Ice Accumulations make for Treacherous Travel Conditions

Ice Accumulation February 12-13, 2008  Source: NWS

Tonight and tomorrow morning’s freezing rain will make for treacherous travel conditions across much of the region.  Although temperatures were slightly warmer today than they have been recently, surface temperatures are still near the critical freezing point in many spots.  The dry air will also cool due to evaporative cooling once the precipitation starts to fall overnight. The cold surface temperatures will allow the rain to freeze on contact in many spots.  That’s known as “freezing rain.”  Even the smallest accumulation of freezing rain on roads and power lines can create dangerous travel conditions and power outages. 

 

There have been several memorable ice storms in the Mid-Atlantic Region during the last 20 years.  Some will remember that during the evening rushour on Virginia’s Primary Election Day in February 2008, there was freezing rain that caused havoc on area roadways.  The Springfield Interchange in Northern Virginia became a virtual parking lot as road crews simply couldn’t treat the roadways amid rushour traffic.  It took hours for most commuters to get home that night and there were scores of accidents due to icy roads.

Also, on February 13-14, 2007, there was a significant accumulation of freezing rain and sleet across the Mid-Atlantic Region that made travel all but impossible on area roads.  There was an accumulation of 2.2” of primarily sleet at National Airport, with a glaze of ice covering most surfaces around the region.  Western and Northern suburbs saw a touch of snow, but this storm was generally sleet and freezing rain.  Finally, in January 1999 there was widespread accumulation of freezing rain across the DC Metro Region that led to significant power outages as windy conditions blew down ice-encrusted power lines and tree limbs.  It took several days to restore power and many people were stuck at home with schools and businesses closed. 

Tomorrow, temperatures are expected to rise during the day, causing the precipitation to change primarily to rain in the morning across the DC Metro Region before ending later in the day.  It’s safer, though, to stay off the roads regardless of the type of winter precipitation – snow, sleet and freezing rain are all very dangerous to travel in.  To read more about the difference between snow, sleet and freezing rain, check out my December 27 blog post.