Slight Severe T-storm Risk Later Today

I’m having a mild out-of-body meteorological experience. There is snow on the ground and you’re telling me there’s a slight risk of tornadoes later today? What the…Doppler?

Last Friday’s historic (horrific) December tornado outbreak over 5 states is still top of mind. Nationwide, December has brought 3,069 record highs and 14 record lows. A lukewarm autumnal hangover has spilled into the holiday season, setting up an atmospheric clash later today. According to NOAA’s Storm Prediction Center there is a slight risk of severe T-storms, with the best chance of straight-line wind damage and isolated tornadoes (!) south of the MSP metro this evening. I pray to God I don’t see a snow-nado. More like a slush-nado after the recent thaw.

Good grief.

Half an inch of rain may fall before temperatures plummet tonight, with northwest winds gusting over 40 mph.

Highs hold in the 20s and 30s from tomorrow into next week with dribs and drabs of snow. Models hint at a cosmetic snowfall Christmas Eve. Even with 50s today I expect a white(ish) Christmas 2021.

Severe T-storm Warnings by Month/Year
Iowa Environmental Mesonet (IEM)

First December Severe Storm Warnings in the Modern Record? Since 1986 the Twin Cities office of the National Weather Service has never issued a severe storm warning for the MPX coverage area. That may change later today.

Wednesday Future Clouds/Precipitation

December Squall Line. Although surface heating is limited (with snow on the ground!) the dynamics aloft may be strong enough for a line of strong to severe T-storms by late afternoon and evening surging northward out of Iowa. Stay tuned.

Balmy Wednesday, Then Blustery and Colder. After rain, wind and a slight tornado risk over far southern Minnesota today the tables turn and a rush of Canadian air beings temperatures a few degrees colder than normal by Thursday, with seasonably chilly weather into next week (and no sign of big storms into Christmas).

ECMWF Temperatures for MSP
NOAA GFS Temperatures for MSP

Colder and Snowier Last Week of December? Winds aloft are still howling from the west 2 weeks out, limiting how much moisture can ultimately reach Minnesota in the form of snow, but weakened Pacific storms may squeeze out a few inches the week after Christmas.

Dylan Moriarty/The Washington Post

Researchers Ponder Why Friday’s Tornadoes Led To So Many Deaths, Despite Ample Warning. Capital Weather Gang provides reasons why this was no ordinary tornado outbreak: “Despite accurate forecasts and timely warnings, Friday night’s tornado outbreak was December’s deadliest on record. Researchers of many stripes, from engineers and forecasters to social scientists, now face the burning question: Why? Experience from past tornado disasters assures that the answers will be complex and multidimensional, taking months if not years to pin down. But the evidence suggests the timing of the tornadoes, coming in the dark of night, their exceptional intensity and the population density of the region hit were all key factors in the catastrophe — which advanced warning could not overcome...”

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Severe Weather “New Normal”, US Emergency Chief Warns After Tornadoes. has the post; here’s an excerpt: …“This is going to be our new normal,” Deanne Criswell, head of the Federal Emergency Management Agency, told CNN’s “State of the Union” as she did a round of national Sunday morning talk shows before she headed to Kentucky to assess the damage and help coordinate the federal response. “The effects that we’re seeing from climate change are the crisis of our generation,” the FEMA chief added. Criswell warned of the challenge that the United States faces in addressing such severe weather events. “We’re seeing more intense storms, severe weather, whether it’s hurricanes, tornadoes, wildfires,” she said on ABC’s “This Week.” “The focus I’m going to have is, how do we start to reduce the impacts of these events?…”

Graphic: NBC News NOW

How “Goldilocks Conditions” Spawned Rare December Tornado Outbreak. NBC News has a look at the meteorological conditions leading up to last Friday’s historic outbreak: “…The rare December tornadoes that tore through Kentucky, Missouri, Illinois, Tennessee and Arkansas were shocking in their intensity and their timing, experts said. And they were the kinds of violent storms that raise worrisome questions about what extreme weather events may look like in a warming world. “The heat and humidity across the South was pretty uncharacteristic for this time of year,” said Victor Gensini, an associate professor of atmospheric sciences at Northern Illinois University. “I remember waking up, looking at the weather maps and saying, ‘Geez, this looks a lot more like late April than mid-December.’” The unseasonable warmth helped fuel volatility in the atmosphere that can generate strong thunderstorms…”

ABC News

How to Help Tornadoes in South and Midwest. Here’s an excerpt with links on how to donate from ABC News: “…While it continues to assess the damage, Red Cross officials said the organization is accepting donations to help the victims. Anyone interested in helping can log onto or call 800-RED CROSS. Mobile phone users can send a quick $10 donation simply by texting “REDCROSS” to the number, 90999. CARE, the international aid organization based in Atlanta, has provided water, food, shelter, and cash assistance to the families affected by the tornadoes. The organization has set up a donation fund for those services...”

