Storm System Recap with Forecast Grade From Tuesday 11/29/22

I have officially brought back the forecast grade system and the first one is from the snow/ice event on Tuesday 11/29/22. Read on for the full details…

Back in 2021 I started the forecast grade system where I would grade my forecasts compared to what actually happened and I will do that for this event plus going forward. The timing of this event went well but the precipitation type was the tricky part of this forecast. As with any dynamic type system, the temperatures aloft help indicate specific precipitation type at the surface.

I have included the two snowfall forecasts below that were issued prior to the event with the first on Monday morning and the second on Tuesday. As Tuesday morning hit, I made the call to bump up totals across northwest Iowa knowing that most areas where good with 2-4″ of snow. However, localized totals of near 6″ were in the cards but it was unclear what specific locations would see this much snow. The snowfall forecast as a whole was decent with a few errors due to more mixed precipitation then snow on the southern extent of the system. So with that, I will give myself a B on the grading scale. I have left out the ice portion of the forecast due to no reports that were received. Both maps and snow totals are below.

Snowfall reports from Tuesday 11/29/22

Decorah: 0.3″

Estherville: 4.0″

Hull: 3.8″

Lake Park: 6.1″

Larchwood: 3.0″

Ocheyedan: 4.0″

Orange City: 4.2″

Riceville: 1.0″

Sergeant Bluff: 2.2″

Spencer: 4.2″

2 NNE of Carpenter: 1.5″

3 NNE of Sioux City: 1.9″