Thursday, July 22, 2010

A "Collapse" of Earth's Upper Atmosphere (and a pretty nice weekend for MN)

A Puzzling Collapse of the Atmosphere's Upper Atmosphere. Hey, don't sweat the T-storms in the forecast later today & tonight, because Earth's "thermosphere" just experienced the largest "collapse" in 43 years, according to scientists. This region of the upper atmosphere (60-400 miles above the ground) always contracts during periods of solar minimums, when there are few sunspots or solar flares, but the magnitude of the recent collapse is 2-3 times larger than anything scientists can explain. There may be a link to elevated levels of carbon dioxide, but right now it's something of a physics mystery. It's a real scientific head-scratcher alright, the details here.

Forecast: Winds + Waves + Oil = Uncharted Waters. An unholy combination, to be sure, but Tropical Storm Bonnie seems likely to pass almost directly over the core of the Gulf oil spill sometime Saturday, landfall somewhere in Texas or Louisiana as early as Sunday. Models keep Bonnie at tropical storm strength, but with Gulf water temperatures in the mid 80s there's still a (small) chance that Bonnie may intensify to hurricane strength before coming ashore. More details on the evacuation of oil workers underway below. Map courtesy of Ham Weather.

"Free Air" Residual moisture and cloud cover left over from a swarm of heavy thunderstorms that swept across southern Minnesota Thursday morning kept temperatures 5-10 degrees cooler than average, only 79 at Rochester (where 1.47" of rain fell). The sun was out longer in St. Cloud, where the mercury hit 80 - clouds kept the Twin Cities cooler, only 75, with .28" before breakfast.

* Slight severe storm risk over far southern MN Friday (best chance of hail/damaging winds south of the Minnesota River). Watches and warnings will probably be issued again later today.

* Showers and storms likely tonight as a weak cool front arrives, locally heavy rainfall amounts.

* Looking a little better for Saturday: wet start, but as winds turn around to the north/northwest skies should clear, with some PM sun likely.

* Pass the Dramamine Saturday: wind will gust between 15-25 mph (from the northwest) with a gradual drop in humidity behind the front.

* Sunday: still the nicer day, plenty of sun, light winds, low humidity.

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

Today: Partly sunny & sticky. Storms possible by evening, a few may be severe, especially south of the Twin Cities. Winds: W 5-10. High: 85

Friday night: Showers and T-storms likely. Low: 70

Saturday: Wet start, a shower early, then partly sunny, WINDY and less humid. Winds: NW 10-20, PM gusts to 25. High: 81

Saturday night: Clearing, more comfortable. Low: 64

Sunday: Mostly sunny and beautiful with light winds and lower humidity. Winds: SE 6-12. High: 85

Monday: Plenty of sun, still very nice. High: 86

Tuesday: Partly sunny, more humidity in the air. High: 87

Wednesday: T-storms, then gradual clearing. High: 83

Thursday: A mix of clouds and sun, probably dry. High: 85

A potentially dangerous tropical storm (Bonnie) is tracking toward the Gulf of Mexico - on a collision course with the oil spill. No idea how that's going to play out for shell-shocked residents of the Gulf coast. Meanwhile much of America is baking through the hottest summer in over a decade, heat indices as high as 105 to 110 from Kansas City to Nashville, Atlanta and Washington D.C.

Record Nation. All those green dots: 24 hour rainfall records. This is a week's worth of records across the USA. Red dots: record highs, yellow dots: record (warm) nighttime lows. I'm impressed with the shear number of records in just one week, 1775 records in all. To see an interactive map with details for each record click here. Data courtesy of Ham Weather, a division of WeatherNation.

Slight Risk. SPC (Storm Prediction Center) has the southern quarter of Minnesota and southern half of Wisconsin in a "slight risk" of severe storms - best chance late afternoon into the evening hours. Most of us will experience a more garden-variety thunderstorm tonight as a cooler front approaches. For the very latest from SPC click here.

Swarm after swarm of severe thunderstorms have formed along the northern fringe of this blast-furnace heat, waves of "MCS" systems flaring up each night, dumping out torrential rains from Iowa into Illinois and the Ohio Valley. The heat-pump high responsible for overwhelming heat has stalled, and so has the stationary front separating 90s and 100s over Missouri from "reasonable" 80s over Minnesota. The main battle-zone has been Iowa, where some farms are still underwater - a few counties have seen THREE times more rain than usual since June 1. Crops are rotting in the fields over southern Iowa - many farmers have been wiped out by these persistent flash floods. Southern Minnesota has been brushed by some of these severe storms, but the the heaviest rains have stayed just to our south. The jet stream, the main superhighway for storms separating hot from cool has been unusually far south, west/northwest winds blowing at speeds as high as 100-125 mph just 8 miles above northern Minnesota, providing more wind "shear", more potential spin for severe storms to form tornadoes, thus the machine-gun fire of numerous tornadoes since June 17. Take your pick: sweltering heat or severe storms? Not sure which I'd rather endure, but there's still no sign of (persistent) 90s advancing north into Minnesota anytime soon.

