Low pressure was centered over southern Kansas during the early afternoon of the 14th with a sharp dryline extending from the low pressure system through central Oklahoma. A moist and very unstable air mass was in place across eastern Oklahoma ahead of the dryline.
Every event with a place to put it. Tap one for its entry below.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS TSA wrote it up.
Low pressure was centered over southern Kansas during the early afternoon of the 14th with a sharp dryline extending from the low pressure system through central Oklahoma. A moist and very unstable air mass was in place across eastern Oklahoma ahead of the dryline. Severe thunderstorms developed along the dryline during the afternoon and moved into eastern Oklahoma during the early evening hours. Large hail up to grapefruit size, damaging wind gusts, and numerous tornadoes occurred as the storms moved through the region.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Tulsa, OK wrote its last area forecast discussion before the first event at Apr 14, 5:14 AM CST, 22 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TULSA OK 614 AM CDT THU APR 14 2011 .AVIATION... CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM. OTHER THAN MVFR VSBYS AT KBVO IN LIGHT FOG FOR A FEW HOURS...VFR CONDITIONS ARE EXPECTED FOR THE NEXT 12 HOURS AT ALL SITES. A SIGNIFICANT STORM SYSTEM WILL SWEEP THROUGH THE AREA THIS EVENING AN OVERNIGHT. A LINE OF THUNDERSTORMS ALONG A DRYLINE WILL MOVE FROM WEST TO EAST THIS EVENING AND OVERNIGHT...AND WILL OFFER REDUCED MVFR/VFR VSBYS AND MVFR CIGS. WINDS WILL SHIFT TO THE WEST NORTHWEST BEHIND THE BOUNDARY...WHICH IS EXPECTED TO BE EAST OF KFSM AFTER 09Z. && .PREV DISCUSSION... /ISSUED 424 AM CDT THU APR 14 2011/ DISCUSSION... LITTLE CHANGE IN THINKING HAS OCCURRED OVER THE PAST 24 HOURS. A POTENT STORM SYSTEM WILL IMPACT THE AREA LATE THIS AFTERNOON INTO TONIGHT RESULTING IN SEVERE THUNDERSTORMS WITH LARGE HAIL...DAMAGING WINDS AND A FEW TORNADOES. LOW LEVEL MOISTURE IS MAKING ITS WAY NORTH ACROSS CENTRAL AND EASTERN TEXAS AT THIS TIME AND WILL CONTINUE TO SURGE NORTH TODAY AHEAD OF A DEVELOPING STORM SYSTEM CURRENTLY OVER THE ROCKIES. SURFACE LOW PRESSURE WILL DEEPEN TODAY AS IT MOVES FROM THE TEXAS PANHANDLE NORTHEAST INTO CENTRAL KANSAS. A DRYLINE WILL TRAIL SOUTH FROM THE LOW AND WILL BE ROUGHLY ALONG THE INTERSTATE 35 CORRIDOR BY LATE AFTERNOON. INITIAL THUNDERSTORM DEVELOPMENT WILL OCCUR TO OUR NORTH ACROSS KANSAS BY MID AFTERNOON WITH EVENTUAL DEVELOPMENT SOUTHWARD INTO OKLAHOMA BY LATE AFTERNOON OR EARLY EVENING. WILL KEEP POPS LOW FOR THE DAYTIME PERIOD AS STORM COVERAGE IS LIKELY TO REMAIN SMALL THROUGH 00Z. FIRE DANGER WILL REMAIN A CONCERN TODAY DESPITE THE INCREASING MOISTURE AND WILL ISSUE A FIRE DANGER STATEMENT FOR THE ENTIRE FORECAST AREA. INITIAL THUNDERSTORM DEVELOPMENT BEFORE SUNSET IS POSSIBLE BOTH