Alert archive / Arkansas / Tornado Watches in 2011

Tornado Watch 335

May 22, 201140 counties in Arkansas; Dunklin County, Pemiscot County, Missouri; 12 counties in Oklahoma

The Storm Prediction Center issued this tornado watch at May 22, 2011, 8:47 PM CDT for 40 counties in Arkansas; Dunklin County, Pemiscot County, Missouri; 12 counties in Oklahoma. It was in force for 7 hr.

The area

The outline as issued.

The facts

Issued
May 22, 2011, 8:47 PM CDT (01:47 UTC)
Expired
May 23, 2011, 4:00 AM CDT
In force
7 hr
Issued by
the Storm Prediction Center
Largest hail expected
2.5 in
Strongest gust expected
70 kt
All 54 counties

Baxter County, AR, Benton County, AR, Boone County, AR, Carroll County, AR, Clay County, AR, Cleburne County, AR, Conway County, AR, Craighead County, AR, Crawford County, AR, Crittenden County, AR, Cross County, AR, Faulkner County, AR, Franklin County, AR, Fulton County, AR, Greene County, AR, Independence County, AR, Izard County, AR, Jackson County, AR, Johnson County, AR, Lawrence County, AR, Logan County, AR, Madison County, AR, Marion County, AR, Mississippi County, AR, Newton County, AR, Perry County, AR, Poinsett County, AR, Pope County, AR, Randolph County, AR, Scott County, AR, Searcy County, AR, Sebastian County, AR, Sharp County, AR, St. Francis County, AR, Stone County, AR, Van Buren County, AR, Washington County, AR, White County, AR, Woodruff County, AR, Yell County, AR, Dunklin County, MO, Pemiscot County, MO, Adair County, OK, Cherokee County, OK, Choctaw County, OK, Delaware County, OK, Haskell County, OK, Latimer County, OK, LeFlore County, OK, McIntosh County, OK, Muskogee County, OK, Pittsburg County, OK, Pushmataha County, OK, Sequoyah County, OK

The radar

The Little Rock radar (KLZK), 128 km from the middle of the area, began a volume at 01:50 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

What SPC expected

The probabilities SPC published with the watch, for the watch area over its life.

Two or more tornadoes
60%
One or more EF2 to EF5 tornadoes
30%
Ten or more severe wind reports
70%
One or more gusts of 65 knots or more
40%
Ten or more severe hail reports
60%
One or more hailstones of 2 inches or more
50%
Six or more combined severe hail and wind reports
95%

Warnings issued inside it

29 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

IssuedProductOfficeCountiesLasted
May 22, 9:00 PM CDTSevere Thunderstorm WarningLZKBoone30 min
May 22, 9:01 PM CDTSevere Thunderstorm WarningTSAPittsburg44 min
May 22, 9:14 PM CDTFlash Flood WarningLZKBaxter, Boone, Marion3 hr
May 22, 9:15 PM CDTSevere Thunderstorm WarningTSACraig, Delaware, Mayes, Ottawa, Rogers60 min
May 22, 9:19 PM CDTFlash Flood WarningTSABenton, Carroll, Madison, Washington6 hr
May 22, 9:30 PM CDTSevere Thunderstorm WarningTSACarroll, Madison60 min
May 22, 9:38 PM CDTSevere Thunderstorm WarningTSALatimer, LeFlore, Pittsburg30 min
May 22, 10:01 PM CDTSevere Thunderstorm WarningLZKBaxter, Marion29 min
May 22, 10:20 PM CDTSevere Thunderstorm WarningLZKLogan, Scott, Yell26 min
May 22, 10:27 PM CDTSevere Thunderstorm WarningTSABenton, Carroll63 min
May 22, 10:33 PM CDTSevere Thunderstorm WarningTSABenton57 min
May 22, 10:37 PM CDTSevere Thunderstorm WarningLZKBaxter, Izard, Marion, Searcy, Sharp, Stone53 min
May 22, 10:46 PM CDTTornado WarningTSABenton44 min
May 22, 10:50 PM CDTSevere Thunderstorm WarningTSACrawford, Sebastian, Washington40 min
May 22, 10:55 PM CDTSevere Thunderstorm WarningTSADelaware35 min
May 22, 11:01 PM CDTSevere Thunderstorm WarningTSACrawford, Franklin, Sebastian59 min
May 22, 11:01 PM CDTTornado WarningTSABenton29 min
May 22, 11:08 PM CDTSevere Thunderstorm WarningMEGClay, Greene, Lawrence, Randolph52 min
May 22, 11:10 PM CDTFlash Flood WarningTSADelaware6 hr
May 22, 11:12 PM CDTTornado WarningTSABenton, Washington33 min
May 22, 11:24 PM CDTTornado WarningTSABenton36 min
May 22, 11:36 PM CDTSevere Thunderstorm WarningTSABenton, Carroll, Madison, Washington39 min
May 22, 11:44 PM CDTSevere Thunderstorm WarningMEGClay, Greene, Lawrence, Randolph46 min
May 22, 11:45 PM CDTTornado WarningTSABenton45 min
May 22, 11:49 PM CDTTornado WarningMEGClay, Greene26 min
May 22, 11:52 PM CDTSevere Thunderstorm WarningLZKJackson, White, Woodruff23 min
May 22, 11:58 PM CDTSevere Thunderstorm WarningLZKIndependence, Jackson, Sharp, Stone47 min
May 23, 12:07 AM CDTSevere Thunderstorm WarningLZKMonroe, Woodruff23 min
May 23, 12:11 AM CDTSevere Thunderstorm WarningLZKBoone, Marion31 min

