Weather wise, it was a really bad spring. Now, The National Climatic Data Center confirms it in a report that labels the climatic events of the past few months as among the worst in history.
Never before have we had so many extreme events in one month. What the report pointedly does not address is whether the extreme weather is a sample of worse to come with climate change. Scientists are mixed on that opinion, but many say that that when the greenhouse effect is combined with the natural variability of climate, weather disasters like tornadoes, floods and wildfires will become, well, routine.
Here is the summary of the report -- which is made somehow more dramatic by its terse language -- and two of the charts.
"The spring of 2011, particularly April, brought extreme weather and climate events to many parts of the United
States. Tornadoes, flooding, drought, and wildfires ravaged many parts of the country during the period, and each of
these extremes broke long-standing records and have been compared to the 'worst such cases' in history.
While similar extremes have occurred throughout modern American history, never before have they occurred in a
single month. There were 875 preliminary tornado reports during April alone, and the confirmed number of tornadoes
will approach the all-time monthly record of 542 tornadoes set in May 2003. Record rainfall along the Ohio River Valley, punctuated with snow melt across the upper Midwest, caused record flooding along the mid and lower
Mississippi River, with water levels surpassing the historic floods of 1927 and 1937. Above-normal precipitation and
vegetative growth during 2010, followed by dry and windy conditions the first five months of 2011, created ideal
wildfire conditions across the Southern Plains where millions of acres of land burned. According to the U.S. Drought
Monitor (USDM), the same region experienced Extreme-to-Exceptional [D3-D4] drought following consecutive months that were record to near-record dry.
Across the Upper Midwest rapid melt of an above-average snowpack during late March through mid-April swelled rivers and caused near record river crests along the Red River in North Dakota and Minnesota. Farther east, across
Minnesota and Wisconsin, a significant portion of the snow melt water found its way into the Mississippi River and
moved southward towards the Gulf of Mexico. Meanwhile, the above-average rainfall across the Ohio Valley, combined
with snow melt, caused the Ohio River to swell to near-record levels. At the confluence of the Ohio and Mississippi
Rivers, the above-average water flow of each combined to cause the Mississippi River to crest at record to near-record levels from Illinois to Louisiana, flooding hundreds of thousands of acres. After judicial directives, the Army Corps of Engineers opened spillways and destroyed levees, flooding rural areas to save major population centers and infrastructure.
On a statewide level, during April, above-normal precipitation was widespread across the northern half of the country, while the Southern Plains and Southeast had near- to below-average precipitation. Below-normal precipitation was observed for the previous six months across the southern Plains, exacerbating drought conditions there. At the beginning of May, 73 percent of Texas was experiencing Extreme-to-Exceptional [D3-D4] drought conditions. Texas had its second driest November through April period, third driest January-April, and driest February-April and March on record. The prolonged dryness fueled several large wildfires, which burned 1.79 million acres (0.72 million hectares) nationally during the month, shattering the previous April record."