Mellow September Continues (are longer, milder autumns causing fall colors to fade?)
- Blog Post by: Paul Douglas
- September 23, 2013 - 9:48 PM
Faded Fall Colors?
Yesterday an article at The PBS Newshour caught my eye, an interview with a professor of plant physiology who has done research into the impact of warmer fall temperatures in recent decades. His theory? Warmer late-season weather tampers with plant photosynthesis, resulting in fewer "anthocyanins", the colors that remain when the green from chlorophyll fades. One of many ways plants & animals are adjusting to a slow-motion climate transformation.
The Minnesota DNR reports 25-50 percent of leaves have ripened over northern Minnesota; peak color in the metro still about 3 weeks away.
This still looks like a good week to stash the lawn chairs into cold storage, maybe take out the water toys and prepare for the inevitable winter to come. No sign of any frost potential in the Twin Cities until the second week of October, at the earliest.
Highs reach the 70s this week, a shot at 80F Friday before a cooler front sparks thunder, maybe even a welcome spell of steadier rain Saturday. Sunday will be the drier, brighter day of the weekend.
Every day of shirtsleeves from now on is a gift. 75-80F is impressive, considering the sun angle today is identical to March 19.
* BWCA file photo above courtesy of Steve Burns.
.4" snow fell on September 23, 1985 in the Twin Cities. The locals were not happy as I (vaguely) recall.
Fall Color Update. Here's the latest information from the Minnesota DNR, pockets of color up north, where 25-50% of leaves are ripening up now. It's still early to predict how moderate drought may impact autumn color around the state.
Average Date Of First Fall Freeze. A "freeze" is defined as sustained nighttime lows colder than 28F, cold enough to end the growing season. A "frost" falls between 28F and 32F, when some plantlife can still survive. Map above courtesy of NOAA and the MRCC, the Midwestern Regional Climate Center.
Mellow. No atmospheric fireworks brewing, at least looking out 1-2 weeks. Highs reach the 70s every day this week, if there is any sun on Friday we may top 80F in the metro area (not bad considering the average high is in the upper 60s). The best chance of rain: Saturday, then clearing on Sunday and slightly cooler early next week. ECMWF guidance above courtesy of Weatherspark.
Florida Soaking - Retrograding Low For New England. Weather systems usually track from west to east. Every now and then systems stall, even drift west or southwest. Such will be the case across northern New England with a cold rain approaching from the northeast. A stalled front fueled with moisture leftover from last week's "Invest 95" tropical depression will result in more torrential rain for Florida, especially the Tampa area. 84 hour NAM Future Radar product courtesy of NOAA and Ham Weather.
A Tropical Storm's Worth Of Rain? High-resolution HRRR models are hinting at enough rain for serious flash flooding along the west coast of Florida, centered on Tampa - St. Petersburg on Tuesday.
Flash Flood Potential. Our internal models show a potential of as much as 6-9" of rain for Tampa, Clearwater and St. Petersburg, Florida by Tuesday afternoon.
Flooding Already Underway. NOAA has issued a Flash Flood Watch for much of Florida, Flash Flood Warnings reported from Ft. Myers and Sarasota into the Tampa - St. Pete market. Additional "waves" of heavy showers and T-storms may prolong flooding into Wednesday, possibly Thursday.
Rainfall Required To End The Drought. Latest data from NOAA and USDA show anywhere from 2-6" of rain is needed to put a serious dent in the drought - the best odds of this coming in October, as more significant storms drop heavy/widespread rain. In theory. Map: Ham Weather.
Nationwide Perspective. The greatest rainfall deficits are showing up over Texas, Arkansas, northern Missouri and much of Iowa, on west into Wyoming, Montana and Idaho. Pockets of abnormally dry weather are beginning to show up in the Mid Atlantic region; New York City now running a 3.6" rainfall shortage. Bad news for farmers in Central Park.
Blowing Dust. The Twin Cities National Weather Service tweeted out this image, showing the blowing dust that closed portions of I-70 in Kansas on Monday.
2013 Hurricane Season Quiet, But Not Over, Experts Warn. Here's a clip from a good article and explainer from NOLA.com in New Orleans: "...The thunderstorms that make up a tropical cyclone are formed when moist air is rising, so the sinking air is believed to be suppressing development. Compounding the suppression factor are strong upper level winds that are shearing off the tops of whatever thunderstorms do form, he said. "This year's Tropical Storms Chantal, Dorian, Erin and Gabrielle each dissipated when they ran into this environment," Feltgen said. "Several tropical waves coming across the tropical Atlantic in recent weeks (in what's referred to as the Cape Verde season because storms tend to form near the Cape Verde islands off the coast of Africa), ran into these environmental issues and failed to develop any further..."
