000 WTNT31 KNHC 220831 TCPAT1 BULLETIN Potential Tropical Cyclone Sixteen Advisory Number 4 NWS National Hurricane Center Miami FL AL162023 500 AM EDT Fri Sep 22 2023 ...LOW PRESSURE STRENGTHENING OFF THE SOUTHEAST U.S... ...TROPICAL STORM CONDITIONS EXPECTED TO BEGIN ALONG THE NORTH CAROLINA COAST LATER THIS MORNING... SUMMARY OF 500 AM EDT...0900 UTC...INFORMATION ---------------------------------------------- LOCATION...30.5N 75.0W ABOUT 330 MI...530 KM ESE OF CHARLESTON SOUTH CAROLINA ABOUT 325 MI...525 KM S OF CAPE HATTERAS NORTH CAROLINA MAXIMUM SUSTAINED WINDS...50 MPH...85 KM/H PRESENT MOVEMENT...N OR 360 DEGREES AT 14 MPH...22 KM/H MINIMUM CENTRAL PRESSURE...1000 MB...29.53 INCHES WATCHES AND WARNINGS -------------------- CHANGES WITH THIS ADVISORY: None. SUMMARY OF WATCHES AND WARNINGS IN EFFECT: A Storm Surge Warning is in effect for... * Duck North Carolina to Chincoteague Virginia * Chesapeake Bay south of Windmill Point * Neuse and Pamlico Rivers * Portions of Pamlico and Albemarle Sounds A Tropical Storm Warning is in effect for... * Cape Fear North Carolina to Fenwick Island Delaware * Albemarle and Pamlico Sounds * Tidal Potomac south of Cobb Island * Chesapeake Bay south of North Beach A Storm Surge Watch is in effect for... * Surf City to Duck North Carolina * Chesapeake Bay north of Windmill Point to Smith Point * Tidal Potomac south of Colonial Beach * Remainder of Pamlico and Albemarle Sounds 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 within 36 hours. 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. 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 500 AM EDT (0900 UTC), the low pressure system was centered near latitude 30.5 North, longitude 75.0 West. The system is moving toward the north near 14 mph (22 km/h). A northwest to north motion is expected during the next couple of days. On the forecast track, the center of the low will approach the coast of North Carolina through tonight, and then move across eastern North Carolina, southeastern Virginia, and the Delmarva Peninsula Saturday and Sunday. Maximum sustained winds are near 50 mph (85 km/h) with higher gusts. Some additional strengthening is forecast during the next day or so, and the low is expected to become a tropical storm before it reaches the coast of North Carolina. Regardless of whether it becomes a tropical storm, the system is expected to bring tropical-storm conditions to portions of the southeast and mid-Atlantic coasts. * Formation chance through 48 hours...high...70 percent. * Formation chance through 7 days...high...70 percent. Tropical-storm-force winds extend outward up to 240 miles (390 km) from the center. The estimated minimum central pressure based on surface observations is 1000 mb (29.53 inches). HAZARDS AFFECTING LAND ---------------------- Key messages for this system can be found in the Tropical Cyclone Discussion under AWIPS header MIATCDAT1 and WMO header WTNT41 KNHC and on the web at hurricanes.gov/text/MIATCDAT1.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... Neuse and Bay Rivers...3-5 ft Pamlico and Pungo Rivers...3-5 ft Chesapeake Bay south of Colonial Beach...2-4 ft Surf City, NC to Chincoteague, VA...2-4 ft Albemarle Sound...2-4 ft South Santee River, SC to Surf City, NC...1-3 ft Chincoteague, VA to Manasquan Inlet, NJ...1-3 ft Upper Chesapeake Bay...1-3 ft Delaware Bay...1-3 ft The deepest water will occur along the immediate coast in areas of onshore winds, where the surge will be accompanied by 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: Tropical storm conditions are expected to first reach the coast within the warning area in North Carolina later this morning, and spread northward into Saturday. RAINFALL: The system is forecast to produce 3 to 5 inches of rainfall, with localized amounts of 7 inches, across eastern North Carolina into southeast Virginia into Saturday. Across remaining portions of the Mid-Atlantic into southern New England, 2 to 4 inches of rainfall are forecast from late today into Sunday. This rainfall may produce isolated urban and small stream flooding impacts. SURF: Swells generated by this system will be affecting much of the east coast of the United States through this weekend. 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 beginning tonight through Saturday for portions of the Mid-Atlantic Coast. NEXT ADVISORY ------------- Next intermediate advisory at 800 AM EDT. Next complete advisory at 1100 AM EDT. $$ Forecaster Cangialosi