Metro frost advisories, Joaquin forecast chaos

Time to cover up those Supertunias.

Frost advisories include St. Cloud and the northeast metro into Wednesday morning. Freeze warnings are flying again for northeast Minnesota and northern Wisconsin.

INCLUDING THE CITIES OF...LONG PRAIRIE...ST. CLOUD...FOLEY...ELK RIVER...BLAINE...STILLWATER...HUDSON...PRESCOTT...MENOMONIE...DURAND...CHIPPEWA FALLS...EAU CLAIRE

201 PM CDT TUE SEP 29 2015

...FROST ADVISORY IN EFFECT FROM 1 AM TO 8 AM CDT WEDNESDAY...

THE NATIONAL WEATHER SERVICE IN TWIN CITIES/CHANHASSEN HAS ISSUED A FROST ADVISORY...WHICH IS IN EFFECT FROM 1 AM TO 8 AM CDT WEDNESDAY.

* TEMPERATURES IN THE LOW TO MIDDLE 30S ARE EXPECTED BY TOMORROW MORNING. SOME ISOLATED SPOTS COULD GET AS COLD AS 30 DEGREES.

* IMPACTS...PLANTS AND VEGETATION OUTDOORS WILL BE DAMAGED OR POSSIBLY KILLED IF PRECAUTIONS ARE NOT TAKEN. CONSIDER COVERING OUTDOOR VEGETATION OR BRINGING PLANTS INDOORS.

As the center chilly dry Canadian high pressure builds over Minnesota, temperatures bottom out near or below freezing across a good chunk of northern Minnesota and Wisconsin.

Here's a closer look at minimum temperatures early Wednesday morning around the metro. Temperatures should be near 32 degrees in low spots in the north and east including Forest lake, Lino Lakes, Hugo, Scandia, and Stillwater.

A few spots west and south of the metro could also see frost tonight. Most of the inner metro core should escape frost early Wednesday morning. MSP Airport will probably bottom out somewhere in the low 40s.

Right on schedule

Late September is typical for the season's first 32 degree temperature in most of northern Minnesota and Wisconsin.

In case you're wondering, late September is also typical for the season's first 32 degree temperature in the cooler metro suburbs. The average date for the first 32 degree temperatures at MSP Airport inside the urban heat island is October 7.

Forecast: Status quo

The next week features a classic early fall weather pattern over Minnesota. Crisp Lake Superior high pressure noses in overhead keeping any rain systems at bay.

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The forecast is in "set it and forget it" mode. Cool sunny days and crisp fall nights. Complaints next door down. Like the sign says: Free beer tomorrow.

Joaquin: Cone of chaos

Nate Silver is widely considered the god of predictions these days. In "The Signal and the Noise: Why So Many Predictions Fail--but Some Don't"  Mr. Silver eloquently describes the so called "cone of chaos" which is the probability zone surrounding hurricane forecast tracks.

Nate must be watching with interest as NOAA's National Hurricane Center and all other meteorologists struggle with the widely divergent spaghetti model solutions for Tropical Storm Joaquin so far. Buyer beware as your local meteorologist tries to exude overconfidence that they have the best solution on where Joaquin will go.

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The cone of chaos with Joaquin is large. A stalled storm that's intensifying, later picked up by erratic upper level winds as it accelerates north in the general direction of the most densely populated major US cities? That's what's keeping meteorologists at NHC up at night these days.

Here's the latest NHC track forecast for Joaquin. And yes, this will probably change tomorrow.

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Most of the model output shows intensification with Joaquin to hurricane status in the next 48 hours.

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Two of the more trusted models, the European and NOAA's GFS steer Joaquin out to sea. Interestingly, tropical disturbance 99L over Florida may actually track along the east coast and be a bigger rain producer than Joaquin if that track notion verifies. Either way, multi-inch flooding rains along the eastern United States is likely to be the biggest weather story as we approach the weekend.

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This is one of my favorite sites for tracking topical systems. Expect more changes and updates as we keep an eye on the progress of Joaquin Wednesday.

Stay tuned.