000 AXNT20 KNHC 282327 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0005 UTC Sun Oct 29 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 2350 UTC. ...SPECIAL FEATURES... Tropical Storm Tammy is centered near 33.2N 57.0W at 28/2100 UTC or 400 nm E of Bermuda, moving E at 13 kt. Estimated minimum central pressure is 997 mb. Maximum sustained wind speed is 40 kt with gusts to 50 kt. Peak seas are 19 ft. Tammy is expected to gradually turn southward and eventually southwestward as a remnant low early next week. Some weakening is forecast during the next 48 hours, and Tammy is forecast to become a post-tropical remnant low early next week. Please read the latest HIGH SEAS FORECAST issued by the National Hurricane Center at website https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml and the latest Tammy NHC Forecast/Advisory and Public Advisory at www.hurricanes.gov for more details. ...MONSOON TROUGH/ITCZ... The monsoon trough enters the Atlantic through the coast of Guinea-Bissau near 12N16W and continues southwestward to 07N20W. The ITCZ extends from 07N20W to 07N37W to 07N54W. Scattered moderate isolated strong convection is from 06N to 17N between 32W and 46W, and from 07N to 15N between 47W and 60W. GULF OF MEXICO... A 1019 mb center of high pressure over the SE United States extends southwestward to the central Gulf of Mexico. A tight pressure gradient between the ridge and Tropical Depression 19-E located over Guatemala and El Salvador offshore waters currently supports fresh to strong winds along the Florida Straits and portions of the SE Gulf of Mexico. Seas over these regions are in the 5 to 9 ft range. Elsewhere in the eastern half of the basin, winds are moderate to fresh from the east with seas of 4 to 6 ft. In the western half of the gulf, winds are mainly moderate from the east-southeast, except off the coast of Yucatan where fresh to locally strong NE winds are noted. For the forecast, high pressure centered across the middle Atlantic coastal states will continue to support fresh to locally strong winds in the southeast and south central Gulf through Sun. Gentle NE winds are expected by Mon as the pressure gradient weakens and high pressure settles over the region. A strong cold front will enter the NW Gulf Mon morning, and move SE across the entire basin by Wed evening. This front will bring gale force winds and quickly building seas over the western Gulf beginning Mon evening. CARIBBEAN SEA... Strong high pressure centered over the middle Atlantic U.S. coast is combining with elongated low pressure across the Caribbean along 68W-69W and into the adjacent Atlantic to support fresh to locally strong NE to E winds in the NW Caribbean. East of 67W, winds are mainly moderate and from the east-southeast and seas are 5 to 6 ft. In the central and SW Caribbean, winds are light to gentle with slight seas. For the forecast, the trough and associated low will shift W-NW through early next week, with winds diminishing across the NW Caribbean on Sun. Scattered to numerous strong thunderstorms occurring along and E of the trough will shift westward with the trough through Mon. Large N-NE swell across the W Atlantic will continue to move through the NE Caribbean Passages through Sun. A strong cold front will enter the NW Caribbean Wed afternoon. ATLANTIC OCEAN... Please see the SPECIAL FEATURES section above for information on TROPICAL STORM TAMMY. In the W Atlantic west of 55W, seas are 8-10 ft in N to NE swell. 10-12 ft seas are from 22N to 28N between 71W and 77W near the Bahamas. Recent scatterometer depicts an area of fresh to locally strong NE winds from 24N to 27N between 71W and 81W, including the Bahamas and Florida Straits. These winds and swell are the combined effects of building high pressure centered over the SE United States and Tropical Storm Tammy centered north of TAFB Waters. A surface trough extends from the coast of Puerto Rico near 18N67W to 30N62W, with 1008 mb low pressure centered along the trough axis near 20N66W. Scatterometer shows strong to near gale force E winds from 19N to 21N between 65W and 67W. Fresh E winds are elsewhere from 18N to 23N between 64W and 67W. The area of low pressure has a low chance of tropical cyclone formation in the next two days. Please see the latest Tropical Weather Outlook at www.hurricanes.gov for more information. East of 55W in the central and eastern Atlantic, 1020 mb high pressures centered near 28N43W and 27N27W guide the weather conditions across the basin. A surface trough is from 10N45W to 13N44W, with strong E winds within 90 nm of the trough axis. Gentle to moderate trades pulse to locally fresh speeds from 08N to 15N near the ITCZ, supporting 8-9 ft seas in this area. Elsewhere, seas are 5-7 ft in open waters. For the forecast W of 55W, Tropical Storm Tammy is expected to move eastward today then move E-SE tonight, while brushing the far NE offshore waters, then turn SE and weaken through Tue. High pressure across the middle Atlantic coastal states is combining with a low level trough than extends from S of Tammy to 1008 mb low pressure located just N of Puerto Rico to produce a large area of fresh to strong winds, with very high seas between Tammy and the Bahamas. These high seas will slowly subside through Sun night. The low pressure is expected to move W-NW cross the SE Bahamas Sun and gradually drift NW through Tue, accompanied by very active weather. A strong cold front will enter the NW waters Wed. $$ Ramos