NEW, WINTER STORM WARNING NORTH

WINTER STORM WARNING NORTH, WINTER WX ADVISORY ELSEWHERE

Our next winter storm is knocking on the door and remains set to arrive mid to late evening. The latest indications are that the track is slightly further south and amounts in the maximum snow band are 1–2 inches higher. This has prompted the NWS to issue a Winter Storm Warning for my counties paralleling HWY 30 in pink. Here, 5–7 inches of snow is expected in places like Cedar Rapids, Maquoketa, Anamosa, Clinton, Mount Carroll, and Sterling/Rock Falls. The rest of the are is under a Winter Weather Advisory. Both the warning and advisory extend from 6:00pm this evening to 6:00am Sunday.

As it stands now, the latest guidance just in from the high resolution CAMS (convective allowing models) shows the potential for 4 to 7 inches of snow in a corridor extending from roughly HWY 20 in the north to I-80 in the south. Not to be picky, but I could see anywhere from the northern Quad City metro area all the way to Dubuque nearing warning criteria snow, which might eventually require warnings. Anyway, that's currently the zone under the gun for 4 to 6, potentially 7 inch accumulations. Here's what the latest raw model output looks like.

The 3K NAM

The HRRR

The NBMv5, a blend of 30 models and ensembles

The 12k NAM

The latest run of the NWS official forecast has also come in a bit higher further south, focused on that region from I-80 north.

It shows 90-95 percent odds of 4 or more inches along the HWY 30 corridor.

Between Dubuque and the Quad Cities, (again close to HWY 30) odds are as high as 70 percent for 6 or more inches.

The far south, especially south of HWY 30, sees amounts of an inch or less but could experience some mixed precipitation and freezing drizzle that could lead to a light glaze that creates hazardous driving conditions, the reason for the advisory in that part of my area. We still have 5–6 hours before snow gets going in the west and spreads east late evening. That's what's new. Roll weather...TS