412 AXNT20 KNHC 181707 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1805 UTC Fri Oct 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 1200 UTC surface analysis and satellite imagery through 1700 UTC. ...SPECIAL FEATURES... Invest 95L and Significant Rainfall for Central America and southern Mexico: Numerous moderate to isolated strong convection continues across the northwestern Caribbean Sea in association with a 1005 mb surface low near 17N84W that is gradually becoming better defined to the north of eastern Honduras. Environmental conditions appear conducive for some additional development over the next day or so, and there is a medium chance of a short-lived tropical depression or storm forming before the system moves inland over Belize and the Yucatan Peninsula of Mexico on Saturday. Regardless of development, locally heavy rainfall is possible across portions of Central America and southern Mexico late this week and into the weekend. This system could bring significant rainfall to Panama, Costa Rica, Nicaragua, Honduras, Guatemala, Belize and southeastern Mexico Friday through Monday next week, increasing the chance for flooding and landslides. Residents in these countries need to monitor this developing situation closely and listen to the latest forecast from their local meteorological agencies. ...TROPICAL WAVES... Refer to the Special Features section above for details on the tropical wave associated with Invest 95L. The axis of an eastern Atlantic tropical wave is near 26W from 19N southward, and moving west at 10 to 15 kt. Nearby convection is discussed in the monsoon trough/ITCZ section below. The axis of a western Atlantic and eastern Caribbean tropical wave is near 64W from 21N southward through a 1011 mb low (Invest AL94) near 19N64W, and moving westward at 15 to 20 kt. Numerous moderate to isolated strong convection is noted from 18N to 24N between 56W and 66W. Further development is not expected due to strong upper-level winds affecting 94L by early next week. ...MONSOON TROUGH/ITCZ... The monsoon trough enters the Atlantic near 10N14W and extends westward to 09N24W. The ITCZ then is analyzed from 10N29W to 06N53W. Scattered moderate to isolated strong convection is active east of 39W between 02N and 16N. The eastern extension of the East Pacific monsoon trough enters the far southwest Caribbean and extends to the coast of northeast Colombia. Scattered moderate convection is noted within 200 nm N of the monsoon trough. ...GULF OF MEXICO... A stationary front extends from central Cuba across the Yucatan Channel and the northern Yucatan Peninsula, the westward across the Bay of Campeche to near Veracruz, Mexico. Scattered showers and isolated thunderstorms are occurring near and in the vicinity of the front. Recent scatterometer and buoy data indicate fresh to strong E to NE winds across much of the Gulf east of 91W. Combined seas across the SE Gulf are estimated to be 7 to 11 ft, locally up to 12 ft near the NW coast of Cuba per recent altimeter data. Seas across the remainder of the Gulf are estimated at 4 to 7 ft. For the forecast, fresh to strong NE winds and rough to very rough seas will continue to affect much of the basin into Sun night as strong high pressure builds over the SE United States. Looking ahead, winds and seas will diminish early next week as the high pressure weakens. ...CARIBBEAN SEA... Please read the Special Features section about potential heavy rainfall into early next week and the possible development of Invest 95L, and the Tropical Waves section for details on the wave near 64W. Aside from the area of low pressure and associated convection over the western Caribbean, moderate to fresh E winds generally prevail across the Caribbean waters. Seas are in the 4-6 ft range, except for 7-9 ft in the Yucatan Channel as northerly swell generated in the wake of a frontal boundary over the Gulf of Mexico is spreading into the northwest Caribbean waters. For the forecast, Low pressure (Invest 94L) centered just NE of eastern Honduras, is gradually becoming better organized. Environmental conditions appear conductive for some additional development, and there is a medium chance of the formation of a tropical depression or storm before the system moves inland over Belize and the Yucatan Peninsula Sat. Regardless of development, locally heavy rain is likely across portions of Central America and southern Mexico through the the weekend. Elsewhere, a stationary front just north of the aforementioned low has fresh to strong winds and rough seas to the north of it over the Yucatan Channel. This front will dissipate tonight but the associated hazardous marine conditions will prevail into the weekend. ATLANTIC OCEAN... A stationary front extends from 31N68W SW to central Cuba, along with a pre-frontal trough about 200-250 nm E of the front. The front is aiding in the development of scattered showers and isolated thunderstorms from the northern Bahamas to the Florida Straits. Fresh to strong NE winds and seas of 8-10 ft prevail west of the front. Fresh to strong winds and seas of 7-9 ft accompany Invest AL94 to the northeast of the Leeward Islands. A surface trough is analyzed near 52W, running from 10N to 16N. No significant convection is noted near this trough, but moderate to fresh east winds are occurring north of the trough axis between 16N and 20N. Farther east, fresh to strong NE winds and 8-10 ft seas are noted off northwest Africa and north of a shear line running from 27N13W to to 23N35W and then to 25N55W. Moderate easterly winds and 5-7 ft seas are noted elsewhere across the basin. For the forecast west of 55W, a nearly stationary front from Bermuda to central Cuba will remain generally in place through the weekend, then dissipate. NW of this boundary, fresh to strong winds and rough seas will prevail into early next week. Farther south, a low pressure trough, Invest 94L, currently just N of the Virgin Islands, will move quickly W and bring fresh to locally strong winds and rough seas to waters N of Puerto Rico tonight and Hispaniola and the Turks and Caicos Sat and Sat night. There is a low chance of tropical formation with this trough during that time. $$ Adams