000 AXNT20 KNHC 300352 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0605 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 0000 UTC surface analysis and satellite imagery through 0400 UTC. ...SPECIAL FEATURES... Low pressure of 1009 mb has developed where a tropical wave intersects the monsoon trough, near 08N37.5W. Scattered moderate isolated strong convection is noted from 03N to 10N between 35W and 45W. Environmental conditions appear generally favorable for development, and a tropical depression could form during the next few days while the system moves west-northwestward at about 20 mph. 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... The axis of a tropical wave is near 37W/38W from 19N southward, moving W at 15 to 20 kt. Scattered moderate and isolated strong convection is noted from 03N to 10N between 35W and 45W. Scattered moderate convection is noted from 00N to 12N between 33W and 46W. Low pressure is centered where the wave intersects the monsoon trough, near 08N37.5W. Please see Special Features section above for more information on the potential for this low to develop into a tropical cyclone. The axis of a tropical wave is near 52W/53W from 19N southward, moving W at around 20 kt. Scattered moderate isolated strong convection is noted from 12N to 15N between 52W and 56W. A 1011 mb surface low is analyzed along the tropical wave near 13N52.5W. There is a low probability that this low will develop into a tropical cyclone. Development, if any, of this system should be slow to occur as the tropical wave moves quickly westward to west- northwestward at 20 to 25 mph, passing through the Lesser Antilles on Wednesday 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 73/74W south of Haiti. There is no significant convection associated to this wave. The tropical wave previously analyzed near 85W has been repositioned to near 82W, south of Cuba. Scattered moderate convection is along the wave axis. ...MONSOON TROUGH/ITCZ... The monsoon trough extends from the coast of Africa near 15N17W to 12N20W to low pres near 08N37.5W to 08N47W. Aside from convection noted in the tropical waves section, scattered moderate isolated strong convection is noted from 00N to 07N between 22W and 30W. GULF OF MEXICO... An upper-level trough runs west-southwest from near the Florida Panhandle across the northern Gulf to over northern Mexico. Divergent flow south of these features is coupling with convergent SE winds to trigger numerous showers and thunderstorms across much of the Gulf basin and surrounding land areas early this evening. A 1011 mb surface low is analyzed near Tampico, Mexico near 22N97W. Scattered moderate and isolated strong convection is noted from 19N to 16N west of 95W. Fresh to near gale force winds and seas of 5 to 8 ft are also noted from 22N to 27N west of 95W. Seas are 3 to 5 ft elsewhere.Moderate to locally fresh E-SE winds prevail across the remainder of the basin, except gentle to moderate south of 22N. 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 fresh 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 2 or 3 days producing showers and thunderstorms. Winds and seas could be higher near thunderstorms. CARIBBEAN SEA... Scattered moderate to strong convection is noted in the SW Caribbean south of 22N and west of 78W including over Panama. Otherwise, no significant convection is noted across the basin south of 18N and east of 80W with a dry trade-wind. Fresh to strong trades are noted in the central Caribbean south of 18N, and in the NW Caribbean north of 16N and west of 84W. Moderate to locally fresh trades prevail elsewhere, except gentle to moderate south of 11N. Seas are in the 6 to 10 ft range in the central Caribbean, 5 to 8 ft in the NW Caribbean, and mainly 4 to 7 ft elsewhere. For the forecast, low pressure along a tropical wave a few hundred miles E of the Lesser Antilles has the potential for slow development as the wave moves quickly W to WNW at 20 to 25 kt, passing near the Lesser Antilles Wed then across the eastern and central Caribbean later this week. Heavy rain is possible in the Lesser Antilles over the next couple of days, regardless of development. Broad low pressure has formed in association with a tropical wave midway between the west coast of Africa and the Windward Islands. Gradually development of this system is also possible over the next few days and the system is showing signs of organization. ATLANTIC OCEAN... Ridging dominates the waters west of 65W with moderate to locally fresh E-SE flow. Seas are 3 to 5 ft across this area east of the Bahamas. Scattered showers and thunderstorms are occurring west of 76W/77W, as well as from 20N to 27N between 65W and 71W due to mid-upper level divergence. To the east, a stationary front extends from 31N35W to 28N54W to 30N58W. Isolated showers are possible near this feature. High pressure ridging prevails both north of and south of the front. Light to moderate anticyclonic winds prevail north of 25N and east of 65W, along with mainly 3 to 5 ft seas. Moderate to locally fresh trades are south of 25N and north of the convergence zone, except fresh to strong from 12N to 16N between 48W and 54W near a vigorous tropical wave and attendant low pressure area. Seas are mainly 5 to 7 ft across this area, except 7 to 9 ft near the area of fresh to strong winds. Fresh to strong N-NE winds are also noted west of the coast of Africa to 20W, north of 19N due to a locally tight pressure gradient, where seas are 6 to 9 ft. 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. $$ AL