WEATHER OUTLOOK

Wednesday Update
Just a quick note that the first of the impulses expected to move along the fast jet stream track will approach on Saturday. It appears that this most likely misses us to our south, according to the ECMWF.

This afternoon’s GFS gives us a light 1 inch accumulation on Saturday, as does the Canadian CMC.

Another impulse moves by Sunday afternoon. The GFS is more aggressive with this second system and gives us a QPF of about 0.30 inches water. The forecast for these systems is low confidence at this time.

from Tuesday..

We’re almost done with the current storm. The “cold air damming” proved to be more persistent than any of the models had forecast; the cold low level temperatures and the mixed precip remained somewhat longer than expected.

We’re continuing in an active weather pattern. The high level wind flow will act as a fast highway for moisture and disturbances to transit across the country–

200 mb flow
200 mb wind flow for the weekend

We’ll be seeing a chance for precipitation almost every 36-48 hours! Note that the track is just to our south.  There are several more chances for snow and mixed precipitation over the next week.   Details are uncertain, but I’m keeping an eye on it.   Stay tuned.

STORM UPDATE

A quick review.  This has been an interesting storm.  As far as QPF predictions went, the NAM was superior to the GFS,  both with the previous snowfall Sunday night and with last night’s light accumulation.   We didn’t get the 0.35 inches of water forecast by the GFS last night.

Another bias this storm seemed to confirm:  the “off-hour” runs of the GFS and the NAM, (the model runs done at 1AM and 1PM eastern time),  should really be ignored.  They often complicate rather than clarify the forecast.    Some of the back and forth with the forecast could have been avoided by ignoring the off hour models.

The new National Blend of Models  (NBM) also did well, especially with forecasting precipitation type- snow vs sleet vs rain.  (PTYPE).

In my neck of the woods, we had less than 1 inch of mixed precipitation accumulate.  There’s a mix of light snow, rain and a bit of ice pellets right now and that should transition to sleet and rain by about noon.    Temperatures remain near 30 and below just outside of the city and should rise above 32 mid day.

The latest NBM shows a transition to all rain about noon to 1 PM here. (gridpoint- Blue Bell).  Later transition will occur further north and west.

Rain, heavy at times,  continues until after midnight tonight.