Thursday Touchdown. The severe storms that rumbled across west central Minnesota Thursday evening dropped a brief tornado 4 miles south of Brandon, west of Alexandria (Douglas County), near Co. Road 7 & 8. There was some damage to a barn and grain bin, no reports of extensive damage or injuries.

Add one more tornado to our list (38 separate torndoes in the Twin Cities coverage area of the National Weather Service since June 17). Thursday evening a brief touchdown near Brandon, in Douglas County (west of Alexandria) damaged a barn and grain bin - no reports of injuries. It turns out the morning rain from an MCS system that dumped 3" rains over far southern Minnesota, just brushing the Twin Cities with morning showers - produced a lingering canopy of clouds that inoculated the southern third of Minnesota from severe weather yesterday. The persistent cloud cover kept us 10-15 degrees cooler than we would have been otherwise - keeping the atmosphere more stable. Farther north and west the sun did break through, creating the instability necessary for a line of severe storms that rumbled into western and northern Minnesota Thursday evening.

Today should be sunnier (highs returning to the 80s) - sticky and unsettled with storms sprouting late this afternoon, pushing east across the entire state tonight. The models are now speeding up this front (again), hinting that MOST of the showers/storms should be east of town by mid morning Saturday. With a north wind pumping drier air into Minnesota we expect a partly sunny sky Saturday afternoon and evening, conditions improving as the day goes on. A weak bubble of high pressure should treat us to a beautiful Sunday with less wind, highs in the upper 70s to low 80s with comfortable humidity levels for late July.

Nothing controversial brewing, no Dog Days (that I can see) looking out 10-15 days. We're escaping the worst of the heat gripping America, and for that I guess we should be grateful. Hey, things are looking up! Only a small severe risk later today, most of the rain falls tonight (when we're snoozing), we probably dry out faster than expected tomorrow, and Sunday may wind up being the stuff of postcards. Not bad at all for the last week of July.

Waiting for Bonnie. The flotilla of BP oil ships and workers has already begun an evacuation from the Deepwater Horizon well - if Bonnie's winds strengthen to the 50-70 mph range by Saturday waves may reach 10-20 feet. The impact on the oil (at water level and under the surface) is unknown, but a counterclockwise circulation around the storm center could (in theory) push some of the oil AWAY from the Louisiana and Mississippi coast - out into the central Gulf. Nobody really knows, because this has never happened before. A story focused on storm preparation is here.

Largest-Ever Tornado Study Ends. Vortex2 is winding up, the armada of meteorologists, tornado researchers and equipment focused on surrounding tornadic storms and trying to gain a better understanding of how and why they form. MSNBC has a good overview and recap here.

How To Predict An Earthquake With a Doughnut. I know - sounds strange, but seismologists in California are using a "doughnut technique" to try to predict the Big One. A recent swarm of smaller tremors has some experts worried - the story is here.

IBM Global Commuter Pain Index Measures World Traffic Congestion. Think your commute is bad? I'm not sure we know what how bad "BAD" can be. Beijing gets top honors, followed by Mexico City - the worst city in the U.S. (not surprisingly) is Los Angeles, followed by New York and Houston. Using computers to simulate and predict traffic is increasing - a fascinating story here.

Climate Stories
More Records. Torrential Fairbanks, Alaska? A new 1 hour rainfall record was just set at Fairbanks. Alaskans are reporting more thunderstorms - farther north than they've ever been observed before in previous generations - more evidence that the climate is warming, shifting weather patterns farther north.

Global Warming Raises Water Shortage Risks in a Third of America's Counties. More than 1,100 counties in the U.S. (about a third of the USA's counties) face the specter of water shortages by mid century as the atmosphere continues to warm up and dry out. I was surprised to see a few of Minnesota's counties on the list - the story in USA Today is here.

* You Can't Explain Away Climate Change. The editorial in the L.A. Times is here.

* "Weather Bane". We haven't heard from the inimitable Senator Inhofe from Oklahoma lately. That's odd, considering Washington D.C. is baking, must of America is experiencing record heat, June was the warmest month (globally) since records were first kept in 1880, the 4th consecutive month of record warmth worldwide. Inhofe built an igloo mocking Al Gore in front of the U.S. Capital after a particularly nasty snowstorm, but now that much of the planet is running a low-grade fever - not a peep from his office. His website is still railing about "climategate", the hacked e-mails that supposedly implicated every single climate scientist on the planet in a sinister, global conspiracy. Click here to read more.

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