(Winter Storm Watch posted for the immediate Twin Cities). I'm updating this hourly as new data arrives. Latest NAM/WRF prints out 2" of liquid - if precipitation were to fall as all snow that would translate into 15-20". No, I don't think we'll see that much, ground temperatures are still relatively mild (snow will melt on contact for the first few hours tonight & Saturday morning), but the odds of at least 4-8"+ for much of the metro area has gone up, based on the latest model guidance.

I still think there will be some rain/sleet mixing in on Saturday, which will keep amounts down a bit, but many towns west of Minneapolis may wind up with 8-10" of slushy snow by Sunday morning, 4-8" for much of the immediate metro, closer to 2-4" east metro, only 1-3" far western Wisconsin. Yes, another day, another utterly impossible weather forecast. Can you believe it was 68 F. just two days ago? And now some towns (west of MSP) are faced with the possibility of 10" of heavy, wet snow.

A few headlines: the farther west you go in the metro area, the better the odds of a significant pile of snow by Sunday morning. Chaska, Medina and Elk River stand a much better chance of 5-10" snow than Stillwater, Woodbury or Shoreview, where final amounts may be closer to 2-3". A cold rain will mix with the snow, especially east of the Twin Cities, for part of the day on Saturday, helping to keep amounts down (a little). Closer to Delano, Willmar, Monticello and Glencoe the storm could be mostly snow. If it doesn't mix with rain or sleet, final amounts to our west could be closer to a foot.

Could anything go wrong with this storm? Absolutely. If the storm veers closer to the metro, takes a track farther west, more rain would mix in, and final snow amounts would come down. This thing is for real - and we all know how it takes 1 or 2 storms for Minnesotans to remember how to drive on snow, right? Thank goodness this is coming on a Saturday, when most of us can sit back, watch it snow (with one eye on college football).

Travel slowly improves Sunday as we dig out from the slush - another chance of a couple inches of slushy snow next Tuesday from a clipper. Maybe this La Nina thing really will amp up the snow this season? Yep, we're due for an "average" winter. More on the storm in the blog, along with a look at how unusual 4 days higher than 60 is in early November, the Atlantic hurricane season is getting longer, is water the new oil of the 21st century, and an ode to "Mad Men", which seems appropriate on a day like today. There's going to be considerable madness in the WeatherNation Weather Center. Stay tuned for updates - as new data arrives we'll keep updating the videos and the Star Tribune weather blog.

Things to consider:

1). Filling up your vehicle with gas. Not expecting any gasoline shortages, but the added weight of a full tank of gas can help with traction.


2). If you have rear-wheel drive consider throwing a few bags of salt/sand in the trunk. This will put more weight over the rear tires and help you get around tomorrow.


3). Stock up on Antifreeze and blue juice for your windshield.


4). If you haven't already done so - consider staking the driveway (so the guy with the plow doesn't chew up your lawn).


5). If you have the option: travel this evening (just a cold rain) or wait until Sunday afternoon/evening. I expect the interstates to be wet/slushy tomorrow - you WILL be able to get around, but it's going to be slow, and we all know it takes one or two storms before Minnesotans regain their confidence in wintry weather.


6). Ground temperatures are still warm (about 45-47 F). That means snow will melt on contact at first (helping to keep final snow accumulations down a bit). I expect interstates and major state/county highways to be mostly wet/slushy tomorrow, but after dark Saturday evening (5-6 pm) those wet roads will start to become icy as temperatures slip below 32 F.


Sun Setting On Autumn. Thanks to WeatherNation meteorologist Bay Scroggins for snapping this photo of the sun setting over Lake Hiawatha, with a vivid "sun dog" visible to the right of the sun, caused by white sunlight being refracted (bent) through millions of tiny, prism-like ice crystals suspended 25,000 feet above the ground. Yes, it was an amazing autumn, a Super-sized Fall this year. But the sun is now as high in the sky as it was the last week of January. That has implications for our weather, as we're all about to discover within 36-48 hours.