2011 Concord, Alabama file
NOAA National Weather Service

The Real Truth About Tornadoes. How strong is the climate signal? Here’s an excerpt of a recent Op-Ed at “…Research data show that climate change caused by human behavior is fueling more frequent and intense weather, such as extreme precipitation and heat waves — so it’s only natural to wonder if this applies to tornadoes, too. Scientists need more data and time to fully address that connection. That said, some high-profile scientists are misleading the American public about what is, and is not, known about global warming and tornadoes. [Something Is Rotten at the New York Times (Op-Ed)] For instance, University of California, Berkeley, professor Richard Muller argued in a recent New York Times opinion piece that “the scientific evidence shows that strong to violent tornadoes have actually been decreasing for the past 58 years, and it is possible that the explanation lies with global warming.” The honest “truth” is that no one knows what effect global warming is having on tornado intensity. Tornado records are not accurate enough to tell whether tornado intensity has changed over time...”

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US Coast Guard

As Floods Slam More US Firms, $50 Billion Economic Drag Expected. Thomson Reuters Foundation has an analysis: “American businesses stand to lose more than 3 million days of operations from flooding in 2022 and will face worsening economic fallout in the coming decades as climate change fuels ever more extreme weather events, researchers said Monday. Next year’s expected damage, based on estimated trends, translates to a nearly $50 billion annual hit for local economies in cities from Miami to Pittsburgh, according to First Street Foundation, a non-profit group that maps climate risk. In a new study, researchers there took a rare comprehensive look at the expected flood risk to businesses and local economies in the United States – a threat often underestimated amid a focus on flooded homes and family losses. “It’s a whole other dimension of flood risk,” said Jeremy Porter, head of research and development at First Street Foundation...”

Probability of 1”+ Snow Cover on December 25

Dreaming of a White Christmas? Your dreams may come true, depending on where you live, of course. The latest 30-year averages, courtesy of NOAA, show some shifts: “…Minnesota. Maine. Upstate New York. The Allegheny Mountains of Pennsylvania and West Virginia. Practically anywhere in Idaho. And of course, the Rockies or the Sierra Nevada Mountains. These are the parts of the United States where weather history suggests you want to be if you’re looking for the best chance of a white Christmas. This map shows the historic probability of there being at least 1 inch of snow on the ground at weather stations across the United States on December 25 based on the latest (1991-2020) U.S. Climate Normals from NOAAs National Centers for Environmental Information (NCEI). Using those station data, experts interpolated values for all locations in the Lower 48...”

Most of California was in extreme drought or worse in early December 2021.
U.S. Drought Monitor/David Simeral, Western Regional Climate Center

“Zero Day” for California Water? Not Yet, but Unprecedented Water Restrictions Send a Sharp Warning. The Conversation has details: “On Dec. 1, 2021, California triggered headlines heard around the world when officials announced how much water suppliers would be getting from the State Water Project. “California water districts to get 0% of requested supplies in an unprecedented decision,” one headline proclaimed. “No state water for California farms,” read another. The headlines suggested a comparison with the “Zero Day” announcement in Cape Town, South Africa, during a drought in 2018. That was the projected date when water would no longer be available at household taps without significant conservation. Cape Town avoided a water shutoff, barely...”

The map shows land surface temperature anomalies from March 19 to June 20, 2020. Red colors show areas that were hotter than average for the same period from 2003-2018; blues were colder than average. Data from the Moderate Resolution Imaging Spectroradiometer on NASA’s Aqua satellite.
Joshua Stevens/NASA Earth Observatory

Arctic Temperatures Soared to an Unprecedented 100 Degrees in 2020, Scientists Confirm. Washington Post’s Capital Weather Gang has an update – here’s an excerpt: “…Shortly after the temperature spike, researchers determined Siberia’s anomalously warm months, as well as Verkhoyansk’s record-breaking temperature in June, were virtually impossible without human-induced climate change. Climate change made the prolonged heat from January to June at least 600 times more likely; such extended heat in the region would occur less than once in 80,000 years without the observed increase in temperatures. To verify the June record, an international committee of experts conducted a thorough analysis of data, including from European weather forecast models. The group also evaluated information from the Russian meteorological agency on the type of equipment used, quality-checks, calibration of the instrument, monitoring techniques and data from surrounding stations...”

