Heat warning continues today; slight to severe risk late tonight into Thursday; real relief Sunday

State Fair heat wave of 2013

Folks will long remember our record setting State Fair Heat Wave of 2013. We can count what looks like the second hottest State Fair ever among the top weather events of the year so far.

The heat wave has put a serious dent in Fair attendance the past few days. There was plenty of room to walk around at the Fair Tuesday after our noon hour "weather show" broadcast with Cathy Wurzer and Mark Seeley. Nobody in line for walleye-on-a-stick? That's a first for me. Hopefully the vendors can make up for the weather related sales plunge later this weekend.

We've knocked off six records so far, and we'll endure one more day of stifling heat before some minor relief temperature and dew point Thursday. Temps still hover near 90 through Saturday. You know it's stinking hot when 90 degrees is a cool front. We'll have to wait until Sunday and Labor Day for any real relief.

A new (and welcome?) concept creeps back into the forecast later tonight and Thursday. Thunderstorms are rumbling across South Dakota today and could graze southwest Minnesota. The best chance for a welcome shot of cooling rain for the metro comes later tonight and Thursday morning. NOAA has posted a slight risk for severe storms over the metro for Thursday.

I think we'll all enjoy some significant relief from the barbaric heat by Sunday and Labor Day.

Excessive heat warning until midnight

We endure one more day of dangerous heat today. Temps in the low to mid 90s and dew points hovering near 70 in the Twin Cities metro and southern Minnesota will push the heat index to over 100 degrees again today. This truly has been a significant late summer heat wave for Minnesota. Just two hours in this brand of heat at the Fair Tuesday and I could feel the stress the rest of the day. This is serious stuff.

Here's the wording from the Twin Cities National Weather Service office.

426 AM CDT WED AUG 28 2013

AN EXCESSIVE HEAT WARNING REMAINS IN EFFECT UNTIL MIDNIGHT CDT TONIGHT.

INCLUDING THE CITIES OF...MADISON...BENSON...MONTEVIDEO...WILLMAR...LITCHFIELD...MONTICELLO...MINNEAPOLIS...BLAINE...ST. PAUL...STILLWATER...GRANITE FALLS...OLIVIA...HUTCHINSON...GAYLORD...CHASKA...SHAKOPEE...BURNSVILLE...REDWOOD FALLS...NEW ULM...ST. PETER...LE SUEUR...FARIBAULT...RED WING...ST. JAMES...MANKATO...WASECA...OWATONNA...FAIRMONT...BLUE EARTH...ALBERT LEA...RIVER FALLS...PRESCOTT...DURAND...PEPIN

* TEMPERATURE: AFTERNOON HEAT INDICES TODAY RANGING FROM 95 TO 100.

* IMPACTS: THE PROLONGED PERIOD OF HOT AND HUMID CONDITIONS HAS COMPOUNDED THE RISK OF HEAT RELATED STRESS AND ILLNESS...ESPECIALLY FOR THE YOUNG AND ELDERLY...THOSE WITHOUT AIR CONDITIONING...AND PEOPLE PARTICIPATING IN STRENUOUS OUTDOOR ACTIVITIES.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE EXTRA PRECAUTIONS IF YOU WORK OR SPEND TIME OUTSIDE. WHEN POSSIBLE...RESCHEDULE STRENUOUS ACTIVITIES TO EARLY MORNING OR EVENING. KNOW THE SIGNS AND SYMPTOMS OF HEAT EXHAUSTION AND HEAT STROKE. WEAR LIGHT WEIGHT AND LOOSE FITTING CLOTHING WHEN POSSIBLE AND DRINK PLENTY OF WATER.

TO REDUCE RISK DURING OUTDOOR WORK...THE OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION RECOMMENDS SCHEDULING FREQUENT REST BREAKS IN SHADED OR AIR CONDITIONED ENVIRONMENTS. ANYONE OVERCOME BY HEAT SHOULD BE MOVED TO A COOL AND SHADED LOCATION. HEAT STROKE IS AN EMERGENCY...CALL 9 1 1.

AN EXCESSIVE HEAT WARNING MEANS THAT A PROLONGED PERIOD OF DANGEROUSLY HOT TEMPERATURES WILL OCCUR. THE COMBINATION OF HOT TEMPERATURES AND HIGH HUMIDITY WILL COMBINE TO CREATE A DANGEROUS SITUATION IN WHICH HEAT ILLNESSES ARE LIKELY. DRINK PLENTY OF FLUIDS...STAY IN AN AIR-CONDITIONED ROOM...STAY OUT OF THE SUN... AND CHECK UP ON RELATIVES AND NEIGHBORS.

The combination of dew points and tmps in the 90s will push the heat index to 100 today in parts of southern Minnesota. Some relief is underway up north.

 Forecast for relief: A slow process

We'll feel some relief from the extreme heat and humidity levels starting on Thursday, but don't look for any sweeping cool fronts yet. Temps will hover near 90 with dew points stubbornly hanging in the upper 60s to near 70 into Saturday. Thunderstorms may flare Thursday and Saturday into Sunday. Real relief comes in the form of a stronger cool front Sunday into Labor Day.

Here's NOAA's Global Forecast System model output into Labor Day via Weatherspark.

Storm chances increase: slight severe risk late tonight and Thursday.

An upper wave is triggering scattered T-Storms in the Dakotas today and they will spill into Minnesota later today through Thursday. The best chance of metro storms comes overnight into Thursday morning. A few of the storms could deliver welcome cooling rains but also pack high winds and some hail.

Here's the latest risk area from NOAA's Storm Prediction Center for Thursday.

State Fair attendance takes a heat hit

No way around it, the intense heat has been a factor in a big drop in State Fair attendance numbers the past few days. Since Sunday, temps are running about +1 degrees vs. 2012 during the fair.

Here are the numbers through Monday from the Minnesota State Fair. I've added daily highs from this year vs. 2012. I expect Tuesday's numbers to take a big hit when they are released today.

Expect fair attendance to pick up this weekend as temps and dew points fall to more comfortable levels.