000 AXNT20 KNHC 230338 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0005 UTC Fri Sep 23 2022...Updated 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 1800 UTC surface analysis and satellite imagery through 2245 UTC. ...Updated Special Features Section... ...SPECIAL FEATURES... Hurricane Fiona is centered near 31.9N 68.1W at 23/0300 UTC or 170 nm W of Bermuda moving NNE at 18 kt. Estimated minimum central pressure is 932 mb. Maximum sustained wind speed is 115 kt with gusts to 140 kt. Numerous strong convection is within 120 nm of the center in the E semicircle and 60 nm W semicircle. Scattered to numerous moderate with isolated strong convection is occurring elsewhere within 360 nm NE quadrant, 240 nm SE quadrant and 180 nm W semicircle. Seas of 12 ft or higher are occurring within 240 nm NE quadrant, 330 nm SE quadrant and 300 nm W semicircle. On the forecast track, the center of Fiona will pass just to the west of Bermuda overnight. Fiona's center will then approach Nova Scotia on Friday. Swells generated by Fiona are affecting the Turks and Caicos Islands, the Bahamas, the southeastern United States coast, and Bermuda. These swells will continue to spread northwestward across the western Atlantic toward the mid-Atlantic and northeast coasts of the United States and Atlantic Canada tonight and on Friday. These swells are likely to cause life-threatening surf and rip current conditions. 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 NHC Forecast/Advisory and Public Advisory at www.hurricanes.gov for more details. Tropical Storm Gaston is centered near 41.0N 31.0W at 23/0300 UTC or 180 nm NW of Faial Island in the central Azores, moving E at 10 kt. Estimated minimum central pressure is 999 mb. Maximum sustained wind speed is 55 kt with gusts to 65 kt. Scattered to numerous moderate convection is noted within 210 nm of the center in the NE quadrant, 150 nm SE quadrant and 120 nm NW quadrant. On the forecast track, the center of Gaston will move near or over portions of the Azores tonight through early Saturday. Swells generated by Gaston are expected to affect portions of the Azores through Saturday. These swells are likely to cause life- threatening surf and rip current conditions. Please read the latest High Seas Forecast issued by the Ocean Prediction Center at website https://ocean.weather.gov/shtml/NFDHSFAT1.php and the latest NHC Forecast/Advisory and Public Advisory at www.hurricanes.gov for more details. ...CARIBBEAN TROPICAL WAVE... A tropical wave extends its axis along 66W across the eastern Caribbean. A 1006 mb low is analyzed along the wave near 12N66W. The environment is forecast to become more conducive for development, and a tropical depression is likely to form in the next day or so. The low is forecast to move west-northwestward and be over the central Caribbean this weekend where conditions are expected to be conducive for additional development. Locally heavy rainfall and gusty winds are likely to affect northern Venezuela, the ABC island chain, and northeastern Colombia this evening. Interests in Jamaica should closely monitor the progress of this system. This system has a high chance for tropical development within the next 48 hours. ...ATLANTIC TROPICAL WAVE... A tropical wave extends its axis along 19W across the eastern Atlantic. A 1006 mb low is analyzed along the wave near 15N19W. Scattered moderate convection is noted within 60 nm of the center of the low. Environmental conditions are forecast to be conducive for some development, and a tropical depression could form by this weekend while the system moves slowly northward, between west Africa and the Cabo Verde Islands. This system has a medium chance for tropical development within the next 48 hours. ...TROPICAL WAVES... Please, read the SPECIAL FEATURES section above for information about the tropical waves. ...MONSOON TROUGH/ITCZ... The monsoon trough passes through the eastern Africa coast near 15N16W to 08N39W. The ITCZ continues from 08N39W to 05N53W. Aside from the convection related to the tropical wave described in the section above, scattered showers are noted in the vicinity of a 1010 mb surface low that is embedded in the monsoon trough near 11N34W. GULF OF MEXICO... Broad anticyclonic wind flow prevails a cross most of the basin. over the western Gulf, a surface trough extends from 25N97W to 21N91W. Gentle to moderate N to NE winds are in the northern half of the basin, and in the far SW Gulf. Light to gentle winds prevail elsewhere. Sea heights are ranging between 2-4 ft. For the forecast...A relatively weak pressure gradient across the Gulf waters will support mainly gentle to locally moderate winds and slight seas through the upcoming weekend. A weak cold front will reach the the NE waters on Fri. On Mon, wind and seas could begin to increase across the Yucatan Channel as a possible tropical cyclone approaches from the NW Caribbean. CARIBBEAN SEA... Please, read the SPECIAL FEATURES section, for more information about the eastern Caribbean tropical wave with tropical development potential. A surface trough extends from the NW Caribbean near 19N88W to 13N75W. Light to gentle variable winds, and sea heights ranging between 1-3 ft prevail across the basin outside of the tropical wave/low system. Fore the forecast...the tropical wave/low is forecast to move west-northwestward and be over the central Caribbean Sea this weekend where conditions are expected to be conducive for additional development. Locally heavy rainfall and gusty winds are likely to affect northern Venezuela, the ABC island chain, and northeastern Colombia tonight. Interests in Jamaica should closely monitor the progress of this system. ATLANTIC OCEAN... Please, read the SPECIAL FEATURES section above for information about Hurricane Fiona, the tropical wave with tropical development potential, and T.S. Gaston. A surface ridge prevails across most of the basin, extending from a 1023 mb high pressure centered near 34N39W. Moderate easterly winds prevail across the area, with sea heights reaching 6 ft at a maximum. The exception is fresh to locally strong N to NE winds, and the sea heights reaching 8 ft between the Cabo Verde Islands and W Africa. For the forecast...Hurricane Fiona will be north of area near 32.8N 67.3W by Fri morning. Swells generated by Fiona will continue to spread northwestward across the western Atlantic toward the mid-Atlantic and northeast coasts of the United States over the next day or so. A cold front will drop south over the north waters early on Fri through Sat night followed by fresh northeast winds and building seas. High pressure will build in behind the cold front. $$ Hagen