000 AXNT20 KNHC 222203 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0015 UTC Mon Dec 23 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 2120 UTC. ..MONSOON TROUGH/ITCZ... The monsoon trough enters the Atlantic near 04N10E and extends to 04N16W. The ITCZ continues from 04N16W to 03.5N40W to the coast of Brazil near 02N51W. Scattered moderate convection is about these boundaries from 04N to 05.5N between 16W and 26W, and from 04N to 05.5N between the Equator to 09N between 36W and 42W. ...GULF OF MEXICO... Broad ridging dominates the Gulf of Mexico, extending from 1035 mb high pressure over the Ohio Valley southwestward to eastern Mexico. This pattern is supporting moderate NNE winds across the eastern Gulf and moderate or weaker NE to E winds elsewhere. Moderate seas of 5 ft or less prevail across the basin. For the forecast, high pressure over the eastern United States will drift eastward and weaken through mid-week, leading to moderate mainly E winds through Mon, becoming SE to S winds Tue through Wed. A cold front is expected to move slowly off the Texas Thu night. ...CARIBBEAN SEA... A cold front extends from Haiti to just south of Jamaica to the NE coast of Honduras. A surface trough has been analyzed over the Mona Passage. Farther south, the eastern extension of the East Pacific Monsoon Trough runs across the far SW Caribbean to a 1009 mb low in northern Colombia. Northerly winds diving southward into the southwest Caribbean and the monsoon trough are producing scattered moderate isolated strong convection in the central and SW Caribbean, generally south of 18N between 73W and 82W. The pressure gradient between a strong ridge over the central United States and the aforementioned front support moderate to fresh N to NE winds and seas of 4-7 ft west of a line extending from Haiti to the border of Panama and Colombia. Locally strong winds are observed via recent scatterometer data in areas of convection. The strongest winds and highest seas are found in the SW Caribbean S of 15N. Moderate to locally fresh E winds are present in the SE Caribbean, while moderate or weaker winds prevail elsewhere. Moderate seas prevail across the basin. For the forecast, moderate to fresh N-NE winds are expected to continue across the western Caribbean tonight, behind the stalling cold front. The front should dissipate by morning, but locally strong NE winds may continue to pulse through the Windward Passage early this week. High pressure will build over eastern Mexico this week, and low pressure over northern Colombia will strengthen. The increasing pressure gradient between these features will lead to fresh to locally strong NE to E winds across much of the basin Mon night through Tue night, diminishing to moderate to locally fresh Wed and Thu. ...ATLANTIC OCEAN... A cold front extends from 31N57W southwestward to the northern coast of Haiti. A trough is noted to the east, from 25N62W to the Mona Passage. Scattered showers and isolated thunderstorms are occurring in the vicinity of the front and trough. A second cold front extends from 31N64W to 27N80W. Moderate N to NE winds are noted behind both fronts. Elsewhere west of 55W, moderate or weaker winds and moderate seas prevail. Moderate period NW to N swell generated behind the second front is moving into the northern waters, producing seas of 7 to 8 ft N of 29N between 64W and 76W. The remainder of the tropical Atlantic is under the influence of a robust subtropical ridge stemming from a 1042 mb high positioned NE of the Azores. The pressure gradient between the ridge and lower pressures in western Africa and the deep tropics support fresh to strong E to NE winds across much of the Atlantic E of 35W and N of 17N. Rough seas are found in these waters, peaking near 12-13 ft north of the Canary Islands. Farther south, moderate to locally fresh E trade winds and moderate seas are present between Africa and the Lesser Antilles, south of 18N, where seas are 5 to 8 ft. In the rest of the basin, moderate or weaker winds and moderate seas are prevalent. For the forecast W of 55W, the cold front from 31N57W to Haiti will remain generally stationary near Haiti, while moving eastward across the remaining Atlantic. This will align this boundary more NE to SW by Mon night and E-NE to W-SW by late Tue. The front will slowly dissipate over southeastern waters through late Tue. High pressure building behind the front will lead to increasing winds E of the Bahamas, with strong winds and rough seas likely Mon night into mid-week, until the frontal boundary dissipates late Tue. $$ Stripling