Strong to severe thunderstorms developed and move along a semi-stationary cold front in East Central Colorado during the afternoon, lasting past midnight.  Large hail up to two and a half inches in diameter was reported with the strongest storm, which produced all the large hail reports as it moved northeast across East Central Colorado. Prolonged heavy rainfall over the same part of East Central Colorado lead to flash flooding during the evening and into the overnight hours.  Rainfall reports in the corridor of heaviest rainfall ranged from 4.60 at Bethune to nine inches near Stratton.  At one point during the night three to five feet of water was flowing over roads between Stratton and Bethune.  Flooding continued into the next day, with two to three feet of water over roads at the same locations.

Flash Flood in KIT CARSON, COLORADO
From 15-APR-16 16:00:00 to 16-APR-16 12:00:00 (MST-7)
Location: BURLINGTON ARPT
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Law Enforcement reported three to five feet of water over the road between Stratton and Bethune.  Flooding was also reported near Bonnie Dam, in the far southeast corner of Yuma county, after midnight.  Radar rainfall estimates place a corridor of seven to ten inches of rainfall over the central part of the county.  Nine inches of rainfall was reportedly measured near Stratton, which lines up well with radar estimates.  Rainfall estimates within the flooding area range from near three inches to ten inches.  Two the three feet of water was reported to still be over the roads between Stratton and Bethune the next morning.

Hail in KIT CARSON, COLORADO
From 15-APR-16 16:27:00 to 15-APR-16 16:27:00 (MST-7)
Location: BURLINGTON ARPT
Magnitude: 2.50 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

The hail ranged from two to two and a half inches in diameter.  Estimated time of report from radar.

Hail in CHEYENNE, COLORADO
From 15-APR-16 14:22:00 to 15-APR-16 14:22:00 (MST-7)
Location: KIT CARSON
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in CHEYENNE, COLORADO
From 15-APR-16 15:28:00 to 15-APR-16 15:28:00 (MST-7)
Location: KIT CARSON
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Hail in KIT CARSON, COLORADO
From 15-APR-16 15:49:00 to 15-APR-16 15:49:00 (MST-7)
Location: BETHUNE
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

Estimated time of report from radar.  Hail ranged from dime to golf ball size from 4 PM MDT to 5:30 PM MDT.

Hail in KIT CARSON, COLORADO
From 15-APR-16 16:01:00 to 15-APR-16 16:01:00 (MST-7)
Location: BETHUNE
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Hail in KIT CARSON, COLORADO
From 15-APR-16 16:00:00 to 15-APR-16 16:00:00 (MST-7)
Location: BURLINGTON ARPT
Magnitude: 2.50 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Estimated time of report based on radar data.

Hail in KIT CARSON, COLORADO
From 15-APR-16 16:15:00 to 15-APR-16 16:15:00 (MST-7)
Location: BURLINGTON ARPT
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail in KIT CARSON, COLORADO
From 15-APR-16 16:23:00 to 15-APR-16 16:23:00 (MST-7)
Location: BURLINGTON ARPT
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Estimated time of report from radar.

Flash Flood in YUMA, COLORADO
From 15-APR-16 17:30:00 to 16-APR-16 04:00:00 (MST-7)
Location: HALE
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Standing water was reported four miles north of Bonny Reservoir during the overnight hours.  Radar rainfall estimates in the flooding area ranged from three to seven inches.  The highest rainfall estimates were in the southeast part of the county, south of Highway 36.

Flash Flood in CHEYENNE, COLORADO
From 15-APR-16 15:45:00 to 16-APR-16 11:00:00 (MST-7)
Location: FIRSTVIEW
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

A COOP Observer 9NNE of Kit Carson, on the west edge of the heavy rainfall area, reported creeks around his location were beginning to overflow an hour or so into the event.  Rainfall estimates from the radar have a swath of four and half to seven inches of rainfall falling in the flooding area.  Radar estimates line up well with rain gauge reports in Kit Carson county, which had even more rainfall.  Based on the COOP report, rainfall and flooding reports in Kit Carson county, radar rainfall estimates and topography, flash flooding occurred across the central part of the county and continued into the next day.  Rainfall estimates range from near three inches to seven inches.