000 AXNT20 KNHC 101755 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1805 UTC Mon May 10 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 1745 UTC. ...Special Features... Caribbean Gale Warning: High pressure located north of the Caribbean Sea combined with the Colombian low will support fresh to strong winds, with frequent gusts to gale force, within about 90 nm of the coast of Colombia through early Tue morning. Then, fresh to strong trade winds will prevail over the south- central Caribbean through Fri. Seas are expected to build to 11 or 12 ft with the strongest winds tonight into early Tue morning. Please read the latest NWS High Seas Forecast issued by the National Hurricane Center, at https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml, for more details. ...MONSOON TROUGH/ITCZ... The monsoon trough enters the Atlantic Ocean through the Sierra Leon/Guinea border at 09N13W, then continues southwestward to near equator at 25W, where latest scatterometer data indicates it transitions to the ITCZ to 01N37W and to near the equator at 44W. Scattered moderate to isolated strong convection is within 120 nm north of the ITCZ between 28W-31W. Scattered moderate convection is within 60 nm north of the ITCZ between 31W-35W. Other scattered moderate convection is west and northwest of the ITCZ from the equator to 05N and west of 46W to inland French Guiana and Suriname. GULF OF MEXICO... Atlantic high pressure extends westward across central Florida and to the central Gulf waters. The overnight Yucatan Peninsula trough has shifted westward into the far eastern Bay of Campeche, but is weakening. Generally gentle to moderate southeast winds are over the eastern half of the Gulf while moderate to locally fresh southeast to south winds are noted over the western half of the Gulf as noted in a recent ASCAT pass there. Seas are generally 4-6 ft W of 90W, and 3-4 east of 90W. Scattered showers and thunderstorms are over the far northern Gulf north of 28N and between 85W-90W. A series of upper-level disturbance along with plenty of instability in that part of the Gulf should allow for this activity to remain quite active through the rest of the afternoon. Frequent lightning and strong gusty winds can be expected with this activity. Scattered to broken high clouds are streaming eastward from central Mexico to the western Gulf south of 27N. As for the forecast: The pressure gradient between a ridge across the Gulf region and lower pressures over Texas and NE Mexico will continue to support moderate to locally fresh southerly winds across the W Gulf through Tue. A surface trough will develop over the Yucatan Peninsula each evening and dissipate over the SW Gulf by morning. Moderate to fresh easterly winds will be associated with this trough. A frontal boundary will linger across the northern Gulf coast through Tue night. Building high pressure across the SE CONUS will push the front across the Gulf on Wed, and it is expected to exit the basin by Fri night. Fresh to strong northerly winds and building seas will follow the front. CARIBBEAN SEA... A Gale Warning in currently in effect for near the coast of Colombia for frequent gusts to gale force. Please, see the Special Features section for more details. A partial ASCAT pass from this morning showed fresh to strong trade winds over the south- central Caribbean. Similar winds are in the Gulf of Honduras. Elsewhere, mainly moderate winds are occurring. Seas are 8-11 ft over the south- central Caribbean, 5-7 ft in the Gulf of Honduras and 4-7 ft elsewhere, except 1-3 ft in the lee of Cuba. A diffluent pattern aloft east of an upper-level trough axis continues to support abundant cloudiness and some shower activity over the eastern Caribbean. Plenty of atmospheric moisture will persist in that region through tonight, and combine with the local effects to maintain unsettled weather in the form of scattered showers and isolated thunderstorms over and near Puerto Rico and Hispaniola. As for the forecast: Fresh to strong trade winds will continue over the south-central Caribbean through Fri. Fresh to strong winds are also expected in the Gulf of Honduras tonight and Tue night. A moisture surge will continue to affect the eastern Caribbean through tonight. ATLANTIC OCEAN... A frontal trough extends from near 31N55W to 28N60W. Isolated showers are possible near the trough. A ridge extending from a 1076 mb high center east of Bermuda, dominates the forecast waters W of 60W. Moderate to fresh southerly winds are noted across the western periphery of the ridge and ahead of a frontal boundary located over the southeastern United States. The remainder of the Atlantic is also under the influence of a ridge, with another high pressure center of 1027 mb localed near 31N45W. Farther east, another high pressure center of 1026 mb is analyzed to the southwest of the Azores and near 35N79W. Moderate to fresh trade winds as depicted in ASCAT data from this morning are across the majority of the tropical Atlantic waters, along with seas in the range of 5-7 ft. As for the forecast: The next cold front will move southward across the western Atlantic on Wed and stall near 31N on Thu. A low will develop along the front on Fri allowing the front to move across the northern forecast waters through late Sat while weakening. High pressure will follow the front. $$ Aguirre