873 AXNT20 KNHC 312346 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0005 UTC Fri Nov 1 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 1800 UTC surface analysis and satellite imagery through 2300 UTC. ...SPECIAL FEATURES... A cold front enters the region near 31N35W and extends southwestward to near 21N44W, then becomes stationary continuing on to the Lesser Antilles to near 16N61.5W. High pressure of 1027 mb is located N of Bermuda and extends a broad ridge south and southeastward behind the front, and 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 high 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. In addition, heavy rainfall will be possible through the weekend from the Virgin Islands westward across the north and northeast portions of the Greater Antilles to eastern Cuba, as the front meanders across the region. This may lead to flash flooding and potential landslides across these islands through the weekend. Please see the latest NWS High Seas Forecast issued by the National Hurricane Center at website https//www.nhc.noaa.gov/text/MIAHSFAT2.shtml and weather bulletins issued by your local weather agency for more details. ...TROPICAL WAVES... A tropical wave is along 55W, south of 15N, moving westward at 5 kt or less. This wave has been interacting with a middle level trough extending southwestward into this area for the past 24 hours and has significant interrupted the westward motion of the wave. Scattered moderate isolated strong convection is noted from 14N to 19N between 49W and 57W. A second tropical wave is analyzed over the central Caribbean along 77W-78W, south of 18N, moving westward at around 20 kt. Scattered moderate convection is noted behind the wave from 13N to 16.5N between 72W and 75W. Other convection across the W Caribbean is associated with the Eastern Pacific monsoon trough and a Central American Gyre (CAG) event that is expected to develop over the next several days. ...MONSOON TROUGH/ITCZ... The monsoon trough enters the Atlantic through a 1008 mb low pressure center near 14.5N16W and continues southwestward to 06N28W and then westward to 06N31W. The ITCZ then continues from 06N31W to 02.5N50W. Scattered moderate isolated strong convection is occurring across a large area from 02N to 11N between 17W and 36W. GULF OF MEXICO... A 1027 mb high pressure center located N of Bermuda extends a ridge southwestward across the SE U.S., north Florida, and into the north central Gulf. This pattern is supporting fresh to locally strong easterly winds over the eastern half of the basin, and gentle to moderate E to SE winds over the western Gulf, except in the Bay of Campeche where mainly gentle NE to E winds prevail. Seas of 5 to 8 ft are found across the eastern Gulf, except to 9 ft within the Gulfstream. Seas of 4 to 6 ft prevail across the western half of the basin, with the exception of 2 to 4 ft in the Bay of Campeche. Scattered showers and thunderstorms across the Texas and southwest Louisiana coastal waters, along and just ahead of an approaching cold front. 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 scatterometer data showed 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 7 ft across much of the northern Caribbean, except 8 to 9 ft in the Atlantic passages and in the lee of Cuba, while seas of 2 to 5 ft prevail elsewhere. Scattered moderate isolated strong convection is noted across the western Caribbean from coastal Yucatan to northern Colombia. Scattered to numerous moderate to strong convection is noted over the northeastern Caribbean, north of 14N and east of 68W, and extends northeastward across the adjacent islands and into the Atlantic, supported by an upper level low center moving southeastward across Hispaniola. Abundant tropical moisture and favorable atmospheric conditions will persist across these two areas 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 day or two. 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, a strong high pressure ridge 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. Large N to NE long period swell entering the NE Caribbean passages today will continue before subsiding late on Sat. Active weather will impact the majority of the basin into the weekend. ATLANTIC OCEAN... Please see the Special Features section above for details regarding building seas behind a front extending across the central Atlantic. Morning satellite scatterometer winds showed most of the area W of 55W with fresh to strong NE winds, and seas of 8 to 14 ft. Scattered to numerous moderate isolated strong convection continues across the NE Caribbean and extends northward to 22.5N across the Atlantic and between 57W and 70W. This convective activity is ahead of an upper-level trough crossing 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 across this area for the next several days. Ahead of the cold front, morning satellite scatterometer data showed fresh to strong S winds ahead of the front, 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. For the forecast west of 55W, a very tight pressure gradient occurring between high pressure centered N of Bermuda and a lingering frontal zone across the north and northeast Caribbean controls the wind regime W of 55W. 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 convection currently is S of about 24N and E of 70W is likely to be further enhanced as a trough develops near Puerto Rico going into the weekend, and it moves west-northwestward across portions of near the Greater Antilles. The present ongoing strong to near gale-force E winds over these same waters may reach gale-force Fri night into the upcoming weekend due to a tightening of the pressure gradient between the trough and the high pressure to the N. Marine interests over these waters should take the necessary action to avoid hazardous marine conditions. Please monitor the latest forecasts and Tropical Weather Outlooks. $$ Stripling