Tornado Watch 407

Issued

May 31, 2008, 6:22 PM CDT (23:22 UTC)

Expired

Jun 1, 2008, 1:00 AM CDT

In force

7 hr

Issued by

the Storm Prediction Center

Largest hail expected

3 in

Strongest gust expected

60 kt

The Vance AFB radar (KVNX), 77 km from the middle of the area, began a volume at 23:21 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

40%

One or more gusts of 65 knots or more

30%

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

90%

• Mesoscale Discussion 1120May 31, 3:48 PM CDT
• Mesoscale Discussion 1127May 31, 7:43 PM CDT
• Mesoscale Discussion 1129May 31, 11:22 PM CDT

000
WWUS20 KWNS 312324
SEL7  
SPC WW 312324
KSZ000-OKZ000-010600-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 407
NWS STORM PREDICTION CENTER NORMAN OK
625 PM CDT SAT MAY 31 2008

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

       EXTREME SOUTH CENTRAL AND SOUTHEAST KANSAS
       NORTH CENTRAL AND NORTHEAST OKLAHOMA

EFFECTIVE THIS SATURDAY NIGHT AND SUNDAY MORNING FROM 625 PM
UNTIL 100 AM 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 50 STATUTE
MILES NORTH AND SOUTH OF A LINE FROM 40 MILES SOUTH OF ALVA
OKLAHOMA TO 45 MILES SOUTH SOUTHEAST OF CHANUTE KANSAS.  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 403...WW 404...WW
405...WW 406...

DISCUSSION...VISIBLE IMAGERY SUGGESTS THAT DEEPENING CUMULUS
CONVECTION ALONG AND N OF AN OUTFLOW BOUNDARY WILL LIKELY DEVELOP
INTO THUNDERSTORMS BY ABOUT 00Z.  STRONG INSTABILITY WILL FEED THIS
CONVECTION FROM THE S...AND VERTICAL SHEAR IS FAVORABLE FOR
SUPERCELLS.  BOUNDARY LAYER DEWPOINTS AROUND 70 F AND SOMEWHAT
ENHANCED SRH ALONG THE BOUNDARY COULD ALSO SUPPORT A COUPLE OF
TORNADOES THIS EVENING.  OTHERWISE...VERY LARGE HAIL WILL BE AN
INITIAL THREAT...WITH SOME POTENTIAL FOR UPSCALE GROWTH INTO A SMALL
MCS ACROSS SE KS/NE OK WITH AN INCREASING THREAT FOR DAMAGING WINDS.

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 27020.


...THOMPSON

Tornado Watches in Oklahoma, 2008Tornado Watches in Kansas, 2008Every tornado watch in 2008

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.