000 AXNT20 KNHC 232227 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0005 UTC Mon Jul 24 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 1800 UTC surface analysis and satellite imagery through 2200 UTC. ...SPECIAL FEATURES... Tropical Storm Don is centered near 45.2N 46.5W at 23/2100 UTC or 290 nm ESE of Cape Race Newfoundland moving NE at 15 kt. Estimated minimum central pressure is 996 mb. Maximum sustained wind speed is 50 kt with gusts to 60 kt. The center of Don is becoming less defined as the storm moves over cooler waters. Moderate convection is within 60 nm on the southern semicircle, but with no convection on the northern part of the storm. Seas in excess of 12 ft extend as far as 150 nm from the center, mainly on the southeast side of the storm. Rapid weakening is expected as Don continues to move northeastward over cooler waters. Please read the latest HIGH SEAS FORECAST issued by National Hurricane Center at website https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml and the latest T.S. Don Forecast/Advisory and Public Advisory at www.hurricanes.gov for more details. ...TROPICAL WAVES... An eastern Atlantic tropical wave has its axis along 25W across the Cabo Verde Islands from 04N to 20N. It is moving westward at 10-15 kt. Scattered moderate convection is seen from 07N to 10N and between 20W-27W. A central Atlantic tropical wave has its axis along 40W from 04N to 20N, moving westward at 10-15 kt. No significant convection is seen associated with this wave. ...MONSOON TROUGH/ITCZ... The monsoon trough axis enters the Atlantic through the coast of Mauritania near 20N16W and continues southwestward to 10N25W to low pressure (Invest 95L) near 11N47W. Scattered moderate convection is noted from 10N to 14N between 47W and 53W. ...GULF OF MEXICO... A pre-frontal trough extends from Tampa Bay, Florida to just off Brownsville, Texas. Scattered moderate to isolated strong convection is noted north of the trough over the north-central Gulf. Scattered showers and a few thunderstorms are noted near a surface trough over the southwest Gulf. A surface ridge extends between these troughs from the Straits of Florida to the lower Texas coast. This pattern is supporting moderate SW to W winds and 2 to 4 ft in the northeast Gulf, and gentle breezes with 1 to 3 ft seas elsewhere. For the forecast, weak high pressure centered near the Florida Peninsula will remain dominant through the Gulf through mid-week. This will support mainly gentle to moderate winds, except over the eastern Bay of Campeche where winds will be enhanced by a daily trough that will emerge off the Yucatan Peninsula nightly. A weak cold front will move into the far NE Gulf tonight, then stall through midweek, providing a focus for showers and thunderstorms in adjacent waters. ...CARIBBEAN SEA... Trade wind convergence is supporting scattered showers and thunderstorms over the far southwest Caribbean, off southeastern Nicaragua and northeastern Costa Rica. Subsident flow aloft on the west side of an upper low centered southeast of Jamaica is suppressing most convection elsewhere over the western Caribbean. Regional radar is showing a few fast-moving trade wind showers over the eastern Caribbean. Regional buoy and land-based observations show fresh to strong trade winds across the south- central Caribbean, where combined seas are 6 to 8 ft. Fresh winds and 4 to 6 ft are noted over the Gulf of Honduras, and moderate winds and seas elsewhere. For the forecast, the pressure gradient between the Bermuda High and lower pressure over Central America and northern South America will maintain strong trades across the central Caribbean tonight. Winds should diminish slightly to fresh to strong Mon through Wed night. Fresh to locally strong trades will occur over the Gulf of Honduras into Mon night. Low pressure over the tropical N Atlantic well east of the forecast waters is expected to weaken to a trough during early this week as it approaches the Lesser Antilles. Some increase in winds and seas may accompany the trough. ...ATLANTIC OCEAN... Please see the SPECIAL FEATURES section for information on Tropical Storm Don in the north-central Atlantic. A 1012 mb low pressure system, designated as Invest 95L, is located near 10.6N46.1W. Shower activity continues to be limited in association with this low. Although environmental conditions are only forecast to be marginally conducive for some gradual development, this system could still become a tropical depression during the next few days while it moves westward across the tropical Atlantic and eastern Caribbean Sea. Unfavorable upper- level winds are forecast when the system moves into the central Caribbean around midweek, decreasing the chances of formation. Interests in the Lesser Antilles should monitor the progress of this system. This low has a low chance of development in the next 48 hours. Please refer to the latest Tropical Weather Outlook at www.hurricanes.gov for more details. Elsewhere, a mid to upper level trough reaches from the north- central Atlantic to 25N65W. Upper divergence aloft associated with the trough is supporting scattered showers and thunderstorms within 120 nm to the southeast of the trough, and around the northern Bahamas. Weak ridging is supporting light to gentle breezes and 2 to 4 ft seas west of 55W. Farther east, 1031 mb high pressure is centered near 35N42W. The pattern is supporting moderate to fresh NE to E winds and combined seas of 5 to 8 ft east of 55W and north of the monsoon trough/ITCZ. For the forecast west of 55W, weak high pressure over the area will change little through mid-week. Fresh trades will pulse nightly N just N of Hispaniola and over the Windward Passage. Elsewhere across forecast waters, winds will be moderate or weaker over most of the area with moderate to locally fresh speeds for waters NE of the Leeward Islands. $$ Christensen