Paul Douglas

“Atmospheric River”, “Bomb Cyclone” and “Snowmageddon”. How Do Scientists Come Up With Weather Terms? Great question. A post at The Durango Herald provides some clarity: “Sierra cement, yellow snow, pineapple express. Haboob, Texas norther, bomb cyclone. They seem like ridiculous terms used to describe a messy bedroom or types of ice cream. But they’re actually weather terms, and meteorologists use them. Sierra cement refers to the heavy, wet snow that often falls on the West Coast. Yellow snow is not urine, but snow turned golden by pine or cypress pollen. And pineapple express is a band in the atmosphere that transports moisture from Hawaii and the tropics to the coasts of the U.S. and Canada. Who develops these terms and how they enter the public lexicon are often murky…”

Looking to Reduce Your Carbon Footprint? Surprise – Your Christmas Tree is Edible. Uh, no. Mental Floss has some important caveats: “…The operative word there is might—not all Christmas trees are edible. As NPR reports, all cypress, yew, and cedar trees are poisonous. And even if your tree is of an edible variety, it may have been treated with pesticides or some other chemical that makes it toxic to ingest. In short, you shouldn’t try to whip up a Christmas tree dish unless you’re positive that yours is a chemical-free spruce, pine, or fir. Once you’ve confirmed that, you can safely begin looking for recipes. A good place to start is How to Eat Your Christmas Tree, a cookbook created by UK-based baker Julia Georgallis and published in October 2020…”

41 F. Twin Cities high temperature on Tuesday.

29 F. average MSP high on December 14.

21 F. high on December 14, 2020.

December 15, 1971: A snowstorm hits Duluth with 10 inches.

WEDNESDAY: Rain, storms – some severe later. Winds: SW 20-45+ High: 54

THURSDAY: Blue sky, chilly breeze. Winds: W 15-30. Wake-up: 23. High: 28

FRIDAY: Mostly cloudy, few flakes. Winds: NE 7-12. Wake-up: 15. High: 23

SATURDAY: Coating or dusting of light snow? Winds: NW 8-13. Wake-up: 16. High: 26

SUNDAY: Partly sunny and brisk. Winds: S 10-20. Wake-up: 14. High: 32

MONDAY: Some sun, stiff breeze. Winds: NW 15-25. Wake-up: 24. High: 28 (falling).

TUESDAY: Mostly cloudy, quiet. Winds: E 7-12. Wake-up: 9. High: 25

Climate Stories…

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CC0 Public Domain

Study: Winter Tornadoes to Get More Powerful as World Warms. A post at caught my eye – here’s a clip: “…The combination of a longer and wider track with slightly stronger winds means some rare winter tornadoes that are killers now will have nine times more the power by the end of the century if carbon dioxide levels continued to rise, according to a study presented at the American Geophysical Union conference Monday. The study, which pre-dates the devastating Mayfield, Kentucky, tornado outbreak, looks at strength and not frequency of big tornadoes as climate change progresses. Not peer reviewed yet, it was presented in poster form as a peak at new research to be published later. “There is a potential for events in the future that are more intense that would not have been as intense in the current climate,” said study author Jeff Trapp, head of atmospheric sciences at the University of Illinois, Urbana-Champaign…”

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From Killer Heatwaves to Floods, Climate Change Worsened Weather Extremes in 2021. has a list of some of the most extreme events of this year: “Extreme weather events in 2021 shattered records around the globe. Hundreds died in storms and heatwaves. Farmers struggled with drought, and in some cases with locust plagues. Wildfires set new records for carbon emissions, while swallowing forests, towns and homes. Many of these events were exacerbated by climate change. Scientists say there are more to come – and worse – as the Earth’s atmosphere continues to warm through the next decade and beyond. Here are some of the events Reuters witnessed over the past year:

February — A blistering cold spell hit normally warm Texas, killing 125 people in the state and leaving millions without power in freezing temperatures.

Scientists have not reached a conclusion on whether climate change caused the extreme weather, but the warming of the Arctic is causing more unpredictable weather around the globe…”

Hold the carbon please…

Zara Party Dresses Are Made From Carbon Emissions. Fast Company reports: “Before it was made into holiday dresses, the silky black fabric used in a new capsule collection from Zara started life as carbon emissions. At a steel mill in China, a startup called LanzaTech uses microbes to turn the factory’s captured emissions into ethanol, something that would usually be made from fossil fuels. The ethanol is then processed into monoethylene glycol, one of the components used to make polyester. Earlier this year, Lululemon announced that it was experimenting with a version of the fabric to make its high-end yoga pants. Inditex, the fashion group that owns Zara, has also been working with the fabric. Zara’s new capsule collection is the first clothing to come to market using the technology. (Because polyester is made from only 20% monoethylene glycol, the new fabric’s climate impact is not eliminated, but it is reduced…”)

Change in favorable tornado days between 1979 and 2020, in days per decade.
Image: Victor Gensini

Tornado Outbreak Offers Climate Warning. Andrew Freedom does a good job of explaining what we know and don’t know – highlighting emerging science regarding attribution. It looks like an apparent south/east shift of traditional Tornado Alley may be a climate signal. Here’s a blurb from Axios: “…Tornado trends, such as a shift in their geographic distribution, and increased variability from year to year, are what scientists expect to see in a warming world, according to Gensini.

