Information on the September 7th severe storms

 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: Information can also be posted on our Facebook page.


Event Summary - Severe thunderstorms on Friday September 7th

A very strong cold front, the first of this fall season, pushed into Northeast OK on Friday afternoon.  Wind gusts behind the front reached 57 mph due to the very tight gradient and rapid pressure rises.  Thunderstorms developed along or just ahead of the front, one of which was a supercell that developed just east of Bartlesville and tracked just north of Nowata.  Eventually, the storm was absorbed into a squall line that swept east southeast across Northeast OK and eventually into Northwest AR.  The supercell produced hail to the size of baseballs and estimated wind gusts in the 80-100 mph range just to the north of Nowata.  The squall line produced 60-70 mph wind over a broader swath, with numerous reports of downed trees, power lines, and roof damage to buildings.  A couple of semi-tractor trailer rigs were overturned on the Will Rogers Turnpike as well.

Preliminary Information on the Nowata supercell (last updated 9 AM Sept 10th 2012):

(Nowata County)

Began: Sept 7 2012 3:16 PM CDT 2 NW Nowata

Ended: Sept 7 2012 3:30 PM CDT 3 E Nowata

Path Lenth: 4 statute miles

Max Path Width: 2 miles

Peak wind (estimated):  80-100 mph

Fatalities: 3

Injuries: 0

Detailed Preliminary Survey Information

An NWS Meteorologist from the Tulsa Forecast Office surveyed thunderstorm damage across central Nowata county where three fatalities had been reported.  A broad swath of damage that extended from northwest of Nowata to east of Nowata was investigated as this was the swath that had the most concentrated wind damage.  Intermittent tree damage and minor damage to structures was found outside of that general area as well.  Several mobile homes were destroyed in that swath, a number of permanant homes received varying degrees of mainly roof and impact damage, and numerous outbuildings, both steel and wood framed, were destroyed.  Three fatalities occurred in a double wide mobile home about 2 miles north of Nowata at about 320 PM.  Numerous trees were uprooted and numerous power poles were snapped by the wind.  The orientation of all the damage within the primary swath strongly suggested a violent downburst had occurred.  Wind gusts within the downburst were on the order of 80 to 100 MPH at times based on some of the higher end damage within the swath. EJC

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, or submit an online report.

 Image captions below the image.  Click on image to open a larger version in a new window. Additional images can be found in the Event Map below.

Supercell developed east of Bartlesville and headed toward Nowata  Supercell storm moving just to the north of Nowata at around 320 PM Squall line as it reaches the Will Rogers Turnpike
Supercell developed near Bartlesville Supercell storm just north of Nowata at around 320 pm  Squall line as it reaches the Will Rogers Turnpike
The squall line as it was heading into NW AR The squall line approaching Fort Smith  
The squall line as it was heading into NW AR The squall line as it was approaching Ft. Smith  


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.

Survey Legend


Maps+: Counties:

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