7-8 January 2011 Snowstorm

 

This storm was a moderate snowfall event that was characterized by the maximum vertical motion through the dendritic growth zone.  Forecast model QPF was suggesting warning level snows in some locations, but looked potentially borderline in many areas.  The important model derived fields in this event were time sections and cross sections of temperature and vertical velocity.  It was clear that a significant column of strong vertical motion was penetrating a layer of -12C to -18C between 850-500 hPa.  This suggested that snow to liquid ratios would likely be high, more toward 15:1 or 20:1.  So, when model QPF was multiplied by 15 or 20, it was apparent many areas could potentially experience warning level snowfalls.  Based on the snow reports, most areas did experience 7 inches of snow or more.  Click on images to enlarge.

 

   

 

QPF 0000UTC 6 January runs of the NAM, GGEM, GFS and ECMWF.

 

   

 

QPF 1200UTC 6 January runs of the NAM, GGEM, GFS and ECMWF.

 

  

 

QPF 0000UTC 7 January runs of the NAM, GFS and ECMWF.

 

 

 

Time sections 1200 UTC 6 January NAM and GFS at KGFL.

 

  

 

Time sections 0000 UTC and 1200 UTC 6 January NAM and GFS at KALB.

 

    

 

Time sections 0000 UTC and 1200 UTC 6 January NAM and GFS in the Catskills.

 

 

 

Time sections 0000 UTC 7 January NAM and GFS at KALB.

 

 

 

Time sections 0000 UTC 7 January NAM and GFS in the Catskills.

 

 

 

Time sections 0000 UTC 7 January NAM and GFS in NW CT.

 

   

 

HPC WWE forecasts from 5 and 6 January.

 

 

 

1200 UTC 6 January GFS 500 hPa and MSLP loops.

 

 

 

Water vapor and visible satellite images.

 

 

Radar loop.