000 AXNT20 KNHC 120005 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0005 UTC Fri Sep 11 2020 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 32N. The following information is based on satellite imagery, weather observations, radar and meteorological analysis. Based on 1800 UTC surface analysis and satellite imagery through 2115 UTC. ...SPECIAL FEATURES... Tropical Storm Paulette is centered near 24.6N 52.7W at 11/2100 UTC or 650 nm northeast of the northern Leeward Islands moving northwest at 11 kt. The estimated minimum central pressure is 989 mb. Maximum sustained wind speed is 55 kt with gusts to 65 kt. Paulette is slightly sheared on its southeast edge from strong upper-level southwest winds. Satellite imagery shows scattered moderate to isolated strong convection within 180 nm of the center in the NW quadrant. Scattered moderate convection is within 210 nm of the center in the NE quadrant. Seas are up to 28 ft near the center, and the 12 ft sea radii extends within 330 nm of the center in the the NW quadrant, within 270 nm of the center in the SW quadrant and within 240 nm of the center in the NE quadrant. An expected motion of Paulette toward the northwest or west-northwest is expected through Sun night, followed by a sharp turn toward the north by late Mon. On the forecast track, the center of Paulette should be near Bermuda Sun night and Mon. Please read the latest HIGH SEAS FORECAST issued by the National Hurricane Center at website-https://www.nhc.noaa.gov/text/ MIAHSFAT2.shtml and the latest Paulette NHC Forecast/Advisory and Public Advisory at www.hurricanes.gov for more details. Tropical Storm Rene is centered near 20.7N 41.1W at 11/2100 UTC or 1010 nm west-northwest of the Cabo Verde Islands, moving west-northwest at 12 kt. The estimated minimum central pressure is 1004 mb. Maximum sustained wind speed is 35 kt with gusts to 45 kt. Satellite imagery from during the afternoon and early evening hours shows convection of the scattered moderate to isolated strong type over the center as well as within 150 nm of the center in the western semicircle. The imagery also indicates that Rene is a rather small system. Seas of 12 ft or greater are within 60 nm of the center in the northern semicircle. Rene is expected to make a turn toward the northwest followed by a turn toward the north-northwest during the next couple of days. Some strengthening is forecast during the next day or so, but a weakening trend will likely begin by late Sun. Please read the latest HIGH SEAS FORECAST issued by the National Hurricane Center at website-https://www.nhc.noaa.gov/text/ MIAHSFAT2.shtml and the latest Rene NHC Forecast/Advisory and Public Advisory at www.hurricanes.gov for more details. Newly formed Tropical Depression Nineteen is centered near 25.4N 79.0W at 11/2100 UTC or about 45 nm east-southeast of Miami, Florida. It is moving west-northwest at 7 kt. The estimated minimum central pressure is 1094 mb. Maximum sustained wind speed is 30 kt with gusts to 40 kt. GOES-16 Satellite imagery shows very deep convection of scattered to numerous moderate isolated strong type within 90 nm of the center in the SE quadrant and within 60 nm of the center in the SW quadrant. Scattered moderate to isolated strong convection is elsewhere from 22N to 26N and between 75W-80W. Tropical Depression Nineteen is forecast to move inland over south Florida early on Sat, move over the southeastern Gulf of Mexico late Sat, and then move northwestward over the north-central Gulf of Mexico on Mon. The depression could become a tropical storm before moving across south Florida overnight. Otherwise it is expected to become a tropical storm on Sun and gradually intensify through Mon. It is expected to produce total rainfall amounts of 1 to 3 inches with isolated maximum amounts of 5 inches across central and southern Florida, including the Florida Keys. This rainfall could produce isolated flash flooding and prolong ongoing minor flooding on rivers in the Tampa Bay area. Please read the latest HIGH SEAS FORECAST issued by the National Hurricane Center at website-https://www.nhc.noaa.gov/text/ MIAHSFAT2.shtml and the latest Tropical Depression Nineteen NHC Forecast/Advisory and Public Advisory at www.hurricanes.gov for more details. A broad area of low pressure, associated with a tropical wave that is located near 28W, is producing a large area of disorganized showers and thunderstorms roughly from 08N-10N between 24W-32W and from 10N to 15N between 26W-34W. Development of this system is forecast, and a tropical depression is expected to form within the next few days while the system moves generally westward at 15-20 mph across the eastern and central tropical Atlantic. This system has a high chance of tropical cyclone formation through the next 48 hours. ...TROPICAL WAVES... A Caribbean Sea tropical wave is beginning to move across portions of central America, with its axis along 86W from 21N southward. It is moving westward at about 15 kt. Scattered showers and thunderstorms are noted across the NW Caribbean from 16N-22N between 84W-86W. ...MONSOON TROUGH/ITCZ... The monsoon trough axis passes through coastal Mauritania near 19N16W and stretches south-southwestward to 14N20W to 12N25W and to 13N34W. Convection near the trough is primarily