Normal September is forecast, while October and November might give the season character.
Some Minnesotans might get by with lighter jackets, while others may need rain gear for their favorite fall outings this year, according to the national Climate Prediction Center.
In its forecast for “meteorological autumn,” released Thursday, the center said conditions favor warmer-than-normal weather from the northeast Arrowhead region into north central Minnesota for September through November. At the same time, the outlook anticipates wetter-than-normal conditions for the Twin Cities and southeastern Minnesota, extending to the southwest corner of the state.
Even coming out of a coolish summer, a fall with generous tomato-ripening time would not be a surprise, meteorologist Paul Douglas said.
“The last 30 years we’ve seen a trend toward longer autumns. The growing season is longer,” he said.
Although Douglas accurately predicted in the spring that this summer would be cool and wet, he added that he tends to put little stock in long-range forecasts.
Even so, he said he is more confident of a warm fall than a wet one, adding that temperature trends are more reliably identified than precipitation trends.
August was averaging 3 degrees below normal through Wednesday in the Twin Cities, and lows have dropped into the 30s in recent days across northern Minnesota. That was expected to change soon, though, with highs in the metro area heading into the 90s early next week. Even International Falls is expected to see temperatures in the upper 80s.
The Climate Prediction Center’s outlook for September alone indicates no clear trends away from normal across Minnesota, meaning the warmer-than-normal fall conditions for the northeast and the wetter-than-normal conditions for the south could be emphatic in October and November.
The outlook reflects the expected impacts around the globe related to sea surface temperatures in the Pacific Ocean, which have been continuing to be neither above nor below normal.
Jeff Johnson, chief science officer for the Burnsville-based weather division of the global energy management firm Schneider Electric, said he expects patterns that have blocked or slowed significant weather variations around this Northern Hemisphere since last winter to continue.
But in his view, that means a cooler fall, kicking in just after the expected State Fair heat wave, and a generally wet one.