BULLETIN Tropical Storm Isaias Advisory Number 27 NWS National Hurricane Center Miami FL AL092020 500 PM EDT Mon Aug 03 2020 ...ISAIAS GETTING BETTER ORGANIZED AND EXPECTED TO MAKE LANDFALL TONIGHT AS A HURRICANE WITH DANGEROUS WINDS AND STORM SURGE... ...STRONG WINDS AND HEAVY RAINFALL LIKELY FROM THE EASTERN CAROLINAS TO THE MID-ATLANTIC COAST TONIGHT AND TUESDAY... SUMMARY OF 500 PM EDT...2100 UTC...INFORMATION ---------------------------------------------- LOCATION...32.0N 79.4W ABOUT 60 MI...100 KM SSE OF CHARLESTON SOUTH CAROLINA ABOUT 120 MI...195 KM SSW OF MYRTLE BEACH SOUTH CAROLINA MAXIMUM SUSTAINED WINDS...70 MPH...110 KM/H PRESENT MOVEMENT...NNE OR 15 DEGREES AT 16 MPH...26 KM/H MINIMUM CENTRAL PRESSURE...993 MB...29.33 INCHES WATCHES AND WARNINGS -------------------- CHANGES WITH THIS ADVISORY: The Tropical Storm Warning has been extended northward to Stonington Maine. The Tropical Storm Warning south of Savannah River has been discontinued. SUMMARY OF WATCHES AND WARNINGS IN EFFECT: A Storm Surge Warning is in effect for... * Edisto Beach South Carolina to Cape Fear North Carolina * Pamlico and Albemarle Sounds, including the Neuse and Pamlico Rivers * Oregon Inlet North Carolina to the North Carolina/Virginia border A Storm Surge Watch is in effect for... * Cape Fear to Oregon Inlet North Carolina A Hurricane Warning is in effect for... * South Santee River South Carolina to Surf City North Carolina A Tropical Storm Warning is in effect for... * Savannah River to South Santee River South Carolina * North of Surf City North Carolina to Stonington Maine * Pamlico and Albemarle Sounds * Chesapeake Bay * Tidal Potomac River * Delaware Bay * Long Island and Long Island Sound * Martha's Vineyard, Nantucket, and Block Island A Tropical Storm Watch is in effect for... * North of Stonington to Eastport Maine 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 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 Storm Surge Watch means there is a possibility of life- threatening inundation, from rising water moving inland from the coastline. A Hurricane Warning means that hurricane conditions are expected somewhere within the warning area. A Tropical Storm Warning means that tropical storm conditions are expected somewhere within the warning area, generally within 36 hours. A Tropical Storm Watch means that tropical storm conditions are possible within the watch area, generally within 48 hours. 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 PM EDT (2100 UTC), the center of Tropical Storm Isaias was located by NOAA Doppler weather radars near latitude 32.0 North, longitude 79.4 West. Isaias is moving toward the north-northeast near 16 mph (26 km/h), and this general motion accompanied by a gradual increase in forward speed is expected through tonight followed by a further increase in the forward speed on Tuesday. On the forecast track, the center of Isaias will approach the coasts of northeastern South Carolina and southern North Carolina within the hurricane warning area this evening. The center will then move inland across eastern North Carolina early Tuesday morning, move along the coast of the mid-Atlantic states on Tuesday, and continue across the northeastern United States Tuesday night. Data from NOAA Doppler weather radars indicate that maximum sustained winds are near 70 mph (110 km/h) with higher gusts. Some strengthening is forecast later this afternoon or early evening, and Isaias is expected to make landfall tonight at or near hurricane strength along the coast of northeastern South Carolina or southern North Carolina. Only gradual weakening is anticipated after Isaias makes landfall in the Carolinas and moves across the U.S. mid-Atlantic region tonight and Tuesday. Tropical-storm-force winds extend outward up to 125 miles (205 km) from the center. During the past couple of hours, a sustained wind of 45 mph (72 km/h) and a gust to 52 mph (83 km/h) were measured by a Weatherflow site at Folly Beach Pier, South Carolina. The estimated minimum central pressure is 993 mb (29.33 inches). HAZARDS AFFECTING LAND ---------------------- Key messages for Isaias can be found in the Tropical Cyclone Discussion under AWIPS header MIATCDAT4, WMO header WTNT44 KNHC, and on the web at www.hurricanes.gov/text/MIATCDAT4.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... South Santee River SC to Cape Fear NC...3-5 ft Edisto Beach SC to South Santee River SC...2-4 ft Cape Fear NC to the North Carolina/Virginia border including Pamlico Sound, Albemarle Sound, Neuse and Pamlico Rivers...2-4 ft Savannah River to Edisto Beach SC...1-3 ft North of the North Carolina/Virginia border to Martha's Vineyard including the Chesapeake Bay, the Tidal Potomac River, Delaware Bay, Long Island Sound, Block Island Sound, Narragansett Bay, Buzzards Bay, and Vineyard Sound...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: Hurricane conditions are expected within the hurricane warning area in South and North Carolina this evening and tonight, with tropical storm conditions spreading onshore in the next few hours. Widespread tropical-storm-conditions are expected in the tropical storm warning area from coastal North Carolina to the mid-Atlantic states, including portions of the Chesapeake Bay region, tonight and Tuesday, with wind gusts to hurricane force possible. These winds could cause tree damage and power outages. Tropical storm conditions are expected to reach southern New England Tuesday afternoon and northern New England Tuesday night and early Wednesday. RAINFALL: The following rainfall accumulations are expected along and near the track of Isaias: Carolinas and the Mid-Atlantic: 3 to 6 inches, isolated maximum totals 8 inches. Eastern New York and western New England from Connecticut to New Hampshire: 2 to 4 inches, isolated maximum totals 6 inches. Western and northern Maine: 1 to 3 inches. Heavy rainfall along the East Coast, near the path of Isaias, will result in flash and urban flooding, some of which may be significant in the eastern Carolinas, Mid-Atlantic and Northeast through Wednesday. Widespread minor to moderate river flooding is possible across portions of the Carolinas and the Mid-Atlantic. Quick-responding rivers in Northeast will also be susceptible to minor river flooding. TORNADOES: A few tornadoes will be possible near northeastern South Carolina coastal areas by early this evening, before spreading across eastern North Carolina tonight into Tuesday morning. A couple of tornadoes will be possible on Tuesday from eastern Virginia northeastward into southern New England. SURF: Swells generated by Isaias are affecting portions of the Bahamas and the southeast coast of the United States and will spread northward along the U.S. east coast during the next couple of days. These swells are likely to cause life-threatening surf and rip current conditions. Please consult products from your local weather office.