Tornado Watch 308

Issued

May 19, 2011, 12:46 PM CDT (17:46 UTC)

Expired

May 19, 2011, 10:00 PM CDT

In force

9 hr

Issued by

the Storm Prediction Center

Largest hail expected

3 in

Strongest gust expected

70 kt

The Altus AFB radar (KFDR), 118 km from the middle of the area, began a volume at 17:48 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

50%

One or more EF2 to EF5 tornadoes

30%

Ten or more severe wind reports

40%

One or more gusts of 65 knots or more

40%

Ten or more severe hail reports

70%

One or more hailstones of 2 inches or more

80%

Six or more combined severe hail and wind reports

95%

• Mesoscale Discussion 810May 19, 12:30 PM CDT
• Mesoscale Discussion 814May 19, 3:44 PM CDT
• Mesoscale Discussion 816May 19, 5:21 PM CDT
• Mesoscale Discussion 819May 19, 7:47 PM CDT
• Mesoscale Discussion 821May 19, 9:36 PM CDT

801 
WWUS20 KWNS 191751
SEL8
SPC WW 191751
OKZ000-TXZ000-200100-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 308
NWS STORM PREDICTION CENTER NORMAN OK
1250 PM CDT THU MAY 19 2011

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

       WESTERN OKLAHOMA
       NORTHWESTERN TEXAS

EFFECTIVE THIS THURSDAY AFTERNOON AND EVENING FROM 1250 PM UNTIL
800 PM CDT.

TORNADOES...HAIL TO 3 INCHES IN DIAMETER...THUNDERSTORM WIND
GUSTS TO 80 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE
AREAS.

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 55 STATUTE
MILES EAST AND WEST OF A LINE FROM 20 MILES NORTHEAST OF ALVA
OKLAHOMA TO 100 MILES SOUTH OF CHILDRESS TEXAS.  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 307...

DISCUSSION...STORMS HAVE BEGUN TO DEVELOP NEAR THE DRYLINE AND
LIKELY WILL INCREASE IN COVERAGE THROUGH THE AFTERNOON IN UNCAPPED
AND WARMING AIR MASS.  THE ENVIRONMENT HAS BECOME STRONGLY UNSTABLE
WITH MLCAPES NEAR 3000 J/KG AND DEEP LAYER SHEAR IS SUFFICIENT FOR
SUPERCELLS.  THE GREATEST THREAT WILL BE LARGE HAIL...THOUGH THE
RISK FOR TORNADOES WILL INCREASE THROUGH THE AFTERNOON AS THE LOW
LEVEL WINDS NEAR AND EAST OF THE DRYLINE ARE EXPECTED TO BACK AND
INCREASE IN SPEED THROUGH THE AFTERNOON.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 3 INCHES. EXTREME TURBULENCE AND SURFACE
WIND GUSTS TO 70 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
550. MEAN STORM MOTION VECTOR 21020.


...IMY

Tornado Watches in Oklahoma, 2011Tornado Watches in Texas, 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.