Monday, June 29, 2009
Mostly June with a risk of September
Well there you have it, a typical manic, hyper-active weekend of full-bodied weather in late June, which sort of sums up all the craziness we've enjoyed in recent months. After a rainy start Saturday we were able to salvage some wind-whipped sunshine Saturday afternoon, popcorn cumulus clouds racing across the sky as if on fast-forward. Hail peppered many western counties by afternoon as instability thunderstorms sprouted, quickly dissipating after dark. Today, looking out at WHITECAPS I had to do a double-take. If it wasn't for the canopy of green overhead I would have sworn I'd been transported to late September of even early June. Why the gale-force winds with tropical storm force gusts? Blame an unusually strong storm stalled over the Great Lakes, and a strong contrast air pressure between that "low" and a fair weather "high" draped over the Rockies. Air spiraling into that partial vacuum over Lower Michigan accelerated directly overhead, turning on 20-35 mph sustained winds, with a few gusts above 50 mph. For a time a High Wind Warning had to be issued for the Bemidji area for gusts as high as 60 mph! And not a thunderstorm in sight (just a cold soaking far north, where it must have looked and felt like early April). I saw a few brave boaters wrestling with their pontoons and waverunners, but they didn't seem to be having all that much fun, looking as if they had all made a wrong turn and steered directly into the path of Tropical Storm Fern.
Peak wind gusts observed Sunday, courtesy of the Duluth office of the National Weather Service.
* 76 degree high Sunday, peak wind gusts close to 40 mph.
* .60" of rain fell (officially) at STC over the weekend (most of that coming Saturday morning, but the St. Cloud area is still experiencing a .63"+ rainfall deficit for June. Rainfall so far this month: 3.47" (that compares to 2.8" of rain in the Twin Cities so far this June).
* Windy again today, a few gusts over 30 mph, but rain should remain just to our east, over Wisconsin.
* Mostly-dry, uneventful week, low dew points will reduce the risk of anything severe.
* 4th of July Preview: mostly-dry, mostly-nice, but a few degrees cooler than average. Overall grade for the 3 day stretch: B+ (details below).
From space storms look like giant "comma-clouds", and it's pretty hard to miss the storm spinning up over western Ontario and the Great Lakes, the result of unusually chilly Canadian air spurting south of the border. That storm is nearly stationary, stuck, promising 2 more days of gusty winds (and even some thick cloud cover and rain as close as Wisconsin).
Courtesy of WSI, here are predicted wind speeds for 1 pm today. The yellow-shaded regions of central & eastern Minnesota, as well as much of Wisconsin, should see sustained winds over 20-25 mph much of the day, winds dropping off rapidly farther west across the Dakotas.
Today will be a marginal step in the right direction with SLIGHTLY less wind and enough sun for mid 70s, afternoon gusts still topping 25, even 30 mph. Not a great day for hang-gliding or high-rise window-washing. Patchy clouds may clip far eastern Minnesota, even a little rain from the Minnesota Arrowhead southward to Eau Claire, Menomonie and Wausau, Wisconsin. If you're driving east on I-94 toward Madison you will run into a cold rain and gusty winds.
Predicted weather map for 1 pm today, showing showery rains across the Great lakes and much of New England. Weather systems are in a temporary "blocking pattern", a holding pattern, some would say a rut, but at least we'll be far enough away from the storm to enjoy cool, comfortable sunshine, with humidity levels more like late September than the last few days of June.
Are you a white-knuckle flier? Before your next flight consider checking out this site, where you can get a prediction of expected turbulence at the altitudes most commercial jets fly, between 20,000 and 45,000 feet. This Aviation web site shows a variety of forecasts out into the future; late yesterday it was hinting at moderate turbulence over much of Minnesota (no kidding) with severe turbulence near Denver, which is really quite common over the central Rockies, the result of high-speed (jet stream) winds passing over the uneven peaks of the Colorado Rockies. That's why you often experience a pronounced BUMP on your flight to Vegas or L.A. a little less than halfway into the trip.