ALONG THE DRYLINE TO OUR WEST AND ALSO WELL AHEAD OF THE DRYLINE NEAR THE LEFT EXIT REGION OF A STRONG UPPER LEVEL JET. THESE STORMS ARE LIKELY TO BE SUPERCELLULAR WITH LARGE HAIL...DAMAGING WINDS AND TORNADOES ALL LIKELY. STORM COVERAGE WILL INCREASE AFTER DARK WITH STORMS EVENTUALLY BECOMING MORE LINEAR...WHICH WILL LESSEN THE TORNADO AND HAIL THREATS BUT MAINTAIN THE DAMAGING WIND POTENTIAL. FRIDAY WILL BE A RAW DAY WITH COOL TEMPERATURES...CONSIDERABLE CLOUD COVER AND STRONG WEST TO NORTHWEST WINDS. A FEW SHOWERS MAY OCCUR ACROSS PARTS OF NORTHEAST OKLAHOMA AND NORTHWEST ARKANSAS...AND MAY CONTINUE INTO FRIDAY NIGHT IN SOME PLACES. EVEN WITH THE COOLER TEMPERATURES...FIRE DANGER WILL REMAIN VERY HIGH IN PLACES THAT DO NOT RECEIVE SIGNIFICANT RAINFALL OVER THE NEXT 24 HOURS. SKIES WILL CLEAR QUICKLY LATER FRIDAY NIGHT AND EARLY SATURDAY AND A WARMING TREND WILL THEN ENSUE. TEMPERATURES WILL RETURN TO WELL ABOVE NORMAL LEVELS BY LATE IN THE WEEKEND INTO THE FIRST PART OF NEXT WEEK. SOUTHWEST FLOW ALOFT WILL RESULT IN AN UNSETTLED WEATHER PATTERN WITH PERIODIC CHANCES OF SHOWERS AND THUNDERSTORMS. THE BEST CHANCE FOR SIGNIFICANT RAINFALL AND SEVERE WEATHER MAY BE IN THE TUESDAY AND TUESDAY EVENING TIMEFRAME AS A COLD FRONT PUSHES INTO THE AREA. WENT A BIT WARMER THAN GUIDANCE ON TEMPERATURES TODAY AND THEN STAYED CLOSE TO GUIDANCE TEMPERATURES TONIGHT THROUGH SATURDAY. FAVORED THE ECMWF OVER THE GFS MOS FOR TEMPERATURES THROUGH MOST OF THE EXTENDED PERIODS. && .PRELIMINARY POINT TEMPS/POPS... TUL 81 48 58 39 / 20 70 30 10 FSM 81 52 61 40 / 20 80 20 10 MLC 81 51 62 39 / 20 60 10 10 BVO 81 47 56 36 / 20 70 40 10 FYV 77 50 56 36 / 20 90 40 20 BYV 77 50 56 36 / 20 90 40 30 MKO 81 51 60 39 / 20 80 20 10 MIO 79 47 56 37 / 20 90 50 20 F10 81 51 61 39 / 20 60 10 10 HHW 81 52 68 41 / 20 50 10 10 && .TSA WATCHES/WARNINGS/ADVISORIES... OK...NONE. AR...NONE. && SHORT TERM...99 LONG TERM....99 AVIATION...23
HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE TULSA OK
519 AM CDT THU APR 14 2011
ARZ001-002-010-011-019-020-029-OKZ049-053>076-151000-
ADAIR OK-BENTON AR-CARROLL AR-CHEROKEE OK-CHOCTAW OK-CRAIG OK-
CRAWFORD AR-CREEK OK-DELAWARE OK-FRANKLIN AR-HASKELL OK-LATIMER OK-
LE FLORE OK-MADISON AR-MAYES OK-MCINTOSH OK-MUSKOGEE OK-NOWATA OK-
OKFUSKEE OK-OKMULGEE OK-OSAGE OK-OTTAWA OK-PAWNEE OK-PITTSBURG OK-
PUSHMATAHA OK-ROGERS OK-SEBASTIAN AR-SEQUOYAH OK-TULSA OK-WAGONER OK-
WASHINGTON OK-WASHINGTON AR-
519 AM CDT THU APR 14 2011
...OUTBREAK OF SEVERE THUNDERSTORMS TODAY...
...TORNADO THREAT WITH ISOLATED SUPERCELLS...
THIS OUTLOOK IS FOR NORTHWEST AND WEST CENTRAL ARKANSAS AS WELL AS
MUCH OF EASTERN OKLAHOMA.
.DAY ONE...TODAY AND TONIGHT.
TORNADO.
RISK...ELEVATED.
AREA....EASTERN OKLAHOMA.
ONSET... LATE AFTERNOON.
AREA AT GREATEST RISK...NORTHEAST OKLAHOMA.
SEVERE THUNDERSTORM.
RISK...SIGNIFICANT.
AREA...EASTERN OKLAHOMA AND NORTHWEST ARKANSAS.
