000 AXNT20 KNHC 100545 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0605 UTC Mon Jul 10 2023 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 0500 UTC. ...TROPICAL WAVES... An Atlantic tropical wave has its axis along 44W from 06N to 19N, moving westward at about 20 kt. A brought area of scattered moderate convection is seen on either side of the wave from 09N to 18N between 38W-50W. Latest scatterometer data showed fresh northeast- east winds in the vicinity of the tropical wave. A tropical wave in the eastern Caribbean Sea has its axis along 63W from the coast of Carupano Venezuela to 19N, and is moving westward at 15-20 kt. No significant convection is noted at this time. A central Caribbean tropical wave has its axis extending from the southeastern Bahamas to across western Haiti, and continues to inland Colombia near 08N75W. This wave is moving westward at about 15 kt. Scattered to isolated strong convection is seen over Haiti, on both sides of the wave axis. ...MONSOON TROUGH/ITCZ... The monsoon trough axis enters the Atlantic through the coast of Senegal near 14N17W. It extends southwestward to near 08N25W, where it transitions to the ITCZ and continues to 08N32W to 10N42W. The ITCZ resumes at 11N45W and continues to the coast of Guyana near 08N58W. Aside from convection mentioned above under the Tropical Waves section , scattered moderate convection is within 120 nm south of the ITCZ between 29W-35W, and north of the ITCZ from 09N to 15N between 54W to 59W. GULF OF MEXICO... Weak Atlantic high pressure ridging stretches southwestward across South Florida, the Florida Keys and the Straits of Florida to the southeastern Gulf waters. Its associated gradient is allowing for generally light to gentle anticyclonic flow across the basin, with seas 2-4 ft. Scattered to numerous showers and thunderstorms, some on the strong side are producing frequent lightning and locally strong winds and seas. This activity is moving east-southeastward over the far northeastern Gulf. This activity is ahead of an upper- level shortwave trough and spreads well inland northern Florida, the Florida Panhandle, Alabama, Mississippi and Louisiana. Another area of scattered to numerous showers and thunderstorms is seen in the Campeche Bay in association with the interaction of a surface trough and an eastern Pacific tropical wave. For the forecast, a ridge will continue to dominate the Gulf waters while a trough will develop over the Yucatan Peninsula each evening and move offshore. Under this weather pattern, moderate to fresh winds will pulse north and west of the Yucatan peninsula during the late afternoon and evening hours. Elsewhere, gentle to moderate winds and slight seas will prevail. CARIBBEAN SEA... Please see the Tropical Waves section above for more details on a couple of tropical waves that are moving through the basin. Fresh to strong trade winds are in the south-central Caribbean as a result of the pressure gradient between a broad central Atlantic high pressure and relatively lower pressure found in Colombia, where the climatological low is located. Resent data from the scatterometer shows northeast to east strong to near gale-force winds right of the coast of Colombia. Within this area seas are 6 to 9 ft. Fresh trade winds are elsewhere in the central Caribbean along with seas of 5-7 ft. In the eastern and western Caribbean, trade winds are gentle to moderate along with seas of 3-6 ft. GOES 16 Saharan Air Layer Tracking Products is depicting an area of Saharan Dust in the eastern Caribbean and moving west. This area of dust will move over Puerto Rico and the U.S Virgin Island this morning. Across the area affected by this, expect lower dewpoint temperatures and haze skies. For the forecast, fresh to strong winds and rough seas are expected over the central Caribbean through at least Tue. Fresh to locally strong winds will pulse in the Gulf of Honduras at night through Tue night, then mainly moderate to fresh winds prevail. Generally moderate winds and seas will persist elsewhere. Looking ahead, a tropical wave is forecast to bring an increase in winds and seas across the waters E of the Leeward Islands on Tue, and over the NE Caribbean on Wed. Fresh to strong NE winds are expected in the Windward Passage ahead of the wave axis by Wed night. ATLANTIC OCEAN... A 1026 surface high pressure is analyzed near 36N25W, and a 1026 mb high is located near 32N32W. In general, broad high pressure covers the Atlantic north of 20N and east of 70W. West of 70W, the high pressure becomes a ridges axis that stretches southwestward to South Florida, the Florida Keys and the Straits of Florida. South of 20N, the gradient is allowing for moderate to fresh trade winds along with seas of 6-8 ft. North of 20N, the gradient supports gentle to moderate anticyclonic winds along with seas of 3-6 ft. Scattered showers and thunderstorms are occurring north of 29N between 61W-71W. This activity is shifting eastward as it is being sustained by an upper-level trough that extends from offshore the eastern U.S seaboard, southwestward to the NW Bahamas. Scattered to numerous showers and thunderstorms are pushing offshore central and northern Florida to near 79W in association with a surface trough. This activity contains frequent lightning and may be accompanied by locally higher winds and seas. An upper-level low is identified on water vapor imagery near 26N52W. Last GOES-E visible imagery shows high clouds rotating cyclonically from 22N to 28N and between 49W-55W An area of Saharan Dust (also referred to as the Saharan Air Layer), typical for this time of year, is moving throughout the Atlantic Ocean as depicted by GOES 16 Saharan Air Layer Tracking Products. While another Saharan Air Layer outbreak seems to be on going. Therefore, expect patches of dust through the basin with lower dewpoint temperatures and haze skies. A cluster of showers and thunderstorms are seen exiting the coast of Guinea. This convection may be associated with the next tropical wave. For the forecast W of 55W, a ridge will remain in place while a trough persist off the Carolina and Georgia coasts. The pressure gradient between these two features will support moderate to fresh SW winds north of 27N through Tue. A developing low pressure just N of the forecast region could bring increasing winds over the NE waters Tue night into Wed. The northern end of a tropical wave is forecast to impact the waters north of the Leeward Islands and Puerto Rico on Wed, and north of Hispaniola, including approaches to the Windward Passage by Wed night. Light to gentle winds will persist elsewhere along the ridge axis. $$ KRV