevailing elsewhere. ...HISPANIOLA... The interaction of a tropical wave (with axis across the island) with the aforementioned upper-level low over the western Caribbean will maintain the risk of scattered showers and thunderstorms across Hispaniola this afternoon and early evening hours. Similar weather conditions are expected on Tuesday. ATLANTIC OCEAN... Two tropical waves and a trough are analyzed over the tropical Atlantic. See Tropical Waves section above for details. In addition, a 1012 mb low pressure, associated with the remnants of T.D. Four, is added to the 1200 UTC analysis/surface map near 22.5N64W. A cluster of moderate to isolated strong convection is within about 150 nm east semicircle of low center. A trough extends from the low center to near 30N64W. Experimental GOES-16 shows some inverted-V pattern in the cloud field in association with this trough. To the east of the trough, an upper level low located near 28N57W is also producing some shower activity. The Bermuda-Azores high extends a ridge across the remainder of the forecast region. An extensive area of African Saharan dust is reaching 40W based on the Saharan Air Layer Tracking Product from CIMSS. For additional information please visit http://www.hurricanes.gov/marine $$ GR