Discussions around it

SPC mesoscale discussions over the same counties from four hours before the watch to its end.

The nearest sounding before it

Springfield, MO (KSGF), launched 00:00Z, 1.8 hours before the alert went out and 140 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Springfield, MO at 00:00Z on 2011-05-23Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 3961 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Springfield, MO at 00:00Z on 2011-05-23The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 183 square meters per square second.19395878Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
3961 J/kg
Mixed-layer CIN
-3 J/kg
Mixed-layer LCL
641 m above ground
0-6 km bulk shear
45 kt
0-1 km storm-relative helicity
183 m²/s²
0-3 km storm-relative helicity
180 m²/s²
Significant tornado parameter
3.7
Supercell composite
15.9

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

832 
WWUS20 KWNS 230148
SEL5
SPC WW 230148
ARZ000-MOZ000-OKZ000-230900-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 335
NWS STORM PREDICTION CENTER NORMAN OK
850 PM CDT SUN MAY 22 2011

THE NWS STORM PREDICTION CENTER HAS ISSUED A
TORNADO WATCH FOR PORTIONS OF

       NORTHERN ARKANSAS
       THE SOUTHERN MISSOURI BOOTHEEL
       EASTERN OKLAHOMA

EFFECTIVE THIS SUNDAY NIGHT AND MONDAY MORNING FROM 850 PM UNTIL
400 AM CDT.

TORNADOES...HAIL TO 2.5 INCHES IN DIAMETER...THUNDERSTORM WIND
GUSTS TO 80 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE
AREAS.

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 140 STATUTE
MILES EAST AND WEST OF A LINE FROM 50 MILES EAST NORTHEAST OF
FLIPPIN ARKANSAS TO 45 MILES EAST SOUTHEAST OF POTEAU OKLAHOMA.
FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH
OUTLINE UPDATE (WOUS64 KWNS WOU5).

REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR
TORNADOES AND SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH
AREA. PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR
THREATENING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS
AND POSSIBLE WARNINGS.

OTHER WATCH INFORMATION...THIS TORNADO WATCH REPLACES TORNADO
WATCH NUMBER 330. WATCH NUMBER 330 WILL NOT BE IN EFFECT AFTER
850 PM CDT. CONTINUE...WW 323...WW 325...WW 326...WW 327...WW
329...WW 332...WW 333...WW 334...

DISCUSSION...THUNDERSTORM CLUSTERS WITH EMBEDDED SUPERCELLS/BOWS
WILL PERSIST OVERNIGHT WHILE DEVELOPING ESEWD ALONG A RESIDUAL
OUTFLOW BOUNDARY ACROSS NRN AR.  THE 00Z LZK SOUNDING REVEALED A
RELATIVELY MOIST AND STRONGLY SHEARED ENVIRONMENT THAT APPEARS TO BE
REPRESENTATIVE OF NRN AR...THUS A RISK FOR TORNADOES IS EXPECTED TO
PERSIST WITH SUPERCELLS AND BOW/BOUNDARY INTERACTIONS.  DAMAGING
WINDS ARE ALSO LIKELY THE CELL MERGERS AND BOWING SEGMENTS...AS WELL
AS THE RISK FOR LARGE HAIL GIVEN A RESERVOIR OF STRONG INSTABILITY
ACROSS OK/AR IN ADVANCE OF THE STORMS.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 2.5 INCHES. EXTREME TURBULENCE AND SURFACE
WIND GUSTS TO 70 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
550. MEAN STORM MOTION VECTOR 28035.


