Three invalid severe weather warnings were issued to the greater Washington region on Wednesday from the National Weather Service headquarters in Silver Spring, confusing local officials and news reporters and alarming some residents.
Although no severe weather was in the region, the alerts described a
possible tornado forming near Olney and heading east toward Clarksville. 
The alerts, which said they were test messages, were sent on a
paid-subscription service to local emergency management heads and media organizations, said a spokesman Christopher Vaccaro.
"This is extremely unusual, and in fact, this is exactly what we try to
avoid, because we only want actual tornado warnings to be reaching those who need to know, as opposed to test messages," Vaccaro said.
Although the messages said they were sent by the local forecasting station in Sterling, they stemmed from an emergency messaging test in Silver Spring, Vaccaro said.
Vaccaro said that testing is routine and that only National Weather Service staffers were meant to see the messages. But they were accidentally sent out to the public from 1:50 p.m. to 2:30 p.m., he said.
Shortly afterward, the local office received more than a dozen calls, said Chris Strong, a warning coordination meteorologist at the station. The calls came from local emergency management heads, news reporters and a few residents, said Nikole Listemaa, a senior forecaster at the station.