Graphic credit: NOLA.com, The Times-Picayune.
Supernaturally Quiet Tropics. An unusual amount of subsidence (dry, sinking air) and wind shear over the central and eastern Atlantic may be at least partially responsible for a lack of hurricane activity (only 2 hurricanes so far in the Atlantic - neither affected the USA). In today's edition of Climate Matters we look at the dynamics that form hurricanes, and explain why it's still too early to let our guard down: "WeatherNationTV Chief Meteorologist Paul Douglas goes over some of the recent activity in the tropics or lack thereof. He also shows that just because it's been quiet so far doesn't mean it's time to be complacent."
Typhoon Pabuk Heading North As Usagi Winds Down. Typhoon Usagi brushed Hong Kong will hurricane-force wind gusts early Monday - it's now fizzling into a extra-tropical low pressure system over China, still squeezing out torrential rains. "Pabuk" should pass east of Tokyo, Japan in the coming days. Details from NOAA's Environmental Visualization Laboratory: "Typhoon Pabuk in the northwest Pacific Ocean is moving slowly to the northwest, but is forecast to veer northeast in 48 - 72 hours, skirting the east coast of Japan and picking up speed. The remnants of Typhoon Usagi are over eastern mainland China after coming ashore on Sunday September 22 with winds in excess of 100 mph. This image was taken by MTSAT-2 at 0530Z on September 23, 2013."
The Time The U.S. Military Came THIS Close To Dropping A Nuclear Bomb On North Carolina. I had no idea we came this close to accidently detonating a nuke 250 times more powerful than the bomb dropped on Hiroshima. Slate has the remarkable story - here's a clip: "...A declassified document obtained by author Eric Schlosser sheds new light on the 1961 Goldsboro accident, in which a U.S. Air Force B-52 broke apart in midair over North Carolina, dropping a pair of Mark 39 nuclear bombs on the countryside below. The accident is not news, but just how close the military came to wiping out a swath of the Eastern Seaboard has long been debated. For years the military insisted that the hydrogen bombs were never in danger of detonating. The secret document, written by a nuclear weapons safety supervisor in 1969 and first published by The Guardian today, makes it clearer than ever that was not the case. In fact, three of the four safety mechanisms on one of the bombs were unlocked in the course of the fall. By the time the bomb reached the ground, the only thing preventing it from detonating was a single, simple, low-voltage switch. A short-circuit of that switch as a result of the mid-air breakup—“a postulate that seems credible,” the supervisor writes—could have resulted in mass destruction..." (Image credit here).
Is It O.K. To Watch Football? A violent and dangerous sport? Absolutely. Modern-day gladiators? Possibly. If it's not O.K. to watch football I have no idea how I'm going to spend my weekends between now and early February. But where do you draw the line? What about NASCAR, competitive downhill skiing, gymastics, ice hockey, even Equestrian horseback riding? There are risks everywhere we turn, but this story deals with relative risk, and the potential for debilitating, lifelong injuries. Weighing the various risks, The New Yorker has an article that made me feel a bit guilty rooting for the Broncos and Peyton Manning (on my fantasy football team) last night - here's the introduction: "In the past few years—thanks to a combination scientific study; legal action from current and former players; dedicated reporting; and an increased, though surely belated, openness on the part N.F.L. executives—football fans have been forced to confront something that we already knew from plain sight: the sport is dangerous for the people who play it—for their joints, and bones, and muscles, and, especially, for their brains. The recent settlement between the N.F.L. and thousands of former players or their families, who were suing the league for what they alleged was its failure to inform players about the long-term health risks of concussions and other head trauma, does not resolve the issue for fans..."
* The Top 10 Most Dangerous Sports? Here's a short list from thetoptens.com.
74 F. high in the Twin Cities Monday.
69 F. average high on September 23.
61 F. high on September 23, 2012.
TODAY: More clouds than sun, dry. Winds: S 10. High: 71
TUESDAY NIGHT: Patchy clouds, dry. Low: 50
WEDNESDAY: More sun, very pleasant. High: 75
THURSDAY: Blue sky, warm PM breeze. Wake-up: 56. High: 79
FRIDAY: Summer breeze with a touch of humidity. Late-day T-storm. Wake-up: 60. High: 81
SATURDAY: Periods of rain, cooler. Wake-up: 61. High: 72
SUNDAY: Partly sunny and drier, comfortable with "average" temperatures for late September. Wake-up: 52. High: 68
MONDAY: Plenty of sun, drama-free. Wake-up: 49. High: 67
Could Climate Change Mean A Less Colorful Season? I saw this story on Sunday - thought it was worth sharing on the blog. Here's a video and excerpt from The PBS Newshour: "....And this season may also be the time catch the autumn leaves changing... while you still can. Howie Neufeld, Professor of Plant Physiology at Appalachian State University believes climate change may reduce the effect of the leaves changing colors. In the fall, trees begin to lose their chlorophyll, which gives leaves their green color, and start synthesizing anthocyanins, which give leaves their red color. Orange and yellow colored leaves come from leaves without anthocyanins, which reveal underlying colors as the green from the chlorophyll fades. Neufeld believes warmer temperatures may tamper with plant photosynthesis, resulting in less anthocyanins being synthesized--in short, fewer bright colors in the fall leaves (like those in the video below)..."
