The coldest weather since last February charges into the Washington, D.C. area tonight sending temperatures toppling to levels that would be below normal in January. The Southeast Regional Climate Center projects our weather will more closely resemble what you’d expect in Minneapolis or Juneau at this time of year.

Temperatures may rise to 50 early this afternoon, but then a fierce cold front sweeps through the area by this evening, when temperatures begin their plunge.



High resolution NAM model simulation of temperatures from Monday 2 p.m. to Tuesday at 6 a.m., when temperatures drop close to 30 degrees. (WeatherBell.com)

By Tuesday morning temperatures range from the low 20s in our colder suburbs north and west of the District to the upper 20s downtown (the above model’s temperature projections for downtown are probably a few degrees too cold).

20s may not sound cold, but a biting wind from the northwest follows the front, gusting to 20-25 mph early Tuesday. Wind chills throughout the region only manage teens, with single digit values possible in our coldest areas to kickoff Tuesday.



GFS model wind chill forecast Tuesday morning at 7 a.m. (WeatherBell.com)

Afternoon highs Tuesday struggle and, in many places, fail to reach freezing. Maybe downtown and locations in the southern Maryland eke into the mid-30s – but wind chills hold in the teens to near 20. Consider the average high is 57 – so these temperatures are 20-25 degrees below normal. Tomorrow’s air mass would even be cold by late January standards, when the average high is 42.



GFS model forecast high Tuesday (WeatherBell.com)

The coldest conditions occur Tuesday night, when lows dip to near 20 downtown with teens throughout most suburban areas by early Wednesday morning.



Wednesday morning low temperature forecast from GFS model (WeatherBell.com)

The wind will let up some, but brief gusts to 10-15 mph could well drop wind chills into the high single digits Tuesday night and Wednesday morning, especially north and west of the Beltway.



Wind chill forecast at 7 a.m. Wednesday morning from GFS model (WeatherBell.com)

Relief from the cold Wednesday is only modest, as highs “recover” into the mid-to-upper 30s. Mercifully, the winds relax some more.

Several records at our local airports are “in play” during this cold snap. Dulles (IAD) has a chance to break the record for its coldest low and high temperature on both Tuesday and Wednesday. BWI Airport has a good chance to have its coldest November 18 on record (Tuesday), as well as its coldest low and high temperature on November 19 (Wednesday).

Largely due to long-term warming effect of urbanization, the records for Washington, D.C. (DCA) as observed at Reagan National Airport (prior to the early 1940s, D.C. records were kept at 24th and M St.) are probably safe.

Even though we’ve had chilly weather over the past several days, the cold on Tuesday and Wednesday will be more severe – so please take precautions. Dress in layers, with hats, scarves and gloves. Outreach and efforts to assist the homeless will be particularly important as hypothermia will be a major risk. Finally, you might consider shutting off your outdoor pipes if you haven’t already for the season.