Much needed rainfall limited farmers to 4.2 days suitable for fieldwork during the week ending July 11, according to the USDA, National Agricultural Statistics Service. There were scattered reports of crops lying flat due to strong winds and hail. Field activities included hauling grain, applying fungicides and harvesting hay and oats.
Topsoil moisture levels across Iowa rated 9 percent very short, 31 percent short, 56 percent adequate and 4 percent surplus. In west central Iowa, topsoil moisture levels rated 8 percent very short, 31 percent short, 60 percent adequate and 1 percent surplus.
Subsoil moisture levels statewide rated 16 percent very short, 40 percent short, 42 percent adequate and 2 percent surplus. Districts in northwest Iowa reported subsoil moisture conditions as 78 percent short to very short while subsoil levels in southeast Iowa rated 87 percent adequate to surplus. Ratings in west central Iowa were 24 percent very short, 49 percent short, and 27 percent adequate.
Widespread precipitation helped with stress on crops and forages. Corn silking or beyond reached 21 percent, two days behind the 5-year average. There were scattered reports of corn reaching the dough stage. Iowa’s corn condition improved slightly to 66 percent good to excellent.
Fifty-six percent of soybeans were blooming, 5 days ahead of the five-year average. Fifteen percent of soybeans were setting pods, 5 days ahead of normal. Soybean condition improved to 65 percent good to excellent.
The second cutting of alfalfa hay reached 50 percent complete, one day behind the 5-year average. Hay condition rated 57 percent good to excellent. Pasture condition was rated 43 percent good to excellent. There was little stress on livestock this past week although a few producers reported some pinkeye in cattle.
Preliminary weather summary provided by Justin Glisan, Ph.D., state climatologist, Iowa Department of Agriculture and Land Stewardship – A welcome shift in the storm path brought much-needed precipitation statewide over the reporting period along with a few days of severe weather. A majority of the state’s reporting stations observed above-average rainfall with parts of southern Iowa measuring amounts from one to three inches above average. With clouds and rain present, temperatures were generally seasonal with cooler conditions in the west; the statewide average temperature was 71.8 degrees, 2.6 degrees cooler than normal.
Clear skies and southerly winds greeted Iowans through Sunday afternoon, July 4, as daytime highs ranged from the low to mid 90s north to mid-80s southeast. After Independence Day fireworks fizzled out during the early morning hours, a narrow line of thunderstorms pushed into north-central Iowa, dissipating by sunrise as morning temperatures dropped into the low 70s. A handful of stations reported rain with Northwood (Worth County) measuring 0.70 inch.
Monday was another warm and muggy day as upper 80s and low 90s were recorded across Iowa; the statewide average high was 90 degrees, seven degrees warmer than normal. A thin line of strong thunderstorms with locally heavy downpours formed across extreme northern Iowa later in the evening before dying out very early on Tuesday morning, July 6. Sioux City (Woodbury County) reported 0.01 inch while Sanborn (O’Brien County) observed 0.85 inch. The first of multiple low pressure systems began moving through Iowa during the day, bringing sporadic thunderstorm activity over Iowa’s northern third.
The low’s attendant cold front swept across the state overnight into Wednesday, providing widespread and locally heavy rain in western Iowa. More than 20 stations reported an inch or more with Manning (Carroll County) observing 2.47 inches. The front continued through Iowa before exiting the eastern border before midnight. Overnight lows were cooler behind the front, from the mid-50s northwest to mid 60s southeast.
Rain totals reported at 7 am on Thursday, July 8, highlighted several pockets of 0.50 inch and more in southern and eastern Iowa with general totals of a few tenths at other stations; Centerville (Appanoose County) and Osceola (Clarke County) both measured totals above two inches. Another disturbance brought severe thunderstorms to northwestern Iowa around midnight with scattered hail reports. Heavy rainfall was also observed in the stronger cells; a small sliver of stations from Plymouth to Carroll counties observed totals above 1.50 inches; Remsen (Plymouth County) dumped out 2.01 inches. Widespread totals in the state’s western half ranged from 0.25 inch to an inch with a statewide average of 0.32 inch.
Showers and thunderstorms continued across central Iowa into Friday morning as a potent low pressure system approached southwestern Iowa. A severe-warned discrete supercell thunderstorm fired over Webster County and raced southeast through the Des Moines (Polk County) metro area before dissipating in south central Iowa. The cell produced golf to tennis ball-size hail from Woodward (Dallas County) to Carlisle (Warren County), shredding tree leaves, snapping corn stalks and defoliating soybean fields along a 70-mile path; Woodward reported three-inch hailstones while an observer in Beaverdale (Polk County) collected 3.25-inch hail.
Additional waves of strong and severe thunderstorms formed throughout the evening in southeastern Iowa and then later in the night over western Iowa, persisting across much of Iowa’s southern half into late Saturday morning. Rain totals from the previous 48-hours were highest in southern Iowa with local amounts of 2.00 to 4.00 inches; Chariton (Lucas County) observed 4.13 inches. Iowa’s northern half saw a gradient from a few tenths of an inch to more than an inch farther south; the statewide average total was 0.91 inch.
As the strong disturbance pushed east, rainfall continued through the day as storms refired in western Iowa, with a stronger line of storms moving into central Iowa during the evening. Stubborn showers sat over southeastern Iowa as the system slowly moved out on Sunday morning, July 11. As with the last several days, beneficial rains were poured out of gauges across much of western, central and southeastern Iowa, generally between 0.25 inch to 1.25 inches. Slow-moving storms in Lyon and Sioux counties brought localized totals above 2.50 inches over 24 hours.
Weekly precipitation totals ranged from 0.14 inch at Waterloo Municipal Airport (Black Hawk County) to 4.80 inches in Adair (Adair County). The statewide weekly average precipitation was 1.89 inches while the normal is 0.79 inch. Rock Rapids (Lyon County) observed the week’s high temperature of 97 degrees on July 5, 12 degrees warmer than normal. Estherville Municipal Airport (Emmet County) reported the week’s low temperature of 48 degrees on July 8, 12 degrees cooler than normal.
