| NHC: https://www.nhc.noaa.gov/ 11pm EDT Tuesday advisory forecasts the storm to be a category four hurricane at landfall. Surge as high as 16 feet now forecast around landfall point, with 130 mph winds. Position updates, with intensity, now occur every hour. Hurricane Idalia Tropical Cyclone Update NWS National Hurricane Center Miami FL AL102023 1200 AM EDT Wed Aug 30 2023 ...CATASTROPHIC STORM SURGE AND DESTRUCTIVE WINDS EXPECTED IN THE FLORIDA BIG BEND REGION THIS MORNING WHEN IDALIA MOVES INLAND... ...12 AM POSITION UPDATE... NOAA buoy 42036 recently reported sustained winds of 49 mph (79 km/h) and a gust to 60 mph (97 km/h) in the northern rainbands of Idalia SUMMARY OF 1200 AM EDT...0400 UTC...INFORMATION ---------------------------------------------- LOCATION...27.9N 84.6W ABOUT 120 MI...195 KM SW OF CEDAR KEY FLORIDA ABOUT 175 MI...280 KM S OF TALLAHASSEE FLORIDA MAXIMUM SUSTAINED WINDS...110 MPH...175 KM/H PRESENT MOVEMENT...N OR 360 DEGREES AT 17 MPH...27 KM/H MINIMUM CENTRAL PRESSURE...958 MB...28.29 INCHES $$ Forecaster D. Zelinsky Hurricane Idalia Discussion Number 14 NWS National Hurricane Center Miami FL AL102023 1100 PM EDT Tue Aug 29 2023 Satellite and NWS radar imagery show that Idalia is becoming increasingly more organized. The eye on the Tampa WSR-88D is becoming better defined and the cloud pattern on GOES 16 imagery consists of a growing Central Dense Overcast with a strong convective band over the eastern semicircle of the circulation. Reconnaissance aircraft measurements show that the central pressure is steadily falling and is now around 958 mb. Flight-level and SFMR-observed winds along with Doppler velocity data from the aircraft support an intensity of 95 kt for this advisory. Idalia is now moving faster toward the north or slightly east of north with a motion estimate of 010/16 kt. The hurricane is moving between a mid-level trough over the northwestern Gulf of Mexico and ridge over the Bahamas and Greater Antilles. The system is expected to turn north-northeastward within the next 12 hours, make landfall along the northeastern Gulf coast, and then move northeastward to eastward on the southern side of a mid-level trough moving off the northeast U.S. coast. The 12-hour track forecast point for this advisory has been nudged a bit westward, a little west of the model consensus, but close to the latest GFS and ECMWF solutions. It should be noted that some credible models, i.e. the HAFS-A and HAFS-B predictions, are even a little father west. After landfall, Idalia is expected to move near or along the coast of Georgia and the Carolinas in 24-36 hours. Uncertainty in the track forecast beyond 48 hours remains quite large, with some of the global models turning Idalia southward, while some of the regional hurricane models show the storm moving out to sea. Given the uncertainties, the official track forecast shows a slow southeastward motion in 4 to 5 days. Based on the current strengthening trend and the favorable thermodynamic and oceanic conditions, significant strengthening seems likely up to landfall. The new official intensity forecast calls for Idalia to reach category 4 strength at landfall. This is fairly close to the HAFS And HWRF regional hurricane model simulations. After the center moves back over the Atlantic, significant restrengthening is not anticipated at this time due to the expectation of strong vertical west-southwesterly vertical wind shear. Dangerous winds are likely to spread well inland near the path of Idalia due to its relatively fast forward motion. KEY MESSAGES: 1. Catastrophic impacts from storm surge inundation of 12 to 16 feet above ground level and destructive waves are expected somewhere between the Wakulla/Jefferson County line and Yankeetown, Florida. Life-threatening storm surge inundation is likely elsewhere along portions of the Florida Gulf Coast where a Storm Surge Warning is in effect. Residents in these areas should follow any advice given by local officials. 2. There is the potential for destructive life-threatening winds where the core of Idalia moves onshore in the Big Bend region of Florida, with hurricane conditions expected elsewhere in portions of the Hurricane Warning area along the Florida Gulf Coast. Strong winds will also spread inland across portions of northern Florida and southern Georgia near the track of the center of Idalia where Hurricane Warnings are in effect. Residents in these areas should be prepared for long-duration power outages. Damaging hurricane-force winds are possible in portions of eastern Georgia and southeastern South Carolina where Hurricane Watches are in effect. 