Winter's Polar Express

Bethesda, MD: February 20, 2015

The last week has featured myriad record lows across the Eastern United States that have broken century old records in some cities.  In the Nation’s Capital, yesterday's high temperature was only 22 degrees Fahrenheit with a low of 5 degrees.  That was was the coldest day since February 5, 1996, when the high and low temperatures were 21 and 5 degrees respectively.

Yesterday’s low temperature of 5 degrees at National Airport broke the old record of 8 degrees that had stood since 1896.  It’s rare for Washington, D.C., to have single digit temperatures and rarer still to have any in the second half of February.  The average high and low in Washington, D.C. on February 20 are 48 and 32 degrees.  So that helps demonstrate how rare yesterday’s cold was with yesterday’s high temperature more than 10 degrees colder than the average low.

Before yesterday, no record lows had been set in the Nation’s Capital during the winter since January 1994.  You have to go all the way back to 1970 for the last time Washington, D.C., experienced record cold in February.  Although Dulles Airport fell to a low of 0 degrees yesterday (their coldest temperature of the winter) that narrowly missed breaking the record low of -2.  However, it was the 6^th consecutive day with low temperatures of less than 10 degrees at Dulles Airport.  Baltimore also had their coldest temperature of the winter yesterday setting a new record low of 1 degree.  Baltimore set another record low of 2 degrees this morning and it hasn’t been above freezing there since February 14.

The Mid-Atlantic Region hasn’t been alone in the record cold this week.  The outbreak of arctic air has also caused record lows in New York, Pittsburgh, Cleveland, Atlanta and as far south as parts of Florida.  A significant dip in the jet stream over the Eastern United States has allowed the polar air to make its way all the way south to the U.S. Gulf Coast.  The Nation’s Capital has had some snow this week too to coincide with the record cold.

In fact, the DC Metro Region is split between winter storm warnings to the north and west of town while winter weather advisories are in effect from I-95 south and east of town.  Unlike the storm earlier in the week that brought pure snow, today’s snow will change to a wintry mix of sleet and freezing rain and eventually rain for most of the region.  That’s because the track of this storm is a little different and the atmosphere will not remain cold enough for pure snow.  However, because of this week’s prolonged cold, ground temperatures are below freezing.  That means snow will accumulate as soon as it starts and the potential is there for some ice accumulation too.  

After temperatures climb above freezing tomorrow, more unusually cold air is expected for the start of the new work week.  In fact, more record lows are possible for parts of the Mid-Atlantic Region.  For the latest forecasts on today’s winter storm you can follow my colleagues on the WUSA9 weather team both on-air, online and on the all new WUSA9 news app for your mobile devices.