For the fifth time this year, the high surpassed 80 degrees Sunday! The high temperature at Reagan National was 83 degrees; this is 16 degrees above average and only 6 degrees shy of the record high. What’ll make Monday the hottest day since September 14th when the high reached 87 degrees is an increase in southwest winds (which compress and warm off the Blue Ridge mountains), mostly sunny skies and the recent dryness.
Precipitation is 4.78 inches below average since the start of the year. Being in an abnormally dry spell (near the Bay a moderate drought) and not having any appreciable rain in excess of 0.25 inch since March 2nd, the ground is dry and heats up much more effectively than a moist ground. All these factors will likely push the mercury to near 90 degrees in the District. The warm, breezy weather could trigger brush fires as well.
Highs should come within 5 degrees of the following record highs for Monday:
Reagan Nat’l: 92 in 2002
Dulles: 91 in 2002
BWI: 90 in 2002
Sunday’s pollen count was 11.7; Monday will be even higher, with the primary pollen being maple, oak and ash. The dry winds won’t help matters either. It could be more like a manic Monday for allergy sufferers, so be prepared!
Now, where’s the rain? The same front that triggered the dangerous Central U.S. storms this weekend will move in our direction and likely move through around Midnight Monday. The problem is the best upper-level support will move into Canada as the front moves east, so the front will lose its identity by the time it reaches the Appalachian Ridge. We should see a band of showers fall apart across the western Maryland highlands with just a wind shift to the Northwest in the District late Monday as the front pushes through.
What about later this week? There is growing potential that a stronger storm system will push into the Mid-Atlantic Friday/Saturday and then wrap up the coast, bringing the potential for at least one-half inch of rain followed by cooler temperatures.
Of course, stay with the ABC7 Weather Team and WTOP for the latest forecasts this week! Stay safe and for allergy sufferers, temperatures will cool into the 70s Tuesday and then 60s by Wednesday.