Temperatures skyrocketed 14 degrees yesterday between noon and 1 p.m. on a day that saw a recordtyping high temperature reading of 85 degrees at Washington National Airport.
The high, which was recorded at 3:05 p.m. tied a record for an Oct. 23 that was set in 1947. Forecasters, who predict crisp and cooler temperatures for today, said yesterday's summer-like weather was caused by a warm air front that extended from northeast Pennsylvania to western Kentucky.
The front was expected to travel east toward the Atlantic Ocean causing minor rainfall and breezy weather, overnight. Temperatures today were expected to be in the low to mid-60s.
The surprising interruption in Washington's autumn weather yesterday was telescoped between noon and 1 o'clock when the temperature at National Airport jumped from 69 to 83 degrees.
"Temperatures on the ground and in the lower atmosphere were pretty cool all night," said Richard Crouthamel, a weather service forecaster. "During the early-morning hours, a warm southerly air flow from the front began slowly to heat up those ground temperatures. When the ground temperatures equaled those in the higher atmosphere, the overall temperature from a mixture of the two just shot everything up."
The humidity dropped from 66 percent to 30 in the same interval.
"That's because the air on the ground was more moist than that in the higher atmosphere, and when the equilibrium was met the air became "drier," Crouthamel said. "There was much more drier air higher up."
Yesterday's high fell far short of the record for an October day, 98 degrees which was set on Oct. 5, 1941.