Posted on March 17, 2015 by Bob Berwyn
Finding a signal amidst the climate noise isn’t easy
Does La Niña increase the odds of tornadoes?
Study finds links between ENSO and tornado frequency in the Southern U.S. Photo courtesy NOAA.
FRISCO — Teasing out a link between large-scale atmospheric patterns and specific weather events isn’t easy against the backdrop of natural variability.
But a new study of the El Niño-La Niña cycle in the Pacific Ocean suggests that La Niña — the cool phase of the cycle — increases the frequency of tornadoes and hail storms in some of the most susceptible regions of the United States.
During La Niña, both vertical wind shear and surface warmth and moisture increase significantly in the southern states, making conditions favorable to severe storm occurrence.
The study, published in the current issue of the journal Nature Geoscience, may help provide more information for medium- and long-range extreme weather forecasts. Continue reading
Filed under: climate and weather, extreme weather, global warming | Tagged: climate, El Nino, ENSO, extreme weather, La Niña, tornadoes | Leave a comment »
Posted on January 26, 2015 by Bob Berwyn
Will global warming intensify extreme weather swings?
How will climate change affect ENSO?
FRISCO — Global warming could increase the frequency of extreme La Niña events in the Pacific Ocean, with more droughts in southwestern United States, floods in the western Pacific regions and increased Atlantic hurricane activity.
The international study, published in Nature Climate Change, used advanced modeling to show how increased land-area heating, combined with more frequent El Niños, will feed a cycle of extreme La Niñas. Continue reading
Filed under: climate and weather, Drought, El Niño, extreme weather, global warming | Tagged: climate science, El Nino, ENSO, extreme weather, global warming, La Niña | 1 Comment »
Posted on January 6, 2014 by Bob Berwyn
Glen Canyon Dam. Photo via U.S. Bureau of Reclamation.
Arizona researchers to focus on Colorado River flows as feds grant $7 million for 50-plus research projects
By Summit Voice
FRISCO — Arizona-based researchers will lead an effort to pinpoint how global warming will affect Colorado River flows in the coming decades, with an eye toward exploring links between Pacific Ocean climate patterns like El Niño/La Niña cycles and the occurrence of extreme wet or dry conditions.
The two-year study will result in a streamflow projection product that better accounts for physical mechanisms of weather and climate on a regional and local scale, that can be directly used by water resource providers.
The research project is one more than 50 studies funded by grants from the U.S. Department of Interior’s regional climate centers as part of President Obama’s Climate Action Plan to reduce carbon pollution, move the economy toward clean energy sources and begin to prepare communities for the impacts of climate change. Continue reading
Filed under: climate and weather, Colorado, Colorado River, Drought, extreme weather, global warming | Tagged: climate change, Colorado River, Department of Interior, ENSO, Environment, global warming, Sally Jewell | 1 Comment »
Posted on November 22, 2013 by Bob Berwyn
NOAA’s winter outlook offers little relief for Arizona, New Mexico
By Bob Berwyn
FRISCO — Drought conditions may persist across the southwestern U.S. this winter and may redevelop across the Southeast, according to the seasonal outlook from NOAA’s Climate Prediction Center.
“Even though we don’t have La Niña, the atmosphere across the Pacific seems to be stuck in a La Niña mode … It’s been quite surprising to us, how persistent the pattern is,” said Mike Halpert, acting director of the Climate Prediction Center.
Parts of the Southwest, especially New Mexico, have been experiencing one of the driest periods on record, and Halpert said there is “decent agreement” in the CPC’s models on the climate signal that has resulted in the persistent trend. Continue reading
Filed under: climate and weather, Drought, El Niño, La Niña | Tagged: climate, Climate Prediction Center, drought, El Nino, ENSO, La Niña, Southwest, winter weather outlook | 2 Comments »
Posted on September 13, 2013 by Bob Berwyn
Study shows how external influences shape Pacific weather patterns
New research may help show how global warming will affect El Niño.
By Summit Voice
FRISCO — By studying coral samples from a remote Pacific atoll, Australian researchers say they’ve found evidence that external influences can change the intensity of the periodic El Niño cycle. By extension, they said, human-caused global warming could also alter the pattern, though the observational record is too short to determine whether that’s already happening.
The research was led by scientist with the ARC Centre of Excellence for Climate System Science and published in Nature Geoscience.
“Our research has showed that, while the development of La Niña and El Niño events is chaotic and hard to predict, the strength of these events can change over long time spans due to changes in the global climate,” said one of the paper’s authors, Australian climate researcher Dr. Steven Phipps. Continue reading
Filed under: climate and weather, El Niño, global warming | Tagged: climate, El Nino, ENSO, global warming, La Niña | Leave a comment »
Posted on August 24, 2013 by Bob Berwyn
Fall and winter outlook still murky
Seasonal weather forecasters look out to sea surface temperatures in the equatorial Pacific to get an idea of what weather patterns may bring.
Without a stron El Niño or La Niña in the outlook, forecasters are not confident of projecting pronounced temperature or precipitation anomalies.
By Bob Berwyn
FRISCO — With no strong El Niño or La Niña on the horizon, forecasters are struggling even more than usual to develop seasonal outlooks for the western U.S. The periodic El Niño-La Niña cycle is a large-scale shift in the Pacific involving a complex interplay of winds, ocean currents and sea surface temperatures.
In the U.S. the warm El Niño phase is associated with wetter than average conditions in the Desert Southwest and California, and can result in below average precipitation in the Pacific Northwest.
La Niña, on the other hand, has been linked with Southwestern drought conditions and heavy precipitation in the Pacific Northwest. That persistent moist flow off the northwestern Pacific can also favor parts of Colorado with good winter snows, but the ENSO climate signal is more marginal in Colorado than in other areas. Continue reading
Filed under: climate and weather, Colorado, Drought, El Niño, La Niña, seasons, Snow and weather, Summit County snow and weather | Tagged: climate, Colorado winter snow, El Nino, ENSO, La Niña, seasonal forecast, weather | Leave a comment »
Posted on July 15, 2013 by Bob Berwyn
Early warning could help regional preparedness efforts
A new climate model could help project El Niño conditions a year in advance.
By Summit Voice
FRISCO — Forecasting the emergence of El Niño well in advance has long been a goal of climate scientists and a team of German researchers say they may have devised a model that extends the lead time to a year.
Published recently in the Proceedings of the National Academy of Sciences, their paper describes how the model uses high-quality data of air temperatures as the basis for making long-term projections about El Niño, a warm phase of a periodic Pacific Ocean cycle that affects climate and weather around the world.
“Enhancing the preparedness of people in the affected regions by providing more early-warning time is key to avoiding some of the worst effects of El Niño,” said Hans Joachim Schellnhuber, director of the Potsdam Institute for Climate Impact Research, who co-authored the paper with Josef Ludescher, of Justus-Liebig Universität Giessen. Continue reading
Filed under: climate and weather, El Niño, La Niña | Tagged: climate, climate projections, El Nino, ENSO, Hans Joachim Schellnhuber, Potsdam Institute for Climate Impact Research | Leave a comment »