For Litany Of U.S. Cities, 2012 Temperatures Are Unprecedented
JR: Here are two Climate Central pieces on the amazing heat waves that hit the country.
by Andrew Freedman, via Climate Central
Four major heat records fell in a stunning new climate report from 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. Read more