Tornado Watch 850

Issued

Sep 17, 2011, 2:30 PM CDT (19:30 UTC)

Expired

Sep 17, 2011, 11:00 PM CDT

In force

9 hr

Issued by

the Storm Prediction Center

Largest hail expected

2 in

Strongest gust expected

60 kt

The Vance AFB radar (KVNX), 48 km from the middle of the area, began a volume at 19:32 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

10%

Ten or more severe hail reports

80%

One or more hailstones of 2 inches or more

30%

Six or more combined severe hail and wind reports

95%

• Mesoscale Discussion 2183Sep 17, 2:02 PM CDT
• Mesoscale Discussion 2186Sep 17, 5:49 PM CDT
• Mesoscale Discussion 2187Sep 17, 10:17 PM CDT

387 
WWUS20 KWNS 171936
SEL0
SPC WW 171936
KSZ000-OKZ000-180400-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 850
NWS STORM PREDICTION CENTER NORMAN OK
230 PM CDT SAT SEP 17 2011

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

       SOUTHWEST AND SOUTH CENTRAL KANSAS
       NORTHWEST AND NORTH CENTRAL OKLAHOMA

EFFECTIVE THIS SATURDAY AFTERNOON AND EVENING FROM 230 PM UNTIL
1100 PM 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 90 STATUTE
MILES EAST AND WEST OF A LINE FROM 40 MILES SOUTH SOUTHEAST OF
ENID OKLAHOMA TO 45 MILES NORTHEAST OF DODGE CITY KANSAS.  FOR A
COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE
UPDATE (WOUS64 KWNS WOU0).

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.

DISCUSSION...TSTMS EXPECTED TO FORM IN THE NEXT HOUR OR SO NEAR
INTERSECTION OF DRY LINE/CONFLUENCE ZONE ARCING EWD ACROSS FAR ERN
PARTS OF THE OK/TX PANHANDLE...AND WNW-ESE ORIENTED OUTFLOW
BNDRY/WARM FRONT OVER NRN OK.  IN THIS AREA...COMBINATION OF SFC
HEATING...CONTINUED LOW LVL MOISTURE INFLOW /AVERAGE DEWPOINTS IN
THE UPR 60S F/...AND WEAK LARGE SCALE FORCING FOR ASCENT ASSOCIATED
WITH UPR IMPULSE NOW OVER SW KS EXPECTED TO FURTHER DESTABILIZE
REGION.  AREA VWP DATA AND FCST WIND FIELDS SUGGEST POTENTIAL FOR A
FEW SUPERCELLS...ENHANCING THE RISK FOR LARGE HAIL/HIGH WIND.
TORNADOES ALSO WILL BE POSSIBLE...MAINLY WITH ANY STORMS THAT MOVE
MORE OR LESS PARALLEL TO/IN TANDEM WITH OUTFLOW BNDRY/WARM FRONT.

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
550. MEAN STORM MOTION VECTOR 27020.


...CORFIDI

Tornado Watches in Kansas, 2011Tornado Watches in Oklahoma, 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.