Latest NAM data just became available.  QPF values nearly the same, with the heaviest precip falling during the afternoon hours.   Morning hours: 0.20 inches  afternoon: 0.47, evening 0.06 water equivalent.

The trend is towards lower temperatures at the critical heights of 3000 and 6000 feet.   Temperatures at these levels remain right at or below freezing and do not rise later.  Temperatures in the upper atmosphere, as reflected by the 500 mb thickness level is marginal for snow, but still supports wet snow.

So maybe we do get that 4 or 5 inches on grassy surfaces just outside of the city.   Roadways significantly less.

So  far, the models have been correct with the timing (starting about 8 AM) and the precipitation type (snow).   I was beginning to be concerned about the accuracy of the forecast when I woke up and the outdoor temperature was 34 degrees.

But once the precipitation started, temperatures dropped to 31.

The 2AM run of the NAM has the QPF almost 0.80 inches, but much of the heavier precipitation will fall in the afternoon, according to the NAM.   This most recent NAM run has the temperatures at 6000ft (800 mb) moving above freezing during the later half of the afternoon,  allowing the snow to mix or change to rain or a mix…..so another parameter has shifted towards decreasing snow totals.

The grassy surface vs road accumulation difference is already apparent.   Getting the final accumulations numbers correct with this storm is probably both meaningless and impossible.  I think you get the idea.

I’ll update when the next NAM FOUS data becomes available about 10:45 AM.