Yes, we have a wind theme going today - another NOAA graphic (constantly updating) that shows winds at ground level. The light-blue shaded area displays sustained winds over 15 knots, about 17 mph. To get the latest information click here and then click on "wind streamlines".
Now you know why most of the wind turbines being installed are all in southwestern Minnesota, the wind capital of the Land of 10,000 Weather Extremes. On average the wind blows much faster, and much more consistently south/west of the Minnesota River, especially on a bluff of higher land called the Buffalo Ridge near Lake Benton.
The USA has been called the Saudi Arabia of Wind (among other things) and we happen to live on the edge of the windiest part of our country, stretching from north Texas northward across the Plains into the Dakotas and southwestern Minnesota. The USA just passed Germany as the biggest producer of wind-energy in the world, but as of 2008 only 1% of our total electricity output was provided by wind-power (up from .9% in 1999). A Dept. of Energy study showed that, in theory, wind power from just Texas, Kansas and North Dakota could produce enough wind energy to power our entire nation. Of course there's the problem of modernizing the grid that carries electricity from these vast wind farms to major population centers on both coasts, considerable amounts of new infrastructure will have to be constructed to get the electricity to where it's needed the most, but the potential to harvest this (free) wind energy is enormous. For a great overview of wind power (and potential) check out this article in Wikipedia.
O.K. Please indulge me with just one more graphic. I thought this was (vaguely) interesting. You can see the month-by-month plot of average wind speeds for the USA (green line) vs. St. Cloud (red line). On average, in late June, our average wind speed (averaged over 24 hours/day) is about 10 mph, vs. the U.S. average of 8 mph - not a huge difference, granted. Minnesota tends to be far windier than the rest of the nation during the spring and fall season.
Sorry for the Wind 401 lecture/sermon, but since we're experiencing a spell of unusually windy weather (for summer, at least) I thought that was somewhat relevant. What you really want to know is: "Paul, will I need shorts and t-shirts for the 4th of July weekend, or a boat, flippers and scuba gear?" Great question. This does look like a fairly quiet, dry week of weather across the state, temperatures reaching 80, closer to average, by midweek. Here are a few headlines for the all-important holiday weekend weather:
Friday (July 3): Possibly the mildest day with highs near 80, maybe low 80s over southern Minnesota. A few T-storms may bubble up over far northern Minnesota late in the day ahead of a weak cool front forecast to drop out of Canada. Grade: B+
Saturday (July 4). Weak frontal passage early with a slight chance of a shower/sprinkle during the morning hours, but sun should be on the increase during the afternoon, with dry, more comfortable weather for evening fireworks. Highs in the mid to upper 70s. Grade: B
Sunday: (July 5). A northwesterly flow should set up statewide, resulting in temperatures about 5 degrees cooler than average, mostly mid 70s, maybe a few degrees cooler far north. But the sun should be out most or even all of the day, coupled with low dew points, and a light breeze. Again, more like mid September than early July, but a little free air conditioning on the 5th of July has a nice ring. Grade: A- (the only reason I'm not giving it an A is because some will complain about the cool evening temperatures; lake water temperatures may be warmer than air temperatures Sunday!)
Today: Plenty of sun, still windy, still comfortable with low humidity. Winds: NW 15-30. High: 74
Tonight: Clear and almost chilly for late June. Low: 54
Tuesday: Sunny, still breezy. High: 75
Wednesday: Mix of clouds and sun, a bit milder. High: 78
Thursday: Partly sunny, temperatures close to average. High: near 80
Friday: Hazy sun, slight chance of late-day thunder (more numerous storms far north). High: 81
Saturday (4th): Morning clouds, risk of a shower. Plenty of sun by afternoon/evening. High: 77
Sunday: Cool, comfortable sunshine most of the day, probably dry. High: 75
Monday: Bright sun, light winds. High: 74