Winter Storm Watch Posted. The NWS has issued  a watch for the entire metro area - west to St. Cloud. A watch means a potential for 6" or more of snow in a 24 hour period. I have a hunch the NWS may upgrade this watch to a warning by this evening. Think twice about driving late tonight through Sunday morning. Roads are going to become snow-covered and very slippery, with the worst travel conditions coming Saturday night, as temperatures dip below 32 F and wet/slushy roads turn to ice. If you have to travel this weekend, try to leave this evening, and wait until Sunday afternoon/evening to attempt the drive back into the Twin Cities metro area.



Go Big Or Go Home. First accumulating snow of the season - how 'bout a cool foot or more for much of the Twin Cities metro? Here is the latest NAM/WRF solution, strongly suggesting 8-12" of slushy, wet snow, while suburbs east of St. Paul pick up 3-6". Each run gets more and more impressive. Could this storm still blow up? Yes, but the odds of not seeing at least a plowable 4"+ accumulation are small, and getting smaller with each passing hour.



Ripe Track For Snow. I saw the latest projected path of the storm (from NOAA's NCEP) and chills went up my spine. If this verifies (and it's looking increasingly likely) this would be a nearly perfect track for heavy, wet snow in and around the Twin Cities. The big question: will there be enough warm air in the lowest mile of the atmosphere to keep most of the precipitation falling as a cold rain on Saturday? As time goes on each computer run is colder (and snowier), the track probably far enough east to insure mostly-snow. The latest model run keeps the lowest mile of the atmosphere < 32 F. for MOST of the day Saturday and Saturday night, meaning more snow than rain. A little rain/sleet will probably mix in from time to time, keeping total snowfall totals down (a little), but I don't see how we wind up with anything less than 4-6", and I have a strong hunch the west metro may pick up closer to 8-12". See the projected track for yourself here.


Why can't a forecast ever be black or white? Confidence level is now moderate to high (the models are all coming into alignment): the NAM/WRF is agreeing with the GFS and a few other models tracking the storm farther east, meaning a more rapid changeover to snow Saturday, implying heavier amounts of accumulation in and around the metro area. This may wind up being one of the 2 or 3 biggest snowfalls of the entire winter season. And to think, on paper it's still "autumn." Was it really almost 70 2 days ago?




"Skew-T" Here is a cross-section of the atmosphere, valid 5 pm Saturday. The line going straight up is a "sounding", a temperature plot throughout the entire cross-section of the atmosphere above the Twin Cities. To get (all) snow temperatures have to be consistently below 32 F - even a thin layer of air warmer than 32 F. can trigger a changeover to rain. The models are hinting at wet snow mixing with rain late morning Saturday, but temperatures during the afternoon are forecast to warm (ever so slightly) - to just above 32 throughout the lowest 2,500 to 3,000 feet of the atmosphere - which SHOULD mean rain mixing in with the snow. Then again - it's a VERY close call and I'm nervous. The air overhead will be rising rapidly Saturday - which can cool the air, which could be just enough to tip precipitation over to (mostly) snow, especially western suburbs. Bottom line: we're right on the edge - and if the temperature winds up being 1-3 degrees colder overhead, much of the metro could wind up with 5-10" of snow.That is still a very distinct possibility (although I'm leaning more toward 1-2" east suburbs, 2-4" downtowns, with as much as 4-8" far western suburbs, from Chaska, Delano and Excelsior to Medina, Rockford, Elk River and the greater St. Cloud area. There could be a 10" difference in snowfall totals over the span of 50 miles.


Omen Of What's To Come? Check out an impressive "quad-camera-split" approach to covering "breaking weather news" in Regina, Saskatchewan - where it's finally starting to look like winter. The YouTube clip is here.



Unusual November Warmth. From the local Chanhassen office of the National Weather Service: "Many communities across the area saw 60° or warmer from Sunday through Wednesday.  These readings were 15° to nearly 25° above normal in places.  This has been one of the latest four-day stretches of 60° weather in the Twin Cities.  Since 1938, a four day period of 60° or warmer weather had happened in November only seven times in Minneapolis (once every decade or so).  Just last year had five days in a row hit 60° during the same week, from November 6th through the 10th.   The average last 60° day in the Twin Cities is November 6th." More details on why it was so warm - for so long - in this post from the NWS.



