June 12, 2008
Recent Months Wettest On Record In Missouri
Farmers impatiently awaiting the next chance to get back into their wet fields likely won’t be shocked by the latests news. The past six months mark Missouri’s wettest December-May period on record, according to a University of Missouri Extension climatologist with the Commercial Agriculture program.
Precipitation across the state averaged just over 30 inches from December 1 through the end of May. Since 1896, precipitation during this period has averaged 18.72 inches, said Pat Guinan. The previous record was the six months ending in May 1973, which saw 29.21 inches of precipitation.
The southern two thirds of the state have recorded at least seven inches above the average rainfall for the sixth month recording period, with Wright County taking top honors with 20.49 inches of precipitation above the normal six-month average. Reynolds County was a close second with 20.46 inches and Cape Girardeau had 20.43 inches more rain than the average.
Local farmers may be surprised to learn that northeast Missouri is fairly close to the normal rainfall levels during that six-month recording period over those 30 years.
As a matter of fact, through May, Knox County had 1.5 inches below the average precipitation. Clark County was just 0.07 inches above the average and Scotland County had 2.79 inches more rain than normal.
Already in just over a week in June, Scotland County has recorded more than six inches of rain, including 2.2 inches or precipitation during the severe storms Sunday evening.
Across the state, prodigious rainfall has saturated soil, putting Missouri corn farmers weeks behind schedule in planting, forcing many to consider switching to soybeans or other crops.
According to the National Agricultural Statistics Service, fieldwork was at a near standstill due to another week of heavy rains over most of the State. Some field crops were flooded in the northwest district with topsoil moisture rates at surplus levels across nearly half of Missouri. Spring tillage is still just 78 percent complete, 23 days behind a year ago and over a month behind normal.
The state has also endured more than its usual share of tornadoes. Since January 1, nearly 60 tornadoes have hit Missouri, almost twice the number the state sees in a typical year. On May 10, a devastating twister killed 15 people in Newton and Barry counties, making it the deadliest single tornado to strike Missouri in almost 50 years.
The culprits behind the state’s wet and windy weather include above-normal temperatures in the southern United States and below-normal temperatures in the north. “The larger contrast in air masses provides more opportunity for unstable weather,” Guinan said.
Running between these air masses is the jet stream. During most winters, this high-altitude air current travels across the southern U.S. “This year that has not been the case,” he said. “It’s been a few hundred miles to the north, pretty much running from the central Rockies to the Great Lakes area. That puts Missouri in the storm track.”
The jet stream changed its itinerary thanks to the La Niña phenomenon, a recurrent cooling of surface waters in the equatorial Pacific. (There is also a corresponding interval of higher-than-normal water temperatures, which climatologists call El Niño.)
La Niña has been losing strength since February. Does that mean calmer, sunnier days lie ahead? Climate scientists are confident that the answer is “maybe”: The National Weather Service’s Climate Prediction Center forecasts equal chances of high, low and normal amounts of rainfall in Missouri this summer.
To add insult to injury, below-normal spring temperatures abruptly gave way to above-normal temperatures in many parts of Missouri at the end of May. High humidity has made the warm weather especially oppressive.
“It seems like an early start to summer with the hot and sticky weather that we’re already feeling across a good part of the state,” Guinan said.
The good news, he said, is that the Climate Prediction Center anticipates below-normal temperatures on average from June through August.