Tropical rainstorm to push onshore in Carolinas packing flooding rain, storm surge

A tropical rainstorm will push onshore in the Carolinas packing coastal flooding, gusty winds and flooding rain for some states in the East into midweek. Other locations may have their first rain in over a week.

A tropical rainstorm will expand drenching downpours, gusty winds and rough surf to the Carolinas through Tuesday. AccuWeather meteorologists warn that flooding rain will ramp up in some areas, and coastal flooding and beach erosion will continue, regardless of whether the rainstorm organizes enough to be named.

"The only thing that held back the system near the Carolinas from becoming a named subtropical storm was the lack of a closed circulation," AccuWeather Lead Hurricane Expert Alex DaSilva said, "The open-sided storm was producing heavy rain, severe thunderstorms and sustained winds near 50 mph as of Monday morning."

Gusts to 67 mph, which are the intensity of a strong tropical storm, were observed on a fishing pier at Wrightsville Beach, North Carolina, on Monday morning. Tropical-storm-force winds range from 39-73 mph. Rainfall of 13-19 inches has already fallen into the midday hours on Monday along the North Carolina coast since the start of the weekend. A band of rain from the Atlantic has been acting like a tremendous firehose of water in eastern North Carolina.

While the storm will continue to quickly lose wind energy as it moves inland Monday night, heavy rain with flooding problems will continue and spread inland.

A subtropical storm has both tropical and non-tropical characteristics. Often a subtropical storm has a sweep of dry air on one side, as the storm near the Carolina coast exhibited.

AccuWeather meteorologists have designated the tropical rainstorm as a 1 on its RealImpact™ Scale for Hurricanes because of all storm impacts and risks to lives and property and it is not based on the Saffir-Simpson Hurricane Wind Scale.

The heaviest downpours and gustiest conditions associated with the tropical wind and rainstorm were skewed to the north and northwest of the center of low pressure--a condition that will continue as the storm moves inland.

Regardless of official designation by the National Hurricane Center (NHC), tides will run well above the historical average along much of the Carolina and southern Virginia coasts to the point where storm surge flooding of 1-3 feet will occur with locally higher levels into at least Tuesday.

The storm surge is above the routine elevated tide levels associated with the full moon.

Some coastal roads may be blocked by high water or washed out by high tide levels and wave action. These conditions can also put more beachfront homes at risk in the Outer Banks of North Carolina.

Whenever a tropical system makes landfall, there is the risk that severe thunderstorms trigger brief tornadoes or waterspouts that move onshore in beach communities. Localized power outages will spread inland as the storm moves along.

As the rainstorm moves well inland, it will lose wind intensity at midweek. Storm surge, seas and winds on the coast will subside. However, heavy rainfall from the storm will push inland. It will be enough to push small streams out of their banks, trigger urban flooding and cause significant rises on some of the rivers in the area from the Carolinas to Virginia, regardless of existing drought.

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There is a widespread zone where 2-4 inches of rain is forecast to fall from the Carolinas to Virginia, where large pockets of 4-8 inches of rain are likely in eastern areas and back toward the southern Appalachians.

Enough moisture will spill northward from the inland-tracking storm to spread some rain into much of Maryland, Delaware, New Jersey, southern and eastern Pennsylvania and central and eastern West Virginia mainly on Tuesday. It would be the first rainfall in over a week for many of these locations.

Another spinoff storm to form along East Coast

Just as Francine helped to spin up the tropical rainstorm along the Carolina coast this weekend, the tropical rainstorm may spin up a new feature from the middle to the latter part of this week along the mid-Atlantic coast.

The upcoming spinoff storm has the best chance of spreading some rain into portions of the central Appalachians and southern New England. The same storm has the potential to trigger flooding downpours in parts of the mid-Atlantic to southeastern New England.

How strong that storm becomes and its track will determine how extensive rain versus dry air will be in the Northeast. It is possible the dry wedge of air that set up over a week ago holds its ground from the eastern Great Lakes to the central Appalachians and perhaps part of the Atlantic coast.

This new storm may increase the risk of coastal flooding and rough surf from New England to the Carolinas later his week, after a midweek lull.

New area to watch in tropics near US

Elsewhere, Gordon, which formed a few days ago, has weakened to a tropical depression while over the middle of the Atlantic.

AccuWeather meteorologists are monitoring another zone for tropical development that could affect the United States and other land areas next week.

"The current development risk currently covers a broad zone from the central Caribbean to part of the southwestern Atlantic and the eastern Gulf of Mexico," DaSilva said.

Should a tropical storm form and overcome wind shear, the waters will be very warm, which could foster quick strengthening.

A strong area of high pressure along the New England coast could heighten the risk of coastal flooding and beach erosion next week, even if a tropical system remains to the south.

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