000 AXNT20 KNHC 121029 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 1205 UTC Tue Jul 12 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. ...TROPICAL WAVES... An eastern Atlantic tropical wave has its axis along 25W from 04N to 19N, moving westward at 10-15 kt. Clusters of scattered moderate convection are noted within 240 nm E of the wave from 07N to 10N, and within 180 nm W of the wave from 06N to 10N. A central Atlantic tropical wave has its axis along 47W/48W from 06N-20N. It is moving westward at 15-20 kt. Dry Saharan air is preventing convection from developing north of 07N, but scattered moderate convection is noted near the wave axis from 05N to 07N between 45W-48W. A central Caribbean tropical wave has its axis along 75W south of 18N to inland central Colombia, moving westward at about 17 kt. No significant convection is noted at this time with this wave. Only isolated showers are possible along and near the wave axis over Colombia. The previous western Caribbean tropical wave has moved inland over Central America. It is analyzed along 90W south of 19N to the eastern Pacific Ocean, moving westward at 10-15 kt. Increasing numerous moderate strong convection surging westward is over the eastern Pacific waters southwest of Guatemala, El Salvador and Honduras. ...MONSOON TROUGH/ITCZ... The monsoon trough extends from the coast of Gambia near 13N17W to 09N24W to 11N32W to 07N45W. The ITCZ extends from 07N49W to the coast of Guyana near 08N59W. Aside from the convection mentioned above, scattered moderate to isolated strong convection is within 240 nm south of the trough between 28W-32W. Scattered moderate convection that recently emerged off the coast of Africa is seen from 05N to 11N between 13W-21W. Similar activity is within 120 nm south of the trough between 40W-45W and within 60 nm north of the trough between 35W-40W. GULF OF MEXICO... A weak surface trough near southeastern Louisiana in combination with an upper-level trough is generating scattered showers and isolated thunderstorms over the north-central Gulf. A weak ridge oriented east-west roughly along 24/25N E of 90W continues to dominate the remainder of the Gulf of Mexico, supporting gentle to moderate south to southwest winds across the north-central and northeast Gulf. An associated 1016 mb high center is analyzed near 24N84W. An overnight ASCAT satellite data pass showed gentle to moderate east winds over the south-central Gulf. Gentle south to southwest winds are over the far western Gulf. Seas are in the range of 2-3 ft throughout the Gulf. For the forecast, the weak ridge along 24N/25W E of 90W will begin to shift northward on Wed. A weak surface trough that extends from southeastern Louisiana to near 29N88W is expected to linger in the vicinity of the north-central Gulf through Fri. Instability created by this feature along with that of a nearby upper-level trough should allow for very favorable conditions leading to active weather impacting most of the central and NE Gulf waters through the rest of the week. Low pressure may develop from the surface trough later in the week. Light to gentle winds are expected across the Gulf on Fri, except near the surface trough and over the eastern Bay of Campeche where winds will be enhanced by a thermal trough coming off the Yucatan peninsula at night. CARIBBEAN SEA... A large upper-level low is centered near Puerto Rico and the Virgin Islands. However, a large outbreak of dry Saharan air is covering the eastern half of the Caribbean, limiting showers east of 76W. The only area of showers east of 76W is present in the southeastern Caribbean, south of 14N and east of 67W, where broken clouds with isolated showers are present. Farther west, isolated showers and thunderstorms are over the northwestern Caribbean near the Cayman Islands and south of Cuba, enhanced by a rather narrow upper-level trough that extends from Tampa Bay, FL south-southwestward to Belize. In the southwestern Caribbean, scattered moderate to isolated strong convection is noted in association with the east segment of the eastern Pacific monsoon trough south of 12N between 78W-81W. An overnight ASCAT satellite data pass showed strong trade winds in the south-central Caribbean Sea offshore northeast Colombia and in the Gulf of Venezuela. Fresh trade winds are present elsewhere east of 80W from 10N-18N. Mainly moderate trade winds continue elsewhere, except for fresh in the Gulf of Honduras, and gentle south of Cuba. Seas are 6-8 ft in the south-central Caribbean, 4-6 ft elsewhere over the eastern and central Caribbean, and 2-4 ft in the NW Caribbean. For the forecast, high pressure over the north-central Atlantic will maintain moderate to fresh trade winds across the eastern Caribbean, and fresh to strong trade winds in the central portion of Caribbean through early Thu. The fresh to strong trade winds in the central portion will diminish in coverage by Thu evening and change little through Sat night. Gentle to moderate east to southeast winds in the northwestern Caribbean will increase to moderate to fresh on Tue, then diminish to gentle winds on Fri. East winds in the Gulf of Honduras will increase to strong on Tue night and continue to pulse at night through Thu. ATLANTIC OCEAN... An upper-level trough extending from Tampa Bay, Florida to Belize is inducing isolated showers and thunderstorms over the NW Bahamas and Straits of Florida. Another upper-level low is located near Puerto Rico and the Virgin Islands, but dry Saharan air as observed in the GOES-E RGB dust imagery is preventing any showers from developing in the area. Elsewhere, the subtropical Bermuda- Azores High continues to dominate the Atlantic. The subtropical ridge axis stretches west-southwestward from a 1028 mb high pressure center located well north of the area at 37N32W to 31N50W to 27N65W and to the Florida Keys. Gentle to moderate winds are present across the entire area north of 20N and west of about 47W along with seas of 4-6 ft as noted in a couple of overnight altimeter data passes. Latest ASCAT data passes depict fresh to strong northeast winds east of 35W and north of 20N, where seas are likely 7-10 ft. In the tropical Atlantic, fresh northeast to east trade winds and seas of 6-8 ft are present from 10N-20N between 35W-60W as were detected by the overnight altimeter data passes. For the forecast west of 55W, the aforementioned high pressure ridge will build westward on Tue, then begin to lift northward on Wed, reaching near 30N on Thu and to N of 31N Fri allowing for moderate to fresh south to southwest winds over the waters east of NE Florida to become light to gentle southeast to south winds Fri through Sat night. Moderate to fresh east winds will continue south of 25N through the next few days, except between the southeastern Bahamas and Hispaniola, where winds will be fresh to strong at night. $$ Aguirre