AM rain & thunder; Major break in MN & USA heat wave late next week

AM rain & thunder Wednesday

Locally heavy downpours possible

Latest Twin Cities radar loop

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Source: Twin Cities NWS

Heat Wave Breaks: Major break in MN & USA heat wave next week?

94 degrees high temp at MSP Airport Tuesday

22 days at or above 90 degrees in the metro so far in 2012

5 years since we’ve logged more 90 degree days (27 days in 2007)

607 “Cooling Degree Days” (CDD) in the metro so far in 2012

342 CDD is average to date

398 CDD at this point in 2011

77% increase we’re paying 77% more than average this year for AC in our homes

70s? Highs in the 70s in the metro by the weekend of July 28th?

(Highs in the 60s up north and into the northern metro??)

Worst of summer heat and humidity over after this weekend?

Spotty showers & T-Storms through Wednesday

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Source: Twin Cities NWS

Welcome pattern change next week?

I first posted this morning on the chances for a major break in our prolonged summer heat wave by late next week.

Confidence is growing with each passing model run that a major pattern change, a shift in the upper winds to a northwest flow late next week will bring substantial and prolonged relief from the summer heat wave of 2012.

If the models verify the big inflamed “heat pump high” that’s been parked over the central Midwest will break down and shift west over the Rockies next week. That will open the door for a northwest flow in the upper atmosphere, and a series of cooler fronts should push south from Canada starting last next week.


Source: NOAA/NCEP GFS Model

The cooler drier air masses could drop temps as much as 20 degrees in Minnesota, with highs in the 70s by the weekend of July 28th. The pattern should also bring substantial relief to the eastern half of the USA, where temps have been dangerously hot for weeks from St. Louis to the East Coast.

Steamy & thundery weekend first?

Today’s cool front easing south will provide marginal relief from the heat the rest of this week. Highs should be held back into the 80s, and scattered storms may bring cooling rains through Wednesday.

The heat and humidity are not far away though (it is still July), and it looks like southerly winds will bring back the 90s and humidity as soon as Friday…and into the weekend.

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Source: NOAA/ Iowa State University

Tropical Downpours: Heavy rain potential this weekend?

A stationary front may set up in southern Minnesota this weekend. With plenty of tropical moisture around, there could be plenty of fuel for heavy, slow moving T-Storms that can unleash tropical downpours and potentially heavy rainfall totals in southern Minnesota.

There is no way to accurately forecast flash flood events like the 1987 “Twin Cities Superstorm” several days in advance (or even several hours in advance) but stationary fronts loaded with tropical moisture in weak synoptic environments are ripe for triggering slow moving T-Storms packing torrential downpours.

Stay tuned, but we could be in for a steamy and thundery weekend into early next week before the cool fronts start marching south later next week.

No Free AC: Costly summer of 2012

Are humming along with your AC yet this summer? Mine is running so much I’m tempted to sing along.

As grateful as I am for my AC unit on the 110th anniversary of the invention of the air conditioner, I’m afraid to look at my Excel bill this month.

So far in 2012 we’ve logged 607 “Cooling Degree Days” ain the metro. That’s 177% of average and 153% more than last year to this date.

Bottom line? We’re paying at least 77% more than last year to cool our homes in the unrelenting summer of 2012. If your annual AC bill is $500 on average, it’s running to the tune of a cool $885 this year. That’s $385 bucks we could have used for new tires on the car, gas for the boat etc. The good news? We saved at least that much in heating costs last (non) winter.

Worst of summer heat & humidty over?

It may be too early to say we’re done with extreme heat this summer. After next week’s cool fronts, I expect we’ll see another run into the 90s in August as we head toward State Fair time…but with lower sun intensity 100 degrees is (thankfully) much harder to reach as we move through August.

Still, I think the hottest, most sustained stretches of 90 to 100 degree heat may be history in Minnesota after this weekend. Hang in there!

Stay cool, and bring on the cold fronts next week!


  • Tyler

    Paul, last winter our abnormal warm temperatures were “offset” by unseasonable cold temperatures in Eastern Europe. Has anything similar occurred globally this summer? Is there somewhere in the northern hemisphere where the temps have run cooler than normal?