15th straight warm month; Excellent Labor Day Weekend; Fall outlook

Labor Day Weekend Weather Headlines:

+0.8F temps vs. average in August 2012 at MSP Airport

15th straight warmer than average month at MSP Airport (and most of Minnesota)

28 days at or above 90 degrees so far in 2012

Most in 24 years since 1988 when we logged a record 44 days

Excellent Labor Day Weekend forecast: Only slight chance of rain Sunday night into Labor Day morning?

Source: Twin Cities NWS

Lower 70s for highs by late next week!

Blue Moon Friday night August 31st! (Next "Blue Moon" July 31st, 2015)

Meteorological Fall begins Saturday, September 1st

Fall Outlook: Warmer than average (again?)

15 in a row and counting:

August 2012 rallied to become the 15th consecutive month with warmer than average temps in the metro. The last cooler than average month was May 2011.

August opened with two 90 degree days, and then a series of cool fronts swept south. The period from August 4th - 22nd featured 15 of 19 days cooler than average.

The largely AC free month ended with 2 more 90 degree days this week...for a total of 4 this month and 28 for the summer of 2012 so far. That's the 10th highest number of 90 degree days in a year in the metro going back to 1872, and the most in 24 years since the record of 44 days set in 1988.

Overall this looks like it may go down as the 3rd hottest summer on record in Minnesota (after 1988 & 1934) pending final numbers.

Labor Day Forecast: Does it get any better?

Let's see...time to come up with the "perfect" summer holiday weekend forecast.

Pleny of sun? Check.

Highs in the 80s? Roger that.

Comfy air masses...dew points in the 40s & 50s? On it.

Warm lakes for a last long weekend of swimming & fun on the water? Yep.

Just a slight chance of rain & thunder, preferably at night? Why not?

All things considered, you just can't draw it up any better than this weekend for the "last" unofficial weekend of summer.

Saturday: Bright sun & warm & dry. High 86. (70s along Lake Superior) Light SE wind 5-10 mph.

Sunday: Mostly sunny & warm. High 88. Slight shower/T-Storm chance in northwest MN.

Sunday Night: 30% chance for scattered showers & T-Storms

Labor Day: Early AM shower/ T-Storm chance metro & SE MN, then partly cloudy & warmer. High near 86. West wind 5-10 mph.

Fall Outlook: Warmer (and drier) than average?

"The trend is your friend." - Craig Edwards

When in doubt, don't buck meteorological trends. That's the common wisdom among forecasters in the weather biz.

The latest CPC outlook favor warmer than average temps for the Upper Midwest for meteorological fall (Sep-Oct-Nov) 2012.

Source: NOAA/CPC

That said, my own analysis (and the CPC seems to agree) is for cooler than average weather for the Upper Midwest starting late next week and possibly favoring the first half of September.

Source: NOAA/CPC

A series of cool front may actually make it feel like September around here by late next week. You know...back to school, the first few changing leaves...and actual coolness in the morning air with dew covered grass?

Yeah, it's like that.

Overall the development of El Nino favors another milder than average winter in Minnesota, but ENSO cycles show less predictability for fall temps.

Twin Cities NWS uses "Dual Pol" in Au8gust 23rd Carver County tornado.

We've had 34 tornadoes this year in Minnesota. Thankfully they've pretty much all avoided the Twin Cities metro. The August 23rd Carver County tornado came the closest...and gave the NWS office in Chan a good opprtunity to fire up the new "Dual Polarization" doppler.

As the storm passed over Glencoe, the air flowing into the storm's updraft began to intensify. The combination of the easterly winds flowing into the updraft, and westerly winds of the descending rear inflow jet, caused a low level circulation to form (Fig 3). This circulation ended up producing a short-lived EF-0 tornado that tracked just northwest of Norwood Young America in western Carver County.

Figure 3: The images above follow the leading edge of the storm and show how the base velocity (0.5o) changes over time during the few minutes prior to and after the tornado. The green/blue colors show where the air is moving northeast towards the radar, while the red/orange colors show where the air is moving westward away from the radar. The legend on the left is in knots. This set of images follows the formation and eventual dissipation of the circulation as it moves across western Carver County (white arrows/circle).

Source: Twin Cities NWS

Perfect 'Burbs Weather:

So, what does a weather guy do on his night off anyway?

He gets a great blast from the past.

Thursday evening's weather was perfect for the Suburbs show out at the Minnesota Zoo. If you've never seen a show there, I highly recommend it...what a great venue.

The 'Burbs put on a great show Thursday night. It was the first time I had seen them since I booked them as the Band Chair for Macalester Springfest days back in the ...um...early 80s. Great show guys!

Image Credit: Paul Huttner-MPR News

Once in a "Blue Moon:"

This could be the weekend where something (good?) occurs that only happens "once in a Blue Moon."

Image: www.moongiant.com

At 8:58PM CDT the "Blue Moon" will be full and rising n the eastern sky. This is the 2nd full moon in August. What makes a blue moon? Moongiant.com explains.

What is a Blue Moon?

The modern day definition of a Blue Moon is when there are 2 full moons in one Month. A full moon occurs roughly every 29.5 days and on the rare occasions when the full moon falls at the very beginning of a month there is a good chance a Blue Moon will occur at the end of the month. According to this definition the next blue moon will occur on August 31, 2012.

Source: moongiant.com

Blue moons occur on average every 2.8 years. The next Blue Moon is July 31st, 2015...so enjoy the weekend of the "Blue Moon" as we close the books on the Summer of 2012!

PH