Posted on May 12, 2015 by Bob Berwyn
Western U.S. counties violating current and proposed ozone air quality standards. Map courtesy Jeremy Nichols/ClimateWest blog.
La Niña weather pattern found to contribute to spikes in western ozone levels
FRISCO — Spring ozone formation in parts of the western U.S. appear to be linked with the hemispheric La Niña weather pattern, when the path of the jet stream forces high altitude ozone down to ground level.
After discovering the link, a team of researchers say their findings may help forecast harmful ozone episodes well in advance, which could have implications for attaining the national ozone standard. Continue reading
Filed under: air quality, climate and weather, Environment, La Niña | Tagged: air pollution, air quality, climate, Environment, La Niña, ozone | 1 Comment »
Posted on May 6, 2015 by Bob Berwyn
Heat shifts from Far West to Southeast
Much of the U.S. was warmer than average in April 2015.
FRISCO — Last month ended up as the 17-warmest April on record, with an average temperature for the 48 contiguous states at 53.1 degrees Fahrenheit, making it the warmest April since 2012, according to the new monthly State of the Climate summary from NOAA’s National Climatic Data Center. Continue reading
Filed under: climate and weather, El Niño, extreme weather, global warming | Tagged: April 2015 temperature records, climate, climate change, Environment, global warming | 1 Comment »
Posted on April 19, 2015 by Bob Berwyn
Forecast for wet spring helps ease concerns
A drought donut around Colorado?
By Bob Berwyn
FRISCO — Above-average reservoir storage and forecasts for a wet spring season could help keep Colorado out of drought trouble — even though statewide precipitation has been below average for the entire water year to-date, starting last October. As of mid-March, 40 percent of Colorado was classified as being in severe drought conditions, with only 25 percent of the state drought-free. Continue reading
Filed under: climate and weather, Colorado, Drought, extreme weather, global warming, Summit County snow and weather | Tagged: climate, Colorado, Colorado weather, drought | 1 Comment »
Posted on April 10, 2015 by Bob Berwyn
A dwindling snowpack means increased fire danger. This low spring snowpack in 2012 was followed by a severe wildfire season in Colorado.
‘The next several weeks are going to be critical in terms of precipitation’
FRISCO — Early snowmelt and above-average temperatures have upped the fire danger across parts of the Rocky Mountain and high plains region, federal officials said this week, forecasting a more active wildfire season than last year.
“This year we are expecting an average to above-average fire season,” said Rocky Mountain Area Coordination Center fire meteorologist Tim Mathewson. “A repeat of a 2000, 2002, 2006 and 2012 historic fire season is unlikely at this time; however, the next several weeks are going to be critical in terms of precipitation.” Continue reading
Filed under: climate and weather, Colorado, Drought, Environment, seasons | Tagged: climate, Rocky Mountains, snowpack, wildfire danger, Wildfires | Leave a comment »
Posted on April 8, 2015 by Bob Berwyn
Near-record heat across the West
March 2015 temperatures were near record warm from the upper Midwest to the Pacific Coast. Map courtesy NOAA.NCDC.
FRISCO — March 2015 will go down in the books as the 12th-warmest on record across the contiguous U.S. The average temperature for the month was 45.4 degrees Fahrenheit, 3.9 degrees above the 20th century average and the warmest since 2012. Continue reading
Filed under: climate and weather, Drought, Environment, global warming | Tagged: climate, climate change, global warming, March 2015 U.S. temperatures, National Climatic Data Center | Leave a comment »
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 March 12, 2015 by Bob Berwyn
A NASA visualization of Hurricane Floyd approaching the Florida coast in 1999. Hurricane Floyd formed from a tropical wave moving off the coast of Africa to become one of the largest and strongest Atlantic Hurricanes on record.
Spatial cloud coverage offers clues to tropical storm formation
FRISCO — Closely monitoring thunderstorms over Africa may help meteorologists develop better forecasts for Atlantic hurricane development.
“Eighty-five percent of the most intense hurricanes affecting the U.S. and Canada start off as disturbances in the atmosphere over Western Africa,” said Tel Aviv University Prof. Colin Price, who recently published a new study on hurricane formation in Geophysical Research Letters. “We found that the larger the area covered by the disturbances, the higher the chance they would develop into hurricanes only one to two weeks later.”
Working with graduate student Naama Reicher of the Department of Geosciences at TAU’s Faculty of Exact Science, Price analyzed satellite images of cloud cover to track the variability in cloud cover blocking the earth’s surface in West Africa during hurricane season.Using infrared cloud-top temperature data gathered from satellites, Prof. Price assessed the temperatures of the cloud tops, which grow colder the higher they rise. He then compared his cloud data with hurricane statistics — intensity, date of generation, location, and maximum winds — from the same period using the National Hurricane Center data base. Continue reading
Filed under: climate and weather, extreme weather, tropical storms and hurricanes | Tagged: Atlantic hurricanes, Cape Verde hurricanes, climate, extreme weather, hurricane forecasting, hurricane formation, tropical storms | Leave a comment »