Thursday, May 6, 2010

Payback Time

Top 10 Late Season Snowfalls. I can only imagine how thrilled Minnesotans were on May 20, 1892, when the Twin Cities was blanketed under 3" of snow. If we do get 1-2" of slush we'll wind up on the Top 10 List. What a great honor huh? Source: National Weather Service. To read more (if you have the stomach) click here.

Dark Anniversary. Yesterday marked the 45 year anniversary of Minnesota's worst tornado outbreak. Five monstrous tornadoes swept through the western and northern suburbs of the Twin Cities, four of them large, violent, long-lasting F-4 twister with winds estimated at over 200 mph. 13 Minnesotans lost their lives, 683 people were injured, the death toll might have been several orders of magnitude higher had it not been for live, blow-by-blow accounts on WCCO-AM radio, which did an exemplary job keeping listeners informed. The National Weather Service had warnings out on all the tornadoes - they did an incredible job as well. A great summary of a very difficult chapter in Minnesota's weather history is here.

While we were skipping through March and April, not a meteorological care in the world, the atmosphere was brewing and brooding, waiting. In my weather career I've come to respect nature, realizing full well the fact that there is no such thing as a free lunch. Beautiful weather, the stuff of postcards and laughter on the beach is - usually - followed by spells of foul weather. It's the natural order of things, the cyclical nature of weather. You can't sustain (indefinitely) the good times, or the bad. It's the ying and yang of weather.

Thursday Almanac. The clouds thinned, the sun made a brief, cameo appearance, but temperatures were on the cool side, a high of only 45 at International Falls (a taste of the chilly Canadian air surging south), 56 at St. Cloud and 54 in the Twin Cities, already .04" of rain at Redwood Falls by 7 pm Thursday.

We just enjoyed the warmest March and April in modern-day records, an incredible spell of 60s and 70s, a spell of remarkably sunny days that would make the Chamber of Commerce proud. Did you really - honestly - think we'd sail right into summer without any payback? For the last 60 days I've been living with a nagging low-grade fever, a sense of dread I just couldn't shake, waiting for the other shoe (or boot) to drop. Well, it's here. The good news: the atmosphere will be warm enough for mostly-rain through the evening hours - the BULK of the precipitation will fall as rain. By Friday evening enough cold air will filter south out of Canada to turn rain over to snow, from north to south, across the great state of Minnesota. It will probably snow for 4-8 hours Friday night, and there is a GOOD chance you will wake up to 1-2" of slush Saturday morning, maybe 3" northern suburbs.

May - or March? Here is what the most reliable model (NAM) is predicting in terms of accumulating snow - about 1-3" by Saturday morning, heaviest amounts north metro. My hunch: 1-2" of slush for most of us between 10 pm tonight and 6 am Saturday morning - but again, it will be GONE by midday Saturday.

Continuity. The models are all predicting a changeover from rain to snow by tonight, as the lowest mile of the atmosphere cools down to near 32, a stiff north wind blowing at 15-25 mph. It could be a slushy, icy mess after midnight, although ground temperatures are still relatively mild, snow will probably melt on contact until after midnight. Be careful if you're out late tonight, roads may become slushy and slick late.

Deep breath. The good news: whatever snow falls will be mostly-gone by 10 or 11 am Saturday morning. By mid afternoon the pain (of May shoveling) will vanish, a dull ache - as the sun comes out, temperatures poke above 50, puddles begin to dry up. Sunday looks better (for mom) with enough sun for low 60s, enough sun for a respectable tan (or burn). Only in Minnesota can the same person who shoveled snow on a Saturday - wind up with a painful sunburn one day later. Good grief. We must be living in a different weather-universe.

F-F-F-Frost! Yes, those beautiful daffodils and tulips popping up in your garden may freeze their buds off by Saturday morning, temperatures very close to freezing. If in doubt cover them up (newspapers, canvas or plastic) or bring them indoors, if that's an option - I don't think we'll see a widespread freeze, but a frost is likely, especially northern suburbs.

We get a brief break over the weekend, in-between storms, before the next surge of southern moisture arrives next week, another 1 to 1.5" of rain by Tuesday and Wednesday of next week. 30.3% of Minnesota (eastern third) is in a moderate drought - if this keeps up, if the storm parade continues and accelerates, some towns could go from drought to flood in the span of a few weeks. Amazing.

An End To The Drought? Nearly 1" of rain falls tonight, spiked with wet snow tonight. We get a break from Saturday through Monday, before the next storm dumps another 1 to 1.5" of rain next Tuesday and Wednesday. Your lawn/garden will be in very good shape within 1 week, moisture coming in the nick of time for spring planting.

So the drought is doomed. Farmers are happy (about the spring rains FINALLY arriving). Saturday morning may trigger a mix of gasps, screams, (expletives) and a lot of very excited kids. Anyone who truly loves snow may get a charge when they look out the window. Take a few photos - any snow on the ground will be fleeting (sun as high in the sky as it was back in early August). Looks like we're about to make national headlines (for all the wrong reasons). The national media just can't resist a "snow in May in Minnesota" story. That's catnip for the networks. Watch, wait and see.

How To Build a Time Machine. Stephen Hawking has some specific ideas on how to go back in time, or maybe forward in time, if you so choose. I'm working on a mock-up of a time machine in my garage right now. My wife thinks I'm nuts! The story is here.

African Ice Cap Splits: Global Warming Blamed. Some strange things are happening on the summit of Africa's second highest peak, in Uganda. The ice cap is roughly 1/4 as big as it was in the 1950s. The story is here.

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

Today: A cold rain - raw. Winds: East 10-20. High: 45

Friday night: Rain changes to snow, 1-2" slush by morning (2-4" far north metro, towards Mille Lacs, Princeton and Taylors Falls). Low: 33

Saturday: Slushy, gray start, snow melts by late morning. Some PM sun. Winds: NW 10-20. High: 54

Sunday (Mother's Day - don't forget!) Partly sunny, springy again. Winds: SE 5-10. High: 63

Monday: Mostly cloudy, showers possible late. High: 57

Tuesday: Steadier, heavier rain likely. More wet snow late up north? High: 56

Wednesday: Mostly cloudy, windy and cool. High: 56

Thursday: Milder with intervals of sun. High: 62

No comments:

Post a Comment