As arctic air slides into the region, the forecast models for the weekend bear watching.
A split flow in the upper atmosphere and an active southern branch of the jet stream is spawning potential snow system. The flow is chaotic, something the forecast models don’t handle very well. The big question is how far north these southern disturbances will project snow.
Major model differences:
There are some pretty remarkable differences and “divergent solutions” between the models regarding the weekend forecast at this point. Depending on which model turns out to be right, Saturday could either be sunny and cold, or cloudy with steady light snow adding up to 1″ to 3″ for much of southern Minnesota.
Sunday into Monday could either feature a storm sliding south and producing significant snowfall for Wisconsin or Chicago, or veer north and sideswipe southeast Minnesota (and possibly even the metro) with a shot of snow.
Right now I’m leaning toward a solution which features just a chance of light snow Saturday, with the bulk of a southern branch storm sliding southeast of Minnesota Sunday into Monday.
But stay tuned for updates as the modles (hopefully) sort things out Friday….
Could NWS funding cuts affect forecast accuracy in Minnesota?
There is big talk in Washington these days about proposed budget cuts for NOAA and the National Weather Service. Some proposals cut the NWS budget by about 30%.
Suggested impacts of such cuts could include closing NWS offices (there was already consolidation years ago which closed the NWS office in International Falls) reducing maintenance on the doppler radar and NOAA weather radio networks and even reducing the number of upper air soundings from every 12 hours to once daily or even once every two days.
While I don’t always jump on the NWS bandwagon, it is clear to me this is not the place to start cutting budgets. Studies have shown that accurate weather forecasts save the U.S. economy as much as 4-billion dollars annually! Most of this data comes directly in one form or another from NOAA & NWS.
One area where we might see an immediate catastrophic forecast impact would be if either the number or frequency of upper air soundings is reduced. These twice daily soundings are used as initial input into numerical forecast models that we use every day to make our weather forecasts.
If the geographic coverage or frequency of upper air data input feeding into the models is reduced, it would likely drastically affect model performance.
Twin Cities upper air sounding today.
One area that could wreak havoc for Minnesota is on model performance for winter storms.
Many of our major winter storms cross the Pacific before moving into the upper air weather balloon “grid” over North America. Once the systems get “sampled” by the upper air grid, the models have much better data on storm strength, movement and thermal profile…all of which are critical in determining how much rain or snow will fall in Minnesota, and where.
This is why you’ve heard me talk about the futility of trying to predict snowfall totals more than 24 to 48 hours in advance. The forecast models just don’t have enough accurate data on the storm until the system moves over the west coast!
If we had to wait even longer to sample storms coming off the Pacific it could be a disaster on model accuracy with winter storms. Forecasting winter storms is already one of the most difficult forecasts a meteorologist in Minnesota has to make. I can’t imagine how much worse the projections would be without accurate and timely upper air data feeding into the models every 12 hours!