Alberta Clipper - 05 DEC 2007

Source:
NASA Earth Observatory

An energetic clipper system put 3 - 7" of high-fluff snow on the ground in the DCA - BWI - ACY area last Wednesday. Forecasts generally underestimated the storm-total snowfall.

Temperatures in the crystal factory were -12°C...the low end of favorable conditions for growing stellar dendrites. Other contributing factors were 1) strong veering vertical wind profile...2) 'moist' boundary layer...3) column stretching as the impulse migrated east of the mountains...4) track of the 5H vort max...and 5) SN:H20 of 30:1...all of which were well-modeled by NWP well in advance of the event.