8:30 p.m. update: Looks like the D.C. area may be done with storms this evening except for Southern Maryland and the Baltimore area. However, still need to keep an eye on an area of storms in southern Pennsylvania, which we’ll do.
7:50 p.m. update: Main storm of interest in area is in from southeast Fairfax County, southwestward through southern Prince William County and into southern Fauquier County. A Severe T’storm Warning associated with this storm is in effect until 8:15 p.m. for southwest Fairfax and northeast Prince William counties.
5:30 p.m.: D.C. hit 100 today, setting a new record for the date and marking the 5th 100+ of the year. Both Dulles and BWI reached 99, one shy of their record.
Earlier: The heat just keeps on giving even if we’re ready for it to stop, we may even pick up another record high today (as if we needed one). Our streak is now at 15 days 90+, which puts us above all other years in streak length except for five. After a record hot July, I wish I had some better news right away, but highs today in the mid-90s to near 100 are about what we’ve come to expect. There is perhaps a light at the end of the tunnel this week though, but probably not as soon as some would like.
Through Tonight: Isolated to perhaps scattered showers and storms (40% chance) already moving over parts of the area are a threat through the evening and into at least the early part of the night as a spoke of energy passes by and a cold front nears. Coverage should not be terribly great, but anyone who gets a storm could see very heavy rain as well as a risk for damaging wind. Lows eventually fall to the upper 60s in the coolest suburbs while hovering around the mid-70s downtown.
Tomorrow (Tuesday): Behind the front we should see plenty of sun and a bit cooler temperatures. But as we saw over the weekend, without any significant cooler air moving in, a northwest wind can still scorch the area. Look for highs to reach the mid-90s most spots, but humidity should be down again so it won’t feel terribly oppressive.
90+ days: With 39 under our belt where do we stand year-to-date with other memorably hot years? 2010 is still the leader of the pack through August 1 with 44, but we’ve caught up considerably over the past week or so. We’re currently tied for 4th with 1872. 1980, the other (besides 2010) top all-time 90+ for a year at D.C. with 67 is still relatively low on the list, with 32 year-to-date. It also had the most on record in August and September though, so it was, in some ways, a “late bloomer.”
Pollen update: Susan Kosisky of Walter Reed writes, “Our grass count is LOW (NAB range) at 2.88 grains/cubic meter, which is more moderate for our area. Cattail, plantain, nettle and chenopod/amaranth family pollen members contribute to a LOW weed count at 3.83 gr/cubic meter. Mold spores are in the MODERATE range at 7421.44 spores/cubic meter.”
Earlier storm updates (no longer current)
6:45 p.m. update: Storms are widely scattered, but two are noteworthy: 1) A severe cell in northeast Prince George’s county between I-95 and 50 which may contain some small hail; it’s headed SE toward southern Anne Arundel county 2) A cell in central Loudoun county that - if it holds together - would affect northwest Fairfax county in about 30 minutes, reaching the beltway in about an hour. We’ll keep you posted. I’d give it a 30% chance of making it inside the beltway and into the District.
6:00 p.m.: A Flash flood warning warning has been issued until 9 p.m. for southeast Loudoun county including Brambleton, Dulles, Leesburg, and South Riding
6:20 p.m.: Severe thunderstorm warnings are in effect for most of Loudoun county, southern Frederick county, western and central Fairfx county and around the intersection Montgomery, Howard, Anne Arundel and Prince George’s county. All of this activity - which so far has largely avoided the District is headed southeast. Torrential rain, hail and some isolated damaging wind gusts are possible with these storms.
5:45 p.m.:Thunderstorm activity is isolated to scattered, but storm along northeast section of beltway from College Park to Landover in northern Prince George’s county is quite severe (warning through 6:15 p.m). Hail to 1” has been reported. CWG forecaster Brian Jackson reported damage to his car in College Park from hail.