Alert archive / Arkansas / Tornado Watches in 2007

Tornado Watch 716

October 17, 200745 counties in Arkansas

The Storm Prediction Center issued this tornado watch at Oct 17, 2007, 11:38 PM CDT for 45 counties in Arkansas. It was in force for 3 hr.

The area

The outline as issued.

The facts

Issued
Oct 17, 2007, 11:38 PM CDT (04:38 UTC)
Expired
Oct 18, 2007, 2:37 AM CDT
In force
3 hr
Issued by
the Storm Prediction Center
Largest hail expected
2 in
Strongest gust expected
60 kt
All 45 counties

Arkansas County, AR, Baxter County, AR, Boone County, AR, Bradley County, AR, Calhoun County, AR, Clark County, AR, Cleburne County, AR, Cleveland County, AR, Conway County, AR, Dallas County, AR, Desha County, AR, Drew County, AR, Faulkner County, AR, Fulton County, AR, Garland County, AR, Grant County, AR, Hot Spring County, AR, Independence County, AR, Izard County, AR, Jackson County, AR, Jefferson County, AR, Johnson County, AR, Lincoln County, AR, Logan County, AR, Lonoke County, AR, Marion County, AR, Monroe County, AR, Montgomery County, AR, Newton County, AR, Ouachita County, AR, Perry County, AR, Pike County, AR, Polk County, AR, Pope County, AR, Prairie County, AR, Pulaski County, AR, Saline County, AR, Scott County, AR, Searcy County, AR, Sharp County, AR, Stone County, AR, Van Buren County, AR, White County, AR, Woodruff County, AR, Yell County, AR

The radar

The Little Rock radar (KLZK), 46 km from the middle of the area, began a volume at 04:41 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
50%
One or more gusts of 65 knots or more
40%
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
80%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Oct 17, 11:44 PM CDTSevere Thunderstorm WarningLZKFaulkner, Pulaski31 min
Oct 17, 11:50 PM CDTSevere Thunderstorm WarningLZKGrant25 min
Oct 18, 12:10 AM CDTSevere Thunderstorm WarningLZKBaxter, Marion, Newton, Searcy, Stone50 min
Oct 18, 12:13 AM CDTSevere Thunderstorm WarningLZKJefferson, Lonoke, Pulaski32 min
Oct 18, 12:29 AM CDTSevere Thunderstorm WarningLZKGrant46 min
Oct 18, 12:46 AM CDTSevere Thunderstorm WarningLZKJefferson29 min
Oct 18, 1:14 AM CDTSevere Thunderstorm WarningLZKFulton31 min
Oct 18, 1:17 AM CDTSevere Thunderstorm WarningLZKMonroe, Prairie, Woodruff28 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, 4.6 hours before the alert went out and 251 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 2007-10-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1262 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 2007-10-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 266 square meters per square second.1939587897Sfc1 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
1262 J/kg
Mixed-layer CIN
-8 J/kg
Mixed-layer LCL
618 m above ground
0-6 km bulk shear
61 kt
0-1 km storm-relative helicity
266 m²/s²
0-3 km storm-relative helicity
287 m²/s²
Significant tornado parameter
2.4
Supercell composite
8.3

Open this sounding in Storm Lab

The text

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

000
WWUS20 KWNS 180420
SEL6  
SPC WW 180420
ARZ000-181100-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 716
NWS STORM PREDICTION CENTER NORMAN OK
1120 PM CDT WED OCT 17 2007

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

       MUCH OF ARKANSAS

EFFECTIVE THIS WEDNESDAY NIGHT AND THURSDAY MORNING FROM 1120 PM
UNTIL 600 AM 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 80 STATUTE
MILES EAST AND WEST OF A LINE FROM 60 MILES WEST OF MONTICELLO
ARKANSAS TO 35 MILES NORTHEAST OF FLIPPIN ARKANSAS.  FOR A
COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE
UPDATE (WOUS64 KWNS WOU6).

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 713...WW 714...WW 715...

DISCUSSION...CLUSTERS OF INTENSE THUNDERSTORMS CONTINUE TO
RE-DEVELOP ACROSS AR AS UPPER TROUGH ROTATES THROUGH REGION.  VERY
STRONG VERTICAL SHEAR PROFILES /3KM SRH OVER 500 M2/S2/ AND
DEWPOINTS IN THE LOWER 70S WILL MAINTAIN A RISK OF SUPERCELLS
CAPABLE OF TORNADOES AND DAMAGING WINDS THROUGH MUCH OF THE NIGHT.

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 24035.


...HART

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Oct 17, 7:09 PM CDTTornado WatchSPCAshley, Chicot, Clay, Craighead, Crittenden, Cross and 8 more7 hr
Oct 17, 8:10 PM CDTMesoscale DiscussionSPCAshley, Baxter, Benton, Boone, Bradley, Calhoun and 48 more95 min
Oct 17, 10:56 PM CDTMesoscale DiscussionSPCArkansas, Baxter, Boone, Bradley, Calhoun, Carroll and 64 more64 min
Oct 18, 12:27 AM CDTMesoscale DiscussionSPCCraighead, Crittenden, Cross, Lee, Mississippi, Phillips and 2 more93 min
Oct 18, 1:31 AM CDTTornado WatchSPCClay, Craighead, Crittenden, Cross, Greene, Lawrence and 6 more4 hr
Oct 18, 2:02 AM CDTMesoscale DiscussionSPCArkansas, Baxter, Clay, Cleburne, Cleveland, Conway and 27 more58 min
Oct 18, 4:08 AM CDTMesoscale DiscussionSPCCraighead, Crittenden, Cross, Greene, Mississippi, Poinsett67 min
Oct 18, 1:31 PM CDTTornado WatchSPCClay, Craighead, Crittenden, Cross, Greene, Lee and 4 more9 hr
Oct 18, 5:39 PM CDTMesoscale DiscussionSPCCrittenden, Mississippi66 min

Nearby

Tornado Watches in Arkansas, 2007Every tornado watch in 2007

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.