000 AXNT20 KNHC 281735 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1805 UTC Sat Oct 28 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 1200 UTC surface analysis and satellite imagery through 1700 UTC. ...SPECIAL FEATURES... Tropical Storm Tammy is centered near 33.3N 58.7W at 28/1500 UTC or 310 nm ENE of Bermuda, moving E at 10 kt. Estimated minimum central pressure is 995 mb. Maximum sustained wind speed is 45 kt with gusts to 55 kt. Peak seas are 21 ft. This eastward motion is expected to continue today, followed by a turn to the southeast tonight. Early next week, Tammy is forecast to turn southward and eventually southwestward as a remnant low. Some weakening is forecast during the next 48 hours, and Tammy is forecast to become a post-tropical remnant low early next week. Swells generated by Tammy will continue to affect Bermuda through today. These swells are likely to cause life-threatening surf and rip current conditions. Please consult products from your local weather office. 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 08N20W. The ITCZ extends from 08N20W to 08N55W. Scattered moderate isolated strong convection is from 07N to 13N between 53W and 58W, and from 06N to 13N between 35W and 47W. The East Pacific monsoon trough extends from the coast of Nicaragua near 11N84W to 1008 mb low pressure near 12N75W to the coast of Colombia at 12N72W. Scattered moderate convection is south of 13N and between 73W and 80W. GULF OF MEXICO... 1024 mb high pressure over the SE United States extends southwestward over the Gulf of Mexico. The tight pressure gradient currently supports moderate to fresh E winds across the basin, with locally strong winds in the Florida Straits. Seas are analyzed at 4-7 ft across the Gulf, in agreement with satellite altimeter data and surface observations. A surface trough is analyzed in the south-central Bay of Campeche. For the forecast, high pressure centered across the middle Atlantic coastal states will continue to support fresh to strong winds in the southeast and south central Gulf through early 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... A surface trough extends from Ponce, Puerto Rico, to near Curacao. Recent scatterometer data shows moderate SE winds to the east of the trough axis. Scattered moderate convection is from 12N to 17N between 62W and 66W. Seas are 8-9 ft in the Mona Passage other Atlantic Passages as a result of NNE Atlantic Swell and winds near the trough axis in the W Atlantic. In the NW Caribbean, NE winds are fresh to locally strong. Winds are gentle to moderate elsewhere. Seas are 4-7 ft across the Caribbean. For the forecast, strong high pressure centered over the middle Atlantic U.S. coast is combining with elongated low pressure across the Caribbean along 67W-68W and into the adjacent Atlantic to support fresh to locally strong NE to E winds in the NW Caribbean. This trough will shift 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 NW 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. $$ Mahoney