Philly Winter Weather Update 7 AM

So the issues with last evening’s model runs continue with the 1 AM reruns of the GFS and NAM.

Here are  the contradictions and forecast dilemma:  Both models have high QPF values (GFS about 0.50) and  NAM (increased to over 0.60 inches water) but they differ in the handling of the low pressure development.  The GFS has us waking up to 2 inches of snow Tuesday morning.   The NAM has us waking up to a light coating at best.  They differ by almost 18 hours for the heavy QPF.   So something is wrong, possibly with both models handling of this developing system.

If this were a different scenario, I would change my current forecast from the current 1-3 inches to the QPF-based 5-7 inches when all is said and done Tuesday night.

Essentially, I don’t think the models are right and the 1-3 inches is a hedge on what could be a fizzler of a storm.   HOWEVER,  a small voice is beginning to say, “don’t ignore the models QPF”

(I heard KYW’s forecast this morning and they’re going with the same “1-3 ….with 6 inches in some locations”.   Hey, what locations??   Wow, talk about a hedged forecast!  Yet another forecast from them ‘sanitized for your protection’. )

So here’s where we are at:  If this morning’s models continue to crank out high QPF values, we have to start taking this seriously and expect higher snow amounts on Tuesday.  I’ll update sometime mid day today….(this is not my full-time job).