3. Areas of flash, urban, and moderate river flooding, with locally considerable impacts, are expected across the Florida Big Bend, central Georgia and South Carolina, through eastern North Carolina into Thursday. FORECAST POSITIONS AND MAX WINDS INIT 30/0300Z 27.7N 84.5W 95 KT 110 MPH 12H 30/1200Z 30.0N 83.9W 115 KT 130 MPH...ON COAST 24H 31/0000Z 32.3N 81.3W 70 KT 80 MPH...INLAND 36H 31/1200Z 33.5N 78.6W 50 KT 60 MPH...OVER WATER 48H 01/0000Z 33.8N 75.0W 50 KT 60 MPH 60H 01/1200Z 33.5N 72.5W 50 KT 60 MPH 72H 02/0000Z 32.9N 71.0W 45 KT 50 MPH 96H 03/0000Z 32.0N 69.4W 45 KT 50 MPH 120H 04/0000Z 31.0N 68.4W 45 KT 50 MPH $$ Forecaster Pasch Hurricane Idalia Advisory Number 14 NWS National Hurricane Center Miami FL AL102023 1100 PM EDT Tue Aug 29 2023 ...IDALIA STILL STRENGTHENING... ...FORECAST TO BE AN EXTREMELY DANGEROUS CATEGORY 4 INTENSITY AT LANDFALL... SUMMARY OF 1100 PM EDT...0300 UTC...INFORMATION ----------------------------------------------- LOCATION...27.7N 84.5W ABOUT 125 MI...200 KM W OF TAMPA FLORIDA ABOUT 185 MI...300 KM S OF TALLAHASSEE FLORIDA MAXIMUM SUSTAINED WINDS...110 MPH...175 KM/H PRESENT MOVEMENT...N OR 10 DEGREES AT 18 MPH...30 KM/H MINIMUM CENTRAL PRESSURE...958 MB...28.29 INCHES WATCHES AND WARNINGS -------------------- CHANGES WITH THIS ADVISORY: The Tropical Storm Warning for the Dry Tortugas is discontinued, and the Tropical Storm Watch for the Lower Florida Keys is discontinued. SUMMARY OF WATCHES AND WARNINGS IN EFFECT: A Storm Surge Warning is in effect for... * Englewood northward to Indian Pass, including Tampa Bay A Hurricane Warning is in effect for... * Middle of Longboat Key northward to Indian Pass, including Tampa Bay A Tropical Storm Warning is in effect for... * Chokoloskee northward to the Middle of Longboat Key * West of Indian Pass to Mexico Beach * Sebastian Inlet Florida to Surf City North Carolina A Storm Surge Watch is in effect for... * Bonita Beach northward to Englewood, including Charlotte Harbour * Mouth of the St. Mary's River to South Santee River South Carolina * Beaufort Inlet to Drum Inlet North Carolina * Neuse and Pamlico Rivers North Carolina A Hurricane Watch is in effect for... * Mouth of the St. Mary's River to Edisto Beach South Carolina A Tropical Storm Watch is in effect for... * North of Surf City North Carolina to the North Carolina/Virginia border * Pamlico and Albemarle Sounds A Hurricane Warning means that hurricane conditions are expected somewhere within the warning area. Preparations to protect life and property should be rushed to completion. A Storm Surge Warning means there is a danger of life-threatening inundation, from rising water moving inland from the coastline, during the next 36 hours in the indicated locations. For a depiction of areas at risk, please see the National Weather Service Storm Surge Watch/Warning Graphic, available at hurricanes.gov. This is a life-threatening situation. Persons located within these areas should take all necessary actions to protect life and property from rising water and the potential for other dangerous conditions. Promptly follow evacuation and other instructions from local officials. A Tropical Storm Warning means that tropical storm conditions are expected somewhere within the warning area. A Storm Surge Watch means there is a possibility of life- threatening inundation, from rising water moving inland from the coastline, in the indicated locations during the next 48 hours. For a depiction of areas at risk, please see the National Weather Service Storm Surge Watch/Warning Graphic, available at hurricanes.gov. A Hurricane Watch means that hurricane conditions are possible within the watch area. A Tropical Storm Watch means that tropical storm conditions are possible within the watch area, generally within 48 hours. Additional warnings will likely be required tonight or on Wednesday. For storm information specific to your area in the United States, including possible inland watches and warnings, please monitor products issued by your local National Weather Service forecast office. DISCUSSION AND OUTLOOK ---------------------- At 1100 PM EDT (0300 UTC), the center of Hurricane Idalia was located near latitude 27.7 North, longitude 84.5 West. Idalia is moving toward the north near 18 mph (30 km/h). A northward to north-northeastward motion is expected through tonight, with Idalia's center