...THOMPSON

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 22, 7:52 PM CDTMesoscale DiscussionSPCBaxter, Benton, Boone, Carroll, Conway, Crawford and 13 more53 min
May 22, 11:46 PM CDTMesoscale DiscussionSPCClay, Cleburne, Conway, Craighead, Crawford, Cross and 23 more89 min
May 23, 5:07 AM CDTMesoscale DiscussionSPCBaxter, Benton, Boone, Carroll, Crawford, Fulton and 10 more113 min
May 23, 7:38 AM CDTMesoscale DiscussionSPCBenton, Carroll97 min
May 23, 9:14 AM CDTMesoscale DiscussionSPCClark, Cleburne, Conway, Crawford, Dallas, Faulkner and 26 more91 min
May 23, 9:57 AM CDTMesoscale DiscussionSPCLafayette, Little River, Miller33 min
May 23, 10:34 AM CDTMesoscale DiscussionSPCBenton, Carroll, Fulton86 min
May 23, 12:10 PM CDTMesoscale DiscussionSPCLafayette, Miller65 min
May 23, 12:12 PM CDTMesoscale DiscussionSPCBaxter, Benton, Boone, Carroll, Clay, Craighead and 13 more93 min
May 23, 1:16 PM CDTMesoscale DiscussionSPCBaxter, Clay, Craighead, Fulton, Greene, Independence and 5 more89 min
May 23, 1:34 PM CDTSevere Thunderstorm WatchSPCClay, Cleburne, Conway, Craighead, Crittenden, Cross and 20 more6 hr
May 23, 3:58 PM CDTMesoscale DiscussionSPCClay, Cleburne, Conway, Craighead, Crittenden, Cross and 20 more92 min
May 23, 5:07 PM CDTMesoscale DiscussionSPCBenton, Crawford, Washington23 min
May 23, 5:24 PM CDTTornado WatchSPCCrawford, Franklin, Sebastian, Washington4 hr
May 23, 6:18 PM CDTMesoscale DiscussionSPCCleburne, Craighead, Crittenden, Cross, Faulkner, Independence and 11 more87 min
May 22, 8:26 PM CDTTornado WatchSPCBarry, Bollinger, Butler, Cape Girardeau, Carter, Crawford and 33 more8 hr
May 22, 10:24 PM CDTMesoscale DiscussionSPCBollinger, Butler, Cape Girardeau, Madison, Perry, Sainte Genevieve and 2 more66 min
May 23, 5:41 AM CDTMesoscale DiscussionSPCBarton, Bates, Cedar, Dade, Hickory, Jasper and 5 more94 min
May 23, 6:08 AM CDTSevere Thunderstorm WatchSPCBarry, Barton, Bates, Benton, Camden, Cass and 34 more7 hr
May 23, 10:55 AM CDTSevere Thunderstorm WatchSPCAudrain, Bollinger, Boone, Butler, Callaway, Cape Girardeau and 28 more7 hr
May 23, 12:37 PM CDTMesoscale DiscussionSPCCity of Saint Louis83 min
May 22, 8:10 PM CDTMesoscale DiscussionSPCAtoka, Bryan, Carter, Choctaw, Coal, Garvin and 11 more65 min
May 23, 2:08 PM CDTMesoscale DiscussionSPCAlfalfa, Beckham, Blaine, Caddo, Canadian, Comanche and 15 more97 min
May 23, 2:30 PM CDTTornado WatchSPCAlfalfa, Beckham, Blaine, Caddo, Canadian, Cleveland and 26 more8 hr
May 23, 6:51 PM CDTMesoscale DiscussionSPCBlaine, Caddo, Canadian, Cleveland, Comanche, Cotton and 12 more84 min
May 23, 3:20 AM CDTMesoscale DiscussionSPCClay, Davidson, Fentress, Jackson, Macon, Overton and 9 more85 min
May 23, 4:24 PM CDTMesoscale DiscussionSPCBedford, Benton, Carroll, Cheatham, Chester, Davidson and 29 more96 min
May 23, 4:57 PM CDTSevere Thunderstorm WatchSPCBedford, Benton, Carroll, Cheatham, Chester, Davidson and 29 more4 hr

Nearby

Tornado Watches in Arkansas, 2011Tornado Watches in Oklahoma, 2011Tornado Watches in Missouri, 2011Every tornado watch in 2011

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.