September Heat Wave: Approaching 19 days of 90+ heat; 20 degrees cooler by late next week?

Endless Summer

It’s been a strange summer this year.

First, a reluctant rain and snow filled spring. Only five days managed to reach 80 degrees by mid-June. Summer finally began June 16 as temperatures finally pushed into the 80s consistently. Then six weeks of summer that reached a crescendo with a July heat wave. Then three weeks of “summerfall” with frost warnings and elusive reports of flurries up north. Now, a late August heat surge powers into the Dog Days of September.

At least we’re getting a little payback for the “missing spring” of 2013. Warm lakes and 90 degrees on Sept. 7. I’ll take it.

Now if we can just get a little rain on parched lawns and crops.

92 degrees – High Friday at Minneapolis St. Paul Airport at 2:46 p.m.

+16 degrees vs. average high of 76 for Sept. 6

17 days at or above 90 degrees this year in the metro

13 days average number of 90 degree days at MSP

31 days of 90+ in 2012

Image: Twin Cities NWS

Counting 90s

For a while this year it looks like we might struggle to get to 10 days at or above 90 degrees. That number is way back in the rear-view mirror and fading fast. Saturday should be day #18 of 90+ heat this year. Monday could be day 19.

After a brief puff of cooler and less humid air Sunday with temps in the lower 80s (still five to seven degrees above average) the heat returns in full force Monday as temps push 95+ degrees in the metro and southern Minnesota.

Here’s the Euro model’s take on weekend temps and on cranking out two more days of 90+ with temps as hot as 96 degrees on Monday.

Image: Euro data via Weatherspark

Will Monday’s high near 95 degrees be the hottest day for the rest of the year? Probably.

Cool Front Ahead

The weather maps are locking onto a solution that will bring some more September-like air south into Minnesota later next week. Monday’s heat wave could be sandwiched by some welcome rain chances. The best chance for a cooling and hopefully meaningful lawn/crop soaking? Late Sunday night into Monday morning, and again Monday night into Tuesday. Here’s the model output “meteogram” from the National Oceanic and Atmospheric Administration via Iowa State University. (You have to love weather data from a school whose nickname is “Cyclones.”)

Image: NOAA via ISU

Return To September

Both the Euro and Global Forecast System models agree on a return to more September-like temps by the middle of next week. High in the 70s and lows in the 50s will seem refreshingly nice.

Image: Euro model data via Weatherspark

That’s where the agreement stops. The Euro keeps things chilly next weekend with highs in the 60s, The GFS returns the warm air and highs in the 80s lingering past Sept. 20.

Image: GFS data via IPS Meteostar

Stay tuned on that one.

Northern Minnesota holds the best rain chances over the next seven days, with scant totals in the drought areas central and south.

7 day rainfall outlook. Image: NOAA