ZCZC MIATCPAT5 ALL TTAA00 KNHC DDHHMM BULLETIN Tropical Storm Idalia Advisory Number 18 NWS National Hurricane Center Miami FL AL102023 1100 PM EDT Wed Aug 30 2023 ...IDALIA PRODUCING VERY HEAVY RAINS OVER THE CAROLINAS... SUMMARY OF 1100 PM EDT...0300 UTC...INFORMATION ----------------------------------------------- LOCATION...33.0N 80.0W ABOUT 15 MI...25 KM NNW OF CHARLESTON SOUTH CAROLINA MAXIMUM SUSTAINED WINDS...60 MPH...95 KM/H PRESENT MOVEMENT...NE OR 45 DEGREES AT 21 MPH...33 KM/H MINIMUM CENTRAL PRESSURE...987 MB...29.15 INCHES WATCHES AND WARNINGS -------------------- CHANGES WITH THIS ADVISORY: The Storm Surge Warning has been discontinued south of the Savannah River. The Tropical Storm Warning has been discontinued south of the Savannah River. SUMMARY OF WATCHES AND WARNINGS IN EFFECT: A Storm Surge Warning is in effect for... * Savannah River northward to the South Santee River South Carolina A Tropical Storm Warning is in effect for... * Savannah River northward to the North Carolina/Virginia border * Pamlico and Albemarle Sounds A Storm Surge Watch is in effect for... * Beaufort Inlet to Ocracoke Inlet North Carolina * Neuse and Pamlico Rivers North Carolina A Storm Surge Warning means there is a danger of life-threatening inundation, from rising water moving inland from the coastline 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. For a depiction of areas at risk, please see the National Weather Service Storm Surge Watch/Warning Graphic, available at hurricanes.gov. Interests in Bermuda should monitor the progress of Idalia. For storm information specific to your area, 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 Tropical Storm Idalia was located near latitude 33.0 North, longitude 80.0 West. Idalia is moving toward the northeast near 21 mph (33 km/h), and this general motion is expected to continue through tonight. An eastward to east-southeastward motion is forecast to begin on Thursday and continue through Saturday. On the forecast track, the center of Idalia will move near or along the coast of South Carolina through tonight, and then just offshore of the coast of North Carolina on Thursday. Idalia will then move over the western Atlantic into the weekend. Maximum sustained winds have decreased to near 60 mph (95 km/h) with higher gusts. Little change in strength is forecast during the next 48 hours, and Idalia is expected to remain a tropical storm when if moves off the coast. Tropical-storm-force winds extend outward up to 205 miles (335 km) from the center. A sustained wind of 48 mph (78 km/h) and a gust to 58 mph (94 km/h) were recently reported from saildrone SD-1045 which is located off the South Carolina coast. The estimated minimum central pressure is 987 mb (29.15 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 storm surge and 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... Beaufort Inlet, NC to Ocracoke Inlet, NC...2-4 ft Savannah River to South Santee River, SC...2-4 ft Neuse and Bay Rivers...2-4 ft Pamlico and Pungo Rivers...2-4 ft South Santee River, SC to Beaufort Inlet, NC...1-3 ft Ocracoke Inlet, NC to Duck, NC...1-3 ft Altamaha Sound, GA to Savannah River...1-3 ft The deepest water will occur along the immediate coast in areas of onshore winds, where the surge will be accompanied by large 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: Tropical storm conditions are occurring within the tropical storm warning area along the coast of South Carolina, and will spread across coastal sections of North Carolina tonight through Thursday. RAINFALL: Idalia is expected to produce a storm total of 4 to 8 inches of rainfall with isolated maxima up to 10 inches from eastern South Carolina through eastern North Carolina into Thursday. These rainfall amounts will continue to lead to areas of flash, urban, and moderate river flooding, with considerable impacts. The trailing moisture band from Idalia may produce an additional 1 to 2 inches of rainfall over the central Florida Peninsula into Thursday. SURF: Swells generated by Idalia along the eastern and central Gulf coast will continue to subside tonight and Thursday. Swells will affect the southeastern U.S. coast during the next few days. These swells are likely to cause life-threatening surf and rip current conditions. Please consult products from your local weather office. TORNADOES: A couple of tornadoes will be possible through daybreak Thursday across coastal North Carolina. NEXT ADVISORY ------------- Next intermediate advisory at 200 AM EDT. Next complete advisory at 500 AM EDT. $$ Forecaster Pasch NNNN