Two weeks ago I wrote about how our local National Weather Service (NWS) office in Sterling, Va. issued a staggering 205-210 severe weather warnings for the area (from central Va. to northern Maryland, not including the eastern shore) during June. And I showed that there were, in fact, a slew of damage reports in Va., Md. and the District. No doubt it was a very stormy month. Nonetheless, I wonder whether the number of warnings was excessive and how many of the storm warnings were actually false alarms...
In order for a thunderstorm to qualify as severe, it must contain:
* wind gusts in excess of 57 miles an hour and/or
* hail with a diameter of at least 3/4 inch (the size of a penny or dime)
But a lot of storms for which warnings were issued weren't even close to meeting these criteria, at least where I happened to be. And a quick and dirty look at the statistics confirms this suspicion.
For example, in the District, 18 storm warnings were issued in June, but only seven reports of severe weather meeting this criteria (all for wind) were documented.
I understand that the NWS errs on the side of caution in the interest of protecting life and property. I also recognize that just because storm impacts are weak where I happen to be means nothing when a tree falls on a car just two miles down the road. And I know there were surely undocumented instances of severe weather.
Still, I think our local NWS office needs to take a serious look at how well their warnings are actually verifying and what percent are false alarms. And in the warning process, they should consider whether overwarning the public may numb them to the risk of dangerous conditions when the weather is truly severe.
Based on my experience as a forecaster and a citizen, I'd argue for a more conservative approach to issuing warnings.
Now it's time for you to weigh in...