Dreaming of a white Thanksgiving?

For the record, Sunday’s high in the Twin Cities was a balmy 57, just 2 degrees away from a record high (set in 1998, when the strongest El Nino on record was underway in the Pacific). Rochester, Minnesota reported an amazing 60-degree high – on November 22! We’re less than a month away from the Winter Solstice, when the sun is lowest in the sky, and records are falling, left and right. Yesterday was a bit otherworldly, between the mild temperatures and thick fog, most prevalent just to our east, across Wisconsin. Fog may cause some travel delays again today, a Pacific storm capable of squeezing out a few random (rain) showers today, tonight and tomorrow. Have no fear, the atmosphere aloft will be plenty warm for plain old rain through Tuesday night. But as a secondary jolt of Pacific moisture and energy arrives Wednesday, reinforcing a stalled storm in the upper atmosphere hovering above the Great Lakes, rain will gradually mix with and then change over to wet snow. The latest models are hinting at a couple inches of slushy snow late Wednesday and Wednesday night (the heaviest amounts predicted for southeastern Minnesota, where as much as 3-4″ is predicted). I’m starting to think that Thanksgiving ’09 may be a white one, after all. Whatever snow does fall will quickly melt Thanksgiving day as temperatures rise above freezing, but the more I stare at the maps, the more convinced I’m becoming that this may be one of those 1 in 3 Thanksgivings with at least an inch or more of snow on the ground.

Enough snow to shovel by Thanksgiving Day? The GFS computer model prints out a nice little bulls-eye of accumulating snow over southeastern Minnesota, the heaviest amounts predicted just south/east of St. Cloud and the Twin Cities, where 1-2″ may pile up Wednesday night. It’s starting to look like a white Thanksgiving. BTW, statistics show that roughly 1 in 3 Thanksgivings are “white”, with at least 1″ of snow on the ground at 6 am.



White Thanksgiving? Here is the latest WRF/NMM model output, valid 6 am Thursday morning. The graphic shows accumulated precipitation between 6 pm Wednesday night and 6 am Thursday morning, hinting at some .3 to .5″ precipitation amounts. Assuming a quick 1:10 ratio (1″ of rain = 10″ of wet snow) you could easily envision some 2-5″ snowfall amounts over southeastern MN – IF the computer models are right. Stay tuned.

The good news: any accumulating snow will fall Wednesday night, probably after rush hour (although the precise timing is still in doubt). I predict you’ll be extra-happy you won’t have to wrestle with area highways and freeways Thursday morning – a great day to sleep in ’till the crack of noon, and just ignore the slush outside your window. Friday looks dry for power-shopping, enough sun for an afternoon high near 40. Next Saturday appears to be the nicer, kinder, gentler day of the weekend with fading sun and highs well up in the 40s – probably dry as a weak bubble of high pressure hangs on. Next Sunday could be a different story, a vigorous cold front whipping up snow showers and flurries – another (light) accumulation possible, especially late in the day, after sunset. If you’re planning to fly or drive next weekend I don’t expect any problems or issues Saturday. You may want to leave a little early Sunday, or risk a little slush on area highways after 4 or 5 pm Sunday afternoon. Yep, it’s no secret the weather maps are starting to look more like winter, and, well – stating the obvious: we’re long overdue for a real cold front at this latitude. We’ve been living on borrowed time. By the end of November there will be NO doubt in your mind that the winds of winter are catching up with Minnesota. The weather-honeymoon was nice while it lasted (think about it, November was a piece of cake, weatherwise) but coats, parkas and heavy jackets will stage a comeback within a week or so. With the exception of Wednesday night it looks like a fairly uneventful week. Don’t be shocked if you wake up to an inch or two of slushy, sloppy snow Thanksgiving morning – roads mainly wet after 9 or 10 am. But shopping and after-Thanksgiving travel will not be melodramatic this year – one more thing to be thankful for.

Bufkit “sounding” for Wednesday. This enhanced meteorological tool shows the temperature of the atmosphere overhead Wednesday night, temperatures below 4,000 feet consistently below 32 F, cold enough for mostly snow. The graphic on the left shows a changeover from rain to snow, forecast to take place late Wednesday or Wednesday evening.

Cross-Section of the atmosphere, from now through next Sunday. The green/red regions show the relative thickness of moisture forecast to drift overhead, the 0 Celsius temperature trend takes a downward dip during the day Wednesday, suggesting a changeover from rain to snow. A lack of moisture from Thanksgiving Day into Saturday means a lack of significant precipitation, rain or snow, with temperatures recovering above 40 F. by the end of the week. Get ready for a little midweek snow – we’re due.

Paul’s Outlook for the Twin Cities

Today: Gray and foggy with occasional light showers and sprinkles, unseasonably mild. Winds: SE 5-15. High: 53

Tonight: Still relatively mild with a little light rain and drizzle. Low: 44

Tuesday: A few periods of rain, turning slightly cooler. High: 48

Wednesday: Colder with light rain mixing with, and eventually changing over to wet snow. High: 41 (falling into the 30s by afternoon).

Wednesday night: Wet snow likely, potential for 1-3″ of slush (maybe some 3-5″ amounts for southeastern MN). Low: 30

Thanksgiving Day: Lingering flurries, slushy start, roads mostly-wet after 10 am. High: 38

Friday: Partly sunny, breezy and dry. High: 42

Saturday: Better day of the weekend for travel. Fading sun, relatively mild. High: 46

Sunday: Windy and colder with snow flurries and snow showers – a light accumulation possible by evening. High: 35

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