Friday, June 11, 2010

Cool & Cloud-Cluttered

So here we are - another weekend - wondering what can possibly go wrong, and what time? Today should be EVEN NICER than last Saturday! Do you remember what happened last Saturday? How can any of us forget - a drenching, soaking, all-day rain that left just about everyone (but farmers) with a daylong scowl. Today will be better, far from perfect, but most of the daylight hours should be dry, with more clouds than sun, the weather slowly souring by late afternoon and evening, with a few hours of showers likely tonight as an "upper air disturbance" drifts across the state.

Odds are we'll all wake up to some puddles Sunday morning, but this wrinkle of chilly air aloft shows no sign of stalling - it should keep on sailing east into Wisconsin, promising intervals of sun by midday and afternoon, a cool north breeze - more like late September than mid June.

Friday Almanac. A stubborn cloud deck kept Minnesota cooler than normal for the 11th day of June, a high of only 56 in grand Marais, 55 in Duluth and 58 up at International Falls. St. Cloud struggled to 71, 76 in the Twin Cities and a balmy 82 in Rochester, on the warm side of the front. Over 3" of rain soaked Redwood Falls and Willmar, a cool .79" in the Twin Cities, .84" at St. Cloud.

"MCS" Mesoscale Convective System. As predicted a smear of heavy thunderstorms rumbled across the state late Thursday night into the early morning hours Friday, squeezing out more than 2" from near Litchfield to Monticello, 2 week's worth of rain in less than 6 hours. This graphic from the National Weather Service (NOAA) web site shows estimated rainfall amounts derived via Doppler radar.

Unsettled Saturday. There may be some fleeting sun during the morning/midday hours Saturday, but the approach of another weak frontal boundary from the Dakotas will push showers into far southern/western MN by late afternoon/evening - the best chance of a few hours of rain, even a clap of thunder, coming Saturday night.

The best chance of spying the sun? Morning and midday hours today, again Sunday afternoon and evening. The farther north/west you travel across the state, the less sunshine on the weather menu - I expect little sun to speak of today over far western MN, where showers may arrive by afternoon. Showers spread into the Brainerd Lakes area by this evening, reaching St. Cloud and metro area lakes Saturday night. Lingering clouds/showers first thing Sunday should give way to a slow drying/clearing trend during the day Sunday, intervals of sun possible by afternoon/evening.

Free Air Conditioning. Mid June? As far as the atmosphere is concerned this weekend will feel more like mid May, highs in the 60s north and central, maybe some low to mid 70s over the southern third of the state. Expect more clouds than sun, but slather on sunscreen anyway - you can still get a painful burn, even with patchy mid and high level clouds. Keep in mind the potential to burn has nothing to do with the air temperature - and everything to do with the date/sun angle. You can get a whopper of a sunburn with highs in the 50s and 60s....really!

Not a spectacular weekend by any stretch - no picture-postcard-perfect blue sky stretching from one horizon to the next, but here is what I can promise (other than sunrise/sunset). It will be COMFORTABLE, temperatures as much as 15 degrees cooler than average by Sunday. Yes, it will be cool for the lake, especially up north on Sunday, in fact lake water temperatures may be warmer than air temperatures! Odd, considering we're a little more than a week away from the summer solstice.

A Few Headlines:

Warmest Day: Today, expect highs in the 70s (60s up north).

Wettest Period: Tonight, as much as 4-7 hours of rain, amounts under .20"

Winds: today: northeast (AM), becoming southeasterly (PM) from 10-15. Sunday: North (10-20), a bit choppy on area lakes.

* The U. of MN's Professor Mark Seeley has an excellent weekly wrap-up of Minnesota weather here.