forecast to reach the Big Bend coast of Florida on Wednesday morning. After landfall, the center of Idalia is forecast to turn toward the northeast and east-northeast, moving near or along the coasts of Georgia, South Carolina, and North Carolina late Wednesday and Thursday. Hurricane Hunter aircraft data indicate that maximum sustained winds are near 110 mph (175 km/h) with higher gusts. Additional strengthening is forecast, and Idalia is expected to become a major hurricane during the next few hours 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 Wednesday. Hurricane-force winds extend outward up to 25 miles (35 km) from the center and tropical-storm-force winds extend outward up to 160 miles (260 km). The estimated minimum central pressure based on Hurricane Hunter aircraft observations is 958 mb (28.29 inches). HAZARDS AFFECTING LAND ---------------------- Key messages for Idalia can be found in the Tropical Cyclone Discussion under AWIPS header MIATCDAT5 and WMO header WTNT45 KNHC, and on the web at hurricanes.gov/text/MIATCDAT5.shtml STORM SURGE: The combination of a dangerous storm surge and the tide will cause normally dry areas near the coast to be flooded by rising waters moving inland from the shoreline. The water could reach the following heights above ground somewhere in the indicated areas if the peak surge occurs at the time of high tide... Wakulla/Jefferson County line, FL to Yankeetown, FL...12-16 ft Ochlockonee River, FL to Wakulla/Jefferson County line, FL...8-12 ft Yankeetown to Chassahowitzka, FL...7-11 ft Chassahowitzka, FL to Anclote River, FL...6-9 ft Carrabelle, FL to Ochlockonee River, FL...5-8 ft Anclote River, FL to Middle of Longboat Key, FL...4-6 ft Tampa Bay...4-6 ft Middle of Longboat Key, FL to Englewood, FL...3-5 ft Indian Pass, FL to Carrabelle, FL...3-5 ft Englewood, FL to Bonita Beach, FL...2-4 ft Charlotte Harbor...2-4 ft Mouth of the St. Mary's River to South Santee, SC...2-4 ft Beaufort Inlet to Drum Inlet, NC...2-4 ft Pamlico and Neuse Rivers...2-4 ft South of Bonita Beach to Chokoloskee, FL...1-3 ft South Santee, SC to Beaufort Inlet, NC...1-3 ft Drum Inlet to Duck, NC...1-3 ft Chokoloskee, FL to East Cape Sable, FL...1-3 ft Flagler/Volusia County Line, FL to Mouth of St. Mary's River...1-3 ft Indian Pass to Mexico Beach...1 to 3 ft Florida Keys...1-2 ft The deepest water will occur along the immediate coast in areas of onshore winds, where the surge will be accompanied by large and dangerous waves. Surge-related flooding depends on the relative timing of the surge and the tidal cycle, and can vary greatly over short distances. For information specific to your area, please see products issued by your local National Weather Service forecast office. WIND: Hurricane conditions are expected within the hurricane warning area in Florida early Wednesday morning, with tropical storm conditions beginning within the next few hours. Tropical storm conditions will begin within the tropical storm warning area along the Florida Gulf coast and the Florida west coast soon. Hurricane conditions are possible within the hurricane watch area along the coasts of Georgia and South Carolina Wednesday and Wednesday night. Tropical storm conditions are expected to begin on Wednesday in the warning area along the east coast of Florida, Georgia, and South Carolina, and spread into North Carolina Wednesday night and Thursday. Tropical storm conditions are possible within the watch area in North Carolina by Thursday. RAINFALL: Idalia is expected to produce a swath of 4 to 8 inches of rainfall with isolated maxima up to 12 inches from the Florida Big Bend through central Georgia and South Carolina, and through eastern North Carolina into Thursday. These rainfall amounts will lead to areas of flash, urban, and moderate river flooding, with locally considerable impacts. SURF: Swells generated by Idalia are affecting the southwestern coast of Florida and will spread northward and westward to the north-central Gulf coast through Wednesday. These swells are likely to cause life-threatening surf and rip current conditions. Please consult products from your local weather office. TORNADOES: A few tornadoes are possible tonight from the coast of west-central Florida northward into the Florida Big Bend region. The tornado risk will shift into southeast Georgia and the coastal Carolinas on Wednesday. NEXT ADVISORY ------------- Next intermediate advisory at 200 AM EDT. Next complete advisory at 500 AM EDT. $$ Forecaster Pasch |