000 AXNT20 KNHC 131100 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1205 UTC Tue Dec 13 2022 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 1030 UTC. ...MONSOON TROUGH/ITCZ... The monsoon trough passes through the coast of Africa near the border of Guinea and Guinea-Bissau near 11N15W and extends to 09N19W. The ITCZ continues from 09N19W to 04N27W to 03N40W to 00N50W. Isolated moderate convection is noted from 04N-06N between 31W-45W. GULF OF MEXICO... A weak stationary front is draped across the northern Gulf coast, which is leading to cloudiness and isolated showers for the northern Gulf, north of 28N. Earlier ASCAT and recent buoy data show fresh SSE winds over the western Gulf of Mexico, where seas are 3 to 5 ft. Fresh SE winds are occurring south of the Florida Panhandle in association with a surface trough. Seas are 2-4 ft in this area. Elsewhere, gentle to moderate winds and 1-3 ft seas prevail. For the forecast, high pressure ridging over the area will shift eastward through tonight as a cold front approaches eastern Texas. Fresh to strong SE return flow and building seas are expected in the western and central Gulf through tonight as the cold front approaches the NW Gulf. The front is expected to move over the NW Gulf Wed morning, reach from Tampa Bay, Florida to the eastern Bay of Campeche by Thu night, and from the Straits of Florida to the northeastern Yucatan Peninsula by late Fri. The front is expected to become stationary and weaken from the lower Straits of Florida to the far south-central Gulf Sat and Sat night. A line of thunderstorms is expected to accompany the front Wed and Wed night across the NW and north-central Gulf. Strong N winds are expected behind the front Wed in the western Gulf, diminishing to moderate to fresh northerly winds behind the front later for the central and eastern Gulf. Seas will build to a peak of about 9 ft in the NW Gulf Wed, then shift to the NE Gulf late Wed night into early Thu, before subsiding during the afternoon. CARIBBEAN SEA... Most of the Caribbean Sea is under fairly tranquil conditions with no significant convection to note. Gentle to moderate trade winds prevail over a majority of the basin. The exception is within 180 nm of the coast of Colombia, where moderate to fresh winds are occurring. Seas are 4 to 6 ft across the eastern and southern Caribbean, except up to 8 ft in the Mona and Anegada Passages due to large northeasterly swell from the Atlantic. Elsewhere, seas are mainly 2 to 4 ft. For the forecast, little change in these conditions is expected through tonight. Winds will increase slightly across the basin beginning Wed as high pressure builds to the east of Florida. Large long-period N to NE swell will continue to propagate through the NE Caribbean passages for much of the week. ATLANTIC OCEAN... A cold front extends from 31N61W to a weak 1012 mb low pressure center near 28N71W to Grand Bahama Island. Scattered showers and tstorms are noted within 45 nm either side of the frontal boundary east of 70W and north of 27N. Fresh N winds are occurring north of the front with seas of 8-11 ft in mixed N wind waves and NE swell. A surface trough is analyzed from 27N69W to the N coast of Haiti near 20N73W. Scattered showers and tstorms are seen from 23N-25N between 69W-71W. A 1016 mb high pressure is centered near 22N67W. To the south of the aforementioned cold front, winds over the western Atlantic are gentle, due to ridging that extends from the high pressure center. However, seas are still 8-10 ft east of the Bahamas due to large, long-period NE swell. Farther east, a surface trough extends from 17N48W to 10N56W. Scattered moderate convection is noted from 08N-18N between 45W-61W. Total Precipitable Water imagery shows plentiful moisture content in this area. A 1017 mb high pressure is centered near 22N35W. This high is along a surface ridge that connects to the 1016 mb high pressure near 22N67W, mentioned above. To the north, an eastward-moving cold front extends from 31N23W to 27N33W. This front has weakened since yesterday. Mostly gentle winds prevail from 20N-30N between 35W-53W but large swell is keeping seas elevated in the region. For the forecast west of 55W, the cold front in the western Atlantic will reach from near 30N55W to the central Bahamas this evening, then weaken on Wed as high pressure builds in east of Florida. Moderate to fresh N winds will come in behind this front today. Large long-period N to NE swell will continue to affect much of the area for the next couple of days. A large and powerful low pressure system north of the area will bring strong to near gale force W winds Wed night through Thu night to the waters east of 65W and north of 27N. Very large seas can be expected in this area. Farther west, fresh to strong southerly winds are expected to develop offshore NE Florida beginning Wed night as a strong cold front approaches the southeastern U.S. coast. The front is forecast to move off the coast late Thu, reach from near 31N75W to West Palm Beach, Florida early Fri, and from near 31N64W to the Florida Keys early Sat. The fresh to strong southerly winds will shift eastward across the northern and central waters through Sat, while fresh west to northwest winds are expected behind the front. $$ Hagen