  • Projections show an increase in major outbreaks in the mid-South and Southeast in particular, he said.
  • Harold Brooks, senior scientist at the National Severe Storms Laboratory in Oklahoma, who also studies tornadoes and climate change, told Axios that the increase in days with favorable conditions for tornadoes in the South and Southeast already stands out as a climate-related signal.
  • Gensini compared tornado attribution today to the steroids era of baseball. Pinning an individual home run on steroid use is difficult, he said, but in the aggregate the trends are evident...”

Tornado Watches, 2007 – 2017

How the Climate Crisis is Affecting Tornadoes. has a good explainer about “attribution” – how a warming climate may be impacting tornado frequency and intensity: “…When you start putting a lot of these events together, and you start looking at them in the aggregate sense, the statistics are pretty clear that not only has there sort of been a change — a shift, if you will — of where the greatest tornado frequency is happening,” Gensini told CNN. “But these events are becoming perhaps stronger, more frequent and also more variable.” Research by Gensini found that over the past four decades, tornado frequency has increased in vast swaths of the Midwest and Southeast, while decreasing in parts of the central and southern Great Plains, a region traditionally known as “tornado alley.” Some studies also indicate climate change could be contributing to an eastward shift in tornado alley, for instance, resulting in more tornadoes occurring in the more heavily populated states east of the Mississippi River, such as this tornado outbreak…”

Minnesota’s lakes have lost an average of two weeks of ice coverage over the last 50 years as temperatures have risen because of climate change. The loss of ice has wreaked havoc on aquatic life, causing algae blooms, depleting oxygen and making it impossible for some species to survive.

As Winters Warm, Minnesota Lakes Have Lost About Two Weeks of Ice Coverage Over Last 50 Years. Star Tribune reports: “Minnesota lakes are losing one of the main things that makes them special: ice. Winters have warmed to the point that the state’s lakes have lost an average of two weeks of ice coverage since the late 1960s, according to data released Friday by the Minnesota Pollution Control Agency and Department of Natural Resources. The loss of ice has been one of the main drivers of toxic algae blooms, which have shut down lakes across the state, as well as a key reason that walleye, cisco, lake trout and other cold water-loving fish have been struggling and losing territory to species such as bass. “Fish are cold-blooded, and temperature is the driving force to every aspect of their lives, including reproduction and survival,” said Sarah Strommen, DNR commissioner. “Many lakes are becoming unsuitable for walleye and they’re becoming too hospitable for invasive species...”

Source: Minnesota Department of Natural Resources, Chart: Rilyn Eischens, Minnesota Reformer.

Minnesota Winters Trending Milder Over Time. Minnesota Reformer takes a look at all the ways our winters are being transformed – in slow motion: “…Minnesota winters are warming 13 times faster than our summers, researchers say. And although it can still feel never-ending, our coldest season is getting shorter. The growing season is two weeks longer than it was in the 1950s, according to the Minnesota Climate Adaptation Partnership. As overall winter temperatures trend warmer, we’re experiencing fewer days of extreme cold. This chart shows the number of days each year with daily high temperatures below zero in the Twin Cities. Dark blue lines indicate more days below zero, and white lines indicate no below-zero days that year. Since 1900, there have been 24 years in which Twin Cities daily high temperatures never dipped below zero. Nine of them took place between 2000 and 2020, compared to just two such years between 1900 and 1920...”

Climate Central

2021 in Review: The World Promises Change After Another Year of Extreme Climate Disasters. Here’s the intro to a photo-heavy review from Bloomberg: “This will go down as among the hottest of the past 170 years, and the horrors of global warming were on full display. There were deep, possibly permanent drought conditions in some countries, devastating floods in others, and ever-more destructive wildfires. Greek villages burned, riverbanks burst in Germany and Brazil’s farms frosted over. If one heat wave stood out from the pattern, it was in the usually temperate region of North America’s Pacific Northwest. It was also a year of climate breakthroughs, both technological and political. Wind power and batteries kept getting cheaper and better. The proportion of new electric passenger vehicles sold worldwide has now reached 10% of the total, according to BloombergNEF. In Iceland, meanwhile, the largest complex ever built to remove carbon dioxide from the air sprang to life...”