Wednesday Warmth. September-like warmth swept northward into the Upper Midwest the first half of the week, boosting temperatures 20-30 degrees above average for the second week of November. The Twin Cities registered a record-setting 68, but there were dozens of records highs (and record warm nighttime mins as well). Click here for an interactive map, courtesy of Ham Weather.


Offshore System Will Stir Up Wind And Big Surf. A major nor'easter has stalled off the coast of New England, whipping up some 30 mph. winds and 8-13 foot seas. The fact that this storm has stalled MAY have an impact on our weekend storm here in Minnesota. It (vaguely) reminds me of the Halloween Superstorm, where "The Perfect Storm" stalled off the coast of New England, causing our storm to stall over Lake Superior, prolonging our snow, piling up over 27" of the white stuff over 3 days. No, I'm not  predicting 27" of snow this weekend - but any time systems slow down and stall meteorologists get even more nervous. The story is here.



Scientists Discover Unknown Lizard Species At Lunch Buffet. Yes, it's one of the stranger headlines I've stumbled upon recently on the web, but scientists made a striking discovery recently -- at a lunch buffet in Vietnam. The story from CNN is rated PG, for pretty gross.




Thursday Recap. Yesterday felt more like fall, no question, but readings were still 5-10 degrees warmer than average. .17" of rain fell Wednesday night as a cool front sailed across town, Thursday highs ranging from 44 at Alexandria to 48 in St. Cloud, 52 in the Twin Cities.


Paul's Star Tribune Outlook for the Twin Cities and all of Minnesota:


TODAY: Gray, PM rain develops. Winds: NE 7-12. High: 43


FRIDAY NIGHT: Cold rain likely. Low: 33


SATURDAY: Winter Storm Watch. Heavy wet snow, mixing with rain/sleet at times. Winds: NE 15-25. High: 36


SATURDAY NIGHT: Periods of wet snow, potentially treacherous travel conditions. Low: 30


SUNDAY: Snow tapers to flurries by afternoon. Travel conditions slowly improve as the day goes on. Total accumulations of 8-12" (west metro) to 2-4" (east metro). High: 38


MONDAY: Intervals of sun, November-like. High: 41


TUESDAY: Clipper arrives, slushy mix late PM? High: 39


WEDNESDAY: Lingering flakes, cold wind. High: 38


THURSDAY: Cool sun, dry sky. High: 36


Our worst fear as meteorologists? #1). Forget to wear pants in front of the green-screen. #2). Miss the EF-4 tornado because you're home having dessert, and #3). Predicting flurries, only to wake up the next morning to a cool foot of flurries. That's why weather-droids (as a profession) tend to overpredict snow. We live in mortal fear of another Armistice Day Blizzard (weather guys in Chicago predicted flurries - we wound up with 18" flurries with 10 foot drifts). 


I can't remember the last time when we didn't have to "worry" about a changeover from rain to snow - a "pure snowstorm", no unpleasant additives, like sleet or freezing rain. The bottom line: the closer the next storm tracks to home, the better the chance warmer air will get wrapped up into the circulation, tilting precipitation over to rain vs. snow. The farther east the storm tracks, deeper into central Wisconsin, the greater the odds we'll have enough cold air in place for mostly snow. Bottom line: the rain/snow line will set up VERY close to the Twin Cities Saturday, mostly rain for southeastern MN and the St. Croix Valley, the far west metro (west of Chaska and Medina) may see mostly snow. Some 5-10" snowfall amounts are possible from Mankato and Glencoe to Delano, Willmar, Monticello and St. Cloud. The farther west you travel tomorrow, the better the chance of snow.


Tune in later today as we factor in the latest computer runs - I want to see if there are any trends, any consistency in how the models are nudging the storm track. The most accurate model: the NAM/WRF, is printing out close to 1.7" of liquid precipitation. if that were to all fall as snow we'd wind up with 13-18" of snow in the Twin Cities. I don't think that's going to happen. I think there will be some rain mixing in much of the day Saturday, especially from the downtowns on east toward Stillwater and Red Wing.


