Hard Freeze Saturday
Farewell to Bugs and Ragweed!

Minnesota has experienced tornadoes as early as March 18, 1968; as late in the season as November 16, 1931. The Gopher State has seen tornadoes as early as March 18, 1968 - as late in the season as November 16, 1931. 2015 saw 20 tornadoes in Minnesota; fewer than average. Nationwide it was the 4th relatively quiet year in a row for twisters.
On April 14, 1886 Sauk Rapids was leveled by a massive tornado that left 72 dead. The twister was 800 yards wide; a tornado vortex so big and powerful the Mississippi River was temporarily "swept dry". St. Cloud, which experienced a glancing blow, went on to become the largest city in central Minnesota.
I find it vaguely fascinating that an 1883 F5 tornado resulted in the Mayo Clinic in Rochester. A small 1981 tornado in Roseville was the inspiration behind a "Best Buy" sale that spun up a national chain based in Bloomington.
A silver lining to horrifying tornadoes? Sometimes tragic circumstances have happy endings.
No weather drama brewing, just an inevitable cold frontal passage today. Tomorrow will feel like "football weather"; time to dig out the heavy jackets. Skies clear and winds ease Friday night, setting the stage
for a freeze Saturday morning. A cool, sunny weekend is shaping up; more 60s return early next week. 
Another Gusty Day. The arrival of a colder front puts the squeeze on our atmosphere again today, sustained winds forecast to peak around 20 mph between 2 PM and 5 PM (with gusts over 30 mph at times). Source: Aeris Enterprise.
Hard Freeze Potential. Temperatures in the suburbs are forecast to dip into the upper 20s by 6 AM Saturday morning, possibly long enough for a hard freeze, the best chance of a killing freeze outside the 494/694 freeway.
Canadian High. Although hardly chilling air a 15-20F degree drop in temperature will whip up strong winds today. But winds ease late Friday and Friday night, a clearing sky setting the stage for a frost or freeze by Saturday morning. A strong pressure gradient whips up 15-20 mph winds again Sunday as milder air surges north. NAM data: NOAA.
Getting Closer. The animation above, courtesy of NOAA and AerisWeather, shows accumulated snowfall over the next 10 days; snow showers pushing across the Great Lakes into New England. Ground temperatures are still mild so most of that snow will melt on contact, maybe a few inches for Montreal?
What Hiatus? Warmest September, Worldwide, on Record. Records date back to 1891; here's an excerpt from Japan Meteorological Agency: "The monthly anomaly of the global average surface temperature in September 2015 (i.e. the average of the near-surface air temperature over land and the SST) was +0.50°C above the 1981-2010 average (+0.82°C above the 20th century average), and was the warmest since 1891. On a longer time scale, global average surface temperatures have risen at a rate of about 0.63°C per century..."
Massive El Nino Is Now "Too Big to Fail", Says Scientist. The Los Angeles Times has the story - here's the introduction: "An El Niño that is among the strongest on record is gaining strength in the Pacific Ocean, and climate scientists say California is likely to face a wet winter. “There’s no longer a possibility that El Niño wimps out at this point. It’s too big to fail,” said Bill Patzert, climatologist for NASA’s Jet Propulsion Laboratory in La Cañada Flintridge. “And the winter over North America is definitely not going to be normal,” he said. Just three weeks ago, the National Weather Service’s Climate Prediction Center raised the odds of California getting doused with a wetter-than-average winter..."
Graphic credit above: "Satellite images comparing Oct. 1, 2015, and Oct. 2, 1997, show large areas of white, which indicate high sea levels -- a reflection of high sea temperatures. The images show how this year's El Nino could be as powerful as the one in 1997, the strongest El Nino on record." (NASA Jet Propulsion Laboratory).
2015 Has Been A Year of Record-Breaking U.S. Weather Events. It's a fairly long list - here's an excerpt from Huffington Post: "Catastrophic flooding in South Carolina since last week shattered state rainfall records and shocked longtime residents and officials, who said they've never seen rain so powerful. But it's hardly the first extreme, record-breaking weather event in the U.S. this year. Floods, hurricanes, wildfires and other extreme events are becoming more frequent and more intense because of climate change, experts warn, and that's never been more apparent than in 2015. Here's a look at some of the record-breaking weather-related events that have hit the U.S. this year..."
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The American Cities Most Threatened by Rising Sea Levels. Not a climate model, but actual observations: sea levels are rising - the question is how much more, and how quickly? Here's an excerpt from Mashable: "...The cities of Jacksonville, Virginia Beach, Sacramento and Miami follow New York in terms of the size of the population that could avoid submergence if steep carbon cuts were to take place in the next couple of decades versus a business-as-usual course, according to data provided by the study's authors. In Virginia Beach, for example, the difference between a high and low emissions scenario means the contrast between seeing the entire city submerged under the Atlantic, and only a portion of it reclaimed by the sea. The study raises the possibility that the cultural legacy of cities ranging from New York to Boston to Miami and New Orleans are at existential risk..." (File photo: Andrew Demp, Yale).
America Is Increasingly Dependent on Just Two Crops, and It's Putting Us All At Risk. Quartz has an interesting read; here's a clip: "...In a study published in August in PLOS One, US researchers have quantified for the first time how much species diversity we are losing, due to our focus on major commodity crops—up to 19% in some areas. The danger of a drop in crop species diversity has been recognized for decades now: As farmers plant more and more commodity crops like corn, they’re planting fewer alternatives, leading to a loss in crop diversity, which makes the country’s food supply more vulnerable to problems like pests or climate change..." (Image credit: NebraskaCorn.org).
A Megacity Without Water: Sao Paulo's Drought. TIME has a sobering update on what's happening right now in Brazil, and how other cities may face similar water shortages in the years to come. Here's an excerpt: "The biggest city in the Western hemisphere is facing its greatest water crisis in over 80 years — and climate change is only part of the problem. Millions of residents in São Paulo, Brazil face daily water shutoffs unless the city manages its water better. It is not only a problem of drought. The city of 20 million is plagued by failing infrastructure across the city, and it has been unable to deliver the water it does have to residents in need. Without major changes to the city’s infrastructure and planning, commentators say the crisis is bound to continue..."
File photo above: "View of drought in Rio Jacarei, region of Joanopolis, interior of Sao Paulo, southeastern Brazil, on February 14, 2014. The level of Cantareira System, abastace dam that almost 9 million people in Sao Paulo is in 18.7%, the lowest level since 1974." Photo by: LUIS MOURA/picture-alliance/dpa/AP Images
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Minor Reality Check - Hard Freeze Saturday - Ragweed and Bugs Facing ...