Saturday, January 16, 2010

January Slush, Mush & Rain?

Special Prediction: Between noon and 3 pm today the lights may dim. Timid neighbors will break speed limits getting home from church. Streets will be desolate - deserted by 12:01 pm. Store owners will play Solitaire on their PC's. Rumor has it there's a big football game on Fox. Fingers crossed.

Weather Headlines

* January Thaw lingers today, highs close to freezing statewide.

* Cooler Monday through Wednesday with plenty of sun, good travel conditions.

* Icy mix possible Thursday, just nuisance amounts expected.

* Heavier rain/ice by next weekend. Computers hinting at mostly rain next Saturday, ending as a few inches of snow next Sunday - Monday.

Warm enough for rain next weekend? This is a Bufkit image, a meteorological tool, which (strangely) reads from right to left. If you click on the image and bring it full screen you can see the days of the week at the bottom. This is a predicted cross-section, a slice of the atmosphere, showing significant moisture arriving by the weekend on powerful southerly winds at all levels of the atmosphere. I've circled the 0-line (Celsius), with is 32 F. If you look carefully you can see 32+ temperatures more than 7,000 feet above the ground, hinting at a significant rain event late Friday into much of Saturday. I know, not good news for snow lovers hoping to hang on to the 10" of snow currently on the ground.

Yes, this is real progress. A year ago Friday the high was a crisp -6, after waking up to a hair-freezing low of -30. Yesterday's high of 31 (above) was 13 degrees above average for mid January here on the tundra, and with the sun out it felt like a relative bargain. International Falls soared to 43, shattering the old record of 38 set in 1919.

Predicted temperatures aloft for next Saturday at 1 pm. Temperatures throughout the lowest 5,000 - 7,000 feet of the atmosphere are predicted to be warmer than 32 F, warm enough for rain. This "Skew T" analysis tool suggests a cool-down a week from today; I still wouldn't be surprised to see a "plowable" amount of snow at the tail-end of the storm Sunday PM into Monday, Jan. 24.

A cooler front pushes across the state today, yesterday's mild southwest breeze switching around to the northwest with patchy clouds, a few flurries north. Even so, enough mild air may mix down from a few thousand feet above the ground for a shot at freezing. It looks like a good day for Vikings victory (plan on intervals of sun, slushy roads and temperatures near 30 around noon if you're lucky enough to be holding tickets for the big game). A weak shot of Canadian air follows the frontal passage, highs confined to the 20s for the first half of the new week - but blue sky draped overhead will help. Hey, we're heading into what is (historically) the coldest 2 weeks of the entire year. That's why the forecast of RAIN by the weekend is so odd to me. That's right: R-A-I-N. In fact the GFS model prints out nearly 1" of rain late Friday and Saturday, gradually changing over to wet snow Sunday as temperatures aloft begin to chill down again - maybe a few inches of snow at the tail-end of this next big storm.

Outlook for a week from today. The models are fairly consistent bringing a very wet, southern storm due north late in the week, pulling enough warm air into its circulation for a period of rain late Friday into Saturday, probably changing over to wet snow during the day Sunday. The exact timing is very much up in the air, but heavy rain is possible next Saturday, ending (possibly) as a few inches of snow next Sunday and Monday. Stay tuned....

Rain in mid January is no more a sign of climate change than a string of subzero nights earlier this month disproves the theory that man is (inadvertently, accidentally) impacting our climate. These are examples of WEATHER, not climate. Weather: CNN Headline News (without Nancy Grace, please). Climate is the History Channel. Enough of that, but it is a little strange that the 2010 St. Paul Winter Carnival may kick off with moderate rain and highs in the low to mid 30s. Stating the obvious (which I've become damn good at) our 10" of snow currently on the ground is going to get very slushy, mushy, sloppy and soft. If you want "good" snow try to head out today, or the first half of this week.

The Sportsman's Show is going on - next week it's the Boat Show, sure signs that we will (eventually) enjoy a well-deserved spring here in Minnesota. I just checked out the latest GFS extended 15 day computer outlook - it keeps us in the 20s and 30s through the first day of February. No arctic spankings for the next 2 weeks (but we are undoubtedly moving into a stormier, wetter, weather pattern).

I can't prove this scientifically - I haven't seen a research paper or journal article, but based on anecdotal evidence (just following the weather patterns for nearly 3 decades) it seems that we're seeing less arctic air overall, fewer hours below zero. But the arctic punches that do come screaming south of the border seem to be briefer, and more intense, more fleeting. It may be my imagination, but I don't think so. During the decade from 2000 to 2009 the number of nights with 40 below F. nighttime lows from International Falls to the BWCA was a quarter of what it was in the 1970s, when the winters seemed to be harsher, hanging on even longer. Now we seem to get 2 or 3 brief, concentrated smacks of subzero, but the sheer duration of debilitating cold isn't as bad as it was a generation ago. We'll see if it's a fluke, a blip, an aberration, or a true trend.

So there you go - we hang onto a precious January Thaw today, a few degrees cooler Monday through Wednesday, but skies (and roads) should remain dry. A little mixed precipitation may streak into Minnesota from the south as early as Thursday, but the main event (which will first wreak havoc across southern California, sparking flooding rains, mudslides and rare snow within sight of the Hollywood sign in L.A.) arrives next weekend. The majority of precipitation may fall as rain, but Sunday could get increasingly snowy, sloppy and slippery on area highways, some problems lingering into next Monday.

In the meantime say a prayer for the Haitian people, and stock up on heart-healthy food to last you from roughly noon through 3:30 pm. Rumor has it there's a football game on. We'll see if it really is our manifest destiny this year. The short-term forecast calls for a massive front of purple and gold!

Paul's Outlook for the Twin Cities

Today: More clouds than sun, a few passing flurries possible. Winds: NW 5-10. High: 34

Tonight: Patchy clouds. Low: 19

Monday: Partly sunny, few degrees cooler (still well above average). High: 31

Tuesday: More sun, a bit chillier. High: 28

Wednesday: Clouds increase. High: 27

Thursday: A light mix of wet snow, ice, rain possible - potentially slushy. High: 29

Friday: Overcast, a cold rain possible late, possibly freezing on some surfaces. High: 31

Saturday: Rain and freezing rain, possibly heavy. Significant icing possible. High: 33

Sunday: A changeover back to mostly snow. High: 32

Monday (Jan. 25): Snow begins to taper, potential for a couple inches. High: 28

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