Thursday thaw, how cold will Minnesota get this winter?

Winds of change

Welcome to another free ride on Minnesota's temperature roller coaster this week.

It's all about wind direction when you live in the at 45 degrees north latitude in the middle of the sprawling continent we call North America. No nearby oceans to mute temperature extremes. No major mountain ranges to deflect contrasting inbound air masses. Minnesota is at the mercy of the air masses the prevailing winds blow our way.

In the next few days we'll be reminded just how freely air masses with extremely different temperatures sweep across Minnesota.

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  • 5th sub-zero day so far this winter Wednesday morning at MSP

  • 10 average number of sub-zero days to date at MSP

  • Milder Wednesday afternoon

  • Brief thaw in southern Minnesota Thursday PM

  • Season's coldest air mass surges south this weekend

  • + 12 minutes total daylight gained this week

  • White tailed deer bucks shedding antlers this week (Minnesota Weatherguide Calendar)

Frontal zone

Tuesday's Arctic front sweeps east. A Pacific warm front comes tantalizingly close Thursday. As winds shift from northwest to south at ground level, temperatures respond upward and peak Thursday afternoon. Patchy light snow develops north of the front. Expect another light snowy dusting or two and a some light icing potential as the fronts sweep by in the next 72 hours.

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NOAA

Temperature roller coaster

Check out the NOAA's NAM model temperature loop below. Milder air edges into southern Minnesota Thursday, then the next sub-zero purple blob surges south courtesy of the Canadian Arctic this weekend.

200 112 nam temp loop
NOAA data via College of Dupage

Winter's coldest air mass?

The European (ECMWF) model is often the most aggressive (and accurate) with Arctic outbreaks in winter. I have my doubts we'll get to -20 in the metro as the latest ECMWF output suggests, but 2 to 3 nights with lows between -10 and -16 seem probable Saturday through Monday. Temps struggle to reach zero once again this weekend. February may still have some cold weather tricks up her sleeve, but this could be the coldest air mass of winter.

Real winter. Real volatility. The forecast maps look more like stock futures charts these days.

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Weatherspark ECMWF data

Another "Zone 5" winter?

If we don't hit -20 degrees in the metro this winter, it will be another "Zone 5" winter in the Twin Cities metro core. USDA plant hardiness zones are based on the average annual minimum temperature extreme each year. As you can see from the map below, the Twin Cities is listed as Zone 4, with average expected annual minimum temperature between -20 and -30 degrees across the metro.

200 MN winter hardiness zones
USDA

But looking back at actual temperatures data, 13 of the past 16 winters at the airport have recorded the lowest winter minimum temps warmer than -20 degrees. In other words, 13 of the past 16 winters in the Twin Cities urban core have been "Zone 5" winters. If we manage to avoid dipping to -20 next weekend, it could be another Zone 5 winter for the metro urban core.

Jack Falker is a rose gardener and climate watcher in the Twin Cities area. He's been keeping tabs on winter minimum temperatures in the Twin Cities and several other Midwest locations for the past 55 years. Jack's analysis confirms the trend of rapidly warming winters in the Twin Cities.

CC winter hardiness zones Twin Cities 2015
Jack Faulker

The trend line is obvious, and Jack's assessment that the Twin Cities will soon have regular Zone 6 winters fits with observed climate trends.

Here's an excerpt from his blog, The Minnesota Rose Gardener.

Hi Paul... I read your blog quite often and am a sustaining member of MPR. For several years now, I have been doing 50-plus year statistical analysis on Minneapolis-St. Paul winters and comparing them with winters in other upper-Midwest cities. The results are pretty amazing in that we can see very distinct warming trends developing. And it has become much easier to predict that these trends will continue and that we will see warmer winters going forward. The meteorological winter of 2015-16 began on December 1st and what we are now seeing is exactly what the trend line shows we should expect: temperatures are much warmer than average, an average which itself has been pulled significantly upward over the last 55 years. Below (above) is my chart for the 55 winters beginning in 1961, through 2015, in the Twin Cities. What it shows is that since year 2000, all but three of our winters have been in USDA Zone 5 or higher, even though the USDA continues to rate MSP as Zone 4 (based on data that is now 10 years old). What's most important here is the upward slope of the trend-line, which, as mentioned above, is predictive. What the trend-line shows, if you extend it, is that MSP will be firmly in Zone 6 within the next three or four years.

3rd Minnesota Climate Adaptation Conference January 28th

Here's a great opportunity to learn more about how climate change is affecting all things Minnesota. Minnesota's 3rd Climate Adaptation Conference is January 28th.

A reminder that the third-annual Statewide Climate Adaptation Conference will be held on Jan. 28 at the DoubleTree by Hilton in north Minneapolis. This year's conference is designed for local officials, planners, engineers, natural resource practitioners and others who want to learn more about adaptation strategies that have worked or are being tested in various sectors of our community infrastructure including tribal communities, energy industry, local foods, emergency management, communication (media) and water resources.

We will learn from several major corporations how they are addressing climate adaptation at the morning plenary session and will have a mayor’s panel at lunch to hear from several community decision makers.

New this year is a tools cafe, where you can learn about various tools that are available to communities, as well as a poster session in the afternoon.

solar
U.S. Department of Energy

Climate Change Jobs: Solar boom shows 20 perecent job growth in 2015

On MPR's Climate Cast I've talked many times about the potential economic "moon shot" that the transition to green energy presents. The ongoing solar boom is a clear example of how the transition to clean energy is creating jobs in the climate change sector. Here's another powerful data point on how the solar boom is fueling job growth and reducing emissions at the same time from Bobby Magill at Climate Central.

The U.S. solar power industry continued its hiring spree in 2015, growing nearly 12 times faster than overall U.S. employment.

The solar industry has seen 123 percent growth in employment since 2010, adding 115,000 jobs in that time. Last year, industry employment totaled 208,859, with 35,000 new jobs added in 2015, up from about 31,000 in 2014, according to the annual solar jobs census released by The Solar Foundation on Tuesday.

“Solar is surging,” former U.S. Labor Secretary Hilda Solis said in a statement. “Renewable energy employment is on track to transform our world, helping to lessen our reliance on coal and other polluting fossil fuels.”

The foundation had expected jobs in the industry to grow by 36,000, but it missed that projection. Overall, year-over-year employment growth in the U.S. solar power industry was somewhat flat, growing by 20.2 percent in 2015, down from 21.8 percent in 2014. Growth in 2013 was 19.9 percent, adding 23,682 jobs that year.