ONSET...LATE AFTERNOON.
FLASH FLOOD.
RISK...LIMITED.
AREA...EASTERN OKLAHOMA AND NORTHWEST ARKANSAS.
ONSET...THIS EVENING.
HEAVY RAIN.
RISK...LIMITED.
AREA...EASTERN OKLAHOMA AND NORTHWEST ARKANSAS.
ONSET...THIS EVENING.
SIGNIFICANT WINDS.
RISK...LIMITED.
AREA...EASTERN OKLAHOMA AND NORTHWEST ARKANSAS.
ONSET...MID MORNING .
FIRE WEATHER DANGER.
RISK...ELEVATED.
AREA...EASTERN OKLAHOMA.
ONSET...MID MORNING.
DISCUSSION...
A SIGNIFICANT SEVERE WEATHER EVENT...INCLUDING SUPERCELLS AND
TORNADIC POTENTIAL...IS LIKELY LATE THURSDAY AFTERNOON AND EVENING.
MOISTURE WILL SURGE NORTH TODAY AHEAD OF AN APPROACHING DRYLINE WITH
LOW TO MID 60 DEW POINTS BY LATE AFTERNOON AS A SURFACE LOW DEEPENS
OVER SOUTHEAST KANSAS AND NORTHEAST OKLAHOMA.
LATER TODAY...A DRYLINE IS EXPECTED TO BE NEAR INTERSTATE 35
LATE THIS AFTERNOON...AND NEAR HIGHWAY 75 BY MID EVENING. AHEAD OF THE
DRYLINE...A LOW LEVEL JET WILL AID IN TRANSPORTING AMPLE LOW LEVEL
MOISTURE INTO EASTERN OKLAHOMA AND NORTHWEST ARKANSAS.
IMPRESSIVE DEEP DIRECTIONAL SHEAR AND SPEED SHEAR WILL PRODUCE
SUPERCELLS ON...OR IN ADVANCE OF THE DRYLINE LATE THURSDAY AFTERNOON
AND EVENING.
THE WIND SHEAR FROM AN APPROACHING 110 KNOT UPPER JET AND SURFACE
BASED INSTABILITY WILL BE SUFFICIENT FOR A THREAT OF
TORNADOES...ESPECIALLY WITH THE INITIAL DEVELOPMENT LATE THIS
AFTERNOON. AS THUNDERSTORMS MOVE FURTHER INTO EASTERN OKLAHOMA AND
NORTHWEST ARKANSAS...THE TORNADO RISK WILL LIKELY DIMINISH AS STORMS
BECOME LINEAR WHILE INCREASING IN AREAL COVERAGE.
VERY LARGE HAIL...WITH POTENTIAL TO EXCEED 2 INCHES IN
DIAMETER...AND DAMAGING STRAIGHT LINE WINDS WILL BE THREATS
THROUGHOUT THE EVENT. STORMS ARE EXPECTED TO EXIT EASTERN OKLAHOMA
AND NORTHWEST ARKANSAS AFTER MIDNIGHT THURSDAY NIGHT.
ADDITIONALLY...FIRE DANGER WILL ALSO REMAIN A CONCERN...PARTICULARLY
EARLIER ON THURSDAY PRIOR TO THE LOW LEVEL MOISTURE RETURNING TO THE
AREA. TIMING OF THE DRY LINE SUGGEST FIRE DANGER BY LATE AFTERNOON
OR EARLY EVENING SHOULD REMAIN OUTSIDE OF CRITICAL RED FLAG LEVELS
FOR AREAS WEST OF HIGHWAY 75.
SPOTTER AND EMERGENCY MANAGEMENT ACTION STATEMENT...
ACTIVATION OF THE REGIONAL SPOTTER NETWORK EXPECTED.
THE EVOLUTION OF THIS SEVERE THREAT SHOULD BE CLOSELY MONITORED...
ESPECIALLY IN REGARD TO ANY OUTDOOR ACTIVITIES LATE THURSDAY
AFTERNOON AND EVENING.
EXTENDED DISCUSSION...
ENERGY WITHIN SOUTHWESTERLY UPPER FLOW WILL RESULT IN THUNDERSTORM CHANCES
RETURNING BY LATE SUNDAY. IMPROVED CHANCES FOR ORGANIZED STORM
DEVELOPMENT WOULD COME TUESDAY AND TUESDAY NIGHT AS A COLD FRONT AND
THE NEXT SIGNIFICANT UPPER SYSTEM MOVE INTO THE SOUTHERN PLAINS.
