Saturday, August 27, 2011

Surge Inundates Virginia; 8.5-foot surge reported in NC

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Quote from Source: A look at the flooding in Pamlico County. Early reports tell us the flooding is VERY bad here. via @BrittanyyRice

Quote from The Weather Channel:
Coastal Concern: We've already seen a surge of 8.5 feet in parts of North Carolina. This doesn't bode well for the Hampton Roads and Norfolk metro areas during high tide. A storm surge of up to 5 to 9 feet above ground level is forecast in the Lower Chesapeake region, coinciding with a high tide. This could bring record flooding to parts of the cities of Norfolk and Chesapeake, Va.


This evening NOAA Tides and Currents gauges are reporting surge levels between 4 and 5 feet in portions of North Carolina and Virginia. Surge levels are rising quickly in DE with surge levels approaching 3 feet at Lewes, Delaware. Keep in mind that storm surge is very localized and gauges often do not record the highest surge levels.

Heavier bands of rain are now over the Delmarva Peninsula, much of New Jersey and Southeast Pennsylvania. The NHC forecasts winds, and associated surge levels, to increase along the Delmarva Peninsula, Jersey Shore, Long Island, Long Island Sound, and southeastern New England tonight.

Although our coastal flooding research group primarily focuses on events that impact the Gulf of Mexico, some lessons that we learned along the Gulf Coast may apply to Irene's storm surge on the East Coast.

One lesson we learned is that sometimes surge does not show up where you may expect it, and then it does show up in the place or at the time you might not expect it. Take, for example, Tropical Storm Ida, which impacted the Gulf Coast in November, 2009. Ida's peak storm surge was actually located to the left of the storm track, which defies conventional wisdom about peak surge locations. Although Ida tracked just east of the Louisiana delta, and made landfall in Alabama, the peak surge from this event was actually a 6.53-foot surge at Bay Gardene, Louisiana.

A second lesson that Ida taught us had to do with the surge timing. In some locations, such as Shell Beach, LA, the storm surge peaked as Ida moved away from the area and winds shifted to the north. This pushed water that had built up towards the southern tip of Lake Borgne, generating peak surges for this event in some locations. It might seem impossible that a location could observe the peak surge during offshore winds, but that's what happened at Shell Beach during Ida.

As we watch Hurricane Irene march up the East Coast tonight, please take precaution and avoid areas vulnerable to storm surge. Remember that sometimes surge surprises us and if that cuts off an evacuation route or strands someone in a vehicle, the situation could quickly turn deadly. Stay tuned to the National Hurricane Center, the National Weather Service, and your local media outlets for the latest forecasts.

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