Alert archive / Arkansas / Tornado Watches in 2006

Tornado Watch 320

May 9, 200616 counties in Arkansas; 8 counties in Missouri; 11 counties in Oklahoma

The Storm Prediction Center issued this tornado watch at May 9, 2006, 5:07 PM CDT for 16 counties in Arkansas; 8 counties in Missouri; 11 counties in Oklahoma. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued
May 9, 2006, 5:07 PM CDT (22:07 UTC)
Expired
May 9, 2006, 10:55 PM CDT
In force
6 hr
Issued by
the Storm Prediction Center
Largest hail expected
3 in
Strongest gust expected
60 kt
All 35 counties

Baxter County, AR, Benton County, AR, Boone County, AR, Carroll County, AR, Crawford County, AR, Franklin County, AR, Fulton County, AR, Izard County, AR, Madison County, AR, Marion County, AR, Newton County, AR, Searcy County, AR, Sebastian County, AR, Sharp County, AR, Stone County, AR, Washington County, AR, Barry County, MO, Howell County, MO, McDonald County, MO, Oregon County, MO, Ozark County, MO, Shannon County, MO, Stone County, MO, Taney County, MO, Adair County, OK, Cherokee County, OK, Creek County, OK, Delaware County, OK, Mayes County, OK, Muskogee County, OK, Okmulgee County, OK, Rogers County, OK, Sequoyah County, OK, Tulsa County, OK, Wagoner County, OK

The radar

The Western Arkansas radar (KSRX), 94 km from the middle of the area, began a volume at 22:07 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
50%
One or more EF2 to EF5 tornadoes
30%
Ten or more severe wind reports
40%
One or more gusts of 65 knots or more
40%
Ten or more severe hail reports
80%
One or more hailstones of 2 inches or more
60%
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 9, 5:19 PM CDTSevere Thunderstorm WarningSGFOzark56 min
May 9, 5:32 PM CDTSevere Thunderstorm WarningTSACherokee, Muskogee58 min
May 9, 6:11 PM CDTSevere Thunderstorm WarningSGFOzark49 min
May 9, 6:15 PM CDTFlash Flood WarningSGFOzark5 hr
May 9, 6:15 PM CDTFlash Flood WarningSGFOzark17 hr
May 9, 6:21 PM CDTSevere Thunderstorm WarningTSASequoyah54 min
May 9, 6:24 PM CDTSevere Thunderstorm WarningTSACherokee53 min
May 9, 6:33 PM CDTTornado WarningTSASequoyah42 min
May 9, 6:34 PM CDTTornado WarningSGFOzark41 min
May 9, 6:43 PM CDTTornado WarningSGFHowell47 min
May 9, 7:07 PM CDTFlash Flood WarningSGFHowell6 hr
May 9, 7:10 PM CDTSevere Thunderstorm WarningTSAOkmulgee65 min
May 9, 7:14 PM CDTTornado WarningTSASequoyah61 min
May 9, 7:17 PM CDTSevere Thunderstorm WarningLZKFulton58 min
May 9, 7:27 PM CDTTornado WarningSGFHowell18 min
May 9, 7:46 PM CDTSevere Thunderstorm WarningSGFHowell, Oregon23 min
May 9, 7:54 PM CDTTornado WarningTSASebastian66 min
May 9, 7:58 PM CDTSevere Thunderstorm WarningTSAMuskogee31 min
May 9, 8:12 PM CDTTornado WarningTSASequoyah33 min
May 9, 8:14 PM CDTSevere Thunderstorm WarningLZKFulton61 min
May 9, 8:53 PM CDTTornado WarningTSASebastian57 min
May 9, 8:56 PM CDTSevere Thunderstorm WarningTSAMuskogee19 min
May 9, 8:58 PM CDTSevere Thunderstorm WarningTSAHaskell, Sequoyah62 min
May 9, 9:26 PM CDTFlash Flood WarningTSASebastian3 hr
May 9, 9:46 PM CDTFlash Flood WarningTSAFranklin119 min
May 9, 9:53 PM CDTSevere Thunderstorm WarningTSAFranklin32 min
May 9, 9:53 PM CDTFlash Flood WarningTSASequoyah67 min
May 9, 10:14 PM CDTSevere Thunderstorm WarningTSAMayes, Wagoner76 min
May 9, 10:18 PM CDTFlash Flood WarningSGFDouglas, Ozark12 hr

