Third hottest State Fair on record; Summery comeback means warm September?

Lingering Summer of 2013

Minnesota’s first salvo of fall like air arrived on schedule this Labor Day weekend. A frosty 32 degrees in tiny Togo in northern Minnesota this morning reminds us September has arrived.

The “better late than never” summer of 2013 went out with a steamy bang last week, saving the hottest week of summer for the last week of August. The 3rd hottest State Fair ever? It looks like that’s where we land pending confirmation from the Minnesota Climatology Working Group. Now it appears the summer of 2013 is not ready to give up just yet.

The weather maps suggest several more 80+ degree days and at least one or two more shots at 90.

Image: Euro model data via Weatherspark

Our “light switch summer” that started cool and wet flipped to dry mode in late June. Now drought has crept back into the weather lexicon with 50 percent of Minnesota in drought mode again. That percentage is growing fast.

Summer returns this week, and shows signs of sticking around well into September. Still several more lake and beach days ahead in the forecast.

Image: Twin Cities NWS

Summer of 2013: Warm and dry

Despite some predictions of a cool wet summer early on, nature flipped the switch and turned the tables on weather patterns this summer.

All three months of meteorological summer finished warmer than average in the metro, breaking the string of four consecutive cooler than average months that started in February and lasted into a reluctant spring in May.

Here are the numbers from the Twin Cities National Weather Service.

June +0.1 degrees

July +1.2 degrees

August +3.5 degrees

August and Summer 2013 Climate Summaries

August was the tale of two months that had one common story. The two tales involved temperatures. The first half of the month continued the trend of below normal temperatures that started in the second half of July. Then, in the middle of the month, the weather pattern quickly switched and the second half of the month switched to having well above normal temperatures, with several record highs being set between the 25th and 27th. In fact, the last week of August ended up being the warmest week of the entire summer, with MSP recording 6 straight days with highs of 90 degrees or higher from the 24th through the 29th.

Image: Twin Cities NWS

The common story though for both of the August temperature regimes were the dry conditions that dominated the entire month. Once we combined the heat to go along with the dry weather at the end of the month, we quickly saw drought conditions expand across the entire area, with the entire area now categorized as being in moderate drought.

The August that started cool flipped to extreme summer mode the last 2 weeks.  Here are the daily temps from NWS.

Image: Twin Cities NWS

Overall summer ends up +1.6 degree at MSP.

Image: Twin Cities NWS

Third hottest Fair on record?

We logged six consecutive days at or above 90 during the fair — a new record. When you factor in the cooler temps that drove record attendance this weekend, it looks like the average daily high temp for the fair will end up at 88.2 degrees.  That should be good enough for the four hottest State Fair on record, pending final tally from Minnesota Climatology Working Group today.

Image: Minnesota Climate Working Group

“Flash Drought” Creeps Back:

The summer water spigot turned off abruptly in late June, and we’ve been trending dry since July with rainfall around 3″ below average. Without rain in summer, a higher sun can evaporate soil and lake moisture rapidly. That’s why some like the Wall Street Journal are throwing the term “flash drought” around to describe the rapid onset of drought conditions this August.

When Minnesota goes from 10 percent to 50 percent drought in a week, you know it’s hot —  and getting dry in a hurry.

Image: US Drought Monitor

September outlook: Still warm and dry

As we ease into September, the outlook from the Weather Lab is for a warm and dry month.

Here’s what I’m seeing as we look ahead into September.

-Temps +5 to +12 degrees through Sept. 10

Image: NOAA Climate Prediction Center

Briefly cooler (60s and 70s) next week, but warmer than average temps (80s) overall into Sept. 18.

Image: NOAA GFS model data via IPS Meteostar

Arctic Oscillation in mostly positive phase, which supports warmer than average temps in Minnesota

Image: NOAA Climate Prediction Center

Weather Lab Outlook: Warmer than average overall in September. (Highest probability between +1 to +4 degrees for MSP.) Continued on the dry side. Rainfall likely below average for September. Overall: Deepening drought this month in Minnesota and Upper Midwest.

I’ll enjoy the warm sunny days, but hope my outlook for rainfall is wrong and we get some meaningful rains this month.