000 AXNT20 KNHC 301631 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1805 UTC Wed Jun 30 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 1630 UTC. ...SPECIAL FEATURES... Broad low pressure of 1008 mb located where a tropical wave intersects the monsoon trough near 09N42W, about midway between the African coast and the Lesser Antillies is producing scattered moderate to isolated strong convection from 06N to 10N between 40W and 48W. Environmental conditions appear generally favorable for development, and a tropical depression is likely to form during the next few days while the system moves WNW at 15 to 20 kt. Interests in the Windward and Leeward Islands should closely monitor this system as it will likely be moving through that region on Friday. Please read the latest Tropical Weather Outlook at www.hurricanes.gov, for more information. ...TROPICAL WAVES... A newly analyzed tropical wave axis is along 24W from 15N southward, moving W at 15 kt. Scattered moderate convection has developed from 00N and 07N between 21W and 31W. The axis of a tropical wave is near 40W from 19N southward, moving W at 15 to 20 kt. Please see Special Features section above for more information on the potential for low pressure associated with this wave to develop into a tropical cyclone. The axis of a tropical wave is near 57W from 19N southward, moving W at 20 to 25 kt. Scattered moderate isolated strong convection is noted from 11N to 16N between 52W and 59W. A low pressure center previously associated with this low has diminished overnight, and significant development of this system is unlikely while it moves quickly west. This wave will pass through the Lesser Antilles today and then across the eastern and central Caribbean Sea later this week. Regardless of development, this system could bring locally heavy rainfall to portions of the Lesser Antilles during the next couple of days. The axis of a tropical wave is near 75W, south of eastern Cuba, moving W around 10 kt. Scattered moderate convection has developed in association with this have in and near the Windward Passage. A tropical wave is analyzed near 83W, south of western Cuba, moving W around 5 kt. Scattered moderate to isolated strong convection is noted from 18N to 22N between 80W and 87W as well as in the Gulf of Honduras. ...MONSOON TROUGH/ITCZ... The monsoon trough extends from the coast of Africa near 17N17W to 09N23W to low pres near 09N40W to 07N47W. The ITCZ has formed from 07N47W to 06N52W. All convection in the vicinity of these features is related to tropical waves described in the sections above. GULF OF MEXICO... An upper-level trough extends from the Florida panhandle to near the Yucatan Peninsula. Scattered moderate to isolated strong convection is being generated by this trough, stretching from 23N to 30N between 83W and 89W. Scattered moderate convection has also developed in the SW Gulf W of 92W and south of the U.S.-Mexico border. Moderate to locally fresh winds are occurring in the southwest Gulf, with generally gentle to moderate SE winds elsewhere. Seas are 3 to 6 ft in the western Gulf and 2 to 4 ft in the eastern Gulf. For the forecast, a ridge will dominate the Gulf waters over the next several days producing mainly moderate E to SE winds. Fresh E to SE winds are expected at night near the western Yucatan Peninsula through Fri due to local effects induced by a thermal trough. Another trough will persist over the SW Gulf over the next several days producing showers and thunderstorms. Winds and seas may be higher near thunderstorms. CARIBBEAN SEA... See Special Features section above for details on the potential for a low pressure currently centered midway between Africa and the Windward Islands to develop into a tropical depression over the next few days. High pressure prevails north of the area. The pressure gradient between this area of high pressure and climatological low pressure over Colombia is supporting fresh to strong winds over the central Caribbean. Fresh winds are also noted over the Gulf of Honduras. Moderate to fresh winds prevail elsewhere. Seas are in the 7-10 ft range over the central Caribbean, highest just north of Colombia. Seas are in the 5-7 ft range over the NW Caribbean, and 4-6 ft elsewhere. For the forecast, a tropical wave currently located a couple hundred miles east of the Lesser Antilles has only a low chance of development as it moves quickly W to WNW at 20 to 25 kt. However, as it passes through the Lesser Antilles today and then across the eastern and central Caribbean Sea later this week, locally heavy rain from disorganized showers and thunderstorms can be expected. Farther east, a broad low pressure associated with a tropical wave midway between the west coast of Africa and the Windward Islands is producing widespread showers and thunderstorms that are showing some signs of organization. Conditions appear favorable for development and a tropical depression is likely to form during the next few days while the system moves WNW around 20 kt. The system may impact the Windward and Leeward islands Friday. ATLANTIC OCEAN... A stationary front that had been weakening along 30N, E of Bermuda, has dissipated overnight, leaving high pressure dominating the basin. Convection is confined to between Florida and the Bahamas and in an area from 20N to 25N between 63W and 73W. N of 20N, generally gentle to moderate winds prevail, with fresh trades to the S. Seas S of 20N are 5 to 7 ft, with 3 to 5 ft seas elsewhere. Winds and seas are higher in and near the tropical waves described in the Tropical Waves section above. Also, an area of 8 to 10 ft seas generated by earlier strong winds is noted between the Cabo Verde islands, the Canary Islands, and the African coast. For the forecast W of 65W, the Atlantic ridge will build westward and dominate the forecast waters the remainder of the week. Fresh to strong winds are expected just N of Hispaniola Thu night through Sun night due to the pressure gradient between the Atlantic ridge and a couple of tropical wave passages over the Caribbean Sea. $$ NATIONAL HURRICANE CENTER