By Brad Spakowitz
Correspondent
These seasonal outlooks are created by some of the government’s best climatologists and forecasters, using sophisticated computer models incorporating knowledge of how the atmosphere behaves, sea surface temperatures, climatological averages, analogs (years that were similar to the current year), recent trends, and of course, forecaster experience.
So what does the official NOAA winter forecast say?
For the second year in a row, La Niña conditions have developed and are expected to continue into winter.
I know what you’re thinking, “What does that mean?”
La Niña occurs when a large, persistent area of cooler-than-normal, sea-surface temperatures develop in the central and eastern tropical Pacific Ocean, altering wind and weather patterns across North America and the globe.
Although every La Niña event plays out differently, there are some general weather patterns that are somewhat predictable.
The northern U.S. is typically colder than average; the south is typically warmer and drier.
The Pacific Northwest and the Ohio-Tennessee valleys are typically wetter than average.
For Wisconsin, most La Niña winters are slightly colder and wetter, but it’s certainly not guaranteed.
The problem for Wisconsin is we are right on the edge of where it is typically colder and where it is not; and right on the edge of where it is typically wetter and where it is not, leaving us somewhere in-between, so it can go either way with temperatures and precipitation.
And of course it can also go in a totally different direction, like last winter, which featured a brief arctic outbreak from early to mid-February, but overall, was much warmer and much less snowy than average.
Armed with knowledge of how last winter played out, the NOAA experts have refined this winter’s outlook for this second-year-in-a-row (double-dip) La Niña.
This year’s forecast calls for a good chance of above-normal temperatures and above-normal precipitation across eastern Wisconsin and the Great Lakes.
I can’t argue with the temperature outlook.
It has been warmer than average for 17 of the past 24 months, so odds lean in that direction.
Regarding the outlook for above-average precipitation, I fear it conjures up images of a very snowy winter, but I’m not so sure that will be the case.
The first five months of this year were quite dry.
Thereafter, precipitation has been variable but sporadic, and often interspersed with dry spells of roughly five to 10 days.
Through it all, precipitation year-to-date is pretty close to the 30-year average.
My hunch is this trend will continue, winter precipitation will be close to normal (or perhaps a little above normal), but I’d be surprised if it turned out to be a really snowy winter.
Now that I threw that out there, I hope I didn’t jinx us.