Tropical Storm Isaias Intermediate Advisory Number 25A
NWS National Hurricane Center Miami FL AL092020
800 AM EDT Mon Aug 03 2020
SUMMARY OF 800 AM EDT...1200 UTC...INFORMATION
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LOCATION...30.2N 80.1W
ABOUT 100 MI...155 KM ESE OF JACKSONVILLE FLORIDA
ABOUT 250 MI...400 KM SSW OF MYRTLE BEACH SOUTH CAROLINA
MAXIMUM SUSTAINED WINDS...70 MPH...110 KM/H
PRESENT MOVEMENT...N OR 355 DEGREES AT 13 MPH...20 KM/H
MINIMUM CENTRAL PRESSURE...994 MB...29.36 INCHES
WATCHES AND WARNINGS
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CHANGES WITH THIS ADVISORY:
None.
SUMMARY OF WATCHES AND WARNINGS IN EFFECT:
A Storm Surge Warning is in effect for...
* Edisto Beach South Carolina to Cape Fear North Carolina
A Storm Surge Watch is in effect for...
* Cape Fear to Duck North Carolina
* Pamlico and Albemarle Sounds
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...
* Flagler/Volusia County Line Florida to South Santee River South Carolina
* North of Surf City North Carolina to west of Watch Hill Rhode Island
* Chesapeake Bay south of North Beach
* Tidal Potomac River south of Cobb Island
* Delaware Bay
* Long Island and Long Island Sound
* Pamlico and Albemarle Sounds
A Tropical Storm Watch is in effect for...
* Watch Hill Rhode Island to Stonington, Maine
* Martha's Vineyard, Nantucket, and Block Island
Interests elsewhere along the northeast coast of the United States should monitor the progress of Isaias. Additional watches or warnings may be required later today.
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. 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, in the indicated locations during the next 48 hours.
A Hurricane Warning means that hurricane conditions are expected somewhere within the warning area, in this case within 24 hours. Preparations to protect life and property should be rushed to completion.
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.
DISCUSSION AND OUTLOOK
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At 800 AM EDT (1200 UTC), the center of Tropical Storm Isaias was located by an Air Force Reserve reconnaissance aircraft and NOAA Doppler weather radars near latitude 30.2 North, longitude 80.1 West. Isaias is moving toward the north near 13 mph (20 km/h). A turn toward the north and north-northeast along with an increase in forward speed is expected later today and Tuesday. On the forecast track, the center of Isaias will pass well east of the Georgia coast through this morning. The center of Isaias will then approach the coast of northeastern South Carolina and southern North Carolina within the hurricane warning area later today. The center will then move inland over eastern North Carolina tonight, and move along the coast of the mid-Atlantic states on Tuesday and into the northeastern United States by Tuesday night.
Maximum sustained winds are near 70 mph (110 km/h) with higher gusts. Some strengthening is anticipated today, and Isaias is forecast to regain hurricane strength before it reaches the coast of northeastern South Carolina or southern North Carolina tonight. Slow weakening is forecast 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 hour a wind gust to 40 mph (65 km/h) was observed at the St, Augustine Pier, Florida, and a sustained wind of 34 mph (55 km/h) and a gust to 40 mph (65 km/h) were measured by a Weatherflow station at the Jacksonville Beach
Pier, Florida.
The estimated minimum central pressure is 994 mb (29.36 inches).
HAZARDS AFFECTING LAND
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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 Cape Hatteras NC including Pamlico Sound, Neuse and Pamlico Rivers...2-4 ft
Flagler/Volusia County Line FL to Edisto Beach SC...1-3 ft
North of Cape Hatteras NC to Cape May NJ including Albemarle Sound, Chesapeake Bay, the Tidal Potomac River, and 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 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 through tonight.
Tropical storm conditions will spread northward within the Tropical Storm Warning area from Florida to southern New England through Tuesday afternoon.
Tropical storm conditions are possible in the Tropical Storm Watch area in New England beginning late Tuesday.
RAINFALL: The following rainfall accumulations are expectedalong and near the track of Isaias:
Northwest Bahamas: Additional 1 to 3 inches, isolated storm totals 12 inches.
Eastern Florida and coastal Georgia: Up to an additional 1 to 2 inches.
Carolinas and the mid-Atlantic: 3 to 6 inches, isolated maximum totals 8 inches.
Southeast New York and much of New England: 2 to 4 inches, isolated maximum totals 6 inches.
Heavy rainfall will result in flash and urban flooding, some of which may be significant in the eastern Carolinas and the mid-Atlantic, through midweek along and near the path of Isaias across the East Coast of the United States. Widespread minor to moderate river flooding is possible across portions of the Carolinas and the mid-Atlantic. Additionally, quick-responding rivers in the southern Appalachians and Northeast will be susceptible to minor river flooding.
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 ripcurrent conditions. Please consult products from your local weather office.
TORNADOES: A few tornadoes will be possible over coastal South Carolina beginning this evening, spreading across eastern North Carolina tonight into Tuesday morning. A couple tornadoes will be
possible on Tuesday from eastern Virginia northeastward into southern New England.
