930 AXNT20 KNHC 151121 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 721 AM EDT Wed Jul 15 2020 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 1030 UTC. ...TROPICAL WAVES... A tropical wave is in the E Atlantic extending from 03N to 20N with axis near 20W, moving W at 10-15 knots. Scattered moderate isolated strong convection is from 05N-12N between 12W-26W. A tropical wave is in the central Atlantic extending from 03N-20N with axis near 35W, moving W at 15 knots. The wave is in the dry air environment of the Saharan Air Layer, which is hindering convection at the time. A tropical wave is in the central Atlantic extending from 03N-20N with axis near 49W, moving W at 10-15 knots. The wave is also within the dry air environment of the Saharan Air Layer, which is hindering convection at the time. ...MONSOON TROUGH/ITCZ... The monsoon trough extends from the coast of W Africa near 12N16W to 09N22W to 11N28W to 09N34W to 08N47W. The ITCZ begins near 07N50W to 06N57W. For information on convection, see the Tropical Waves section. GULF OF MEXICO... Stable and fair weather conditions prevail across the basin under the influence of a middle to upper level ridge. Deep-layer dry air is noted in both water vapor and microwave layered precipitable waters imagery. These weather conditions are expected to prevail through at least Thu. In terms of winds, the pressure gradient between low pressure along Mexico and a surface ridge over the Gulf is supporting moderate to fresh return flow W of 90W. Light to gentle variable winds are across the remainder basin. A ridge will dominate the Gulf waters through late Thu maintaining gentle to moderate winds and slight seas with the exception of moderate to locally fresh winds near the W coast of the Yucatan peninsula due to local effects. Looking ahead, the ridge will shift north starting mid week, ahead of a trough that will move westward across Florida and into the southeast Gulf. CARIBBEAN SEA... Except for the Lesser Antilles and adjacent waters where showers are ocurring due to a surface trough moving through that area, the remainder basin N of 15N is devoid of convection in part due to the presence of dry air from the Saharan Air Layer. In the SW Caribbean, S of 15N W of 80W, a middle to upper level inverted trough supports scattered showers and tstms over Nicaragua and adjacent waters. Prevalent Atlantic high pressure extending a ridge to the northern Caribbean waters will sustain fresh to strong winds in the south-central basin and portions of the SW Caribbean through the weekend. Near gale force winds are expected along the coast of Colombia through Wed night along with fresh to strong winds in the Windward Passage and Gulf of Honduras. Otherwise, a tropical wave will enter the tropical N Atlantic waters tonight and enter the E Caribbean on Thu with showers. ATLANTIC OCEAN... A surface trough over central and northern Florida adjacent waters supports isolated showers and tstms N of 27N. To the south, middle to upper level divergence supports a cluster of showers and tstms near the southern Bahamas and Turks and Caicos Islands. The remainder Atlantic basin N of 20N is under the influence of the Bermuda-Azores high which supports fair weather conditions at the current time. The trough north of the Bahamas will persist through Wed, then shift west as high pressure rebuilds in the region. This pattern will maintain moderate to fresh trade winds N of Hispaniola and near the Windward Passage through the weekend. $$ Ramos