The morning low out at BWI this morning reached 38 degrees, setting a new record for a May 19 in Baltimore. The previous record had stood for only six years, having been set on this date in 2003.

The National Weather Service has not posted it yet (at this writing). But I've called it to their attention, so it may pop up in their data shortly.

The low out on the WeatherDeck this morning was a bracing 36 degrees. With the heat off for the season, the blanket and spread were not quite enough for us this morning as the dawn broke. Getting up seemed the better choice. 

Here at Calvert & Centre streets, the low was 46 degrees. There were no new records at either Dulles International (low was 38 degrees, record 36), or Reagan National (low was 45 degrees, record 43). 

The high-pressure system that moved into the region late yesterday (left) had shoved all the clouds away by this morning (see satellite photo above) and dried out the atmosphere. As winds died down around sunset, that set up the perfect conditions for radiational cooling. So much of the meagre warmth we accumulated yesterday radiated back into space overnight, driving temperatures down.

The relative humidity readings today are headed rapidly downward - from 78 percent around sunrise to 44 percent at this writing (and still falling). The barometer, meanwhile, has been headed in the opposite direction, holding steady now at around 30.50 inches.

The forecast shows we can expect temperatures to warm to around 80 degrees by tomorrow, and hang around that mark right into the weekend. The sunny skies will linger, too, at least until Sunday, when chances for showers and thunderstorms begin to rise again.