Friday, January 06, 2012

Weather History: Ice, Ice Baby

January 1994 was known around here as the month of ice.  Several events moved through the Delaware Valley over the course of the month, spreading freezing rain across the immediate city and suburbs...and in some cases, bringing snow to the Lehigh Valley.  Philadelphia picked up four inches of snow in January 1994 while Allentown picked up 34", benefiting from its location away from the ocean and having a touch of elevation.  The month was also punctuated by an arctic outbreak that brought Philadelphia its last subzero low to the present day on the 19th of January.   The first of the ice events occurred on January 3rd and 4th -- a nor'easter that brought a mixed bag of rain and snow to the East Coast and brought some freezing rain to those in the suburbs to the north of Philadelphia.  It was an event on the 7th and 8th, however, that caused more significant headaches into the city itself.

The ice storm on the 7th was a minor storm in the scale of storms that have impacted us over the course of our history (a minor low travelling along the jet stream is nothing 'major' in comparison to the Superstorm or a hurricane) but its 0.35" of freezing rain that fell on the 7th and into the predawn hours of January 8th caused a bevy of problems around the Delaware Valley because of its duration, lasting nearly 24 consecutive hours.   The satellite image below shows the stream of moisture coming from the Pacific northeast through Texas and into the Mid Atlantic, pulled northeast into the train of weak low pressure that rode along the jet.

Some of the video of the ice storm (above, there are three parts on YouTube that have been submitted) is shown above.  The image about three minutes in of Paul Moriarty standing on a vacant Schuylkill Expressway was telling of how the ice was causing problems on area roads.

The atmospheric look shows the fetch of moisture (green shading) stretching from Louisiana and Texas northeast through the Mid Atlantic.  The yellow line (the freezing line at 5000' in the atmosphere) was to the city's north but the surface was at or below freezing through much of the region, resulting in our icy encasement.   At the peak of the ice storm, nearly 600,000 lost power.

Two years later, almost to the day, the Blizzard of '96 made its own headlines.