It was truly a one storm show within this North Central Kansas area on this Thursday evening, as a large, very slow-moving supercell presided over much of the northern half of Phillips County for about four hours, causing flooding rains, large hail and even sparking a few brief, lightning-induced grass fires along its leading (southern) edge in advance of the heavy rain core. Above all else, flash flooding/areal flooding was the main impact. Though ground-truth gauge reports were very limited, radar data strongly supported that much of the northern half of the county received a widespread 2-4 inches of rain, with particularly some north central locales likely registering at least 4-6 (there was even an unofficial report of 9 in the bullseye of heaviest rain). True flash flooding subsided before sunrise on Friday the 29th, but emergency management reported that a number of rural gravel roads had been (or were still) covered with water, particularly within a zone 5-10 miles north of Phillipsburg. In addition, a CoCoRaHS observer six miles east of Phillipsburg reported early on the 29th that a nearby creek (likely Big Creek) was in flood due to the deluge several miles upstream (merely 0.12 fell at his residence). Besides flooding, large hail was the main impact from this storm, as there were a handful of reports of stones ranging from 1-2 diameter. These large hail reports originated from as far north as Highway 183 near the Nebraska border, as far west as the Prairie View area and as far southeast as roughly seven miles east-northeast of Phillipsburg.
Breaking down event evolution, this supercell initiated about 20 miles north of the state line in Harlan County Nebraska around 4 p.m. CDT, within an axis of modest surface moisture convergence along a weak trough axis extending northeastward out of western Kansas.  However, given an extremely slow southward storm motion, its leading edge did not reach far northern Phillips County until around 6:30 p.m. CDT. Over the next few hours it crept slowly south through northern portions of the county before becoming nearly stationary particularly between 9-10 p.m. CDT. Finally, between 10-10:30 p.m. CDT this storm steadily weakened and dissipated, but not before reversing course and making a last minute shift back north toward the state line. Although the Phillips County supercell was clearly the weather story of the night within North Central Kansas, several hours later (mainly between 2:30-5:30 a.m. CDT on the 29th) scattered storms flared up over much of the area before departing off to the north/east. Radar data suggested that a few marginally-severe hail cores might have briefly occurred with this activity (mainly in Phillips/Mitchell counties), but there were no verifying reports. In the mid-upper levels, this was a weakly-forced event as North Central Kansas resided under fairly benign quasi-zonal flow (even subtle weak ridging), well-downstream from a larger-scale trough that remained well to the west during the evening (over the Intermountain West). As a result, deep-layer wind shear was not overly-strong, averaging around 35 knots. In addition, low-level moisture was seasonably-modest, with surface dewpoints peaking only mid-50s (F). However, due in part to afternoon temperatures climbing a bit higher than anticipated (highs mid-80s), mixed-layer CAPE topped out as high as 1500-2000 J/kg. Ultimately, the combination of healthy instability, modest shear and eventually an increasing low level jet proved sufficient to sustain the Phillips County supercell for several hours.

Hail in PHILLIPS, KANSAS
From 28-APR-22 17:50:00 to 28-APR-22 18:20:00 (CST-6)
Location: WOODRUFF
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Fire Department/Rescue

Hail up to golf ball size was reported along this path.

Hail in PHILLIPS, KANSAS
From 28-APR-22 19:36:00 to 28-APR-22 19:36:00 (CST-6)
Location: PRAIRIE VIEW
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in PHILLIPS, KANSAS
From 28-APR-22 19:40:00 to 28-APR-22 19:40:00 (CST-6)
Location: AGRA
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in PHILLIPS, KANSAS
From 28-APR-22 20:09:00 to 28-APR-22 20:45:00 (CST-6)
Location: PRAIRIE VIEW
Magnitude: 2.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail ranging in size from pennies up to two inches in diameter was reported along and near this path.

Flash Flood in PHILLIPS, KANSAS
From 28-APR-22 20:45:00 to 29-APR-22 02:45:00 (CST-6)
Location: LONG IS
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Emergency management reported several roads had been affected by flash flooding overnight (including some washouts), and a few still had water covering them into the daytime on the 29th. An NWS Hastings employee in the area came across at least three spots along Hunter Road where grooves had been cut into gravel roads. Most of the damage to roads was concentrated in an area approximately 5-10 miles north of Phillipsburg. Radar data strongly supported that much of the northern half of the county received a widespread 2-4 inches of rain, with particularly some north central locales likely registering at least 4-6 (there was even an unofficial report of 9 in the bullseye of heaviest rain).