.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY.
FRIDAY...VERY HIGH FIRE WEATHER POTENTIAL...HIGH WIND POTENTIAL.
SATURDAY...VERY HIGH FIRE WEATHER POTENTIAL.
SUNDAY...THUNDERSTORM POTENTIAL...VERY HIGH FIRE WEATHER POTENTIAL
...HIGH WIND POTENTIAL.
MONDAY...THUNDERSTORM POTENTIAL...VERY HIGH FIRE WEATHER POTENTIAL.
TUESDAY...THUNDERSTORM POTENTIAL...VERY HIGH FIRE WEATHER POTENTIAL
...HIGH WIND POTENTIAL.
WEDNESDAY...THUNDERSTORM POTENTIAL.
EXTENDED DISCUSSION...
ELEVATED FIRE DANGER WILL CONTINUE ON FRIDAY AS STRONG NORTHWEST
WINDS IN THE WAKE OF A COLD FRONT CONTRIBUTE TO RAPID FIRE SPREAD
CONDITIONS.
SOUTHWESTERLY UPPER FLOW WILL RESULT IN THUNDERSTORM CHANCES
RETURNING BY LATE SUNDAY. IMPROVED CHANCES FOR ORGANIZED STORM
DEVELOPMENT WOULD COME TUESDAY AND TUESDAY NIGHT AS A COLD FRONT AND
NEXT SIGNIFICANT UPPER SYSTEM MOVE INTO THE SOUTHERN PLAINS.
BREEZY CONDITIONS WILL MAINTAIN AT LEAST PERIODIC HIGH FIRE
SPREAD POTENTIAL INTO NEXT WEEK.
WWW.SRH.NOAA.GOV/TULSA CONTAINS ADDITIONAL INFORMATION.The national radar mosaic for the moment the first event began.
38 hail, 25 tornado, 22 thunderstorm wind. Local standard time, as filed.
Emergency management reported a few power poles were blown down by strong thunderstorm wind and some outbuildings received minor damage.
Strong thunderstorm wind blew down several trees and damaged roofs at Rogers State University.
A tornado snapped large tree limbs. A storm chaser witnessed this tornado. Maximum estimated wind in the tornado based on the damage was about 75 mph.
Thunderstorm wind gusts up to 70 mph were reported by emergency management.
Thunderstorm wind gusts up to 60 mph were estimated.
A tornado damaged a metal building and a permanent home. It also snapped power poles and trees. Maximum estimated wind in the tornado based on this damage was about 115 mph. Several storm chasers witnessed this tornado.
The Oklahoma Mesonet site near Wynona measured 63 mph thunderstorm wind gusts.
A brief tornado developed over open country. The tornado resulted in no known damage.
Storm chasers for KOTV witnessed a brief tornado over open country. The tornado resulted in no known damage.
Spotters with Washington County Emergency Management witnessed a brief tornado over open country. The tornado resulted in no known damage.
Strong thunderstorm wind blew down trees onto power lines.
Strong thunderstorm wind blew down several trees near Lone Star School on Hickory Road.
This is the first of two segments of this tornado. In this segment, the tornado snapped or uprooted several large trees. It was witnessed by storm chasers. Maximum estimated wind in the tornado based on the tree damage was 105 mph. The tornado continued into Okmulgee County, Oklahoma.
This is the first of two segments of this tornado. In Washington County, this tornado uprooted several trees. Maximum estimated wind in the tornado based on this damage was 95 mph. The tornado continued into Nowata County, Oklahoma.
This is the second of two segments of this tornado. The tornado continued into Okmulgee County, producing no known damage in Okmulgee County as it remained over mostly open country until it dissipated. The rope stage of this tornado was recorded by storm chasers.
This is the second of two segments of this tornado. In Nowata County, the tornado damaged several permanent homes and snapped or uprooted trees. Maximum wind in the tornado based on this damage was about 105 mph.
KOCO storm chasers witnessed this brief tornado. The tornado resulted in no known damage.
Strong thunderstorm wind blew down large tree limbs.
Thunderstorm wind gusts up to 65 mph were estimated about 1 mile north of Rogers State University.
A tornado snapped or uprooted a number of large trees. Maximum estimated wind in the tornado based on this damage was about 105 mph.
