Update at 5:35 p.m. Both Dulles and BWI had their coldest high temperatures on record for the date, reaching just 15 and 18 degrees. At Dulles, this was the coldest high temperature so late in the season on record. We have an updated forecast posted and have lowered our forecast temperatures slightly overnight. Follow this link for the latest: PM Update: Bitter wind chill, record-challenging cold on Friday; SchoolCast
Original post from 12:03 p.m.
A record that has stood for almost 120 years may be left in the dust Friday in the District — as the coldest air mass of the season smothers the region.
The lows Thursday morning in the Washington area, from the high single digits to low teens (with wind chills from -5 to -10) were not record-breaking, but the core of this polar vortex-infused cold is still to come.
Today’s high temperatures — from 16 to 22 — are likely to be the coldest on record for the date at Dulles Airport and might be at BWI (existing records are 28 at Dulles from 1993, and 19 at BWI from 1903). Reagan National Airport, the weather station for the District, has already reached at least 18 degrees today, so it will not have a record cold afternoon (the existing record is 16 from 1903).
But Friday morning’s lows — ranging from around -2 to 7 degrees — seem destined to be record-breaking in the District.
We think the District’s low temperature Friday morning (as measured at Reagan National Airport) will probably drop to about 4-7 degrees, which would break the record of 8 degrees Fahrenheit set in 1896 (when temperatures were measured downtown at 24th and M streets). Amazingly, if the District manages to set a record low, it will be the first time it has done so in winter since 1994.
Although earlier forecasts suggested the District itself could drop below zero Friday morning (it would have been the first time since 1994), that now seems unlikely as a breeze will mix the air enough to prevent temperatures from truly bottoming out.
But this breeze will make the air actually feel colder. Tonight’s wind chill factor dips as low as -10 to -15.
BWI is also likely to set a record low Friday morning, matching or even toppling the existing low mark of 4 set in 1979. Dulles, interestingly, may be most challenged to set a record as the existing mark is a bone-chilling -2F, but it definitely has a chance.
— Howard Bernstein (@hbwx) February 19, 2015
All three airports could set new records for coldest high temperatures on Friday as the existing record highs are 18 at BWI and the District from 1896, and 26 at Dulles from 1972. Forecast highs are 15-20.
At Dulles and BWI, highs may well hold below 20 for two consecutive days Thursday and Friday. If they do that, it would be the second instance this week but something not previously accomplished since Jan. 19 and 20, 1994.
To end with some good news, the average high in Washington reaches 50 degrees in just six days.