Moisture levels vary greatly across Iowa

Iowa farmers had 5.3 days suitable for fieldwork during the week ending July 22, according to the USDA, National Agricultural Statistics Service. Some farmers had to spend time surveying damage from the tornadoes, high winds and hail that struck parts of the State on Thursday. Regular activities included harvesting hay and applying chemicals.

Topsoil moisture levels across Iowa rated 3 percent very short, 12 percent short, 77 percent adequate and 8 percent surplus. Levels in west central Iowa rated 7 percent short, 89 percent adequate, and 4 percent surplus.

Subsoil moisture levels rated 5 percent very short, 13 percent short, 74 percent adequate and 8 percent surplus. Subsoil moisture levels in west central Iowa rated 3 percent short, 90 percent adequate and 7 percent surplus.

Flood-related nutrient loss and crop damage remain a concern in the northern two-thirds of the state, while subsoil moisture levels in south central and southeast Iowa considered short to very short are nearing 75 percent.

Eighty-eight percent of the corn crop has silked, one week ahead of last year and 11 days ahead of the 5-year average. Seven percent of the corn crop has reached the dough stage, three days ahead of last year and two days ahead of average. Corn condition rated 79 percent good to excellent.

Eighty-one percent of the soybean crop was blooming, with 40 percent of the soybean crop setting pods, five days ahead of last year and six days ahead of the average. Soybean condition rated 76 percent good to excellent.

The second cutting of alfalfa hay reached 86 percent complete, 10 days ahead of average. Drier conditions were favorable for harvesting hay. Hay condition rated 69 percent good to excellent. Pasture conditions declined slightly to 58 percent good to excellent. Cooler temperatures have provided livestock with some relief from high temperatures experienced in previous weeks.

Iowa preliminary weather summary provided by Justin Glisan, Ph.D., state climatologist, Iowa Department of Agriculture and Land Stewardship – A series of fast-moving cold fronts moved across the state on Monday and Tuesday, July 16-17, bringing measurable rainfall to eastern and southern Iowa. Fairfield (Jefferson County) reported 0.59 inches July 16. Lee County observed accumulations between 0.01 and 0.05 inch on Tuesday. Cooler air moved in behind the fronts, bringing below-normal to normal temperatures for the rest of the week.

Average highs were in the low- to mid-80s for much of Iowa, with Oskaloosa reporting the week’s high temperature of 94 degrees on the July 16.

On Wednesday, July 18, a thunderstorm complex moved into the state during the evening hours. Pottawattamie, Fremont and Taylor Counties all reported rainfalls of more than an inch. Thursday was an active day as a strong low pressure system over Minnesota and an attendant warm front draped over central Iowa fired up discrete severe supercell thunderstorms.

There were more than 27 preliminary reports of funnel clouds and tornadoes, with Bondurant, Marshalltown and Pella taking direct hits; these locations reported catastrophic damage and some injuries. The Pella and Marshalltown tornadoes were rated at EF-3, with estimated peak winds at 144 mph; the Bondurant tornado was rated at EF-2, with estimated winds of 115 mph.

The storms sped through Oskaloosa and Ottumwa into Van Buren and Lee Counties, where heavy rain and hail were reported. Widespread measurable rain was also observed in Iowa’s northeast quadrant, with Waukon (Allamakee County) recording 3.03 inches of rain, the week’s highest total.

Conditions calmed on Friday, July 20, as the low pressure moved into Wisconsin through early Saturday morning. Lingering isolated thundershowers brought rainfall to Clayton, Dubuque, and Jackson Counties; Guttenberg reported nearly an inch of rain. Sunday, July 21, was cooler and mostly dry.

Average temperatures were variable across the state, with eastern Iowa up to eight degrees below normal.

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