Provided by Justin Glisan, Ph.D., State Climatologist, Iowa Department of Agriculture and Land Stewardship
Unseasonably cold conditions blanketed Iowa during the reporting period with negative departures of up to 20 degrees across northwest Iowa. The statewide average temperature was 36.0 degrees, 14.3 degrees below normal. Drier-than-normal conditions were also observed across Iowa’s northern three-quarters with above average snowfall reported across southern Iowa.
A broad area of low pressure continued to push through Iowa on Sunday (12th) with several waves of showers and thunderstorms bringing measurable rainfall. The highest totals were observed along a narrow band stretching from Dallas County northeast to Winneshiek County. Gusty northwest winds built in as the low finally exited Iowa early Monday (13th) morning. Nearly 50 rain gauges had totals at or above one inch with a report of 1.75 inches in Des Moines (Polk County). Totals east and west of the band were generally under 0.50 inch with the statewide average of 0.55 inch. Partly cloudy skies and colder than average conditions were reported across Iowa behind the low, with a few snowflakes observed in west-central Iowa. Highs stayed in the 30s statewide with overnight lows in the teens across the northwest to the mid 20s across the rest of Iowa. On Tuesday (14th) temperatures remained unseasonably cold, generally in the mid-30s to low 40s as cloud cover increased. The statewide average high was 39 degrees, 22 degrees below normal. A more active pattern set in mid-to-late week, bringing multiple waves of precipitation beginning with a weak low pressure moving through southern Iowa during the nighttime hours through early Wednesday (15th). Morning lows dipped into the teens across northern Iowa with 20s reported across the south. Statewide, the average low was 19 degrees, 18 degrees below normal. Light snow was observed across Iowa’s southern half as another wave moved from central to eastern Iowa during the afternoon hours; a narrow west-to-east band of snow also formed across extreme south-central Iowa. Daytime temperatures remained near freezing in southwest Iowa with 40s across the rest of Iowa.
A substantial snowstorm impacted southern Iowa late Thursday (16th) through Friday (17th) morning with measurable snow generally south of Interstate 80. The highest accumulations were reported near the Iowa-Missouri border, where accumulations approached one to two inches per hour. Clarinda (Page County) observed 8.0 inches while across the state Keosauqua (Lee County) reported 7.0 inches. South-central Iowa received the highest totals with Ringgold County stations in Beaconsfield and Mount Ayr reporting 12 inches; Allerton (Wayne County) reported 13 inches. Accumulations dropped off into central Iowa with general totals between three to six inches; the statewide average snowfall was 3.7 inches. Partly sunny skies prevailed through the day as highs reached into the mid to upper 40s, melting a majority of the snow that had fallen just hours before. Existing snowpack reported at 7:00 am on Saturday (18th) was between three to four inches at the Ringgold County stations. The rest of Saturday was pleasant with daytime highs reaching into the 60s under sunny skies and strong southwest winds. Morning temperatures reported on Sunday (19th) remained above average under starry skies, ranging in the upper 30s to low 40s.
Weekly precipitation totals ranged from 0.20 inch in Sioux City (Woodbury County) to 1.86 inches in Donnellson (Lee County). The statewide weekly average precipitation was 0.72 inch while the normal is 0.86 inch. Sioux City Airport (Woodbury County) reported the week’s high temperature of 75 degrees on the 18th, 11 degrees above average. Estherville 4E (Emmet County) reported the week’s low temperature of 9 degrees on the 15th, 24 degrees below normal. Four-inch soil temperatures were in the low 40s north to upper 40s south as of Sunday.