Severe Thunderstorm Watch 34

Issued

Feb 20, 2012, 5:01 PM CST (23:01 UTC)

Expired

Feb 20, 2012, 9:00 PM CST

In force

4 hr

Issued by

the Storm Prediction Center

Largest hail expected

0.5 in

Strongest gust expected

60 kt

The Tulsa radar (KINX), 100 km from the middle of the area, began a volume at 23:03 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

20%

One or more EF2 to EF5 tornadoes

5%

Ten or more severe wind reports

40%

One or more gusts of 65 knots or more

20%

Ten or more severe hail reports

20%

One or more hailstones of 2 inches or more

5%

Six or more combined severe hail and wind reports

80%

• Mesoscale Discussion 138Feb 20, 4:50 PM CST
• Mesoscale Discussion 140Feb 20, 5:37 PM CST

354 
WWUS20 KWNS 202305
SEL4
SPC WW 202305
ARZ000-KSZ000-MOZ000-OKZ000-210300-

URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 34
NWS STORM PREDICTION CENTER NORMAN OK
500 PM CST MON FEB 20 2012

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

       NORTHWEST ARKANSAS
       SOUTHEAST KANSAS
       SOUTHWEST MISSOURI
       EASTERN OKLAHOMA

EFFECTIVE THIS MONDAY AFTERNOON AND EVENING FROM 500 PM UNTIL 900
PM CST.

HAIL TO 0.5 INCH IN DIAMETER...THUNDERSTORM WIND GUSTS TO 70
MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 70
STATUTE MILES EAST AND WEST OF A LINE FROM 45 MILES NORTHEAST OF
CHANUTE KANSAS TO 30 MILES SOUTHEAST OF MUSKOGEE OKLAHOMA.  FOR A
COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE
UPDATE (WOUS64 KWNS WOU4).

REMEMBER...A SEVERE THUNDERSTORM WATCH MEANS CONDITIONS ARE
FAVORABLE FOR 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. SEVERE THUNDERSTORMS CAN AND OCCASIONALLY
DO PRODUCE TORNADOES.

OTHER WATCH INFORMATION...CONTINUE...WW 33...

DISCUSSION...LOW-TOPPED SQLN EXPECTED TO CONTINUE ENE AT 45
KTS...WITH EMBEDDED SUSTAINED STORMS/SHORTER-LIVED SUPERCELLS MOVING
ENE AT 50.  SATELLITE SHOWS THAT ASSOCIATED UPR SYSTEM IS ASSUMING A
NEGATIVE TILT.  THIS WILL ENHANCE STRENGTH/GRADIENT OF LEADING-EDGE
DCVA AND ASSOCIATED FRONTAL CIRCULATION/LOW LVL WIND FIELD.  COUPLED
WITH PRESENCE OF EXISTING STORMS...THIS SUGGESTS A POTENTIAL FOR
CONTINUED INSTANCES OF DMGG WIND...DESPITE NIGHTFALL AND MOVEMENT OF
SQLN BEYOND AXIS OF MAXIMUM LOW LVL BUOYANCY.

AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT
TO 0.5 INCH. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60
KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 350. MEAN STORM
MOTION VECTOR 25050.


...CORFIDI

Severe Thunderstorm Watches in Oklahoma, 2012Severe Thunderstorm Watches in Kansas, 2012Severe Thunderstorm Watches in Missouri, 2012Every severe thunderstorm 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.