Ag Weather Forum

The recently-concluded month of May 2013 was indeed one for the history books on rainfall, temperatures and snowfall. Here is some of the detail that National Weather Service offices posted in the central and northern Corn Belt.

ILLINOIS--

Several locations observed rainfall that was a record, or within the top few wettest May totals. These include: Beardstown 11.44 inches, 2nd wettest May to 1935's 12.74 inches; Galesburg 11.99 inches, a new record--beating the 10.07 inches in 1995; Havana, 11.73 inches, a new record--beating 10.75 inches in 1995; Jacksonville, 9.96 inches, the 4th wettest with the record 12.26 inches in 1935; Peoria 10.41 inches, 2nd wettest to 11.49 inches in 1915; Rushville 10.97 inches, 4th wettest with the record 14.26 inches in 1996; Springfield 10.90 inches, 2nd wettest to 11.81 inches in 1899; Virginia 11.60 inches, a new record--beating 10.66 inches in 1995; Winchester 11.27 inches, a new record--beating 9.13 inches in 1899.

IOWA--

May totals: Cedar Rapids 7.35 inches, 3.20 inches above normal; Burlington 11.50 inches, 6.65 inches above normal; Davenport 8.52 inches, 4.27 inches above normal; Dubuque 7.05 inches, 2.86 inches above normal; Iowa City 7.91 inches, 3.70 inches above normal; Waterloo 10.81 inches, 6.28 inches above normal--the Waterloo record is 11.36 inches in 2004; Des Moines, 7.26 inches, 2.52 inches above normal--the Des Moines record is 11.08 inches in 1996.

MINNESOTA AND WISCONSIN--

Minneapolis-St. Paul 6.24 inches, 2.88 inches above normal; St. Cloud 4.98 inches, 2.03 inches above normal; and Eau Claire, Wisconsin 9.28 inches, 5.82 inches above normal. Eau Claire also had 9.3 inches of snow, by far a record for the month of May.

VERY COOL AS WELL

There are also many references to how cool the month of May 2013 was, especially in relation to the abnormally warm situation a year ago. Temperature averages of around two degrees Fahrenheit below normal are common in the Midwest and the northern Plains.

UPPER AIR PATTERN SIMILAR TO 1993

We have made many references to upper-atmosphere stagnant or blocking high pressure in the far northern latitudes over north-central and northeastern Canada. That feature dominated the upper-air pattern during May, and served to steer the jet stream southward over the Midwest. It was a big factor in allowing the heavy rain systems to form. And, in doing some checking, there was a strikingly similar pattern in place during the summer of 1993, when the Midwest was inundated with flood waters. If and when that blocking high pressure modifies will play a key role in shaping the summer weather pattern.

Bryce

I'm on Twitter @BAndersonDTN

(CZ/ES)