Video credit above: Vimeo/Jamie Scott.
Human Role In Warming "More Certain" - U.N. Climate Chief. The BBC reports; here's an excerpt: "Scientists are more certain than ever that greenhouse gases from human activities are heating the planet, the head of the UN's climate panel says. Rajendra Pachauri made the comments in an interview with BBC News. The panel is due to deliver its latest report on the state of the climate later this week in Stockholm, Sweden. Its last report was criticised after an error on glaciers unveiled other flaws, but Prof Pachauri said procedures had been reformed and strengthened. He also dismissed suggestions of a slowdown in global warming. "There’s definitely an increase in our belief that climate change is taking place and that human beings are responsible,” he told me..."
The Hottest Decade On Record, Despite Cooling Influences. Here's an excerpt of a PDF explaining what's really happening from Climate Nexus:
An Important Step On Global Warming. Here's a clip from an Op-Ed at The New York Times: "...The rules would restrict emissions at new natural gas-fired plants to 1,000 pounds of carbon dioxide per megawatt-hour, and at new coal plants to 1,100 pounds per megawatt-hour. Because existing coal plants, even advanced ones, produce about 1,800 pounds per megawatt-hour, industry will find it virtually impossible to build new coal plants without capturing and storing some or all of their carbon emissions — a technology the administration has promised to promote but which has not been commercially demonstrated on a wide scale. New gas-fired plants should easily fit under the new limits because they now produce only about 800 to 850 pounds per megawatt-hour. The rules for new plants are far less costly and contentious than the rules the Environmental Protection Agency is now drawing up to regulate thousands of existing power plants, the ones producing all those emissions..."
Study: Climate Change To Increase U.S. Thunderstorms. In truth, confidence levels about a warmer, wetter atmosphere spawning more severe thunderstorms is not as high as other phenomena (like extreme rainfall amounts). There is still considerable uncertainty. Here's an excerpt from a story at USA Today: "...Deadly and destructive thunderstorms -- and the violent tornadoes they produce -- are forecast to see a "robust" increase across parts of the USA in upcoming decades due to climate change, says a new study published Monday in the Proceedings of the National Academy of Sciences. Springtime severe thunderstorms could increase by as much as 40% over the eastern USA by the end of the century, says lead author Noah Diffenbaugh of Stanford University. The study is one of the first that's found such a link between climate change and severe storms. Most previous research has been inconclusive..."
Magical Climate Contrarian Thinking Debunked By Real Science. The Guardian has the story - here's an excerpt: "One of the most important concepts to understand when trying to grasp how the Earth's climate works, is that every climate change must have a physical cause. This principle was the basis of our new paper, Nuccitelli et al. (2013). Over the past century, climate scientists have developed a solid understanding about how the climate works and the physical mechanisms that cause it to change. By building that knowledge into complex climate models, scientists have been able to accurately reproduce past observed global surface temperature changes. It's not sufficient to say global warming is the result of "a natural cycle" – which cycle is causing the change? For example, is it due to the Earth's orbital cycles around the Sun, which operate very slowly over periods of thousands of years? Is it changes in solar activity, which has on average remained flat and even declined slightly over the past 60 years? Is it ocean cycles, which shift heat between the oceans and air, and don't cause the Earth to accumulate more heat?..."
Climate Change: IPCC Issues Stark Warning Over Global Warming. Here's a clip from an article at The Guardian: "...Extreme weather events, including heatwaves and storms, have increased in many regions while ice sheets are dwindling at an alarming rate. In addition, sea levels are rising while the oceans are being acidified – a development that could see the planet's coral reefs disappearing before the end of the century. Writing in the Observer ahead of the report's release, the economist and climate change expert Lord Stern calls on governments to end their dithering about fossil fuels and start working to create a global low-carbon economy to curtail global warming. Governments, he states, must decide what "kind of world we want to present to our children and grandchildren..."
Image credit above: "
© 2013 Star Tribune