Tornado Watch 667

Issued

Oct 17, 2012, 5:21 PM CDT (22:21 UTC)

Expired

Oct 18, 2012, 12:41 AM CDT

In force

7 hr

Issued by

the Storm Prediction Center

Largest hail expected

2 in

Strongest gust expected

65 kt

The Little Rock radar (KLZK), 142 km from the middle of the area, began a volume at 22:23 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.

Two or more tornadoes

60%

One or more EF2 to EF5 tornadoes

30%

Ten or more severe wind reports

95%

One or more gusts of 65 knots or more

30%

Ten or more severe hail reports

30%

One or more hailstones of 2 inches or more

20%

Six or more combined severe hail and wind reports

95%

• Mesoscale Discussion 2065Oct 17, 3:44 PM CDT
• Mesoscale Discussion 2066Oct 17, 6:19 PM CDT
• Mesoscale Discussion 2067Oct 17, 6:29 PM CDT
• Mesoscale Discussion 2068Oct 17, 7:35 PM CDT
• Mesoscale Discussion 2069Oct 17, 8:07 PM CDT
• Mesoscale Discussion 2070Oct 17, 9:28 PM CDT

537 
WWUS20 KWNS 172233
SEL7
SPC WW 172233
ARZ000-ILZ000-KYZ000-MOZ000-MSZ000-TNZ000-180700-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 667
NWS STORM PREDICTION CENTER NORMAN OK
525 PM CDT WED OCT 17 2012

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

       ARKANSAS
       SOUTHERN ILLINOIS
       WESTERN KENTUCKY
       SOUTHEAST MISSOURI
       NORTHWEST MISSISSIPPI
       WESTERN TENNESSEE

EFFECTIVE THIS WEDNESDAY AFTERNOON AND THURSDAY MORNING FROM 525
PM UNTIL 200 AM CDT.

TORNADOES...HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND
GUSTS TO 75 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE
AREAS.

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 130 STATUTE
MILES EAST AND WEST OF A LINE FROM 60 MILES NORTH NORTHWEST OF
POPLAR BLUFF MISSOURI TO 30 MILES SOUTHWEST OF PINE BLUFF
ARKANSAS.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE
ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU7).

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 666...

DISCUSSION...TSTMS EXPECTED TO INCREASE RAPIDLY IN NUMBER AND EXTENT
OVER THE NEXT 1-2 HRS...ESPECIALLY FROM S CNTRL AR NEWD INTO SE
MO/SRN IL...AS LEADING EDGE OF STRONG FORCING FOR ASCENT WITH
AMPLIFYING SHORTWAVE TROUGH OVERSPREADS LOW-LVL MOIST AXIS.
STRENGTHENING...DEEP-VEERING WIND PROFILES...WITH 700 MB SPEEDS AOA
45 KTS...COUPLED WITH 40+ KT WEAKLY CONFLUENT LOW-LVL FLOW...MAY
SUPPORT A FEW LONG-LIVED SUPERCELLS POSING A SVR WIND...HAIL...AND
TORNADO THREAT THROUGH LATE TNGT. IN THE MEAN TIME...OTHER STORMS
EXPECTED TO CONTINUE FORMING ALONG SFC COLD FRONT IN NW AR. THESE
TOO MAY EVOLVE INTO SUPERCELLS WITH A RISK FOR SVR WIND...HAIL...AND
POSSIBLY A TORNADO. FINALLY...SQLN WITH EMBEDDED CIRCULATIONS
EXTENDING FROM S CNTRL MO NEWD TO NEAR ST LOUIS EXPECTED TO
ACCELERATE ENEWD...WITH A CONTINUING RISK FOR DMGG WIND AND PERHAPS
ADDITIONAL EMBEDDED SMALL SCALE CIRCULATIONS/BRIEF TORNADOES.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 2 INCHES. EXTREME TURBULENCE AND SURFACE
WIND GUSTS TO 65 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
500. MEAN STORM MOTION VECTOR 29040.


...CORFIDI

Tornado Watches in Arkansas, 2012Tornado Watches in Missouri, 2012Tornado Watches in Tennessee, 2012Every tornado watch in 2012

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.