Severe Thunderstorm Watch 708

Issued

Aug 17, 2009, 3:18 PM CDT (20:18 UTC)

Expired

Aug 18, 2009, 1:00 AM CDT

In force

10 hr

Issued by

the Storm Prediction Center

Largest hail expected

2 in

Strongest gust expected

60 kt

The Amarillo radar (KAMA), 152 km from the middle of the area, began a volume at 20:19 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

30%

One or more gusts of 65 knots or more

30%

Ten or more severe hail reports

30%

One or more hailstones of 2 inches or more

20%

Six or more combined severe hail and wind reports

70%

• Mesoscale Discussion 1905Aug 17, 2:59 PM CDT
• Mesoscale Discussion 1907Aug 17, 5:40 PM CDT
• Mesoscale Discussion 1908Aug 17, 8:34 PM CDT

900 
WWUS20 KWNS 172019
SEL8  
SPC WW 172019
OKZ000-TXZ000-180300-

URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 708
NWS STORM PREDICTION CENTER NORMAN OK
320 PM CDT MON AUG 17 2009

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

       NORTHWEST OKLAHOMA
       CENTRAL AND EASTERN TEXAS PANHANDLE

EFFECTIVE THIS MONDAY AFTERNOON AND EVENING FROM 320 PM UNTIL
1000 PM CDT.

HAIL TO 2 INCHES 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 55
STATUTE MILES NORTH AND SOUTH OF A LINE FROM 25 MILES NORTH
NORTHWEST OF AMARILLO TEXAS TO 10 MILES SOUTH OF ENID OKLAHOMA. 
FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH
OUTLINE UPDATE (WOUS64 KWNS WOU8).

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.

DISCUSSION...THUNDERSTORMS HAVE ALREADY DEVELOPED NEAR AMA ALONG A
SURFACE TROUGH...AND ADDITIONAL STORMS MAY FORM FARTHER TO THE ENE
ALONG THE BOUNDARY IN THE NE TX PANHANDLE AS SURFACE HEATING
CONTINUES.  OTHER STORMS COULD ALSO DEVELOP THIS AFTERNOON ALONG A
STALLED OUTFLOW BOUNDARY ACROSS NW OK.  VERTICAL SHEAR IS AT LEAST
MARGINALLY FAVORABLE FOR SUPERCELLS ON THE IMMEDIATE COOL SIDE OF
THE BOUNDARY...ALONG THE N EDGE OF THE STRONGER SURFACE-BASED
INSTABILITY.  CONVECTION SHOULD INCREASE IN COVERAGE AND PERSIST
THROUGH THE EVENING...WITH LARGE HAIL AND DAMAGING WINDS THE MAIN
SEVERE THREATS.

AVIATION...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 29015.


...THOMPSON

Severe Thunderstorm Watches in Oklahoma, 2009Severe Thunderstorm Watches in Texas, 2009Every severe thunderstorm watch in 2009

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.