So what’s with the snow falling (which was not forecast)?   That’s a great question.  Here’s the short answer—

I wasn’t even looking for the possibility of snow today.   But as soon as I saw the snow, I went back to the high resolution NAM NEST model and saw that it was forecast to 32º or below at key levels of the lower atmosphere with plenty of precipitation occurring after 11 AM.

NAMNEST model 32º F (isotherm) temperatures at 6000 and 3000 feet above sea level (lavender and violet lines) and simulated radar (blue/green shading)

Add to this strong vertical motion and heavy precipitation with dynamic cooling and we got the brief period of snow.

I wish I had forecast that possibility, but I skipped over the thermal profiles this weekend, thinking snow wasn’t a consideration.

As for the professional forecasters and the talking heads on TV,  I don’t know what their excuse is.

Anyhow, this is what makes the weather so interesting.   The forecast might have been off, but at least we know why.

Put another way, often we blame the models for being wrong.  This time, the wrong forecast was due to the forecasters.