Tornado Watch 258

Issued

Apr 30, 2011, 6:48 PM CDT (23:48 UTC)

Expired

May 1, 2011, 2:00 AM CDT

In force

7 hr

Issued by

the Storm Prediction Center

Largest hail expected

2 in

Strongest gust expected

60 kt

The Little Rock radar (KLZK), 66 km from the middle of the area, began a volume at 23:51 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

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%

• Mesoscale Discussion 671Apr 30, 6:31 PM CDT
• Mesoscale Discussion 673Apr 30, 8:47 PM CDT
• Mesoscale Discussion 675Apr 30, 11:39 PM CDT
• Mesoscale Discussion 677May 1, 1:16 AM CDT

706 
WWUS20 KWNS 302351
SEL8
SPC WW 302351
ARZ000-010700-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 258
NWS STORM PREDICTION CENTER NORMAN OK
650 PM CDT SAT APR 30 2011

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

       ARKANSAS

EFFECTIVE THIS SATURDAY NIGHT AND SUNDAY MORNING FROM 650 PM
UNTIL 200 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 50 STATUTE
MILES NORTH AND SOUTH OF A LINE FROM 40 MILES SOUTH OF FORT SMITH
ARKANSAS TO 30 MILES SOUTH OF JONESBORO ARKANSAS.  FOR A COMPLETE
DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE UPDATE
(WOUS64 KWNS WOU8).

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 257...

DISCUSSION...TSTMS HAVE RECENTLY INCREASED IN COVERAGE AND INTENSITY
FROM NE OF BVX TO W OF HOT...LIKELY IN RESPONSE TO A LOW-AMPLITUDE
IMPULSE LIFTING NEWD FROM THE ARKLATEX.  THIS INITIAL ACTIVITY
APPEARS TO BE AT LEAST SLIGHTLY ELEVATED.  HOWEVER...GIVEN THE WARM
AND MOIST BOUNDARY LAYER IN PLACE NAMELY ALONG AND S OF THE I-40
CORRIDOR...POTENTIAL WILL EXIST FOR STORMS TO BECOME SURFACE-BASED
WITHIN A KINEMATIC ENVIRONMENT CHARACTERIZED BY 0-1 KM SRH OF
250-300 M2/S2 PER LITTLE ROCK VWP.  WHILE LARGE HAIL WILL BE THE
PRIMARY HAZARD...TORNADOES WILL BE POSSIBLE WITH ANY SUPERCELLS THAT
CAN BECOME SURFACE-BASED.

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 24030.


...MEAD

Tornado Watches in Arkansas, 2011Every tornado watch in 2011

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.