We’ve moved into the forecast range of some of the shorter-range, higher resolution models.  Sometimes, things fall into the category of “too much information”; this may be one of them.

Start time varies by model.  I still think snow starts between 10 and 12 PM, with some earlier patches of flurries possible.  Some models have it starting about 12-1.

Mixing or changing to sleet  possible as early as 3 PM.   As mentioned yesterday, dynamic cooling may bring the snow back in the picture if precip rates increase enough.

Snow/sleet/rain ends early evening.

For snow totals, this how things are sorting out—

The shorter range models (NAM and NAMNEST) have it warmer aloft, have less total precip  in their afternoon runs and more sleet.  Here’s their latest snow totals at 6 PM Saturday:

NAM NEST Snow totals


More consistent on the higher range has been the GFS model, shown below:

GFS Snow Depth totals 6 PM Saturday


The Canadian is closer to the GFS, the European model is closer to the NAM.

So, let’s turn to the National Blend of Models (NBM).  Here’s the current blended forecast:

NBM Snow Depth forecast

The NBM is my current choice for snow totals with this storm.

Just an aside:  There are problems currently with NOAA weather data centers right now:  Here’s a message that was sent out earlier:

“NOMADS users,

We are experiencing a critical failure in one of our data centers that is forcing us to shut down NOMADS entirely. FTPPRD will still be accessible for both FTP and HTTPS access, but full file download from as well as grib filter and openDAP services will be down.

We have no ETR at this time and will send frequent updates on status.”
So weather data access has been slow and limited this afternoon. My favorite version of the NBM model has been totally shut down.


Update Thu 08:01 AM —We are moving into the range of the higher resolution models during the day today and by this evening’s model runs, things should clarify further.

Based on last night’s GFS, GEFS, NAM SREF, CMC and ECMWF, here are the forecast  trends:

Snow starts 10AM -12 noon.  Some models are leaning towards a later start.  (The high resolution NAM-NEST ( just coming into forecast range)  has a 10 AM start from west to east, but even has some flurries before then.

The current trend for most of the models is less snow accumulation and more of a mix.  The GFS is still in the 1.5 inch range, but the Canadian and ECMWF are closer to an inch or less.   Precipitation ends about 8 PM.

Over the past year, the new National Blend of Models (NBM) has done very well at smartly blending these differences. Here’s the latest NBM  (new version) snow total for 7 PM Saturday evening –

Latest NBM Snow Totals forecast by 7 PM Saturday.   (NBM v3.2 11z run 01-16-20)  Click for larger image

I’ll be updating this evening with the latest models, including the shorter range high resolution models.  Stay tuned.