| Track: https://www.nhc.noaa.gov/refresh/graphics_at5+shtml/?cone Recon should be back in the storm at 7:30am to 8am EDT, both Air Force and NOAA. https://hurricanecity.com/recon/ Recon plan of the day: https://www.nhc.noaa.gov/recon.php Satellite Floater: https://www.star.nesdis.noaa.gov/GOES/floater.php?stormid=AL102023 https://rammb-data.cira.colostate.edu/tc_realtime/storm.asp?storm_identifier=al102023 Gulf satellite: https://www.star.nesdis.noaa.gov/GOES/sector_band.php?sat=G16§or=gm&band=13&length=24 https://weather.cod.edu/satrad/?parms=regional-gulf-13-24-0-100-1&checked=map&colorbar=data Hurricane Idalia Discussion Number 11 NWS National Hurricane Center Miami FL AL102023 400 AM CDT Tue Aug 29 2023 Radar data from western Cuba indicates that Idalia is becoming better organized. Most of an eyewall has formed, with much more curvature in the banding features and overall radar pattern. Satellite imagery also shows the center of Idalia firmly within the central dense overcast. Thus, the initial wind speed is raised to 65 kt, in accordance with the latest TAFB satellite classification. The hurricane is accelerating northward this morning, now moving at about 9 kt. Idalia should move faster to the north or north-northeast through landfall on Wednesday between mid-level ridging over Florida and a trough dropping into the western Gulf of Mexico. There has been a westward shift in the model guidance overnight, perhaps due to the trough tugging Idalia more northward before taking a north-northeast turn. It should be noted that the ECMWF ensemble shows many of its strongest members on the eastern side of its guidance envelope, which is a reasonable place to be given the synoptic pattern. The new NHC forecast is adjusted a little to the west but is now east of the model consensus on the eastern side of the reliable model guidance. After Idalia leaves the eastern United States coastline, the track forecast becomes highly uncertain and little change was made to the previous forecast. With an inner core now present, the stage is set for Idalia to rapidly intensify before landfall. Shear should continue to lower over the cyclone as an upper-level trough departs the northeastern Gulf of Mexico and ridging builds closer to the cyclone. These changes, combined with extremely warm and deep waters the hurricane will be traversing, all strongly point to rapid intensification. The new forecast is similar to the previous one, and confidence is increasing in an extremely dangerous major hurricane making landfall Wednesday along the west coast or Big Bend region of Florida. KEY MESSAGES: 1. There is a danger of life-threatening storm surge inundation along portions of the Florida Gulf Coast where a Storm Surge Warning is in effect, including Tampa Bay and the Big Bend region of Florida. Inundation of 8 to 12 feet above ground level is expected somewhere between Chassahowitzka and Aucilla River. Residents in these areas should follow any advice given by local officials. 2. Hurricane conditions are expected within portions of the Hurricane Warning area along the Florida Gulf Coast, with the potential for destructive winds where the core of Idalia moves onshore. Strong winds will also spread inland across portions of northern Florida near the track of the center of Idalia. 3. Heavy rainfall is expected across portions of western Cuba and may produce areas of flash and urban flooding as well as landslides. 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 beginning today into Wednesday, spreading into portions of the eastern Carolinas Wednesday into Thursday. FORECAST POSITIONS AND MAX WINDS INIT 29/0900Z 23.1N 85.0W 65 KT 75 MPH 12H 29/1800Z 24.9N 84.8W 85 KT 100 MPH 24H 30/0600Z 27.8N 84.3W 105 KT 120 MPH 36H 30/1800Z 30.6N 82.9W 70 KT 80 MPH...INLAND 48H 31/0600Z 32.7N 80.5W 50 KT 60 MPH...INLAND 60H 31/1800Z 33.8N 77.5W 50 KT 60 MPH...OVER WATER 72H 01/0600Z 33.9N 74.4W 50 KT 60 MPH 96H 02/0600Z 33.3N 71.5W 45 KT 50 MPH 120H 03/0600Z 32.5N 70.5W 40 KT 45 MPH $$ Forecaster Blake Hurricane Idalia Advisory Number 11 NWS National Hurricane Center Miami FL AL102023 400 AM CDT Tue Aug 29 2023 ...IDALIA NOW A HURRICANE... ...EXPECTED TO RAPIDLY INTENSIFY INTO AN EXTREMELY DANGEROUS MAJOR HURRICANE BEFORE LANDFALL ON WEDNESDAY... SUMMARY OF 400 AM CDT...0900 UTC...INFORMATION ---------------------------------------------- LOCATION...23.1N 85.0W ABOUT 85 MI...135 KM N OF THE WESTERN TIP OF CUBA ABOUT 370 MI...600 KM SSW OF TAMPA FLORIDA MAXIMUM SUSTAINED WINDS...75 MPH...120 KM/H PRESENT MOVEMENT...N OR 360 DEGREES AT 14 MPH...22 KM/H MINIMUM CENTRAL PRESSURE...981 MB...28.97 INCHES WATCHES AND WARNINGS -------------------- CHANGES WITH THIS ADVISORY: The government of Mexico has discontinued the Tropical Storm Warning for the Yucatan Peninsula. 