000 AXNT20 KNHC 171019 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1205 UTC Mon Oct 17 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 1015 UTC. ...SPECIAL FEATURES... Gulf of Mexico Gale Warning: A cold front will move into the NW this morning. The front will exit the southeastern Gulf by Wednesday. Strong winds are expected across most of the western Gulf behind the front, with gale force northerly winds of 30-40 kt developing offshore Tampico, Mexico on Tue and spreading to the western Bay of Campeche Tue night and Wed. Winds may briefly gust to gale force over the NW Gulf late tonight into Tue. Winds will gradually diminish beginning on Thu as high pressure becomes centered over the region. Wave heights are forecast to build to 12 ft by Wednesday, and reach 16 ft in the southwestern Gulf Wed afternoon and night. Wave heights will slowly subside Thu and Thu night. The strongest winds and highest seas will be off the Mexican State of Veracruz. ...TROPICAL WAVES... A far eastern Atlantic tropical wave has its axis along 35W from 02N to 13N moving westward at 5-10 kt. A large area of numerous moderate to isolated convection is seen from 07N to 15N between 28W-32W and from 06N to 11N between 32W-40W. An overnight ASCAT data pass revealed fresh to strong southwest winds south of the where the wave axis crosses the monsoon trough to near 06N. These winds appear to have been enhanced by the gradient produced by the ongoing convection. A central Atlantic tropical wave has its axis along 53W from 03N to 17N moving westward at 10 kt. Scattered showers and isolated thunderstorms are along and within 240 nm east of the wave. Similar activity is near the northern part of the wave due to mainly a small upper-level low that is located near 19N52W. An eastern Caribbean tropical wave has its axis along 63W from 03N to 18N moving westward around 10 kt. No significant convection is occurring with this wave. A central American tropical wave is along 91W south of 20N. It is moving westward at 10 kt. Scattered moderate to isolated strong convection, in clusters, is over southeastern Mexico, El Salvador, Guatemala, Belize and western Honduras. Isolated showers and thunderstorms are over the western part of Nicaragua. ...MONSOON TROUGH/ITCZ... The monsoon trough axis extends from southern Senegal southwestward to 08N22W and to 09N28W to 11N33W to 08N41W, where latest scatterometer data indicates that it transitions to the ITCZ northwestward to 09N44W and to 11N48W. In addition to convection associated with the tropical wave along 35W, scattered moderate to isolated strong convection is within 240 nm northeast of the ITCZ between 45W-48W. Scattered moderate convection is from 05N to 09N between 20W-25W, and from 07N to 13N between the coast of Africa and 19W. GULF OF MEXICO... A weak surface ridge over the southeastern United States extends into the Gulf of Mexico, with its associated gradient allowing for generally light to moderate easterly winds along with wave heights of 2-3 ft, except for lighter higher wave heights of 3-4 ft in the eastern Bay of Campeche. A weak surface trough is analyzed across the NE Gulf along 88W and N of 24N with no significant convection at this time. The rest of the basin enjoys fairly tranquil weather conditions. Scattered showers and thunderstorms moving westward are just inland the western Yucatan Peninsula south of 20N. This activity is moving offshore over the eastern Bay of Campeche. Numerous showers and thunderstorms are just inland the coast of southeastern Mexico between 92W-95W. For the forecast, a cold front will enter the NW Gulf this morning, reach from the Florida panhandle to southern Texas tonight, and from the Florida southwest coast to near Veracruz, Mexico by Tue night. The cold front is expected to exit the Gulf on Wed. Strong winds are expected across most of the western Gulf behind the front, with gale force winds developing offshore Tampico, Mexico, Tue and spreading to the western Bay of Campeche Tue night and Wed. Winds may briefly gust to gale force over the NW Gulf late tonight into Tue. Winds will gradually diminish beginning on Thu as high pressure becomes centered over the region. Scattered showers and thunderstorms will precede the front. CARIBBEAN SEA... Refer to the section above for details on a tropical wave over the eastern Caribbean. The majority of the Caribbean is under a dry air mass and sinking air as northwest upper-level winds have settled in over the central and western sections of the sea behind a rather broad upper-level trough. This is suppressing the development of any significant convection. Only isolated showers and thunderstorms are noted over the far southwestern Caribbean, where the eastern segment of the eastern Pacific monsoon trough protrudes. Moderate easterly trade winds are in the the central Caribbean and the Gulf of Honduras along with wave heights of 3-5 ft. Elsewhere, light to gentle trade winds and wave heights of 1-3 ft continue. For the forecast, gentle to moderate winds and slight to moderate seas across most of the Caribbean will diminish to mainly light to gentle wind speeds Mon into Tue. Locally fresh winds in the south-central Caribbean and the Gulf of Honduras will continue tonight. Gentle to moderate winds are forecast for the eastern and central Caribbean Tue night into Thu night as two tropical waves move across the region. Otherwise, a cold front is forecast to reach from western Cuba to the Yucatan Channel and to along the northern Yucatan Peninsula Wed night followed by moderate to fresh northerly winds with moderate waves. The front will then weaken as it slowly reaches from central Cuba to the northern Yucatan Peninsula Thu and from east-central Cuba to Belize Fri. ATLANTIC OCEAN... Refer to the section above for details on tropical waves across the basin. The 06Z analysis has a weakening cold front extending from near 31N60W to 27N64W and to 25N68W, where it becomes a dissipating stationary front to the central Bahamas. A surface trough extends ahead of the front from near 31N57W to 24N61W. Scattered moderate convection moving eastward is between the front and the trough, and also along and within 90 nm east of the trough. Overnight ASCAT data indicates moderate to fresh north to northeast winds behind the front, where wave heights are 3-5 ft per altimeter data passes. A rather weak pressure gradient that is being anchored by a 1017 mb high center near 34N39W and a 1015 mb high center near 32N70W is is maintaining light to gentle winds and relatively low wave heights of 2-4 ft over the rest of the western Atlantic. Elsewhere across the forecast domain, mostly moderate trade winds are in the central Atlantic from 10N to 20N and between 30W-50W. Wave heights over these waters are in the 4-7 ft range. A northerly swell is propagating through the eastern Atlantic producing wave heights of 6-8 ft. Gentle to moderate trade winds and wave heights of 3-5 ft are over the remainder of the tropical Atlantic. For the forecast west of 55W, the aforementioned weakening cold will become a frontal trough by early this evening. Another cold front will move offshore the southeastern U.S. this evening, reach from near 31N76W to Fort Pierce, Florida Tue afternoon and from near 31N70W to the NW Bahamas Wed. This front will become stationary from near Bermuda to the central Bahamas, then weaken into Fri. Fresh south winds are forecast ahead of the front and north and northeast of the Bahamas Mon night through Wed, with fresh to strong north winds expected Wed through Thu. A trough is expected to form offshore northern Florida Fri and Fri night. Low pressure may form from the trough afterward. $$ Aguirre