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, 10.1 hours before the alert went out and 105 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 2006-05-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 572 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 2006-05-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 195 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
572 J/kg
Mixed-layer CIN
-109 J/kg
Mixed-layer LCL
735 m above ground
0-6 km bulk shear
39 kt
0-1 km storm-relative helicity
195 m²/s²
0-3 km storm-relative helicity
140 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.2

Open this sounding in Storm Lab

The text

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

000 
WWUS20 KWNS 092206
SEL0  
SPC WW 092206
ARZ000-MOZ000-OKZ000-100400-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 320
NWS STORM PREDICTION CENTER NORMAN OK
510 PM CDT TUE MAY 9 2006

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

       NORTHERN ARKANSAS
       SOUTHERN MISSOURI
       NORTHEAST OKLAHOMA

EFFECTIVE THIS TUESDAY AFTERNOON AND EVENING FROM 510 PM UNTIL
1100 PM CDT.

TORNADOES...HAIL TO 3 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 40 STATUTE
MILES NORTH AND SOUTH OF A LINE FROM 55 MILES SOUTHWEST OF TULSA
OKLAHOMA TO 30 MILES EAST SOUTHEAST OF WEST PLAINS MISSOURI.  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 317...WW 318...WW 319...

DISCUSSION...THUNDERSTORMS ARE EXPECTED TO INCREASE IN AREAL
COVERAGE THIS EVENING ALONG SURFACE BOUNDARY EXTENDING FROM
NORTHEAST OK INTO SOUTHERN MO. AIRMASS ALONG AND SOUTH OF FRONT IS
VERY UNSTABLE WILL MUCAPE VALUES OVER 3000 J/KG AND FAVORABLE
VERTICAL SHEAR.  BEST THREAT OF TORNADOES APPEARS TO BE IMMEDIATELY
NORTH OF REMNANT BOUNDARY ACROSS EAST CENTRAL OK AND NORTHWEST
AR...WHERE BACKED LOW LEVEL WINDS AND STRONGEST INSTABILITY ARE
PRESENT.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 3 INCHES. EXTREME TURBULENCE AND SURFACE
WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
550. MEAN STORM MOTION VECTOR 27030.


...HART

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 9, 4:24 AM CDTSevere Thunderstorm WatchSPCBenton, Carroll, Madison, Washington4 hr
May 9, 6:22 AM CDTSevere Thunderstorm WatchSPCBaxter, Boone, Fulton, Independence, Izard, Marion and 4 more6 hr
May 9, 10:00 AM CDTMesoscale DiscussionSPCClay, Craighead, Crittenden, Greene, Jackson, Lawrence and 4 more2 hr
May 9, 10:05 AM CDTSevere Thunderstorm WatchSPCClay, Craighead, Crittenden, Cross, Greene, Lawrence and 4 more5 hr
May 9, 10:46 AM CDTSevere Thunderstorm WatchSPCArkansas, Clark, Cleburne, Cleveland, Conway, Dallas and 17 more4 hr
May 9, 4:46 PM CDTMesoscale DiscussionSPCBenton, Boone, Carroll, Madison, Washington89 min
May 9, 6:30 PM CDTMesoscale DiscussionSPCBaxter, Benton, Boone, Carroll, Crawford, Franklin and 6 more90 min
May 8, 7:47 PM CDTMesoscale DiscussionSPCAtchison, Holt, Nodaway58 min
May 8, 10:59 PM CDTMesoscale DiscussionSPCAndrew, Atchison, Buchanan, Gentry, Holt, Nodaway and 1 more91 min
May 9, 1:13 AM CDTMesoscale DiscussionSPCAlfalfa, Craig, Grant, Kay, Mayes, Noble and 6 more92 min
May 9, 3:45 PM CDTMesoscale DiscussionSPCAtoka, Bryan, Carter, Choctaw, Cleveland, Coal and 24 more2 hr
May 9, 4:04 PM CDTTornado WatchSPCAtoka, Bryan, Choctaw, Coal, Haskell, Hughes and 12 more7 hr
May 9, 4:56 PM CDTMesoscale DiscussionSPCBeaver, Beckham, Custer, Dewey, Ellis, Harper and 5 more2 hr
May 9, 6:01 PM CDTSevere Thunderstorm WatchSPCBeaver, Beckham, Custer, Dewey, Ellis, Greer and 8 more7 hr

Nearby

Tornado Watches in Arkansas, 2006Tornado Watches in Oklahoma, 2006Tornado Watches in Missouri, 2006Every tornado watch in 2006

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.