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... * Cuban province of Pinar del Rio * Middle of Longboat Key northward to Indian Pass, including Tampa Bay A Tropical Storm Warning is in effect for... * Isle of Youth Cuba * Dry Tortugas Florida * Chokoloskee northward to the Middle of Longboat Key * West of Indian Pass to Mexico Beach * Sebastian Inlet, Florida to Altamaha Sound, Georgia A Storm Surge Watch is in effect for... * Chokoloskee northward to Englewood, including Charlotte Harbour * Mouth of the St. Mary's River to South Santee River South Carolina A Hurricane Watch is in effect for... * Englewood to the Middle of Longboat Key A Tropical Storm Watch is in effect for... * Lower Florida Keys west of the west end of the Seven Mile Bridge * Altamaha Sound northward to South Santee River South Carolina 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. Interests along the southeastern U.S. coast should monitor the progress of this system. Additional watches and warnings along the southeast United States coast will likely be required later today. 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. For storm information specific to your area outside of the United States, please monitor products issued by your national meteorological service. DISCUSSION AND OUTLOOK ---------------------- At 400 AM CDT (0900 UTC), the center of Hurricane Idalia was located by Cuban radar near latitude 23.1 North, longitude 85.0 West. Idalia is moving toward the north near 14 mph (22 km/h). A northward motion is expected today, followed by a faster north-northeast motion later today and Wednesday. On the forecast track, the center of Idalia is forecast to move over the eastern Gulf of Mexico today, reach the Gulf coast of Florida within the Hurricane Warning area on Wednesday, and move close to the Carolina coastline on Thursday. Maximum sustained winds have increased to near 75 mph (120 km/h) with higher gusts. Rapid intensification is likely through landfall, and Idalia is forecast to become an extremely dangerous major hurricane before landfall on Wednesday. Hurricane-force winds extend outward up to 15 miles (30 km) from the center and tropical-storm-force winds extend outward up to 160 miles (260 km). The estimated minimum central pressure is 981 mb (28.97 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... Aucilla River, FL to Chassahowitzka, FL...8-12 ft Chassahowitzka, FL to Anclote River, FL...6-9 ft Ochlockonee River, FL to Aucilla River, FL...5-8 ft Anclote River, FL to Middle of Longboat Key, FL...4-7 ft Tampa Bay...4-7 ft Middle of Longboat Key, FL to Englewood, FL...3-5 ft Englewood, FL to Chokoloskee, FL...2-4 ft Charlotte Harbor...2-4 ft Indian Pass, FL to Ochlockonee River, FL...3-5 ft Mouth of the St. Mary's River to South Santee, SC...2-4 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. Elevated water levels along the southern coast of Pinar del Rio, Cuba will gradually subside today. WIND: Hurricane and tropical storm conditions are expected within the warning areas in western Cuba through this morning. Hurricane conditions are expected within the hurricane warning area in Florida by late today or Wednesday, with tropical storm conditions beginning today. Tropical storm conditions are expected in the Dry Tortugas soon and within the tropical storm warning area along the Florida Gulf coast and the Florida west coast later today. Tropical storm conditions are expected to begin on Wednesday in the warning area along the east coast of Florida and South Carolina Tropical storm conditions are possible along the southeast U.S. coast within the southern portions of the watch area by early Wednesday. RAINFALL: Idalia is expected to produce the following rainfall amounts: Western Cuba: 4 to 7 inches, with isolated higher totals of 10 inches. Portions of the west coast of Florida, the Florida Panhandle, southeast Georgia and the eastern Carolinas: 4 to 8 inches from today into Thursday. Isolated higher totals of 12 inches possible, primarily near landfall in northern Florida. This rainfall may lead to flash and urban flooding, and landslides across western Cuba. 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 today into Wednesday, spreading into portions of the eastern Carolinas Wednesday into Thursday. SURF: Swells generated by Idalia are affecting portions of the southern coast of Cuba and eastern Yucatan. These swells will spread northward along the eastern United States Gulf Coast during the next day or two. 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 will be possible later day along the west central Florida coast. The tornado threat will spread northward into the Florida Big Bend by tonight. NEXT ADVISORY ------------- Next intermediate advisory at 700 AM CDT. Next complete advisory at 1000 AM CDT. $$ Forecaster Blake |