Travel conditions will get worse as the day goes on tomorrow. If you're thinking of driving to St. Cloud or Alexandria consider leaving later today, or maybe first thing tomorrow. The worst conditions will be after dark Saturday evening, as temperatures fall below 32 and wet/slushy roads become very icy. I do expect the NWS to issue Winter Storm Watches, possibly even Winter Storm Warnings by this evening. Stay tuned - we'll keep you posted with the very latest right here.


Slushy Possibilities


Rarely is a forecast ever black or white. It's usually some nebulous/frustrating shade of gray. So it is today: events are conspiring to dump a significant amount of snow on much of Minnesota; some towns could easily see a "plowable" snowfall of 5-10". The question: where will the heavy snow band set up? The most reliable model, the "NAM/WRF", keeps the lowest mile of the atmosphere above 32 F, hinting at a cold rain much of Saturday, maybe a couple of sloppy inches of slush at the tail-end of the storm Saturday night & early Sunday. Other models take the storm farther east, keeping us in the "cold sector", implying a faster changeover to snow. Ugh. Bottom line: confidence level is low. I want to see a few more model runs; see if there is continuity & consistency before going too far out on a (shaky) limb.


Right now the best chance of 5-10" comes from Mille Lacs & St. Cloud to Monticello, Willmar, even Mankato. A jog of just 50 miles in the storm track could make the difference between a cold rain & a cool half foot of slush. Time to stake the driveway and get serious about snow tires. Next week will feel like November; no mega-storms brewing for Thanksgiving week right now.



Is Water The Oil Of The 21st Century? As the atmosphere continues to warm rainfall is becoming more sporadic and unpredictable across much of the planet - most of the supercomputer simulations show an increase in the frequency and intensity of drought in the decades to come. Something many of us take for granted - water - may become even more precious, especially across Asia and Africa. An interesting video from CNBC is here.



Atlantic Hurricane Season Is Getting Longer. Is it a glitch, an aberration, or a trend? Jeff Masters, in his excellent Wunderblog post, has some very interesting observations: "It seems like there have been an unusual number of early and late season tropical storms and hurricanes in the Atlantic in recent years. In 2008, we had four named storms in July, and the second most powerful November hurricane on record. Both 2007 and 2005 had rare December storms, and 2003 featured Tropical Storm Anna, the first April tropical storm ever recorded. This year, Hurricane Tomas made 2010 the fourth straight year with a November hurricane, something that has never occurred in the Atlantic since accurate records began in 1851."




Rapid Warming Boosted Ancient Rainforest. From an interesting article at nature.com: "Most scientists have assumed that, as carbon dioxide levels increase and the Earth warms, plant species diversity in the rainforests will start to dwindle, with plants unable to adapt to the heat. But a new study suggests that the opposite may be true. In the past, rising atmospheric carbon dioxide and higher temperatures actually drove the evolution of far greater numbers of new rainforest plant species than were wiped out."




Climate Scientists Plan Campaign Against Global Warming Skeptics. From an article in the L.A. Times: "The American Geophysical Union plans to announce that 700 researchers have agreed to speak out on the issue. Other scientists plan a pushback against congressional conservatives who have vowed to kill the regulations on greenhouse gas emissions."




EPA Issues Guidelines For Cutting Greenhouse Gases. From an article in USA Today: "Increasing energy efficiency is the focus of the first-ever federal guidelines for reducing greenhouse gas emissions from industrial sources issued Wednesday by the U.S. Environmental Protection Agency. Among the suggestions: replacing dirty fuels used to power oil refineries with cleaner sources and requiring more efficient electricity and energy use with existing power plants to reduce emissions — while not requiring expensive technology upgrades. EPA's new guidance is meant to help states understand how to implement new greenhouse gas reduction requirements while mitigating costs for industry in a bad economy. Most states will use EPA's new guidelines when processing new air pollution permits for power plants, cement factories and other big pollution sources under the federal Clean Air Act."



What? Only AM's 1965-era ad-legend Donald Draper could make the word "what?" into something interesting and memorable. If you're a fan of Mad Men (as I am) you'll like this clip.




Older Post

1-8"? (and that's just across the metro area!)

Newer Post

All Snow (probably no ice/rain). 5-10" expected (potential for a foot western suburbs)