April 21-27, 2011 Record Flooding and Severe Weather Event

 Information on this webpage is considered preliminary.

Event Summary - April 21-27, 2011 Heavy Rain, Record Flooding, and Severe Weather - updated 10:10 am 5/10/11

Severe weather and extreme flooding affected eastern Oklahoma and northwest Arkansas from April 21-27, 2011 along a frontal boundary, which had stalled across the region. The front pushed further eastward by April 27 and was associated with the historic tornadic outbreak across the Deep South Region. A series of upper-level disturbances interacted with the frontal boundary while it was draped across the area, leading to multiple rounds of strong to severe thunderstorms and associated heavy rainfall. By April 24, the once drought-stricken area had become saturated and widespread flash flooding occurred. Storms that continued on April 25 only exacerbated the flash flooding. In addition, rapid rises along area creeks and rivers caused extensive river flooding, especially in the Illinois River Basin, where record flooding occurred.

Several locations across northwest Arkansas and east central Oklahoma measured over 5" of rain in one day, including: Haskell, OK 6.77" (4/24 OK mesonet), Okmulgee, OK 6.76" (4/24 OK mesonet), Prairie Grove, AR 6.07" (4/25, COOP),  Hectorville, OK 5.74" (4/24, OK mesonet), Porter, OK 5.51" (4/24, OK mesonet), Muskogee Davis Field, OK 5.19" (4/24, ASOS), and Hindsville, AR 10E 5.10" (4/24, COOP).  In addition, many locations in this area received 3+ inches of rainfall for 3 days in a row (rain that fell on April 23-25). 

Widespread rainfall totals of 6" to 12" affected east central Oklahoma and northwest Arkansas during the 7-day period ending at 7 am CDT April 28, 2011. Portions of Adair County in Oklahoma and Washington and Benton Counties in Arkansas received 12" to 16" of rainfall during this same time. Rainfall estimate images are shown below. A citizen in Beaver, AR reported 17.7" rainfall total through the evening of April 25 to a local TV station.  For reference, the 30-year normal (1971-2000) April rainfall for Fayetteville, AR is 4.33" and the normal annual rainfall is 46.02".  The widespread flash flooding unfortunately led to 5 fatalities in northwest Arkansas when cars were swept away or stalled in high water.

New Record Floods:

 Major Flooding:

Moderate and Minor flooding also occurred at the following locations: Arkansas River at Van Buren, AR; Lee Creek near Van Buren; Poteau River near Poteau, OK; Poteau River Panama, OK; Flint Creek near Kansas, OK; Deep Fork River near Beggs, OK; Neosho River near Commerce, OK; Spring River near Quapaw, OK, and Polecat Creek near Sapulpa.

 Image captions below the image.  Click on image to open a larger version in a new window.

7-day rainfall total ending at 7am CDT 4/26/11	24-hr rainfall estimate ending 7am CDT 4/22/11	24-hr rainfall estimate ending 7am CDT 4/23/11
24-hr rainfall estimate ending 7am CDT 4/24/11	24-hr rainfall estimate ending 7am CDT 4/25/11	24-hr rainfall estimate ending 7am CDT 4/26/11
4-day rainfall total ending at 11 am CDT 4/26/11	24-hr rainfall estimate ending 7am CDT 4/27/11	24-hr rainfall estimate ending 7am CDT 4/28/11
Hydrograph for the Baron Fork River at Eldon (preliminary values)	Hydrograph for the Illinois River near Watts (preliminary values)	Hydrograph for the Illinois River near Tahlequah (preliminary values)
Fiddlers Bend along the Illinois River.  Water reached approximately the yellow dashed line.	Fiddlers Bend along the Illinois River.  Water reached the blue dashed line.	Fiddlers Bend along the Illinois River. Green home was washed from its foundation. Red home was also moved off its foundation.
Fiddlers Bend along the Illinois River.  Water reached approximately the yellow dashed line.	Flooded business along the Illinois River near Watts. Water reached approximately the blue dashed line.	Suspension bridge on Hwy 187 over the White River.
Releases out of Tenkiller Dam. (photo courtesy of USACE Tulsa District)	Releases out of Tenkiller Dam. (photo courtesy of USACE Tulsa District)	Releases out of Beaver Dam.