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Climate study explores link between El Niño, the polar vortex and extreme cold outbreaks in Europe

Cold snaps more likely during El Niño winters

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How does El Niño affect weather in Europe?

Staff Report

FRISCO —El Niños don’t just affect anchovy fishermen in Peru and the ski resorts of the Sierra Nevada. The somewhat cyclical variation in equatorial Pacific sea surface temps can shift weather patterns worldwide, including in Europe, which may be more susceptible to extreme cold outbreaks in El Niño years, according to a new study led by a University of Colorado, Boulder researcher.

Other research has hinted at the connection, but the new paper is the first to show that El Niños might be linked with Sudden Stratospheric Warming events, when temperatures high in the atmosphere change radically, affect the polar vortex, a belt of winds that form a boundary between the cold Arctic and the temperate mid-latitudes. Sudden Stratospheric Warming weakens those winds, often leading to outbreaks of bitter cold Arctic air across Europe and possibly the eastern U.S. Continue reading

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Climate: Greenhouse gas buildup ‘loads the dice’ for Southwest megadroughts

Odds of 30-year dry spells increase dramatically as global temps rise

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Green bars indicate wet periods, the larger the bar the more unusually wet. In a similar way, yellow indicates dry and droughty periods. The graph stretches from January 1895 on the left to last month on the right, showing how the cycle of droughts alternating with wet years has changed, with dry years becoming more prevalent.

By Summit Voice

FRISCO — Tree ring records clearly show that the southwestern U.S. experienced megadroughts long before the anthropogenic global warming era. One such decades-long dry spell may have been a factor in the collapse of the Anasazi civilization at Mesa Verde.

But the steady buildup of heat-trapping gases in the atmosphere is loading the dice in favor of another megadrought sooner, rather later, according to scientists with Cornell University, the University of Arizona and U.S. Geological Survey. The chances of a decade-long drought is now at least 50 percent, and there’s a 20 percent to 50 percent chance of a 30-year megadrought.

“For the southwestern U.S., I’m not optimistic about avoiding real megadroughts,” said Toby Ault, Cornell assistant professor of earth and atmospheric sciences and lead author of the paper. “As we add greenhouse gases into the atmosphere – and we haven’t put the brakes on stopping this – we are weighting the dice for megadrought conditions.” Continue reading

Climate: UK study eyes links between global warming, extreme flooding

An extratropical cyclone

An extratropical cyclone spread heavy rain across the UK in February 2014. Visit this NASA website for more.

More coastal damage likely as rising seas fuel storm surges

Staff Report

FRISCO —British scientists aren’t quite ready to say that last winter’s record flooding is linked with human-caused global warming, but in a recent study published in the journal Nature Climate Change, they warned that more coastal flooding is likely as sea level rises. Continue reading

Climate: U.S. average temp cooler than average in July

Hot and cold pattern persists

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The yin and yang of climate, with hot readings in the far West and below-average temperatures the Midwest, along the Atlantic seaboard and the deep south. Map courtesy NCDC.

Summit Voice

FRISCO — A hot-and-cold pattern continued over the continental U.S. in July, with some western states reporting record and near-record warmth, while parts of the Midwest were record cold for the month. Continue reading

Study: Ancient El Niño just as strong as today’s

Archaeologists, ocean scientists team up on detailed study of historic climate cycles in Pacific Ocean

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Study offers new clues to past and future El Niños.

Staff Report

FRISCO — Today’s climate models may not do a very good job of predicting changes in the Pacific Ocean El Niño-La Niña cycle, an international team of  scientists said after studying old seashells that display a distinct history of climate variations.

Understanding how El Niño responds to global warming is significant because the undulating rhythm of warming and cooling waters in the equatorial Pacific is a key driver of weather patterns around the world. Some modeling studies have suggested that ancient El Niños may have been weaker than today’s but the new research suggests they were as strong and as frequent as they are now, at least going back about 10,000 years. Continue reading

Morning photo: Monsoon season!

Misty mountains

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Early morning cloudscape pano near Frisco, Colorado.

FRISCO — For a few weeks every summer, Colorado’s weather pattern experiences a seasonal shift that gives us a taste of the tropics. As big high pressure areas move around, moisture often streams into our mountains from the south, keeping the air moist and temperatures relatively warm at night, since the clouds, or even just the moist air, act as a blanket and prevent the day’s warmth from radiating back into space at night. It may be hard to believe, given how much snow we get in the middle of winter, but our monsoon season is actually the wettest time of year in Colorado. And, of course, it’s one of the best times to snap pictures of dramatic cloudscapes. Continue reading

Is Hurricane Iselle headed for Hawaii?

Forecasters eye “hyperactive” tropical Pacific Ocean

NOAA's GOES-West satellite captured this image of a very active Eastern and Central Pacific, hosting three tropical cyclones (from left to right) Genevieve, Iselle and Julio. Image Credit:  NASA/NOAA GOES Project

NOAA’s GOES-West satellite captured this image of a very active Eastern and Central Pacific, hosting three tropical cyclones (from left to right) Genevieve, Iselle and Julio.
Image courtesy NASA/NOAA GOES Project.

Hurricane Iselle track

The forecast track of Hurricane Iselle shows the potential for impacts to Hawaii.

Staff Report

FRISCO — Meteorologists are keeping a close eye on what they describe as a hyperactive tropical Pacific Ocean, and especially on Hurricane Iselle, which is headed straight toward Hawaii with current sustained winds of 140 mph.

Iselle is expected to weaken before nearing the islands in about three days, but could still be packing a tropical storm-force punch, with winds of 60-60 mph. The Category 4 storm is expected to maintain strength for the next day or so before moving over cooler water and weakening. Continue reading

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