000 AXNT20 KNHC 120530 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0605 UTC Fri Aug 12 2022 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... The axis of a tropical wave is along 44/45W from 03N-23N, moving westward at 20 kt. A large envelope of moist air is seen in Total Precipitable Water imagery, in association with the tropical wave. Scattered moderate convection is noted within 270 nm either side of the wave axis from 08N to 14N. The axis of a tropical wave is along 57W from 20N southward to the Suriname/Guyana border, moving westward at 15 kt. The portion of the wave north of 12N is currently enveloped in an area of westward moving Saharan dust. No significant convection is noted with the wave at this time. The axis of a central Caribbean tropical wave is along 70W from the Dominican Republic southward to western Venezuela, moving westward at 15 kt. No convection is noted with the wave at this time over water, but scattered showers and isolated thunderstorms are noted over Hispaniola. The axis of a tropical wave is along 95W, extending from the Bay of Campeche near 20N southward through Oaxaca, Mexico and into the east Pacific. The tropical wave is moving W at 10 kt. Isolated moderate to strong convection is noted over the eastern Bay of Campeche as well as over portions of the Mexican states of Oaxaca, NW Chiapas, SW Tabasco, and SE Veracruz. ...MONSOON TROUGH/ITCZ... The monsoon trough extends from the coast of Senegal near 14N17W to 12N24W to 13N38W to 11N53W. Aside from the convection mentioned in the tropical waves section above, scattered moderate isolated strong convection is noted from 07N to 12N east of 23W, and from 08N to 11N between 33W and 36W. GULF OF MEXICO... A trough over the NW to west-central Gulf of Mexico extends from the surface up to the mid-troposphere near 500 mb. Abundant moisture is seen over the NW Gulf in Total Precipitable Water imagery. Although the coverage and intensity of thunderstorms in the Gulf has diminished significantly overnight compared to during the daytime on Thursday, expect thunderstorms to return to the northwest Gulf during the daytime today as the trough and moisture sticks around. This activity will then continue over the northern Gulf waters through Sat before shifting across the NW Gulf Sun as a frontal boundary stalls near the northern Gulf coast. Locally gusty winds and rough seas are possible within the stronger thunderstorms. Weak high pressure ridging extends from the western Atlantic westward along 29N to 1018 mb high pressure just offshore the Florida Big Bend near 29N83.5W to the N central Gulf. Buoys are currently reporting gentle to moderate wind speeds and 2 to 4 ft seas across the basin. A recent ASCAT satellite wind data pass also shows gentle to moderate wind speeds across most of the basin. The high pressure ridge will shift east-southeast late today through Sun. This will allow for gentle to moderate winds over the basin to weaken to light to gentle into next week. Moderate NE to E winds will pulse to fresh during the late afternoon and evenings off the NW Yucatan peninsula through early next week. CARIBBEAN SEA... A broad upper-level low is centered just east of the Bahamas near 25N74W. An upper-level trough axis extends southwestward from there to eastern Cuba and westward to the Yucatan Peninsula. Upper-level diffluence is enhancing scattered showers and thunderstorms just south of Cuba and over the waters near the Tiburon Peninsula of Haiti. Isolated showers and thunderstorms are occurring over the SW Caribbean in association with the east Pacific monsoon trough. The remainder of the basin is not currently experiencing any significant precipitation. A recent ASCAT satellite wind data pass shows mainly moderate trade winds over the basin. Gentle E winds are likely occurring over the NW Caribbean. A 11/2300 UTC altimeter pass shows seas of 5 to 6 ft in between Jamaica and Panama. NOAA buoy 42059 near 15.3N 67.5W is reporting a significant wave height of 5 ft. Seas across the basin are averaging 4 to 6 ft. The Atlantic ridge extends from the central Atlantic W-SW to northern Florida along 29N, and will weaken through early next week. Fresh trade winds over the central Caribbean will weaken to moderate Sat through Mon, then increase back to fresh late Mon through Tue night. Active weather is possible in the central Caribbean through the upcoming weekend as an upper-level trough parks itself over the Bahamas and Cuba. A broad tropical wave, currently along 45W, is expected to reach the Lesser Antilles Sat night into Sun, move across the eastern Caribbean Sun through early Mon, and across the central Caribbean Mon through Tue night. ATLANTIC OCEAN... A broad upper-level low is centered just east of the Bahamas near 25N74W. Ridging in the low and mid levels to the north of 27N is allowing for only scattered weak showers over the area from 27N- 31N between 69W-75W. A 1019 mb high is centered near 30N76W. This high is along a surface ridge axis that extends from 32N60W to 30N76W to 29N83W. A recent ASCAT pass shows gentle or weaker winds from 26N-31N between 55W-82W. Seas are near 3 ft across that entire area. Moderate trades prevail through the Bahamas and north of the Greater Antilles, except for fresh north of Hispaniola and in the Windward Passage. Seas are likely near 5 ft in this area. Another upper-level low centered near 29N57W is enhancing scattered showers and isolated thunderstorms from 28N-31N between 47W-61W. A surface trough extending from 31N59N to 29N61W is contributing to that activity. A 1025 mb surface high pressure is centered near 31N36W. Moderate to fresh trades and 5-7 ft seas prevail from the monsoon trough to 27N between 30W-55W. Strong NE winds and 7-10 ft seas are likely occurring from 17N-24N between the coasts of Mauritania/Western Sahara and 27W. Gentle winds prevail from 27N-31N between 25W-55W with 3-5 ft seas. The ridge extending from the central Atlantic W-SW to northern Florida along 29N will weaken through early next week as a frontal boundary moves off the eastern seaboard and stalls over the waters east of NE Florida. Moderate to fresh E winds S of 25N will veer to the SE and weaken to gentle early Sat and change little into next week. Light to gentle variable winds are expected elsewhere through the period. A tropical wave will reach the southeast forecast waters between 55W-65W by Sat, bringing a slight increase in winds and seas over those waters through early on Mon. $$ Hagen