Coldest morning since ...
The National Weather Service thermometer at Baltimore-Washington International Thurgood Marshall Airport dropped to an official 47 degrees this morning. You can credit clear skies amid dry Canadian high pressure, and radiational cooling. All the warmth we built up under Saturday's perfect blue skies just radiated back out into space overnight.
Lows in the 40s felt pretty darn cold if you went to bed with the windows open last night. But it was still 5 degrees short of the record. The coldest morning for Baltimore on a Sept. 20 is 42 degrees, last reached on this date in 1959.
The last time we were this cold at the airport was back on June 1, when the mercury touched 46 degrees.
We reached 44 degrees out here on the WeatherDeck in Cockeysville (left). And there were some even colder readings across the region - as low as 41 degrees just over the Pennsylvania line. Sunshine today will bring us back into the 70s. Another fine late-summer afternoon; of course, it can't last.
The high pressure system is moving off the coast today, and we will come into the return flow of the clockwise circulation around the center, bringing us increasingly warm and moist air.
That will mean more clouds, and eventually rising chances for rain and showers as the week rolls along.