000 AXNT20 KNHC 210509 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0605 UTC Wed Sep 21 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 0450 UTC. ...SPECIAL FEATURES... Major Hurricane Fiona is centered near 23.2N 71.8W at 21/0300 UTC or 80 nm N of North Caicos Island moving N at 7 kt. Estimated minimum central pressure is 947 mb. Maximum sustained wind speed is 110 kt with gusts to 135 kt. Satellite imagery shows a clear eye 25 nm in diameter. Numerous moderate to strong convection is noted within 300 nm of center in the NE quadrant, 270 nm SE quadrant, 120 nm SW quadrant and 180 nm NW quadrant. Peak seas are estimated at 36 ft currently and are forecast to build to near 45 ft over the next day or two. A drifting buoy from the Sofar network recently measured seas of 25 ft, about 100 nm NE of the center of Fiona. Heavy rains will continue to impact the Turks and Caicos through this morning. Fiona is forecast to continue strengthening over the next 12 hours, reaching category 4 intensity later today. Fiona is forecast to turn to the NNE and accelerate on Thu. 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 36.2N 43.6W at 21/0300 UTC or 800 nm W of the Azores moving NNE at 16 kt. Estimated minimum central pressure is 1004 mb. Maximum sustained wind speed is 45 kt with gusts to 55 kt. Scattered moderate isolated strong convection is noted within 180 nm of the center in the NE quadrant, 30 nm SE quadrant and 90 nm W semicircle. A turn to the NE and then E is expected over the next 48 hours. 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. A tropical wave has an axis along 56/57W, moving W at 15-20 kt. Scattered moderate and isolated strong convection is noted from 06N to 12N between 51W and 60W. Recent ASCAT data show strong winds from 12N-15N between 55W-58W. Seas with this system are likely as high as 8 to 9 ft currently. The system continues to show signs of organization and it will likely become a tropical depression within the next two or three days. The disturbance is forecast to move west-northwestward across the southern Windward Islands late today and then move toward the central Caribbean Sea late this week. Heavy rainfall and gusty winds are possible across the Windward Islands beginning today. There is a high chance of tropical cyclone development within the next 48 hours. Please refer to the latest Atlantic Tropical Weather Outlook at hurricanes.gov for more details. ...TROPICAL WAVES... A Caribbean Sea tropical wave has its axis near 65W, from 18N southward to southern Venezuela, moving W at 15 kt. Isolated showers are within 60 nm either side of the wave axis south of 13N. ...MONSOON TROUGH/ITCZ... The monsoon trough passes off the coast of southern Senegal near 12N17W to 1012 mb low pressure near 10N31W to 09N37W. The ITCZ continues from 09N37W to 08N48W. Scattered moderate to strong convection is noted from 10N-14N between 16W-19N. Scattered moderate isolated strong convection is seen from 11N-14N between 29W-34W. GULF OF MEXICO... A 1016 mb high pressure is centered over west-central Mississippi. A weak surface trough is oriented north-south just offshore the west coast of the Florida peninsula. Isolated showers and tstorms are noted along the trough from 26.5N-29N between 83W-84W. Moderate NE winds prevail over the central Gulf of Mexico, where seas are likely 3-5 ft. Gentle winds and 1-3 ft seas prevail elsewhere across the Gulf. For the forecast, high pressure over the southeastern U.S. will maintain gentle to moderate easterly breezes and slight seas the next few days. A cold front could reach the NE Gulf on Fri, bringing a brief period of moderate to fresh N to NE winds to the NE Gulf Fri. CARIBBEAN SEA... A recent ASCAT pass shows gentle winds across most of the Caribbean Sea, except for moderate S winds from 15.5N northward between 66W-71W, including the Mona Passage. Seas are 3-5 ft over the eastern Caribbean and 1-3 ft in the western Caribbean. Isolated moderate convection prevails over the central Caribbean between 66.5W-74W. Scattered moderate convection is noted in the far W Caribbean west of 83W from 11.5N-17N, mostly near the coasts of Honduras and Nicaragua. For the forecast, the tropical wave along 57W is forecast to move west-northwestward across the southern Windward Islands late today and then move toward the central Caribbean Sea late this week. This system has a high chance of tropical cyclone formation within the next 48 hours. For more information on this system, please read the Special Features section above. ATLANTIC OCEAN... Please read the Special Features section above for information on Major Hurricane Fiona. Outside of Fiona and the tropical wave along 57W, no significant or eventful weather is occurring in the basin. Winds are gentle to moderate from 20N-31N between 20W-62W. Seas are 3-5 ft across this area. The area of 20 kt or stronger winds directly associated with the circulation of Hurricane Fiona currently extends from 19N-27N between 65W-75.5W. The area of 8 ft seas or greater extends from 20N-28N between 67W-76W. For the forecast W of 55W, Major Hurricane Fiona will move to near 26N71.5W Wed evening, 31N69W Thu evening, and near 39.5N62W Fri evening. Swells generated by Fiona will continue to spread westward across the southwestern Atlantic toward the central and northwestern Bahamas and the east coast of the United States through late week. A cold front will drop southward into the area Fri through Sat night followed by fresh northeast winds. High pressure will build in behind the cold front. $$ Hagen