Weekend weather puzzle (Saturday's print Star Tribune column)

"There is little chance that meteorologists can solve the mysteries of weather until they gain an understanding of the mutual attraction of rain and weekends," quipped Arnot Sheppard. Amen. What I've discovered (the hard way) is this: if the weather turns out better than predicted, that's OK. Acceptable. A "pleasant surprise". But woe unto ye if the weather is WORSE than anticipated; we all lose our sense of humor. Rarely is the forecast black or white, it's usually some nebulous shade of gray. Unless a bubble of high pressure is sunning itself directly overhead there is always a risk of PM, pop-up, instability showers, especially in June, the wettest month of the year.

All hedging aside, this weekend SHOULD be better than last, no all-day wash-outs expected. "Partly sunny" (which means the same thing as mostly cloudy, btw) sums up our expected sky, cloud cover increasing the farther north you go, especially PM hours. Showers are likely statewide Saturday night; a fickle front lifts north Monday, treating far southern MN to a period of rain - latest model runs keep the rain south of the metro area. One thing is certain: you'll need a sweatshirt up north - highs mostly in the 60s, nights dipping into the 40s. No problem keeping your cool!

Flash Flood. Defined as 6" of rain or more in 6 hours or less, flash flooding is a big killer, claiming more lives every year than hurricanes and tornadoes combined. The death toll from the Arkansas flooding is up to 20 - campers were caught totally unprepared by a sudden surge of water coming down a small creek, water levels rising by as much as 20 feet in a couple of minutes. What can you do to lessen the risk when you're camping? Take a NOAA Weather Radio, and program it for the county you're camping in - battery-powered NOAA Weather Radios cost $20-50, and could save your life. Common sense comes into play: keep an eye on the forecast, if you experience sustained heavy rains, move away from any water sources, get to higher ground. If it's pouring for hours on end be proactive, pack up your stuff, and get out of there! USA Today has an update on the Arkansas flooding here, another good overview of what happened here.
Light Show. Check out this YouTube clip from Morgan County, Colorado. Remember: the greater the frequency of lightning (especially cloud to ground) the greater the potential you're dealing with a potential severe storm. T-storms capable of tornadoes and damaging hail are often accompanied by nearly continuous lightning.

* Global Warming Deniers and their Proven Strategy of Doubt. It's deja vu all over again: the perils of smoking, acid rain, the ozone hole, now climate change. A lot of companies have a vested interest in maintaining the status quo - so they've been spending their hard-earned money sowing doubt and uncertainty, and they've been doing a spectacular job in recent months, confusing people with the difference between climate and weather, giving the impression there is still serious doubt and controversy in the scientific community on the topic (there isn't). The science is the science - if people choose not to believe the science, then there's not much to be done. Ideology has trumped logic and science, and I have a bad feeling that it's going to take a series of weather disasters and climate catastrophes before Americans wake up to the reality of what's going on. We've taken a couple of huge steps backward in recent years - I hope we can get back on track before we pass the point of no return. The story is here.

* A Call to Triple U.S. Spending on Energy Research. Bill Gates is a pretty smart guy, you'd have trouble convincing most people otherwise - he believes that climate change is real, and he's putting his money where his mouth is, funding new research into alternative energy sources that don't pump more carbon into the atmosphere. The story in the N. Y. Times is here.

Paul's Conservation MN for the Twin Cities and all of Minnesota

Today: More clouds than sun, still mild. Showers possible far west by afternoon. Winds: NE/SE 10-15. High: 74 (60s north).

Saturday night: Cloudy with showers likely. Low: 58

Sunday: Damp start, clouds giving way to peeks of sun by afternoon - getting better/drier as the day goes on. Winds: N 10-20 (choppy on area lakes). High: 72 (60s north).

Monday: Mostly cloudy - rain probably stays south of Minnesota. High: near 70

Tuesday: Intervals of sun, probably dry. High: 72

Wednesday: Plenty of sun, quite pleasant. High: near 80

Thursday: Feeling more like summer again, partly sunny with a chance of a T-storm. High: 82

Friday: Sticky and warm with more numerous T-storms. High: 84

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