000 AXNT20 KNHC 281753 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1805 UTC Wed Jul 28 2021 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 31N. The following information is based on satellite imagery, weather observations, radar and meteorological analysis. Based on 1200 UTC surface analysis and satellite imagery through 1730 UTC. ...TROPICAL WAVES... An Atlantic tropical wave is along 24W from 18N southward, moving W near 15 kt. This wave has yet to exit the monsoonal circulation off of W Africa. Numerous moderate to isolated strong convection is seen from 07N to 12N between 27W and western Africa. Another Atlantic tropical wave is along 41W from 19N southward, moving W 15-20 kt. Satellite imagery suggest that this wave is surrounding by a broad area of Saharan air that is inhibiting deep convection. A Caribbean tropical wave has been relocated to 76W from 13N southward across Colombia, moving W at 20-25 kt. No deep convection is associated with this wave as dry stable air is immediately located behind this wave across the E Caribbean. Another tropical wave in the western Caribbean is along 90W from Guatemala southward into the eastern Pacific, moving W near 10 kt. Enhanced by an elongated upper-level low just to the NW of the wave, scattered moderate to strong convection is present from 15N to 20N between 88W and 89W, including coastal sections of Belize and Yucatan Peninsula. ...MONSOON TROUGH/ITCZ... A monsoon trough extends across the Mauritania coast at 17N16W to 07N39W. The ITCZ then continues from 07N39W to the coast of Suriname at 06N42W. Beyond convection described above associated with the tropical waves, the Saharan Air Layer is limiting any further convection. ...GULF OF MEXICO... A surface trough is over the W central Gulf from 29N90W to 23N93W. An upper-level low is centered across the NW Gulf near 26N97W. This combination is triggering scattered moderate convection from 27N to 28N between 93W and the central Gulf Coast of Florida. Isolated showers are noted off the northeast coast of Mexico and the southwest Bay of Campeche. Elsewhere, light to gentle winds near the W periphery of the Atlantic ridge prevail across the basin, with seas of 1 to 3 feet. The surface trough remains over the W central Gulf aligned NE to SW, and is accompanied by scattered showers and isolated thunderstorms. The trough will drift toward the NW Gulf and weaken through Thu. In its wake, the Atlantic high pressure will begin to build westward into the Gulf waters on Thu, with a ridge persisting along 27N into Sun. ...CARIBBEAN SEA... Convergent trade winds behind the tropical wave along 90W are producing scattered strong convection over the western basin, into coastal Nicaragua and scattered moderate convection over the southern Gulf of Honduras. Dry stable low level air and generally fair weather prevails to the east of this area. Gentle to moderate trades S of the Atlantic ridge dominate the entire Caribbean basin. Seas of 2 to 4 ft are present over the W basin, and 4 to 6 ft are found over the central and E basin, except to 7 ft off the NW coast of Colombia. Gentle to moderate trade winds are expected across the basin through Thu. The exception will be moderate to locally fresh winds near the coast of Colombia, in the Gulf of Venezuela and Gulf of Honduras, and S coast of Hispaniola. Winds will begin to increase across the E and central Caribbean tonight through Thu night, then persist through the weekend, as the Atlantic ridge builds westward in the wake of a trough moving westward across the Atlc waters north of the Greater Antilles. ...ATLANTIC OCEAN... Scattered moderate convection is noted over the central Bahamas and Great Bahama Bank. For convection elsewhere across the Atlantic Basin, refer to the Tropical Waves and Monsoon Trough/ITCZ sections. The Atlantic ridge extends WSW from a 1029 mb Azores high, across Bermuda to northern Florida. This ridge supports light to gentle winds and seas of 3 to 5 ft N of 24N between 40W and the Georgia- Florida coast. Scatterometer and altimeter data reveal gentle to moderate trades and seas of 4 to 6 ft from 19N to 24N between 47W and the Lesser Antilles. Dry and stable atmospheric conditions across this region are producing generally fair weather. Moderate to fresh trades and seas around 6 to 8 ft are evident near the Canaries Islands N of 19N between the NW African coast and 29W. Gentle to locally moderate SE trades and seas of 5 to 7 ft prevail across the rest of the basin. An inverted trough located along 65W south of 23N will move quickly westward across the SE waters this morning, then continue north of the Greater Antilles and across the southern Bahamas through Thu. Expect fresh to locally strong easterly winds late afternoon through the night just off the N of Hispaniola, including approaches to the Windward Passage, most of the forecast period. $$ Nepaul/Rivera