000 AXNT20 KNHC 231721 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1805 UTC Wed Jun 23 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. ...TROPICAL WAVES... A tropical wave axis is analyzed along 26/27W from 16N southward, moving W at 10-15 kt. Scattered moderate showers prevail within 120 nm W and 180 nm E of the wave axis from 02N-08N. An Atlantic Ocean tropical wave axis is along 43W from 12N southward, moving W at 10 kt. Scattered moderate showers are noted within 270 nm either side of the wave axis from 04N-08N. An Atlantic Ocean tropical wave axis has been repositioned slightly eastward from the previous map, along 55W from 15N southward, based on evidence from satellite imagery. The tropical wave is moving W at 5-10 kt. Scattered moderate convection is noted from 04N-16N between 49W-56W. A tropical wave has been added to the analysis over the central Caribbean Sea, along 70W from the Dominican Republic southward to western Venezuela. The tropical wave is moving W at 10 kt. Scattered showers and isolated tstorms are seen from 16N-18N between 69W-72W. ...MONSOON TROUGH/ITCZ... The monsoon trough passes through the coast of Guinea-Bissau near 12N16W to 05N29W. The ITCZ is from 05N29W to 05N40W. Aside from the convection described in the tropical waves section above, scattered moderate convection is noted along the ITCZ between 30W-37W. Numerous moderate and scattered strong convection is seen off the coast of Africa from 02N-10N between 06W-18W. GULF OF MEXICO... A cold front extends from the coast of Georgia near 31N81W westward to the Alabama/Mississippi border near 31N88W and continues W as a stationary front just inland from the Gulf Coast, to near New Iberia, Louisiana. The front is being supported by an upper-level trough that extends along the U.S. east coast, across northern Florida and into the NE Gulf of Mexico. Scattered showers and isolated tstorms are seen along the Gulf Coast of Florida, extending offshore for about 60 nm, from Key West to Pensacola. Another area of scattered moderate convection is occurring near the Mouth of the Rio Grande River and extending offshore into the western Gulf for about 60 nm. A recent ASCAT pass shows fresh SE winds to the NW of the Yucatan Peninsula, where seas are likely 4-5 ft. Gentle wind speeds are over the eastern Gulf of Mexico, with seas of 2-3 ft. High pressure will prevail across the northern Gulf of Mexico. A diurnally induced trough will develop over the Yucatan each evening. This will result in a pulsing of fresh E to SE winds each night NW of the Yucatan peninsula through Thu night. CARIBBEAN SEA... An upper level low is centered between Jamaica and eastern Cuba. Isolated moderate thunderstorms are seen between western Cuba and the Cayman Islands, as well as between Jamaica and far eastern Cuba. In the SW Caribbean, the monsoon trough is inducing numerous moderate and scattered strong convection south of 11N between 77W-83W. Another area of scattered moderate and isolated strong convection is occurring over the SE Caribbean, from 10N-13N between 60W-67W, due to enhanced moisture in the area in between two tropical waves. This area includes Trinidad, Grenada and the NE coast of Venezuela. A recent ASCAT pass shows fresh NE to E trades in the south-central Caribbean, offshore of Colombia. Fresh to locally strong E to SE winds are likely occurring in the Gulf of Honduras. Moderate trades prevail elsewhere. Seas are 5-6 ft in the central Caribbean and Gulf of Honduras, and 3-4 ft elsewhere, except 1-2 ft south of Cuba. A ridge of high pressure north of the area combined with the Colombian low will continue to support fresh to strong trades over the south-central Caribbean and the Gulf of Honduras through tonight. The ridge will shift northward loosening the pressure gradient with a modest decrease in winds over these areas. ATLANTIC OCEAN... A surface trough is analyzed over the western Atlantic from 31N78W to 28N80W. A line of moderate to strong convection is along, or just east of the surface trough. Isolated showers and tstorms are elsewhere from the NW Bahamas northward, and west of 76.5W to the Florida Peninsula. Farther east, an upper-level low is centered near 28N51W. A surface trough just east of the upper- low extends along 48W from 31N-24N. Scattered moderate convection is seen from 25N-30N between 46W-50W. A 1025 mb surface high pressure near 31N63W extends a surface ridge to southern Florida. A recent ASCAT pass shows gentle to moderate wind speeds north of 23N and west of 40W, except for moderate to fresh east of northern Florida, close to the surface trough. Seas are 3-5 ft across the subtropical Atlantic, except 4-6 ft east of northern Florida. Moderate to fresh trades are south of 23N and west of 40W, where seas are 5-6 ft. Fresh N to NE winds prevail near the coast of Africa, north of 17N and east of 30W, except for strong to near gale force N winds near the coast of Morocco. Seas are 6-8 ft over the NE Atlantic. For the forecast, the surface ridge axis that extends from 31N63W to 26N80W will start to shift northward tonight. This will push the surface trough that is currently located off NE Florida westward into the SE United States by Fri night. Farther southeast, a tropical wave east of the Lesser Antilles will interact with an upper level trough, which will enhance convection with locally higher winds and seas through Fri, east of the Lesser Antilles. A surface trough will form as a result of this system, then move north of the Lesser Antilles Friday night. The trough will continue to move westward across the waters north of Puerto Rico Sat, and north of Hispaniola Sun. $$ Hagen