Sunday, August 9, 2009

Paul's Saturday Close Encounter with a Tornado



This is what I saw from my Tonka Bay dock Saturday evening around 8:30 pm. After glancing at the Doppler radar (on my laptop) I mentioned to no one in particular "this crap seems to be blowing up directly over our heads." We live in a 1930s-built home in Tonka Bay, with a great view to the west/northwest, toward Mound. I ran down to the lake, and I could tell this was no ordinary thunderstorm. The cell was spinning wildly, a classic mesocyclone. Under the "lowering" cloud base I could see little wisps of white, looking like smoke, forming, dissipating, re-forming.

And then the tornado itself became more apparent. At about this time the sirens went off, my kids came running down from the house "Dad, KARE-11 says it's forming right over Mound - do you see anything?" Sure enough, those unconfirmed reports are now CONFIRMED! They too saw the developing tornado over Mound, moving rapidly toward Long Lake. I will provide more Doppler images shortly, and I want to upload the (spinning mesocyclone) video to YouTube for everyone, but in the meantime here are a couple of still pics of the Mound/Long Lake tornado.

Paul Douglas
Tonka Bay, MN

Mound Tornado. Looking toward the west/northwest from our dock in Tonka Bay. Note the lowering wall cloud, which was spinning very noticeably. The RFD (rear flank downdraft) is approaching from the left of the screen (the southwest) with heavy rain/hail to the north/northeast of the tornado. This is the 3rd tornado I've seen, but the FIRST here in Minnesota (both the others were in Oklahoma). It was all a bit surreal, but I'm glad I grabbed my camera and RAN down to the dock when I did!

Mound Tornado #2. The tornado kept "pulsing", trying to gain momentum and circulation, it took a little while to get its act together, at one point not looking terribly organized. But all the ingredients were there - extreme instability, wind shear, dew points in the 70s; all we needed was for something to break the cap (the warm lid acting as a brake on severe thunderstorms) and that's what happened, VERY RAPIDLY to the west of Lake Minnetonka yesterday evening, between 8 and 8:30 pm.

NWS Doppler around 8:30 pm, at roughly the same time the tornado was forming near Mound. The classic "hook echo" is hard to miss - on radar the suspicious cell looks like the number "6". You can also see the warning "path", the polygon defined by the NWS. Warnings no longer encompass an entire county. Too many people were being warned, needlessly. In an effort to refine the warning process (and "cry wolf" less often) the NWS meteorologists began drawing high-threat areas, polygons that outline the area that is MOST likely to see severe conditions in the short term. The system is a definite improvement - I'm looking forward to a day, coming soon, when your Internet-enabled plasma/LCD TV will turn on warning information only for the specific neighborhood homes in the path of a tornado, down to the city block. That seems to be where all this is heading: warn fewer and few people unnecessarily, get the warnings in front of the people who NEED to see them!

The severe cell pushed east, still maintaining the "hook" appearance as it plowed across Long Lake into southwestern Plymouth. Yes, you see a T-storm like this moving in, with high dew points and a tornado watch in effect - time to high-tail it to the basement!

Damage reports from the National Weather Service. The red marker is for the Mound-Long Lake-Plymouth tornado. Green markers show large hail, blue dots show straight-line wind damage. For a complete rundown of all the individual severe weather reports click here.

National Damage Report from SPC for Saturday, August 8. It would appear that the only tornado that formed over the U.S. developed in the west metro of the Twin Cities.

Breathing Easier. You won't have to spend quality time in your basement today, curled up in the fetal position while furiously sucking your thumb and crying for 'mamma. No, an advancing cool front has shoved the main storm threat south & east toward Madison, the Dells and Chicago. A few isolated strong/severe storms may still sprout over far southeastern MN, probably south/east of St. Paul.

Weather Headlines

* Tornado outbreak in the Twin Cities metro area late Saturday. Hardest hit communities: Long Lake, Plymouth area - hundreds of homes damaged, trees down, many still without power (tornado details below).

* 3.06" of rain at MSP the last 2 days, nearly a month's worth of rain since Friday morning!

* Cooler, more stable air arrives today with pop-up instability cumulus, but no late-day T-storm outbreak expected. Expect highs in the low 80s, west/northwest breezes at 10-20 mph.

* Dry week on tap. No significant, widespread rain expected Monday through Thursday.

* Storms arrive Friday and Friday night, should dry out (and heat up again) Saturday.

* Next Sunday: late-day T-storms may complicate outdoor plans, most of the day looks dry, warm, humid with morning/midday sun giving way to increasing PM clouds.

* Making up for lost time....Get ready for a (stinking hot) hot week, low 90s by Wednesday, highs well up into the 80s to near 90 ever day from Tuesday through the end of this week.

Paul's Outlook for the greater St. Cloud area

Today: Partly sunny, breezy, cooler and less humid. Winds: W/NW 10-20. High: 82

Tonight: Clearing, turning cooler, more comfortable. Low: 62

Monday: Plenty of warm sun, a beautiful summer day. High: 84

Tuesday: Sunny and dry - great golfing weather. High: 86

Wednesday: Hot and humid, the sun should be out most of the day. High: 93

Thursday: Still sunny, still very warm. High: near 90

Friday: Showers and storms in the area, unsettled. High: 84

Saturday: Steamy again with tropical sunshine, very humid. High: near 90

Sunday: Sunny start, increasing PM clouds, late-day T-storms. High: 85

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