Recap: Hurricane Irene’s rain and wind in Washington, D.C.

Irene doppler estimated rainfall around Washington, D.C.Around the Washington, D.C. metro region, Irene behaved largely as predicted (at least by the Capital Weather Gang), raking the I-95 corridor and especially points east with wind and rain, with steadily diminishing impacts as you headed west towards Loudoun and Frederick county.

In some respects, the region’s three airports tell the story, demonstrating the rapid waning of impacts in the western suburbs. Reagan National and BWI airports received 3.83” and 4.69” of rain compared to Dulles’ 1.41”. The rain, while soaking, didn’t set any records; heavier rain fell at all three airports in 1971 when tropical storm Doria came up the coast, also on August 27-28.

The peak wind gusts at Reagan National and BWI were 60 and 51 mph, whereas Dulles gusted to just 45 mph. The 60 mph gust at Reagan bested the peak gust there during Isabel (2003) of 58 mph. Reagan National briefly reported a sustained wind of 41 mph, meaning true-to-form tropical storm conditions were observed (tropical storms have sustained winds of at least 39 mph).

Even heavier rain and stronger wind gusts occurred east of the District and Baltimore towards the Chesapeake Bay. In Calvert county, Chesapeake Beach gusted to 72 mph, in Anne Arundel, North Beach gusted to 64 mph and Patuxent River in St. Mary’s county gusted to 64 mph. St. Mary’s was ground zero for flooding rain, with widespread reports of 8-12”.

Here’s a summary of rainfall and peak wind gusts by county integrating National Weather Service, doppler radar, and Cocorahs reports:

District of Columbia: 3-4”, ~60 mph gust

Maryland

Anne Arundel county: 3-6” rain, ~40-64 mph gusts

Calvert county: 6-12” rain, ~68-72 mph gusts

Charles county: 3-4” rain, 46 mph gust

Frederick county: 1-2” rain, 41-55 mph gusts

Howard county: 3-5” rain, 40-54 mph gusts

Montgomery county: 2-3” rain, 35-72 mph gusts (35-54 excluding outlier reading of 72 mph in Gaithersburg)

Prince George’s county: 5-7” rain, ~40-60 mph gusts

St Mary’s county: 8-12” rain, ~40-64 mph gusts

Virginia

Arlington county: 2-3” rain, 60 mph gust

Fairfax county: 2-4” rain, 39-55 gusts

Fauquier county: 1-2” rain, 36 mph gust

Loudoun county: 1-1.5” rain, 32-45 mph gusts

Prince William county: 2-3” rain, 40-60 mph gusts

How was Capital Weather Gang’s forecast?

Capital Weather Gang’s rainfall forecast issued at 5 a.m. on 8/27Our rainfall and wind forecasts shown below (posted Saturday at 5 a.m.) indicate we pretty accurately forecast the distribution of rain totals and winds. However, we were much too low on rain totals in the eastern areas near the Bay and in the Delmarva interior.

How much rain fell where you live? Did you observe any notable wind gusts? Comment below...

Capital Weather Gang’s wind forecast issued at 5 a.m. on 8/27