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

Information on this webpage is considered preliminary and will continue to be updated as the event is analyzed.

Anyone with information that could enhance the record of these storms should contact the National Weather Service Office in Tulsa at 918-838-7838 during business hours, submit an online storm report, or send us an email at: sr-tsa.stormreport@noaa.gov

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:

River Location	Preliminary Crest Height	Crest Time	Previous Record
Illinois River near Watts, OK	28.60 feet	3:00 am CDT 4/26/2011	25.96 feet 7/25/1960
Baron Fork at Eldon, OK	28.51 feet	10:30 pm CDT 4/25/2011	26.77 feet 6/21/2000

Major Flooding:

River Location	Preliminary Crest Height	Crest Time	Current Record
Kings River near Berryville, AR	35.47 feet	7:45 am CDT 4/26/2011	38.91 feet 11/19/1985
Illinois River near Tahlequah, OK	25.97 feet	9:00 pm CDT 4/26/2011	27.94 feet 5/10/1950

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.

Location	5-Day Rainfall Total thru 7am 4/26	7-Day Rainfall Total thru 7am 4/28	Source	Location	5-Day Rainfall Total thru 7am 4/26	7-Day Rainfall Total thru 7am 4/28	Source
Prairie Grove, AR	14.48"	15.15"	NWS COOP Observer	Dutch Mills, AR	10.02"	10.42"	USGS
Hindsville, AR 10E	14.47"	15.78"	NWS COOP Observer	Webbers Falls, OK	9.12"	10.42"	OK Mesonet
Eureka Springs, AR 3WNW	13.26"	14.31"	NWS COOP Observer	Tenkiller Lake	9.07"	9.76"	USACE
Fayetteville, AR	13.14"	13.55"	USACE/USGS	Oktaha, OK 2NE	8.97"	missing	NWS COOP Observer
Hindsville, AR 10NNE	13.13"	14.14"	NWS COOP Observer	Muskogee, OK	8.58"	8.74"	USACE/USGS
Westville, OK	12.48"	13.82"	OK Mesonet	Winfrey, AR	8.56"	9.32"	USGS
Wesley, AR 3N	12.33"	13.26"	NWS COOP Observer	Tahlequah, OK	8.49"	9.71"	OK Mesonet
Fayetteville Drake Field	12.32"	12.77"	NWS ASOS	Okmulgee, OK	8.40"	8.46"	OK Mesonet
Berryville, AR 5NW	12.16"	13.11"	NWS COOP Observer	Haskell, OK	8.31"	8.45"	OK Mesonet
Eldon, OK	11.70"	12.01"	USACE/USGS	Short, OK 1W	8.24"	8.90"	USGS
Beaver Lake, AR	11.05"	12.06"	USACE	Fort Gibson Lake, OK	7.90"	7.95"	USACE
Northwest AR Regional Arpt	10.98"	11.88"	NWS ASOS	Porter, OK	7.49"	7.70"	OK Mesonet
Gravette, AR	10.53"	11.46"	NWS COOP Observer	Spavinaw, OK	7.44"	7.68"	NWS COOP Observer
Berryville, AR	10.52"	11.22"	USACE/USGS	Kansas, OK	7.43"	7.63"	USACE/USGS
Strickler, AR	10.40"	11.21"	RAWS	Short, OK 4S	7.43"	8.37"	USGS
Watts, OK	10.32"	10.89"	USACE/USGS	Muskogee Davis Field	7.33"	7.34"	NWS ASOS
Cookson, OK	10.24"	12.59"	OK Mesonet	Hectorville, OK	7.30"	7.34"	OK Mesonet
Gore, OK	10.16"	10.56"	USGS	Whitefield, OK	7.05"	7.56"	USGS
Odell, AR 2N	10.08"	10.66"	NWS COOP Observer	Lake Eucha, OK	7.01"	7.46"	USACE

Information from this event is still considered preliminary and will be modified based on additional information that may become available to us. Anyone with information that could enhance the record of this event should contact the National Weather Service Office in Tulsa at 918-838-7838 during business hours, or send us an email at sr-tsa.stormreport@noaa.gov, or submit an online report.

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)

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.

Preliminary Event Impact Map This map will be updated as additional information is received. Click on the icons within the map for additional details and/or images related to that impact. Tornado information can be found by clicking on the track.

Tornado Tracks: Due to mapping/GPS software differences and road accessibility along the track, use the plotted tracks for general reference only. Tornado tracks may be updated and/or changed due to storm damage surveys, data analysis, and eyewitness reports.

Storm Survey: Colored icons represent the Storm Survey rating assigned to surveyed damage. Click on the icon for additional information and available photos. You may need to zoom in tightly to see all the available data points when data points are logged close to one another. Links to photos are available in the upper portion of the text window that opens when you click on one of the colored data icons or points.

Hail, Wind, and Flood Reports: Click on the icon for the time, location, and description of the storm report. Click here to submit your storm report.

Other Data: Additional data or images from the event.

Maps

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