000 AXNT20 KNHC 102313 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0005 UTC Sun Jun 11 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 2300 UTC. ...SPECIAL FEATURES... Excessive Rainfall in eastern and central Cuba and the central Bahamas: The upper level trough centered over the far eastern Gulf of Mexico with SW flow extending to the surface continues to maintain an Atmospheric River over Jamaica, Cuba, and the Bahamas. For the 24 hour period ending 1200 UTC on Sat, 12 inches (313 mm) of rainfall was reported at Las Mercedes in Granma, Cuba. This combined with 24 hour rainfall report of 14 inches (360 mm) on Fri, Las Mercedes has observed an impressive total of 26.5 inches (673 mm) of rain over the past two days. Additional 24 hour rainfall reports from Sat morning range from 8-12 inches (200-300 mm) elsewhere in Camaguey, Granma and Las Tunas. Conditions are forecast to improve in eastern Cuba by tonight, but locally heavy rain is expected to continue through Sun in the central Bahamas. Computer model suggests that a plume of tropical moisture will persist over central Cuba and the central Bahamas on Sun. Please refer to the latest forecast from your national meteorological service for more information. ...TROPICAL WAVES... An eastern Atlantic tropical wave is near 27W from 11N southward, moving west at 15-20 kt. Scattered moderate convection is noted from 04N to 08N between 24W and 28W. A central Atlantic tropical wave is near 46W/47W from 12N southward, moving west at 15 kt. A few showers are near the wave axis. A Caribbean tropical wave is near 66W/67W from 11N southward through central Venezuela, moving west at 10 kt. Scattered moderate convection is near the wave axis over Venezuela. ...MONSOON TROUGH/ITCZ... The monsoon trough enters the Atlantic through the coast of Guinea Bissau near 11N15W and continues SW to 06N20W to 05N28W. The ITCZ extends from 05N28W to 04N44W to 05N52W. Clusters of moderate to isolated strong convection are noted from Liberia to Guinea. Similar convection exists from 05N to 08N E of the 17W to the coast of W Africa. GULF OF MEXICO... A weak pressure pattern continues to dominate the Gulf waters supporting mainly light to gentle winds and slight seas. A stationary front is near the Florida/Georgia border, generating showers and thunderstorms. Less convective activity is noted this evening across the Gulf waters compared with the previous couple of days. The mid-upper level trough that was located over the eastern Gulf is now reaching Florida. For the forecast, the weak pressure gradient across the basin will maintain light to gentle winds through this evening. Low pressure along a frontal boundary over Texas will bring moderate to locally fresh return flow over the western Gulf through Tue. By the middle of next week, the area of fresh southerly winds should expand over the western and central Gulf. CARIBBEAN SEA... Please read the Special Features section for information about Excessive Rainfall impacting Cuba. Once again, showers and thunderstorms have flared-up across west and central Cuba during the afternoon hours. A plume of tropical moisture extends from the SW Caribbean across Jamaica into eastern Cuba and the central and SE Bahamas. Showers and thunderstorms are also observed over most of Central America. A diffluent pattern aloft is helping to induce this convective activity. High pressure of 1020 mb located over the central Atlantic near 25N48W extends a ridge westward reaching the NE Caribbean. The pressure gradient between the ridge and the Colombia low supports moderate to locally fresh trades in the eastern and central Caribbean with 4-6 ft seas. SE winds are gentle to moderate in the western Caribbean with 2-4 ft seas. Higher winds are noted near the convection, particularly just off western Jamaica. For the forecast, the pressure gradient between the central Atlantic high pressure and the Colombia low will maintain fresh to locally strong winds in the south central Caribbean through Sun, with moderate to fresh winds elsewhere over the eastern and central Caribbean. Easterly trade winds will increase to fresh to strong while significantly expanding in areal coverage across the central Caribbean Sun night through late next week. Locally strong winds will pulse in the Gulf of Honduras during the afternoon and evening hours Mon through Wed. ATLANTIC OCEAN... Please read the Special Features section for information about Excessive Rainfall for the Bahamas. A cold front crosses just S of Bermuda and extends SW to near 31N67W where it becomes stationary, then continues westward along 30N between 70W and the US Coast. Fresh to strong SW winds are ahead of the front N of 28N between 60W and 70W. Seas are 6-8 ft within these winds. Mainly gentle to moderate E winds are N of the stationary portion of the front with seas of 3-5 ft. As previously mentioned, high pressure located over the central Atlantic extends a ridge towards the Bahamas, where a band of multilayer clouds with embedded showers and thunderstorms is noted affecting mainly the central and SE Bahamas. This 240-270 nm wide band of clouds stretches all the way NE towards Bermuda. A surface trough runs from 30N25W to 21N36W. Some shower activity is near the trough axis. A 1017 mb high is noted over the Canary Islands. Mainly light to gentle winds are observed across the Atlantic E of 50W with seas generally in the 3-5 ft range, except 1-3 ft near the Canary Islands. Moderate to locally fresh trades are E of the Lesser Antilles to 50W with seas of 4-5 ft. For the forecast west of 55W, high pressure extending from the central Atlantic is creating a tight pressure gradient with relatively lower pressures along a frontal boundary extending from Bermuda to Jacksonville, FL. This will maintain fresh to strong SW winds to the southeast of Bermuda through early this evening. As the front weakens, gentle to moderate winds will prevail over the area tonight through early next week. Enhanced thunderstorms will likely continue over portions of the western Atlantic, including the Bahamas, through Sun. By the middle of next week, SW winds could increase a bit north of 29N as a frontal boundary lingers near the southeast U.S. coast. $$ GR