A tornado destroyed a mobile home, injuring three people. Several other mobile homes were severely damaged. Trees were snapped or uprooted. Maximum estimated wind in the tornado based on this damage was about 125 mph.
This is the second of two segments of this tornado, which developed in Atoka County, Oklahoma. A storm chaser witnessed a large cone-shaped tornado over open country. No known damage resulted from this tornado.
A storm chaser observed a brief tornado northwest of Jumbo that was over open country. This tornado produced no known damage.
A tornado snapped or uprooted a number of trees. Power poles were also snapped by this tornado. Maximum estimated wind in the tornado based on this damage was about 100 mph. This tornado was observed by a storm chaser.
A tornado damaged a permanent home, destroyed several outbuildings, and snapped or uprooted a number of trees. Maximum estimated wind in the tornado based on this damage was about 110 mph.
This is the first of two segments of this tornado. In Latimer County, this tornado damaged a home, severely damaged a barn, and snapped or uprooted a number of large trees. Maximum estimated wind in the tornado based on this damage was about 110 mph. The tornado continued into Le Flore County, Oklahoma.
A large tornado snapped or uprooted many large trees. Maximum estimated wind in the tornado based on this damage was about 115 mph.
This is the second of two segments of this tornado. In Le Flore County, this tornado uprooted a number of trees. Maximum estimated wind in the tornado based on this damage was about 95 mph.
A tornado blew down several trees. Maximum estimated wind based on this damage was about 90 mph.
This is the second of three segments of this tornado, which developed over northeastern Atoka County. In Pushmataha County, this large tornado snapped or uprooted many large trees. Maximum estimated wind based on this damage was about 105 mph. The tornado continued into Pittsburg County, Oklahoma.
A tornado that apparently developed over Sardis Lake uprooted a few trees and snapped numerous large tree limbs. Maximum estimated wind in the tornado based on this damage was about 85 mph.
This is the third of three segments of this tornado, which developed in northeastern Atoka County and moved across northwestern Pushmataha County. In Pittsburg County, this tornado snapped or uprooted a number of trees. Maximum estimated wind in the tornado based on this tree damage was about 105 mph.
A tornado rolled a mobile home, injuring three people, damaged the roof of a permanent home, and snapped or uprooted numerous large trees. Maximum estimated wind in the tornado based on this damage was about 105 mph. A storm spotter witnessed this tornado.
The Oklahoma Mesonet station near Hectorville measured 65 mph thunderstorm wind gusts.
The Oklahoma Mesonet station near Wister measured 64 mph thunderstorm wind gusts.
Strong thunderstorm wind destroyed a barn and damaged a home at 153rd Street South and South Mingo Road.
The Oklahoma Mesonet station near Wister measured 73 mph thunderstorm wind gusts.
An anticyclonic tornado damaged a barn and snapped or uprooted trees. Maximum estimated wind in the tornado based on this damage was about 100 mph.
Strong thunderstorm wind damaged the roof of a home.
Strong thunderstorm wind blew down large trees on Highway 271 and Four Star Ranch Road.
Strong thunderstorm wind damaged two homes and blew down numerous trees on Nolia Loop Road east of Nashoba.
Strong thunderstorm wind blew down about a dozen power poles along Highway 51 between 105th Street South and 121st Street South.
Thunderstorm wind gusts of up to 65 mph were estimated with large tree limbs broken off trees.
Strong thunderstorm wind blew down numerous large tree limbs.
Thunderstorm wind gusts of up to 65 mph were estimated. Large tree limbs were blown down.
Strong thunderstorm wind destroyed a travel trailer, destroyed a shed, and blew down trees and power lines.
Strong thunderstorm wind blew down numerous trees and power lines between Oleta and Sobol. One home was also damaged by the wind.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Oklahoma in 2011Every state in 2011This day in weather historyThe tornado archive for Oklahoma, 2011Warnings in Oklahoma, April 2011
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 291279, 291281, 291208, 302758, 291209, 291210, 291211, 291212, 291213, 291214, 291215, 291216, 291283, 302759, 291218, 291284, 302760, 302762, 291219, 291286, 291287, 302765, 291220, 291288, 291221, 291222, 302775, 291223, 302781, 302777, 302786, 291290, 291224, 302787, 291225, 291226, 291227, 291228, 302788, 291292, and more.