A week of snow starts tonight
Tuesday, January 7, 2014
At least 4 distinct waves will influence our weather starting tonight, with snow in the forecast through next Monday. Light snow should start later today as the first weak wave moves over us tonight. Accumulations will wait until cool air enters the area by midnight. Even though the wave is weak, flow is from the northwest so I would expect several inches of snow in the Wednesday morning report.
There may be very little break between waves Wednesday morning before the next wave passes mostly south of the area by late Wednesday afternoon. Again, several inches of accumulation are expected by Thursday morning as we are in favorable moist northwest flow, though cooling is limited.
Perhaps another small break Thursday morning before the next stronger, but splitting wave approaches the area. This is the storm models have been struggling with these past few days. Initially, the European model had the wave cut off from the main jet and staying south of use (a cutoff low), while the American model kept the wave coherent and progressive. As is sometimes the case when model disagree, current model solutions area average the two earlier disparate solutions, with a splitting wave staying mostly coherent and progressive. As a result, snow should begin again later Thursday afternoon and continue into Friday evening. Amounts will be dependent on how much energy is left in the northern half of the split, but amounts currently look in the 3-6” range.
Even though we will be in-between systems early in the weekend, moist northwest flow in a warming and stabilizing airmass will keep clouds and perhaps some very light snow showers going Saturday morning. The fourth wave will be the strongest and coldest of this series, and will affect our area beginning Saturday afternoon. Snowfall looks to peak early Sunday morning and then again Sunday evening as a trailing wave crosses the area. All told, I might expect 6-12” when the Sunday and Monday morning reports are added.
Current long term forecasts have the snow ending after this final wave as a ridge builds over the area. However, there are some indications that the Hudson Bay polar vortex may again expand westward into this building ridge, leading us susceptible to cold air outbreaks by the end of the workweek.