Despite La Nina, US sets 4 Major Heat Records in First Half of 2012
Warmest U.S. Spring On Record: NOAA
Planetark.org, June 8, 2012
So far, 2012 has been the warmest year the United States has ever seen, with the warmest spring and the second-warmest May since record-keeping began in 1895, the U.S. National Oceanic and Atmospheric Administration reported on Thursday.
Temperatures for the past 12 months and the year-to-date have been the warmest on record for the contiguous United States, NOAA said.
The average temperature for the contiguous 48 states for meteorological spring, which runs from March through May, was 57.1 degrees F (13.9 C), 5.2 degrees (2.9 C) above the 20th century long-term average and 2 degrees F (1.1 C) warmer than the previous warmest spring in 1910.
Record warmth and near-record warmth blanketed the eastern two-thirds of the country from this spring, with 31 states reporting record warmth for the season and 11 more with spring temperatures among their 10 warmest.
"The Midwest and the upper Midwest were the epicenters for this vast warmth," Deke Arndt of NOAA's Climatic Data Center said in an online video. That meant farming started earlier in the year, and so did pests and weeds, bringing higher costs earlier in the growing season, Arndt said.
"This warmth is an example of what we would expect to see more often in a warming world," Arndt said.
More long-lasting heat waves, record-high daytime temperatures and record-high overnight low temperatures are to be expected in a warming world, said Jake Crouch of NOAA's National Climatic Data Center.
CARBON DIOXIDE MILESTONE
"And that's what we're seeing," Crouch said by telephone. "We've seen it quite a bit over the last 12 months."
Alaska's spring months were 2.7 degrees F (1.5 C) cooler than average and 10.5 percent wetter and snowier, while drought spread over Hawaii, though exceptional drought was eliminated across the island state.
Warmth was evident in parts of the Arctic in May, where sea ice declined rapidly at first and then more slowly through the month, ending at below average levels for 1979-2000, according to the National Snow and Ice Data Center.
However, there was more ice cover in the Arctic in May 2012 than in May 2011, the center said on Wednesday on its website nsidc.org/arcticseaicenews/ . There was heavy ice in the Bering Sea, but unusually low ice extent in the Barents and Kara Seas.
Another Arctic measurement related to climate reached a milestone this spring, NOAA reported: the concentration of atmospheric carbon dioxide at Barrow, Alaska, reached 400 parts per million, the first time a monthly average for this greenhouse gas passed that level at a remote location.
The level of 450 ppm is regarded by many scientists and environmental activists as the upper limit the planet can afford if global temperature rise is to be kept to within 3.6 degrees F (2 C) this century. Some advocates suggest 350 ppm is a more appropriate target.
The 400 ppm mark for carbon dioxide in less remote locations, such as Cape May, New Jersey, has been reached for several years in the springtime, NOAA said in a statement.
But measurements of carbon dioxide over 400 ppm at remote sites like Barrow - and at six other remote Arctic sites - reflect long-term human emissions of the climate-warming gas, rather than direct emissions from a nearby population center.
The global monthly mean level of atmospheric carbon dioxide was about 394 ppm in April, compared to 336 ppm in 1979, pre-industrial levels of about 278 ppm and ice age levels of about 185 ppm.
Four Major Heat Records Fall in Stunning NOAA Report
Climatecentral.org, June 8, 2012
Four major heat records fell in a stunning new climate report from the National Oceanic and Atmospheric Administration (NOAA) on Thursday. The lower 48 states set temperature records for the warmest spring, largest seasonal departure from average, warmest year-to-date, and warmest 12-month period, all new marks since records began in 1895. While the globe has been tracking slightly cooler than recent years — thanks in part to the influence of now dissipated La Nina conditions in the tropical Pacific — the U.S. has been sizzling.
The average springtime temperature in the lower 48 was so far above the 1901-2000 average — 5.2°F, to be exact — that the country set a record for the largest temperature departure for any season on record since 1895.
Spring 2012 beat 1910, which had held the title for record warm spring, by a healthy margin of 2°F. No doubt much of this was driven by the massive heat wave that gripped the country during March, but unusual warmth continued during April and May, albeit not as intense. Such warming trends are consistent with both the influence of manmade global warming, particularly the prevalence of record warm nighttime temperatures, and natural variability has also favored warmer-than-average conditions so far this year. Studies show that as greenhouse gases continue to increase in the atmosphere, the odds of heat extremes are growing as well.
According to NOAA’s National Climatic Data Center, the spring of 2012 “was the culmination of the warmest March, third warmest April and second warmest May. This marks the first time that all three months during the spring season ranked among the 10 warmest, since records began in 1895.”
Des Moines, Iowa offers a case study of just how warm it’s been. The year-to-date there has averaged a whopping 8 degrees F above average, with many other cities across the country tracking close to that figure as well.
Most of the states that experienced record or near-record warmth this spring were located east of the Rocky Mountains, with 31 states setting records for warmest spring temperatures. Remarkably, not a single state in the lower 48 was cooler than average this spring, and only Oregon and Washington had spring temperatures that were close to average. Although there were exceptions, much of the country had a drier-than-average spring with Colorado, Delaware, Indiana, Utah, and Wyoming coming in with a top 10 driest spring.
The record warmth helped propel the U.S. Climate Extremes Index, which tracks the highest and lowest 10 percent of extremes in temperature, precipitation, drought and tropical storms and hurricanes across the contiguous U.S., to a record-large 44 percent during the March-May period, which was more than twice the average value. “Extremes in warm daytime temperatures (81 percent) and warm nighttime temperatures (72 percent) covered large areas of the nation” were mainly responsible for this record.
Spring was unusual for the pre-season tropical weather, as two tropical storms developed before the official start of the Atlantic Hurricane Season on June 1. Tropical Storm Beryl made landfall near Jacksonville, Fla., on May 28, and brought heavy rainfall to parts of the Southeast that were in the grips of a severe drought. This year marked the third time on record that two tropical storms occurred during May in the North Atlantic Basin.
Major drought has remained elsewhere, though, and drought plus high winds led to ideal conditions for wildfires in the West. The White-Water Baldy Fire Complex in New Mexico, which was the result of two separate fires that combined into a massive conflagration, broke the record set just last year for the largest wildfire in New Mexico history.
