5 February 2011


This was a freezing rain and sleet event with thunder and lightning.  The thunder and lightning was quite remarkable and frequent.  Analysis of area soundings showed instability for parcels above a surface based inversion.  A survey of data during this evening will show the unusual nature of the event.



Above:  500 hPa heights showed a strong system with a negative tilt tracking northeast through the northeastern U.S.


Above:  MSLP analyses show a strong surface low tracking interior of coastal New England, which is a classic track for mixed precipitation over interior NY and interior New England.






Above:  Soundings from Albany, NY (top row) and Upton, NY (bottom row), showing how the soundings became unstable above surface-based inversions.



Above:  Lightning for 1 hour ending 10:10 PM 5 February.



Above:  Radar loop with lightning showing the precipitation evolution.  Note the lines of convection with high reflectivities similar to what we observe in the summer.  Some of the high reflectivities were indicating mixed precipitation over the region.