000 AXNT20 KNHC 311943 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1805 UTC Thu Oct 31 2024 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 1700 UTC. ...SPECIAL FEATURES... A cold front enters the region near 31N36W and extends southwestward to 20N45W. A stationary front then continues from 20N45W to the Lesser Antilles near 15N61W. High pressure of 1028 mb located N of Bermuda dominates the waters W of the front, including Florida, the Bahamas and the Greater Antilles. The strong pressure gradient associated with this system, supports fresh to strong NE winds and rough seas across most of the waters W of 55W. Seas will continue to build on Friday, with a large area of 12-15 ft seas occurring from 55W to the Bahamas between 20N and 26N starting early Friday and lasting through the weekend. Seas will gradually lower early next week. ...TROPICAL WAVES... A tropical wave is along 55W/56W, south of 15N, moving westward at 10 kt. Little to no convection is associated with this wave. A second tropical wave is over the central Caribbean. Its axis is along 76W, south of 18N, moving westward at around 20 kt. Convection near this wave is more associated with the Eastern Pacific monsoon trough and a developing Central American Gyre (CAG) event over the next several days. ...MONSOON TROUGH/ITCZ... The monsoon trough reaches the Atlantic through the coast of Guinea-Bissau near 12N16W and continues southwestward to 06N21W and then westward to 06N34W. The ITCZ then continues from 06N34W to 03N46W. Scattered moderate convection is mostly associated with the monsoon trough, occurring across a large area from the Equator to 15N between the west coast of Africa and 33W. GULF OF MEXICO... A 1028 mb high pressure located N of Bermuda extends a ridge across Florida into the Gulf region, supporting fresh to strong easterly winds over the eastern half of the basin, and moderate to fresh winds over the western Gulf, except in the Bay of Campeche where mainly gentle winds prevail. Seas of 5 to 8 ft are found across much of the Gulf, with the exception of 2 to 5 ft in the SW Gulf. A diffluent pattern aloft is helping to induce scattered showers and isolated thunderstorms across the south- central Gulf. For the forecast, a tight pressure gradient associated with strong high pressure N of Bermuda will continue to support moderate to fresh winds and moderate seas across most of the Gulf region through the upcoming weekend. Fresh to strong E winds are expected in the southeastern Gulf, including the Straits of Florida, through Fri night, then mostly in the Straits of Florida through the upcoming weekend. A broad area of low pressure is likely to develop over the southwestern Caribbean Sea during the next couple of days. CARIBBEAN SEA... Recent satellite derived wind data provide observations of fresh to strong E to NE winds across roughly the northern half of the basin, including the Windward and Mona Passages as well as the Yucatan Channel. Moderate to fresh E winds are analyzed across much of the remaining central and western Caribbean, while the eastern Caribbean is seeing gentle to moderate E winds. Seas are 5 to 8 ft across much of the northern Caribbean, with 2 to 5 ft seas elsewhere. Numerous moderate and isolated strong convection is occurring over the SW Caribbean and northern Colombia, while another area of showers and thunderstorms is noted over the eastern Caribbean, also impacting Puerto Rico, Hispaniola, and the Lesser Antilles. Upper diffluence supports these areas of convection. Abundant tropical moisture and favorable atmospheric conditions will persist over the next several days, supporting periods of heavy rainfall and localized flooding across portions of Central America and the Greater Antilles. For the forecast, a broad area of low pressure is likely to develop over the southwestern Caribbean Sea during the next couple of days. Gradual development is possible thereafter, and a tropical depression could form over the weekend or early next week while the system drifts generally northward or northwestward over the central or western Caribbean Sea. Meanwhile, high pressure present N of the area will continue to support fresh to strong NE to E winds in the lee of Cuba, the Windward Passage, and south of Hispaniola, including the Mona Passage, into the upcoming weekend. Winds will diminish in the Mona Passage by early Fri morning. Large N to NE long period swell will begin to reach the NE Caribbean passages starting Thu. The swell is expected to subside late on Sat. Active weather will impact the majority of the basin into the weekend. Marine interests over these waters should take the necessary action to avoid hazardous marine conditions. Stay updated with the latest forecasts and Tropical Weather Outlooks. ATLANTIC OCEAN... Please see the Special Features section above for details regarding building seas behind a front extending across the central Atlantic. Recent satellite scatterometer data indicates fresh to strong S winds ahead of the front referenced in the Special Features section, generally north of 23N and west of 30W. Farther E of the front, a 1019 mb high pressure situated W of the Canary Islands near 29N21W is in control of the weather pattern across the remainder of the Atlantic forecast region. Gentle to locally moderate anticyclonic flow and moderate seas are observed under the influence of this system. A weak 1011 mb low pressure area and attendant surface trough is near 14N43W is producing some shower activity. A large area of showers and thunderstorms is affecting the Atlantic waters north of the Leeward Islands, Virgin Islands, Puerto Rico and Hispaniola. This convective activity is ahead of an upper-level trough that crosses Hispaniola. Abundant tropical moisture in place and the presence of the upper-level trough will result in the risk of heavy precipitation and severe weather. For the forecast west of 55W, a very tight pressure gradient associated with high pressure centered N of Bermuda controls the wind regime throughout. This pattern will continue to support strong winds and rough to very rough seas over the Western Atlantic through the next few days. Peak seas of 13 to 16 ft are expected E of the Bahamas through Sun, perhaps subsiding some early next week. Active weather that over the waters S of about 25N and E of the Bahamas is likely to be further enhanced if low pressure develops near the southeastern Bahamas and Hispaniola. The present ongoing strong to near gale force E winds over these same waters may reach gale force Fri night and into the upcoming weekend due to a tightening of the pressure gradient between the low and the high pressure to its N. Marine interests over these waters should take the necessary action to avoid hazardous marine conditions. Stay updated with the latest forecasts and Tropical Weather Outlooks. $$ Adams