000 AXNT20 KNHC 110556 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 156 AM EDT Tue Jul 11 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 0515 UTC. An area of showers and thunderstorms reaching 500 nm to the southwest of the coast of Guinea-Bissau may be indicative of a tropical wave emerging into the eastern Atlantic. This will be evaluated for addition to the next surface map at 06 UTC. An Atlantic Ocean tropical wave is along 33W/34W from 05N to 14N southward, moving westward 15 knots. This tropical wave remains well defined in satellite derived wind fields. Scattered moderate convection is noted from 09N to 13N between 33W and 37W. An Atlantic Ocean tropical wave is along roughly 44W from 06N to 15N, moving westward around 10 knots. A fairly well defined and amplified surface trough is noted in satellite derived winds to the north of the tropical wave, while the tropical wave itself remains poorly defined. This feature continues to move slowly west, and will likely come in phase with the more rapid moving tropical wave farther east in the deep tropics. No significant convection is noted with this tropical wave. A trough along roughly 53W remains fairly well defined in the lower to mid levels of the atmosphere, and to a lesser extent at the surface, moving west at 10 to 15 kt. This feature emerged out of the mid latitude areas of the eastern Atlantic a few days ago, and will continue westward in the deep tropics toward the Windward and Leeward Islands into the eastern Caribbean later today. This feature exhibits no deep layer moisture or sensible weather at this time. A tropical wave reaches across the central Caribbean Sea from the Guajira peninsula of northeast Colombia to central Hispaniola and is moving west at 10 to 15 kt. Fairly dry air follows this wave across the eastern Caribbean. No significant convection is noted with it. A tropical wave in the far northwest Caribbean and Gulf of Honduras and is moving onshore along the coast of Belize and the Yucatan peninsula. No significant convection is observed. ...ITCZ/MONSOON TROUGH... The Monsoon Trough passes through Senegal near 14N16W, to 07N33W, 09N40W. The ITCZ extends from 09N45W to 07N55W. Scattered moderate to isolated strong convection is observed from 05N to 11N east of 25W, likely associated with a tropical wave moving off the African coast. Scattered moderate convection is noted 02N to 05N between 30W and 50W. ...DISCUSSION... ...THE GULF OF MEXICO... Broad ridging reaches from the Big Bend area of Florida in the northeast Gulf through the coast of south Texas. The northern extent of a tropical wave is moving into the Yucatan peninsula, and will move across the far southwest Gulf through mid week, enhancing resident overnight troughing. This will support moderate to fresh overnight winds across the southwest Gulf will clusters of showers and a few thunderstorms. A broad upper low over the north central Gulf will continue to support showers and thunderstorms across the Straits of Florida, where moderate to fresh east winds persist south of the ridge. Elsewhere, gentle winds and slight seas will persist. ...THE CARIBBEAN SEA... Strong trade winds persist over the south central Caribbean ahead of and in the wake of a passing tropical wave. The area of strong trade winds is shrinking slightly however as high pressure north of the region weakens. Trade wind convergence continues to support clusters of showers and thunderstorms along the monsoon trough over the southwest Caribbean. Little convection is noted elsewhere with moderate trade wind flow. ...HISPANIOLA... A few overnight showers are forming off the northern coast of the Dominican Republic. However, showers and thunderstorms from the late afternoon and evening appear to have dissipated completely at the end of daytime heating, despite a tropical wave moving across the region. This is due in part to diminishing divergence aloft as an upper low west of the area weakens. Scattered showers and a few thunderstorms are likely once again later today over interior areas with afternoon heating. ...THE ATLANTIC OCEAN... Showers and thunderstorms associated with the remnants of T.D. Four near 22N65W are weakening. Weak 1014 mb low pressure was analyzed at 00 UTC near 22N65W. Since that time, while there appears to be lingering circulation at least in the lower to mid levels of the atmosphere, Buoy 41043 on the southwest quadrant of the circulation shows southeast winds. Supported by recent scatterometer data, this indicates there is no longer a closed circulation at the surface, and is in fact a trough. Farther northeast, an upper low is centered near 28N58W, supporting possible scattered showers from 25N to 29N between 54W and 57W. Elsewhere, broad ridging dominates the Atlantic Ocean north of 22N. For additional information please visit http://www.hurricanes.gov/marine $$ Christensen