IS IT WINTER YET, YOU BETTER BELIEVE IT...
The 14th storm to strike some part of Iowa this winter is now in the books. Here's the swath of snow that it left as it crossed the central Midwest.
Officially a foot of snow fell in Des Moines but some of the surrounding area had totals as high as 14 inches. That is a high end storm. Here's a breakdown of the totals. Notice the lower amounts in far eastern Iowa and Illinois as the storm gradually weakened on its journey east.
Another disturbance is quickly following but it too is weakening and reforming further south. It could bring some very light snow as far north as I-80 this morning but little more than a dusting is expected north of HWY 34. From there south a few spots could see up to an inch of very fluffy snow.
Otherwise, Wednesday will be a cold day with clouds decreasing in the afternoon as the disturbance quickly advances east. Highs around 20 are expected. That leaves us with fair skies and cold temperatures Wednesday night. With the deep snow cover and light winds strong radiational cooling should send temperatures into the range of zero to 5 below
Speaking of that snow cover, here's what's on the ground. Much of the area near and north of I-80 has snow depths that range from 6-14"
You can also see in the graphic below that on average the winter so far has produced at least 2 feet of snow from I-80 north. Dubuque is working on 3 feet with the seasonal total now at 32 inches. The bottom line, most areas are above to well above normal on snowfall and we are only halfway through with winter.
Just looking at teleconnections the negative phase of the AO (Arctic Oscillation) and NAO (North Atlantic Oscillation) are forecast to continue with a negative PNA (Pacific North America). That implies the mean trough will be over the central U.S. and this active weather pattern is likely to continue the next 2-3 weeks. That increases the odds of more snow in the coming days. Another system is in the loop over the Pacific and brings with it our next potential snow Saturday night and Sunday morning.
Owing to the distance, (more than 4 days away), we still need to monitor the track and intensity but all the mid range models show the system and depict a respectable precipitation shield. I'm pretty confident there is going to be another healthy snow event but the location is not as clear cut. As it stands now, my southern counties are most favored.
Here's the evidence which supports the weekend system and that is the raw snow output from the mid-range models. The amounts are far less important than the general idea of strength and geographical placement. The details will improve with time and so will the specifics. Here's the latest model guidance at 10:1 ratios.
The GFS ensemble mean.
The Canadian GEM
With that, I will cut you loose and say thanks for your willingness to explore my thoughts and perspective on my favorite subject, the weather of the Midwest. Stay warm and as I always say, roll weather...
A SECOND PRINTING OF MY NEW BOOK IS ON THE WAY...
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