000 AXNT20 KNHC 292325 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 0005 UTC Wed Aug 30 2023 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 2300 UTC. Hurricane Idalia is centered near 26.1N 84.8W at 29/2100 UTC or 170 nm SW of Tampa, FL, moving N at 14 kt. Estimated minimum central pressure is 972 mb. Maximum sustained wind speed is 85 kt with gusts to 105 kt. Peak seas are near 28 ft. Seas of 12 ft or greater are found within 90 nm W semicircle, 150 nm NE quadrant and 120 nm SE quadrant. A buoy near 25.7N 83.7W recently reported significant wave heights of 20 ft. Numerous strong convection is seen within 75 nm of the center except 60 nm NW quadrant. Scattered moderate isolated strong convection is elsewhere within 450 nm of the center. A northward to north-northeastward motion is expected through tonight, with Idalia's center forecast to reach the Big Bend coast of Florida on Wed morning. After landfall, the center of Idalia is forecast to turn toward the northeast and east, moving near or along the coasts of Georgia, South Carolina, and North Carolina late Wed and Thu. Additional strengthening is forecast, and Idalia is expected to become a major hurricane tonight before it reaches the Big Bend coast of Florida. Idalia is likely to still be a hurricane while moving across southern Georgia, and possibly when it reaches the coast of Georgia or southern South Carolina on Wed. A dangerous and life- threatening storm surge is expected for portions of Florida's Gulf Coast. Areas of flash and urban flooding, some of which may be locally significant, are expected across portions of the west coast of Florida, the Florida Panhandle, and southern Georgia tonight into Wed. Major Hurricane Franklin is centered near 31.4N 69.9W at 29/2100 UTC or 265 nm W of Bermuda, moving NE at 10 kt. Estimated minimum central pressure is 947 mb. Maximum sustained wind speed is 110 kt with gusts to 135 kt. Peak seas are currently up to 40 ft. Seas of 12 ft or greater extend outward to 180 nm SE quadrant and 120 nm SW quadrant. A NOAA buoy located near 31.8N 69.6W recently reported winds of 71 kt gusting to 87 kt and seas of 34 ft. Numerous moderate to isolated strong convection is noted north of 28.5N between 66.5W and 71.5W. A faster NE motion is expected during the next few days. Winds of tropical storm force should move north of 31N by 30/0600 tonight. Winds over 25 kt and seas over 12 ft should move N of 31N by early afternoon Wed. Life- threatening surf and rip currents generated by Franklin are already affecting Bermuda and the east coast of the United States. These conditions are expected to continue during the next several days. Tropical Depression Eleven is centered near 28.2N 51.8W at 29/2100 UTC or 715 nm ESE of Bermuda, moving NNW at 2 kt. Estimated minimum central pressure is 1014 mb. Maximum sustained wind speed is 30 kt with gusts to 40 kt. Peak seas are 10 ft within the area of strongest winds. Scattered moderate isolated strong convection prevails within 210 nm E semicircle. A gradual turn toward the north and north-northeast at a slightly faster forward speed is expected on Wed and Thu. Some slight strengthening is possible during the next day or so, and the depression could become a tropical storm on Wed. 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 Franklin, Idalia, and T.D. Eleven NHC Forecasts/Advisories and Public Advisories at www.hurricanes.gov for more details. ...TROPICAL WAVES... A tropical wave axis is located along 21W, moving W at 10-15 kt. Scattered moderate isolated strong convection is within 120 nm of the wave axis from 12N-17N. Environmental conditions appear marginally conducive for gradual development of this system, and a tropical depression could form later this week while the system moves west-northwestward to northwestward across the eastern tropical Atlantic. This system has a low chance of tropical cyclone development within 48 hours and a medium chance within 7 days. A tropical wave axis is in the Atlantic along 48W, from 17N southward, moving W at around 15-20 kt. No significant convection is evident with this tropical wave. An eastern Caribbean tropical wave axis is along 63W from 17N southward, moving W around 10-15 kt. Scattered moderate convection is evident south of 16N between 56W and 66W. ...MONSOON TROUGH/ITCZ... The monsoon trough passes through coastal Africa near 18N16W to 13N35W. All nearby convection is described in the Tropical Waves section above. ...GULF OF MEXICO... Please read the SPECIAL FEATURES section for details about Hurricane Idalia, which is currently located in the eastern Gulf of Mexico. West of 90W, gentle to moderate winds and seas of 2-5 ft prevail. Isolated moderate convection is over the west-central Gulf. For the forecast, Hurricane Idalia will move to 28.3N 84.5W Wed morning, move inland to near 31.0N 82.9W Wed afternoon, weaken to a tropical storm near 32.9N 80.2W Thu morning, then will be north of area near 33.9N 77.1W Thu afternoon. Idalia is expected to become a major hurricane tonight. High pressure and improving conditions will arrive in the wake of Idalia by Fri. ...CARIBBEAN SEA... Refer to the Tropical Waves section above for details on a tropical wave affecting the Lesser Antilles. Hurricane Idalia is moving northward over the eastern Gulf of Mexico, so conditions in the NW Caribbean are improving. To the south of western Cuba and in the Yucatan Channel, S winds 20-25 kt and seas 7-8 ft still prevail. Scattered moderate to isolated strong convection is present north of 18N between 78W and 86W. Fresh trades and 4-7 ft seas prevail over much of the eastern and central basin. Light to gentle winds and 1-2 ft seas are in the far SW Caribbean. For the forecast, conditions will continue to improve over the NW Caribbean this evening and tonight. Elsewhere, expect increasing trades and building seas over the south-central Caribbean the remainder of the week. ...ATLANTIC OCEAN... Please read the SPECIAL FEATURES section for details about Major Hurricane Franklin, T.D. Eleven, and on Hurricane Idalia in the eastern Gulf of Mexico forecast to impact the waters off the SE United States. Scattered moderate convection is evident from 22N to 29N between 56W and 64W due to the influence of a mid to upper level feature. Away from the influences of Franklin, Idalia and TD Eleven, gentle to moderate winds dominate west of 35W with 4-5 ft seas. East of 35W, fresh NE winds and 6-9 ft seas prevail from the Cabo Verde Islands extending NE through the Canary Islands and continue northeastward from there. For the forecast, tropical storm conditions associated with Franklin will continue to impact the waters north of 27N tonight and tomorrow morning. Hurricane Idalia will move inland to 31.0N 82.9W Wed afternoon, weaken to a tropical storm near 32.9N 80.2W Thu morning, 33.9N 77.1W Thu afternoon, 33.8N 74.2W Fri morning, and 33.3N 71.8W Fri afternoon. Idalia will change little in intensity as it moves to near 32.3N 69.6W Sat afternoon. Expect increasing winds and building seas E of Florida beginning late tonight as Idalia moves across the eastern Gulf of Mexico, and eventually into the W Atlantic. $$ Hagen