Between the mid-afternoon hours of Wednesday the 27th until shortly past midnight on Thursday the 28th, widespread heavy rain-producing thunderstorms affected the majority of this six-county North Central Kansas area (except for most of Mitchell and southeastern Osborne counties, where very little rain fell). Although there were a few reports of slightly-sub severe wind gusts in the 50-55 MPH range, by far the biggest story was flooding rains. The heaviest rain, with amounts of at least 2-4 inches, concentrated in a 20-30 mile wide southwest-to-northeast swath running through northern and western Rooks County, southern and eastern Phillips County and northwestern Smith County. Within this main rain swath, a smaller zone of more significant 4-6 totals targeted much of northwestern/north central Rooks and far south central Phillips counties, including a measured CoCoRaHS total of 5.78 ten miles west-northwest of Stockton. Not surprisingly, this area observed not only fairly widespread flooding of fields and rural roads, but also flooding on area creeks and significant river rises. Most notably, an automated river gauge on the Bow Creek near the Rooks-Phillips line crested around 13.6 feet shortly after midnight, well-above flood stage of 9.0 feet. Law enforcement reported that Bow Creek extended roughly one-quarter mile out of its banks near the Highway 183 bridge. Nearby, a gauge along the North Fork Solomon River near Glade crested at 10.5 feet, just below its 11.0 ft. flood stage. Flooding lingered within parts of the area well into the daytime hours of the 28th before gradually receding.
Timing-wise, thunderstorms started developing over western portions of North Central Kansas as early as 3-5 pm CDT. However, the majority of heavy rain and the onset of flooding issues occurred later in the evening between 8 pm-midnight CDT before storms departed northward into Nebraska. This was a fairly ripe setup for slow-moving, heavy-rain producing storms. In the mid and upper levels, small scale disturbances lifted across the local area, slightly downstream from a parent trough/closed low approaching from Colorado/Wyoming. Meanwhile, the local airmass was quite moist, characterized by impressive precipitable water values generally in the 1.7 to 2 inch range. The increasing coverage of convection toward nightfall was aided by enhanced moisture transport along the axis of a southerly low level jet accelerating to 30-40 knots. Although most unstable CAPE values averaged around 1000 J/kg, weak mid level lapse rates and deep-layer wind shear promoted more of a heavy rain versus severe weather threat.