Irene may spoil your weekend
What is it about these storms that begin with the letter "I"? Remember Isabel in 2003?
Well, forecasters at the National Hurricane Center say Hurricane Irene appears to be headed our way this weekend. They stress that track forecasts this far in advance can be off by 200 or 250 miles. But the computer models still seem to be in close agreement about this one.
They're predicting landfall late Saturday or early Sunday somewhere near the North Carolina/ South Carolina border. It would be the first hurricane landfall on the U.S. mainland since 2008.
From there, Irene seems likely to continue moving north.
Her track after landfall will be of critical importance to Central Maryland and the Eastern Shore. A curve toward the east would put the Baltimore-Washington area on the more benign west side of the storm's center. That would mean less rain and wind, with winds shoving water down the bay.
But a northward track to the west of the Chesapeake Bay could be expected to blow water up the bay, raising the dangers of a large storm surge and destructive coastal flooding. Think of how storms like Hazel in 1954 and Isabel in 2003 producing severe coastal flooding along the bay shores.
UPDATE, 12 noon: The latest National Hurricane Center track forecast still shows Irene approaching the Chesapeake Bay by daybreak Sunday. The center of the "cone of uncertainty" puts the storm at the mouth of the Chesapeake - still at Cat. 1 hurricane strength - by 8 a.m.
At noon Tuesday, Irene was a Cat. 2 hurricane, packing top sustained winds of 100 mph. It was located about 70 miles south of Grand Turk Island in the Bahamas, moving to the west northwest at 12 mph. Forecasters said Irene could reach Cat. 4, with sustained winds above 131 mph, by early Friday morning. It is thought likely to be a Cat. 3 storm at landfall in North Carolina early Sunday morning.
Earlier post resumes below.
The official forecast doesn't sound too dire. The NWS/Sterling is calling for highs in the low 80s, with the chances for showers and thunderstorms rising from 50 percent Saturday to 60 percent Saturday night. The probabilities slip to 40 percent Sunday and Monday.
Here's AccuWeather.com's take on the storm.
AccuWeather.com says Irene's forecast track looks most like Hurricane Bertha, which struck near Wilmington, N.C. in July 1996 and caused tremendous damage along the nearby beach communities of Wrightsville and Topsail Beach. Twelve people died and property damage was estimated at $270 million.
In Maryland, a much-weakened Bertha delivered plenty of rain and wind, and caused widespread power outages. But there was little serious damage, even at Ocean City.
Hurricane Floyd, in 1999, also followed a path similar to that forecast for Irene. It dropped 14 inches of rain on portions of Maryland, and produced winds of 50 to 70 mph. There was a 2 to 3-foot storm surge in the bay. Three Marylanders died and 250,000 lost electric power.
Isabel's path was quite different. It made landfall in North Carolina and drove inland toward West Virginia. Rainfall in Baltimore was not extraordinary, but the counter-clockwise winds around the storm's center drove water up the bay, causing some record storm surge numbers, with tremendous damage around the Inner Harbor, Fells Point and other bayshore communities such as Bowley's Quarters.
There's more below from Prof. Jeffrey Halverson, Associate Professor of Geography and Environmental Systems at UMBC
(Top: NWS, Irene forecast track. Bottom: Floyd, 1999)
"My assessment of Irene this morning is that the storm remains a threat to the Baltimore region. The
good news is that the models seem to be trending toward shifting the center of the storm to the east
of our region. This would keep the really high winds over the Bay and Eastern Shore. And the models
seem more progressive with the storm - moving it away quicker. The bad news is that with the storm
possibly hugging the coast, this could help maintain its intensity, as part of the circulation is still able
to draw warm, humid air off the Gulf Stream. A more intense storm means more intense winds,
across the board. And the models such as GFS still churn out very heavy rain to the right of track.
Should the storm track just along the western side of the Bay, serious storm surge could develop in
the Bay's headwaters. There are still so many uncertainties and many of these hinge on the storm's track, size and intensity as it approaches North Carolina. I've laid out some possibilities here, but bear in mind
that track forecast errors are 200 miles on Day 4, and 250 miles on Day 5...and our skill at predicting
intensity change is not very high. This one is going to have us on pins and needles for days to come. - Jeff"