000 AXNT20 KNHC 180600 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0605 UTC Sun Sep 18 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 0000 UTC surface analysis and satellite imagery through 0555 UTC. ...SPECIAL FEATURES... Tropical Storm Fiona is centered near 16.9N 65.5W at 18/0600 UTC or 65 nm SW of St. Croix moving WNW at 7 kt. Estimated minimum central pressure is 994 mb. Maximum sustained wind speed is 55 kt with gusts to 65 kt. Peak wave heights are reaching 23 ft near the center. Seas 12 ft or greater are within 120 nm of center in the NE quadrant, within 90 nm in the SE and NW quadrants and within 60 nm in the SW quadrant. Numerous moderate to strong convection is noted within 270 nm in the eastern semicircle. A northwestward motion is expected to begin later today and continue through Tuesday. On the forecast track, the center of Fiona will pass southwest of the U.S. Virgin Islands and approach Puerto Rico this morning, and then move near or over Puerto Rico this afternoon or evening. Fiona will then move near the northern coast of the Dominican Republic tonight and Monday, and near or to the east of the Turks and Caicos Islands on Tuesday. Strengthening is forecast, and Fiona is expected to become a hurricane before reaching the southern or southwestern coast of Puerto Rico later today. Additional strengthening is expected on Monday and Tuesday while Fiona moves over the southwestern Atlantic. 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 T.S. Fiona NHC Forecast/Advisory and NHC Public Advisory at www.hurricanes.gov for more details. ...TROPICAL WAVES... A central Atlantic tropical wave has its axis along 37W, south of 16N, moving W at 15 kt. A few showers are observed near the trough axis. Another central Atlantic tropical wave has its axis along 48W, south of 25N, moving W at 15 kt. A weak 1012 mb low pressure is present along the tropical wave near 18N. Strong wind shear is displacing the storm activity well to the northeast of the wave, mainly from 24N to 29N and between 41W and 46W. A recent scatterometer satellite pass captured fresh easterly winds in the northern portion of the low pressure system. Seas in these waters are 5-7 ft. Some slow development of this system is possible during the early or middle part of this week while it moves generally northward, remaining over the central Subtropical Atlantic. The latest Tropical Weather Outlook gives this system a low chance of tropical cyclone formation through five days. ...MONSOON TROUGH/ITCZ... The monsoon trough enters the Atlantic through the coast of Senegal near 14N17W to 08N25W to 07N38W. The ITCZ extends from 07N38W to 08N48W. No deep convection is noted in association with the monsoon trough or ITCZ. GULF OF MEXICO... A ridge over the eastern United States extends into the Gulf of Mexico, supporting mainly gentle to locally moderate easterly winds across the basin. The exception are the nightly pulses of fresh E-NE winds off NW Yucatan. Seas are 1-3 ft, except for 3-4 ft off NW Yucatan. Scattered showers and isolated thunderstorms are evident on satellite imagery in the Florida Straits and Bay of Campeche, while the rest of the Gulf enjoys fairly tranquil weather conditions. For the forecast, high pressure over the southeastern U.S. will maintain gentle to moderate easterly breezes and slight seas the next few days. CARIBBEAN SEA... Please see the Special Features section for information on Tropical Storm Fiona currently located over the northeastern Caribbean Sea. Outside of Fiona, a few showers and isolated thunderstorms are seen off the southern coast of Cuba and in the Windward Passage. Similar storm activity is present within 100 nm of SE Nicaragua, Costa Rica and W Panama. The rest of the basin enjoys fairly tranquil weather conditions. A recent scatterometer satellite pass indicate that fresh to strong easterly trade winds are occurring off southern Hispaniola, especially N of 15N and between 68W and 72W, and also at the entrance of the Windward Passage. Seas in these waters are 4-7 ft. Elsewhere, moderate or weaker winds and seas of 2-4 ft prevail. For the forecast, Tropical Storm Fiona is near 16.6N 64.9W 997 mb, or about 65 nm south of St. Croix at 11 PM EDT moving WNW at 7 kt. Maximum sustained winds 50 kt gusts 60 kt. Fiona will move to near 17.2N 66.0W Sun morning, strengthen to a hurricane near 18.1N 67.3W Sun evening with maximum sustained winds 65 kt gusts 80 kt, move to near the northeast coast of the Dominican Republic near 19.1N 68.5W Mon morning, to near 20.3N 69.4W Mon evening, to near 21.6N 70.2W Tue morning with maximum sustained winds 75 kt gusts 90 kt, to near 23.0N 70.5W Tue night and to near 25.5N 70.5W Wed night with maximum sustained winds 90 kt gusts 110 kt. Residual swell over the eastern Caribbean from Fiona will slowly subside over the eastern Caribbean Mon into Tue. ATLANTIC OCEAN... Please see the Special Features section for information on Tropical Storm Fiona, which is expected to be in the vicinity of the Turks and Caicos early next week. A surface trough extends from 31N80W to the Florida Straits and supports scattered showers and isolated thunderstorms from 23N to 31N and east of the trough axis to 75W. Moderate to fresh easterly winds are found N of 29N and W of 77W, along with seas of 3-5 ft. Fresh to strong trades are noted off NW Hispaniola and SE Bahamas, mainly S of 22N and between 71W and 75W. The remainder of the tropical Atlantic is dominated by a weak ridge over the central Atlantic, allowing for generally tranquil weather conditions. In the eastern Atlantic, fresh to strong N-NE winds are occurring off SW Western Sahara and Mauritania, primarily from 18N to 22N and E of 20W. Seas in these waters are 6-8 ft. Elsewhere, moderate or weaker winds and seas of 3-6 ft prevail. For the forecast west of 55W, Tropical Storm Fiona is over the far northeastern Caribbean Sea near the U.S Virgin Islands, with maximum sustained winds 50 kt gusts 60 kt moving WNW at 7 kt with a pressure of 997 mb. Fiona is forecast to move to near 17.2N 66.0W Sun morning, strengthen to a hurricane near 18.1N 67.3W Sun evening with maximum sustained winds 65 kt gusts 80 kt, move to near the northeast coast of the Dominican Republic near 19.1N 68.5W Mon morning, to near 20.3N 69.4W Mon evening, to near 21.6N 70.2W Tue morning with maximum sustained winds 75 kt gusts 90 kt, to near 23.0N 70.5W Tue night and to near 25.5N 70.5W Wed night with maximum sustained winds 90 kt gusts 110 kt. High pressure will build in the wake of Fiona. $$ DELGADO