000 AXNT20 KNHC 180906 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1205 UTC Mon Nov 18 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 0600 UTC surface analysis and satellite imagery through 0750 UTC. ...SPECIAL FEATURES... Remnants Of Sara is centered near 19.0N 91.5W at 18/0900 UTC or 80 nm SW of Campeche Mexico, moving NW at 11 kt. Estimated minimum central pressure is 1005 mb. Maximum sustained wind speed is 25 kt with gusts to 35 kt. Scattered moderate isolated strong convection is over the SE Bay of Campeche south of 19N and east of 94.5W, and from 20N to 22N between 89W and 91W. The remnants are forecast to dissipate by the afternoon. While strong upper-level winds are expected to inhibit tropical development, the remnant vorticity and moisture could interact with an approaching frontal system and contribute to heavy rainfall along the northern Gulf Coast during the next couple of days. Additional rainfall is expected over northern Honduras. The risk of catastrophic and life-threatening flooding impacts will continue, especially along and near the Sierra La Esperanza. Across portions of Belize, El Salvador, eastern Guatemala, western Nicaragua, and the Mexican State of Quintana Roo, the remnants of Sara are expected to produce additional rainfall. This will result in areas of flash flooding, perhaps significant, along with the potential of mudslides. For more information on the ongoing rainfall threat in southern Mexico/Central America and the expected heavy rainfall along the U.S. Gulf Coast, see products issued by the Weather Prediction Center and 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 final Sara NHC Forecast/Advisory and Public Advisory at www.hurricanes.gov for more details. ...MONSOON TROUGH/ITCZ... The monsoon trough is inland over the African continent. The ITCZ extends from the coast of Sierra Leone at 08N13W to 04N30W to 07N41W to 08N52W. Plentiful scattered moderate isolated strong convection is noted from 01N to 12N between 24W and 50W. Scattered moderate convection is noted from 05N to 09N between 11W and 18W, and from 09N to 15N between 50W and 59W. GULF OF MEXICO... Please refer to the Special Features section for details on the Remnants of Sara. High pressure centered over the SE United States and its associated ridge dominates the basin with moderate to fresh E to SE return flow, except for strong winds extending from the Yucatan Channel and Peninsula to the NW Gulf waters. Seas are 5 to 8 ft across these winds, except 8 to 11 ft in the Texas coastal waters at the tail end of the long SE fetch region. Seas are 2 to 4 ft across the remainder of the basin. For the forecast, high pressure and marine conditions described above will persist today. The next cold front will move into the NW Gulf tonight, reaching from S-central Louisiana to near Tamaulipas, Mexico early Tue, then from Apalachee Bay to Tampico, Mexico early Wed. Reinforcing fresh to strong northerly winds and large seas are forecast across the basin Wed night as the front pushes SE of the basin behind the front starting Wed. The front will push SE of the basin by early Thu with conditions gradually improving through the end of the week as high pressure builds in. Meanwhile, convection associated with the Remnants of Sara, currently over the Yucatan Peninsula, will move into the Bay of Campeche today, eventually merging with the cold front. CARIBBEAN SEA... Please refer to the Special Features section for details on the Remnants of Sara. A cold front extends from the Anegada Passage to south of Puerto Rico and the rest of the Greater Antilles to the NW Caribbean near 19N84W. Scattered showers and isolated thunderstorms are ahead of the front, while fresh to strong NE winds are in the Lee of Cuba to across the NW Caribbean, across the approach to the Windward Passage, and south of the Dominican Republic. Mainly gentle to moderate winds prevail elsewhere, except light to gentle in the SW Caribbean. Seas are 6 to 10 ft in the NW Caribbean, 4 to 6 ft elsewhere where the fresh to strong wind plumes are, and 3 ft or less across the remainder of the basin, except 6 to 8 ft near Atlantic Passages. For the forecast, the Remnants of Sara, and associated convection, currently over the western Yucatan Peninsula will continue to shift away from the NW Caribbean today while dissipating. A cold front from the Anegada Passage to south of the Greater Antilles will stall and gradually wash out through the early part of the week. Fresh to strong winds will pulse in the Lee of Cuba, Windward Passage and south of the Dominican Republic through at least tonight. Fresh to strong winds in the NW Caribbean will diminish by mid-week as a cold front moves toward the area from the NW. The front is forecast to enter the NW Caribbean Wed night, reaching from central Cuba to near NE Nicaragua early Fri with increasing winds and building seas behind it. Meanwhile, seas of around 8 ft in northerly swell in the Atlantic passages will subside today. ATLANTIC OCEAN... Surface ridging anchored by strong high pressure over Georgia is building across the western subtropical Atlantic waters in the wake of a slowing cold front that extends from 31N51W southwest to the Anegada Passage. Scattered showers and tstms are ongoing within 150-210 nm ahead of the front. Remnant seas of 8 to 13 ft in NW to N swell are decaying, but a reinforcing trough just now moving into the N-central waters is bringing reinforcing swell as well as fresh to strong winds near 31N between 60W and 67W. Fresh to strong S-SW winds are also N of 29N in the area of convection. To the east, a 1006 mb occluded low is just N of the area near 32.5N24W with a related trough from 29N23W to 18N30W. Scattered moderate convection is noted from 29N to 31N between 18W and 27W and pushing south with the low. Fresh to strong winds and 8 to 11 ft seas are across this same area. Broad ridging with gentle to moderate winds and 4 to 7 ft seas prevail across the remainder of the waters, except to 8 ft near 11N42W in decaying, remnant NW to N swell. For the forecast west of 55W, a slowing cold front from 25N55W to the Anegada Passage will slowly shift SE while weakening through today. Active convection will persist ahead of the front. Large seas are following the front and will continue through tonight. A reinforcing front or trough will clip the NE waters Tue and Tue night, with increasing winds and building seas. The next cold front may move off the SE United States late Wed night, with another round of increasing winds and building seas. This front may reach from near Bermuda to the central Bahamas by early Fri. $$ Lewitsky