FCST: 1/6-7/10 SNOW and ARCTIC AIR

EDIT: 0530Z/4--Last few model runs have been trending toward less snow for the local area.  The GFS still has us in a 3" to 5" band and the NAM-WRF has us in a 2" to 4" band.  I am looking for continued consistency in the models over the next few runs before I buy into the lower snow totals.  Again, this is a NWLY flow event and not the classical desert SW setup for the local area.  The cold air will also effect the snow accumulations as well.  As I said in the earlier post, I will update the blog with the latest snow totals the models are putting out. ~ CS

GFS forecast Snowfall Accumulation 12Z Thursday morning

NAM-WRF Snowfall Accumulation forecast 12Z Thursday morning

Upper CONUS and Canada Station Plots 0630Z/4

OLD BLOG ENTRY: The models are remaining very consistent in the track and strength of the next storm system.  This system will come in from the northwest as our NWLY flow continues.  I do not expect this storm to be like the Christmas Eve/Christmas Day Blizzard we experienced just a few weeks ago.  However, we could easily receive 3" to 6" of snow, with locally higher amounts, with some blowing of the light snow.  The cold air will change the snow ratio per equivalent liquid precipitation so we will have to watch this as the storm unfolds. 

GFS 96 Hour Accumulated Snowfall prediction
(Valid 6 a.m. Thursday January 7, 2010)

The following model images are depicting Wednesday morning and Wednesday evening. (0Z Thursday is 6 p.m. Wednesday evening and 12Z Wednesday is 6 a.m. Wednesday morinng)

GFS Surface Pressure / SLP / 1000-500 mb Thickness

GFS forecasted 700 mb Vertical Velocites / Heights and Winds

GFS forecasted 500 mb Absolute Vorticity, Heights and Winds

ECMWF forecasted 500 mb Sea Level Pressure and Heights

UKMET forcasted 500 mb Absolute Vorticity and Heights

GEM Pressure, Thickness and Heights 00Z/3 Panels

Winds are forecasted to be in the 15 to 20 mph range with possible higher gusts.  I do not expect the drifting we saw with the last major storm either.  However, the lighter the snow is the easiler it will be to blow around and reduce visibilities during the more moderate bands of snow.

Western Canada Surface temperatures Sunday Janaury 3, 2010

The major story will be the cold air behind the system.  We will most likely experience some of the coldest air we have seen in many years.  A 1047 to 1050 mb high is forecasted to build in as the system moves off to the east and southeast.   Models are still forecasting highs below zero or near zero on Thursday and Friday with overnight lows in the teens below zero.  Factor in the wind and we could easily see windchills near forty below zero. Stay safe and stay warm this next week.  I will update the blog if my forecasted snow amounts change. ~ CS