Tuesday, March 30, 2010

Typical Weather (for May 31)

Weather Headlines

* 75 in the Twin Cities Tuesday (in spite of high clouds), 78 reported at Redwood Falls. 80 is not out of the question by late afternoon Wednesday. 70 at St. Cloud Tuesday afternoon.

* More sun today (nicest day of the week?). Expect fewer, thinner cirrus clouds dimming the sun, shot at mid to upper 70s, nearly 30 degrees above "average" across the southeastern half of MN.

* If you were stuck in traffic on an area freeway and a tornado was approaching would you know what to do, where to go? Check out the video clip below from the recent outbreak in North Carolina (8 tornadoes on Sunday evening alone) and see what one motorist (stranded in a traffic jam) did.

* Straight-line winds can be nearly as damaging as tornadic winds. See what happened when straight-line winds swept into an office parking lot in North Carolina (near Charlotte). You can see mature trees falling in real-time, an unbelievable clip of video.

* Things we're following: spiking brush fire threat (although winds today should be lighter, statewide, generally under 15 mph). Ice out coming 1-2 weeks earlier than usual southern and central lakes, 2-3 weeks earlier than average far northern Minnesota.

* New York City mopping up from 4"+ rain. Boston and Hartford have picked up 3-4" of rain, many rivers in New England are out of their banks, most towns have picked up 1 1/2 month's worth of rain in the last 48 hours.

* Shower (opportunity) Friday into early Saturday - Sunday still looks like the nicer, sunnier day of the weekend - potential for more significant rain by next Tuesday (.50"+?)

* Early ice-out in the Ely, Minnesota area. I was interested to hear what famed explorer and good friend Will Steger had to say about this odd, freakish turn of events. See below.

Tuesday Almanac. Check out these highs and tell me what month it is again? These temperatures are typical for May - a high of 75 is the "normal high" for May 31, Memorial Day!

"Paul, I'm enjoying my STAY-CATION!"

"Paul, I couldn't get away for a spring break - thank you for bringing spring break to me!"

I wish I could take credit for this, but then again, meteorologists get blamed for the bad days, the lousy weather, so forgive us if we TRY to take credit for the good stuff. Hey, you'd do the same thing! Yesterday was a minor disappointment, in spite of 75 degree warmth by late afternoon. The cirrus shield (high, thin clouds about 25,000 feet above the ground) was thicker than expected, dimming the sun, taking the edge off what would have been an otherwise extraordinary day. That, and winds, gusting to 31 mph shortly after lunch yesterday. I turned on my air conditioner for the first time - can't remember a year where I needed air conditioning in late March.

Today may wind up being the nicest day of the week, potentially the most pleasant day to loiter outside since September of last year. If the sun stays out for at least 4-6 hours (likely) we should at least see mid 70s. If the sun is out all day we stand a small chance of experiencing 80 degrees...on the LAST DAY OF MARCH! BTW, the record high for Wednesday is 82 in 1986. We may come very, very close.

Today's Highs. The NAM model is predicting highs well up into the 70s across much of central and southern Minnesota. If the sun stays out we could hit 80, more than 30 degrees above average for March 30. Amazing.

A fizzling cool front washes out over Minnesota today, leaving us with patchy clouds (and considerably less wind). It should be a LOT more comfortable out there, winds under 10 mph most of the day, reducing the risk of rapidly-spreading brush fires. Again, the forecast challenge is cloud cover: if we wind up with a few hours of mid and high level clouds we may have to settle for low 70s. Best case? 80+ Pretty extraordinary for the last day of March, when the normal high is 48 (and the record low is -3 in 1923). Deep breaths.

Thick Cirrus Shield. This sounds lame, but it's true: it's very, VERY difficult to predict high, thin cirrus clouds. Yesterday's canopy of ice crystals suspended 25,000 feet above Minnesota was thicker than expected - even so the mercury hit 75. If skies had been bright & sunny we might have come close to 80 on Tuesday! Today should bring patchy clouds, but more sun, in general, and temperatures a few degrees warmer than yesterday.

Showery rains over the Dakotas may spread east on Friday, but right now I can't get too excited about rainfall amounts, models printing out less than .05" of rain - not much moisture or upper-level support for any substantial rain late in the week. The outlook is more promising for Saturday - rain spreading east across Wisconsin, a clearing trend over Minnesota, highs mostly in the 50s to near 60, but dry weather should be the rule statewide. Sunday STILL appears to be the nicer day of the weekend to sweep out the garage, clean up the yard (pick up after your monster-dog - looking forward to that) or just hanging out on the deck or patio.

Models are still suggesting a real storm by Tuesday of next week, although I'll believe it when I see it. The GFS simulation is printing out over .50" of rain next Tuesday-Wednesday, but it's a little too early to get excited - at least not yet. I want to see a few more computer runs, see if there's some continuity from run to run, see if there's some consistency.

Straight-Line Winds. Check out the high winds that struck the Charlotte, North Carolina area late Sunday. About :45 in you'll see trees coming down into the parking lot - the SUV parked in the foreground almost becomes airborne. Remember, thunderstorm exhaust can produce rain and hail-cooled downdrafts and violent "downburst", chilled air spreading out and accelerating to speeds of over 100 mph. at times, capable of damage equivalent to an EF-1 or EF-2 tornado. Video from WRAL in Raleigh is here.

Freeway Nightmare. You're stuck in traffic on an area freeway, and an EF-3 tornado is approaching. Most of the time you can outrun a tornado, drive (at right angles) away from the tornadic storm. But if traffic comes to a halt, or you can't outrun/out-drive the twister you should NOT seek shelter under a concrete bridge overpass. This actually increases the risk of being hit by flying debris. Get out of the car (yes, you will probably get wet, maybe hailed on) - get away from your vehicle (which is likely to become airborne if/when the tornado hits) and seek shelter in the nearest ditch, protecting your head from flying debris. This - statistically - is the safest place to ride out a tornado, if you can't reach a nearby building in time. Remember, at wind speeds over 90-100 mph your vehicle will BEGIN TO MOVE! You don't want to be in (or under) your car or SUV when that happens. You may feel exposed, but a ditch offers the greatest protection. Check out a harrowing video clip from Sunday's North Carolina outbreak (8 twisters in one evening ) here.

Will Steger. Yesterday Will sent me an e-mail, describing a strange turn of events way up north. Here is what he sent me:

Hi Paul,

I am in Ely. The ice on my small lake went out yesterday. The earliest I have ever seen it. That is fine about the article, I am glad you are writing this. Another thing that is new in Ely, I am not scorned as much in the local bars about my effort to educate people about global warming. Many of the locals are not happy about the warm weather ruining their snow mobile season. It is starting to hit home.


Ice Out on Lotus Lake, courtesy of Trishia Frostad. It came about 12 days ahead of schedule, and the Canada Geese seemed very pleased with this recent turn of events.
Paul's Conservation MN Outlook for the Twin Cities and all of Minnesota

Today: Mix of clouds and sun, typical for late May. Winds: SW 8-13. High: 76 (80 not out of the question if the sun stays out).

Wednesday night: Patchy clouds. Low: 53

Thursday: Increasing clouds, still mild. High: 67

Friday: Cooler, cloudier - passing shower or sprinkle (but nothing heavy/sustained). High: 59

Saturday: More clouds than sun, probably dry (rain across Wisconsin). High: 58

Sunday: More sun, a more pleasant spring day. High: 59

Monday: Dry with intervals of sunshine. High: 62

Tuesday: Steadier, heavier rain may develop. High: 58

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