Stifling heat and humidity returned to the Washington area yesterday after a brief break from record-breaking temperatures in July, and forecasters say more such weather is on the way.
The National Weather Service said yesterday that above-normal temperatures with highs in the 90-to-95-degree range during the day and lows in the low to mid-70s at night should continue at least through the middle of next week.
"It'll be something like those three weeks in July," one forecaster said.
A torrential thunderstorm ripped through parts of the area in mid-afternoon yesterday, bringing only temporary relief.
The temperature at National Airport dropped from 92 degrees at 3 p.m. minutes before the storm broke, to 80 degrees a half hour later. At Dulles International Airport, the drop was even more dramatic - from 97 to 76 degrees in a half hour.
By 7 p.m. both temperature and humidity had begun to creep back to uncomfortable levels. The thermometer read 86 degrees at National Airport, and the humidity had risen from 49 per cent before the storm to 68 per cent at 7 p.m.
In one bit of good news, the Metropolitan Washington Council of Governments canceled its day-old air pollution alert at 3 p.m., as rain and gusty winds flushed out the area's stagnant air.
COG's air quality index reached a high reading of 120 in the "very unhealthy" range Thursday, automatically triggering the pollution alert, but the AQI reached only 75 yesterday at 1 p.m. and had fallen to 60 by 4 p.m. COG declares a pollution alert whenever the AQI at any of its seven air monitoring stations registers at least 100.
Yesterday's official temperature at National Airport was 95 degrees, recorded at 2:35 p.m. This was well below the record of 102 degrees set for the date in 1930.
The thunderstorm that arrived briefly in mid-afternoon was part of a string of squalls stretching from central Virginia to northern Maine, according to the Weather Service.
The renewed heat and mugginess drove many downtown employees out of the parks and back into their offices during the lunch break.
Even so, comfort was fleeting for some, especially federal and District government workers. A new energy-saving directive issued last May by the General Services Administration requires that the minimum temperature in air-conditioned offices of the federal government be raised from 72 to 78 degrees. A District government edict sets the new minimum at 80 degrees.
"We've had no trouble," said Joseph Czajkowski, chief of building operations for the massive, 4,000-employee Housing and Urban Development headquarters building at 451 7th St. SW.
He said the building's hundreds of thermostats are controlled solely by the building engineer so employees cannot adjust them individually.
The culprit causing the current heat wave is a high pressure weather system normally situated over Bermuda that has extended westward toward the Carolina coast, forcing hot, humid air from the Gulf states into the Washington area, according to the weather service.
The so-called Bermuda high also has pushed the customary westerly winds here further north into Canada, depriving the area of [WORD ILLEGIBLE] So far this year, there have been 31 days on which the temperature reached 90 degrees or higher - 20 of them in July alone. The record number of 98-degree days in a single year was 59, in 1965.
COG has declared five pollution alerts totaling 28 days so far this year, only two fewer than the record annual total of 25 days in 1973.