WEST MICHIGAN — We expect cold weather in the middle of winter here in West Michigan, but everybody probably already feels as if we’ve had our fair share of it after the polar plunge and Arctic Blast last week. Not so fast…Climatologists and Meteorologists from the CPC (Climate Prediction Center). Just a little background info…the CPC is the branch of NOAA and the National Weather Service that solely dedicate themselves to the longer term forecasts (or trends) across the nation (temperatures and precipitation primarily).
Notice the attached snapshot is the temperature outlook from the CPC across the nation over the next six to ten days. Notice also that the eastern half of the nation is expected to be below normal (in the color of blue). The bull’s-eye is actually over the Great Lakes, Southeast U.S. and Florida. At the same time the western half of the nation will likely see above normal temps for the same period. Check out Alaska…a 70 percent chance and bull’s-eye of above normal temperatures for them!
Take a look at the eight to 14 day CPC outlook for temperatures (below). Again, the eastern half of the nation expected to be below normal with the highest probability and bull’s-eye occurring (again) over the Great Lakes in purple. It’s actually a 70 percent chance of below normal temperatures for the period.
The Southwest United States has the bull’s-eye for above normal temperatures especially across California, part of the Great Basin of Nevada, and the desert Southwest (70% probability). It’s also interesting to note that more than 2,000 miles to the north/west that Alaska is forecast to be well above normal in temperature for the same period. In fact, CPC puts it at a 60 percent chance of above normal temps.
One last thing…take a look at the jet stream pattern and upper level winds around 30,000 feet (below). Where you can trace the red, oranges, and the yellows is where the core of the fastest moving winds are located. It’s also the dividing line between the cold air to the north and the milder air to the south. Notice the jet stream pushes well north in to Canada over the western U.S. (we call that ridging), and it dips well south from Minnesota all the way to the Gulf Coast and up the Atlantic Eastern Seaboard (we call that a trough). The point is the ridge coincides with milder, above normal temps, while the trough is indicative of a colder air mass (mainly over the eastern half of the nation). This computer forecast model is from the GFS and is valid for next Tuesday evening.
When the pattern changes, our weather will change. Impulses of energy and little disturbances ride along the jet stream and tend to bring unsettled weather like snow and reinforcing shots of cold air. That’s our pattern the next several days. Remember next time we see temperatures soar above normal, the jet stream has probably moved to the north (ridging) and taken the cold air with it. No big warm ups in store, but hopefully our next big thaw back to the 40s or perhaps 50 isn’t too far off. Get more at www.fox17online.com/weather.