Alert archive / Arkansas / Tornado Watches in 2011

Tornado Watch 330

May 22, 201128 counties in Arkansas

The Storm Prediction Center issued this tornado watch at May 22, 2011, 3:24 PM CDT for 28 counties in Arkansas. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued
May 22, 2011, 3:24 PM CDT (20:24 UTC)
Expired
May 22, 2011, 8:54 PM CDT
In force
6 hr
Issued by
the Storm Prediction Center
Largest hail expected
2 in
Strongest gust expected
60 kt
All 28 counties

Baxter County, AR, Boone County, AR, Clay County, AR, Cleburne County, AR, Conway County, AR, Craighead County, AR, Crittenden County, AR, Cross County, AR, Faulkner County, AR, Fulton County, AR, Greene County, AR, Independence County, AR, Izard County, AR, Jackson County, AR, Johnson County, AR, Lawrence County, AR, Marion County, AR, Newton County, AR, Poinsett County, AR, Pope County, AR, Randolph County, AR, Searcy County, AR, Sharp County, AR, St. Francis County, AR, Stone County, AR, Van Buren County, AR, White County, AR, Woodruff County, AR

The radar

The Little Rock radar (KLZK), 125 km from the middle of the area, began a volume at 20:27 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
40%
One or more EF2 to EF5 tornadoes
20%
Ten or more severe wind reports
30%
One or more gusts of 65 knots or more
30%
Ten or more severe hail reports
40%
One or more hailstones of 2 inches or more
30%
Six or more combined severe hail and wind reports
70%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
May 22, 3:55 PM CDTSevere Thunderstorm WarningLZKCleburne, Independence, Izard, Stone, Van Buren50 min
May 22, 4:46 PM CDTSevere Thunderstorm WarningMEGCrittenden, Cross, Poinsett44 min
May 22, 4:54 PM CDTSevere Thunderstorm WarningLZKIndependence, Jackson, Sharp, Stone21 min
May 22, 5:08 PM CDTFlash Flood WarningLZKBaxter, Newton, Pope, Searcy, Stone, Van Buren3 hr
May 22, 5:08 PM CDTSevere Thunderstorm WarningLZKIndependence, Jackson22 min
May 22, 5:15 PM CDTSevere Thunderstorm WarningLZKBaxter, Izard, Stone45 min
May 22, 5:20 PM CDTSevere Thunderstorm WarningMEGCrittenden, Mississippi, Poinsett40 min
May 22, 6:00 PM CDTSevere Thunderstorm WarningLZKIzard, Sharp45 min
May 22, 6:05 PM CDTFlash Flood WarningLZKBaxter, Izard, Stone3 hr
May 22, 6:43 PM CDTSevere Thunderstorm WarningLZKIzard, Sharp32 min
May 22, 6:58 PM CDTSevere Thunderstorm WarningMEGLawrence, Randolph41 min
May 22, 7:08 PM CDTSevere Thunderstorm WarningLZKFulton, Izard, Sharp37 min
May 22, 7:47 PM CDTTornado WarningMEGRandolph43 min
May 22, 8:45 PM CDTSevere Thunderstorm WarningLZKBoone, Marion30 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 12:00Z, 8.4 hours before the alert went out and 166 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 12:00Z on 2011-05-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2645 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 12:00Z on 2011-05-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 424 square meters per square second.193958Sfc1 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
2645 J/kg
Mixed-layer CIN
-122 J/kg
Mixed-layer LCL
678 m above ground
0-6 km bulk shear
44 kt
0-1 km storm-relative helicity
424 m²/s²
0-3 km storm-relative helicity
422 m²/s²
Significant tornado parameter
0.0
Supercell composite
16.9

Open this sounding in Storm Lab

The text

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

236 
WWUS20 KWNS 222025
SEL0  
SPC WW 222025
ARZ000-230300-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 330
NWS STORM PREDICTION CENTER NORMAN OK
325 PM CDT SUN MAY 22 2011

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

       NORTHERN ARKANSAS

EFFECTIVE THIS SUNDAY AFTERNOON AND EVENING FROM 325 PM UNTIL
1000 PM CDT.

TORNADOES...HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND
GUSTS TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE
AREAS.

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 50 STATUTE
MILES NORTH AND SOUTH OF A LINE FROM 40 MILES SOUTHWEST OF
HARRISON ARKANSAS TO 15 MILES EAST SOUTHEAST OF JONESBORO
ARKANSAS.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE
ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU0).

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...CONTINUE...WW 322...WW 323...WW
324...WW 325...WW 326...WW 327...WW 328...WW 329...

DISCUSSION...RAPID AIR MASS RECOVERY IS UNDERWAY THROUGH CNTRL AR TO
THE S OF INTENSIFYING STORMS NW OF LIT.  CURRENT LIT VWP INDICATES A
STRONGLY SHEARED ENVIRONMENT WITH 0-1 KM SRH OF 250 M2/S2 WHICH WILL
SERVE TO ENHANCE UPDRAFT ROTATION.  WHILE LARGE HAIL WILL BE THE
PRIMARY HAZARD WITH ANY SUPERCELLS THAT EVOLVE...TORNADOES WILL BE
POSSIBLE GIVEN THE STRONG LOW-LEVEL SHEAR AND MOIST/LOW LCL AIR
MASS.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 2 INCHES. EXTREME TURBULENCE AND SURFACE
WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
500. MEAN STORM MOTION VECTOR 27030.


...MEAD

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 21, 8:31 PM CDTMesoscale DiscussionSPCArkansas, Ashley, Bradley, Calhoun, Clark, Cleburne and 45 more89 min
May 22, 5:18 AM CDTMesoscale DiscussionSPCArkansas, Calhoun, Clark, Cleburne, Cleveland, Conway and 32 more57 min
May 22, 7:03 AM CDTSevere Thunderstorm WatchSPCArkansas, Bradley, Calhoun, Clark, Cleveland, Conway and 30 more7 hr
May 22, 11:15 AM CDTMesoscale DiscussionSPCArkansas, Bradley, Calhoun, Clark, Cleveland, Conway and 26 more90 min
May 22, 1:06 PM CDTMesoscale DiscussionSPCBaxter, Benton, Boone, Carroll, Fulton, Marion114 min
May 22, 1:09 PM CDTMesoscale DiscussionSPCArkansas, Crittenden, Cross, Grant, Jefferson, Lee and 7 more66 min
May 22, 1:27 PM CDTTornado WatchSPCBenton, Carroll, Crawford, Franklin, Madison, Sebastian and 1 more8 hr
May 22, 3:10 PM CDTMesoscale DiscussionSPCBaxter, Boone, Cleburne, Independence, Izard, Jackson and 9 more65 min
May 22, 3:48 PM CDTMesoscale DiscussionSPCBenton, Carroll, Crawford, Franklin, Madison, Washington117 min
May 22, 5:21 PM CDTMesoscale DiscussionSPCBaxter, Boone, Carroll, Clay, Cleburne, Conway and 22 more54 min
May 22, 6:10 PM CDTMesoscale DiscussionSPCBenton, Carroll, Crawford, Franklin, Madison, Washington65 min

Nearby

Tornado Watches in Arkansas, 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.