Stormy then steamy Fair opener; Cristobal lurks

Batten down the tent strings and fire up the the misters at the Great Minnesota Get Together. It's going to be a potentially wet and sweaty start to the 2014 Minnesota State Fair.

I hope you will join me, Kerri Miller and University of St. Thomas climate change expert John Abraham for a special one-hour Climate Cast at 9 a.m. Thursday at the Fair. One topic: Why is Minnesota so cool during the globe's  third-warmest year on record?

Yes, it's that time of year. It's a special confluence of events in Minnesota. Summer's swan song comes with the realization that September draws near, and that school starts for most in just 13 days.

Time to pack in one last summer canoe trip, camping excursion or family vacation before the  clock strikes midnight on the summer of 2014. Yes, September can bring us delightfully warm days and bug-free nights in Minnesota. But for many of us, in two weeks the school calendar takes over our lives for the next nine months.

Delightful today, thunder by morning

You may not need the alarm clock tomorrow morning. A vigorous warm front bubbles north overnight. The leading edge of a sticky tropical air mass triggers  a wave of nocturnal thunderstorms late tonight, flashing and rumbling toward the Twin Cities by morning.

Here's a look at the maps. The warm front surges north, then stalls over southern Minnesota. The Twin Cities will ride the northern edge of the steamy (and potentially stormy) heat zone this weekend.

Southern Minnesota rides the northern edge of a serious late-summer heat dome by tomorrow. Headed up north? Not so much.

The air mass over the Minny will be juicy this weekend. Check out the dew points in the 70s by late tomorrow across southern Minnesota.

Model differences

Why should today be any different? The GFS and Euro agree on the overall trends, but differ on timing of storms ... and heat this weekend. Right now, Thursday morning and Saturday may shape up to be the wettest periods. But with steamy air and a stalled front around, scattered pop-up T-storms can't be ruled out at any time.

Next week still looks pleasantly cooler, but the Euro has backed off the magnitude of cooling significantly. After a potentially steamy, sweltering Sunday, here's a look at what could be a very pleasant air mass and a great string of days to visit the Fair.

 Tropical trouble? Cristobal lurks

All eyes in the Gulf and Florida ... and the East Coast are on what looks like future Tropical Storm Cristobal. Click the image below and watch how much better the area of convection organizes over the past several hours.

Both the GFS and Euro now show the potential for a storm near the Gulf Coast by next Saturday, but there is still great uncertainty in the eventual track.

Here's the latest trends on track from a great hurricane site, Mike's Weather Page.

And just to show how much change there may be in tracks over the coming days, here's an updated run featuring possible GFS tracks that suggest a shift toward the East Coast.

As we say in the weather biz: Stay tuned.