associated with the Special Features tropical wave along 28W. See Special Features section above. Otherwise, Abundant Saharan air is noted over the far eastern tropical Atlantic suppressing convection from forming along and near the trough. GULF OF MEXICO... As of 2100 UTC, a surface trough is across the central Gulf from near the coast of southern Louisiana at 29N90W to 23N86W. Both satellite imagery and NWS Doppler radar imagery show scattered showers and thunderstorms north of 28N between 88W-90W. This feature could possibly acquire some slow development while it moves westward and then southwestward over the northern and western Gulf of Mexico through the middle of next week. It has a low chance of formation through the next 48 hours. As of 2100 UTC, a stationary front over the western Gulf extends from just east of Galveston, Texas to 26N96W and to inland southeastern Mexico at 19.5N96W. A trough ahead of the stationary front extends from near 24N95W south-southeast to inland Mexico at 19N93W. An elongated upper-level low is identified to be near 27N94W, with a trough extending south-southwest to 20N96W. Resultant atmospheric instability from these features is helping to produce scattered showers and thunderstorms from 20N to 25N between 94W- 97W. Isolated showers and thunderstorms are elsewhere south of 26N and west of 90W and also east of 90W, except for along and within 30 nm of the Florida coast from Cape Sable to near Tampa Bay. This activity is moving to the southwest and contains strong gusty winds and lightning strikes. Similar activity is weakening over Apalachee Bay. Light to gentle winds are noted in the eastern Gulf with fresh winds behind the stationary front as noted in a recent ASCAT pass. Seas are 1-3 ft in the eastern Gulf and 4-7 ft in the western Gulf along and behind the stationary front. As for the forecast, Tropical Depression Nineteen centered near 25.4N 79.0W 1009 mb at 5 PM EDT moving WNW at 7 kt. Maximum sustained winds 30 kt gusts 40 kt. The depression is forecast to move inland over south Florida early on Sat, move into the SE Gulf late Sat, and then move northwestward over the north-central Gulf on Mon while gradually intensifying. Nineteen will move to 25.7N 80.1W Sat morning, 26.2N 81.9W Sat afternoon, strengthen to a tropical storm near 27.3N 83.8W Sun morning, 28.4N 85.2W Sun afternoon, 29.1N 86.3W Mon morning, and 29.5N 87.4W Mon afternoon. Nineteen will change little in intensity as it moves to near 30.0N 89.0W Tue afternoon. Elsewhere, fresh to locally strong northerly winds behind a stationary front that extends from the upper Texas coast southward across the western Gulf will diminish through Sat. The surface trough across the central Gulf will drift westward over the next several days. CARIBBEAN SEA... As of 2100 UTC, a surface trough over the northwestern Caribbean extends from near 21N80W to the northeast coast of Honduras. A small upper-level low moving westward is just southwest of Jamaica. Scattered showers and thunderstorms are seen from 18N to 21N between 77W-79W and also confined to the far southwestern Caribbean along and near the coasts of Panama and southern Costa Rica. Isolated showers and thunderstorms are elsewhere west of 76W. Scattered showers and thunderstorms that developed from daytime heating are over most of the interior of Cuba and over some interior areas of Haiti and the Dominican Republic. An upper level ridge across the eastern Caribbean is inhibiting convection. Moderate trades are north of Colombia with light to gentle winds across the rest of the basin. Seas range from 3-5 ft. As for the forecast, large swell associated with Paulette will affect the Atlantic and Caribbean Passages through this weekend. A tropical wave in the NW Caribbean will exit the basin tonight. Low pressure associated with a strong tropical wave may approach the Tropical N Atlantic waters during the middle of next week. ATLANTIC OCEAN... See the Special Features section for more information on Tropical Storms Paulette and Rene and on recently formed Tropical Depression Nineteen. Outside of Paulette, Rene and Tropical Depression Nineteen, surface ridging extends across the basin. Scattered showers and thunderstorms are seen from 11N to 14N between 38W-55W and from 07N to 11N between 40W-47W. Some showers are moving eastward across the eastern Atlantic, including the Canary Islands, north of 26N between 12W-32W. Gentle to moderate winds are noted across the western and central Atlantic. Fresh to strong winds are in the eastern Atlantic with the strongest winds off the western African Sahara coast. Seas are in the range 5-8 ft. As for the forecast, Tropical Storm Paulette centered will move to 25.9N 55.3W Sat morning, strengthen to a hurricane near 27.5N 57.5W Sat afternoon, 28.7N 59.8W Sun morning, 29.8N 62.3W Sun afternoon, then pass N of the area to 31.1N 64.5W Mon morning, and 32.6N 65.3W Mon afternoon. Large swell associated with Paulette will spread eastward across the offshore waters and continue to build seas this weekend and into early next week. Elsewhere, Tropical Depression Nineteen will move to 25.7N 80.1W Sat morning, then cross South Florida and move to near 26.2N 81.9W Sat afternoon before emerging into the eastern Gulf of Mexico by Sat night. $$ Aguirre