Severe Thunderstorm Watch 574

Issued

Aug 12, 2012, 7:16 PM CDT (00:16 UTC)

Expired

Aug 12, 2012, 11:40 PM CDT

In force

4 hr

Issued by

the Storm Prediction Center

Largest hail expected

2 in

Strongest gust expected

60 kt

Counties Adair County, OK, Cherokee County, OK, Choctaw County, OK, Haskell County, OK, Latimer County, OK, LeFlore County, OK, McCurtain County, OK, McIntosh County, OK, Muskogee County, OK, Pittsburg County, OK, Pushmataha County, OK, Sequoyah County, OK, Camp County, TX, Franklin County, TX, Morris County, TX, Red River County, TX, Titus County, TX

The Western Arkansas radar (KSRX), 139 km from the middle of the area, began a volume at 00:20 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

50%

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 1743Aug 12, 3:29 PM CDT
• Mesoscale Discussion 1746Aug 12, 6:28 PM CDT
• Mesoscale Discussion 1747Aug 12, 8:41 PM CDT
• Mesoscale Discussion 1748Aug 12, 10:26 PM CDT

045 
WWUS20 KWNS 130024
SEL4
SPC WW 130024
OKZ000-TXZ000-130600-

URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 574
NWS STORM PREDICTION CENTER NORMAN OK
720 PM CDT SUN AUG 12 2012

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

       EASTERN OKLAHOMA
       NORTHEAST TEXAS

EFFECTIVE THIS SUNDAY NIGHT AND MONDAY MORNING FROM 720 PM UNTIL
100 AM 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 40
STATUTE MILES EAST AND WEST OF A LINE FROM 35 MILES WEST
NORTHWEST OF POTEAU OKLAHOMA TO 50 MILES SOUTH SOUTHEAST OF PARIS
TEXAS.  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 573...

DISCUSSION...TSTMS FORMING ALONG WSW-ENE PRE-FRONTAL CONFLUENCE LINE
NOW NEAR DURANT OK MAY MOVE/DEVELOP E INTO ADJACENT PARTS OF SE OK
AND POSSIBLY NE TX LATER THIS EVE. WHILE LARGE SCALE FORCING FOR
ASCENT WILL REMAIN WEAK...WEAK CONFLUENCE WILL PERSIST WITHIN FAIRLY
MOIST AND UNSTABLE LOW LVL ENVIRONMENT BENEATH 20-25 KT NWLY MID LVL
FLOW.  THIS SETUP MAY FOSTER A FEW DISCRETE STORMS CAPABLE OF DMGG
WIND AND LARGE HAIL.
FARTHER N...ADDITIONAL ISOLD TO PERHAPS WDLY SCTD STORMS MAY FORM
LATER THIS EVE NEAR COLD FRONT AND PREFRONTAL CONFLUENCE LINE IN NE
OK/FAR SE KS...AND/OR ALONG WEAK WARM FRONT IN NW AR/SW MO. LOW
CONFIDENCE IN THIS SCENARIO SUGGESTS THAT A WW IS UNWARRANTED ATTM
...DESPITE PRESENCE OF AMPLE INSTABILITY/SHEAR FOR SVR STORMS.

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 30020.


...CORFIDI

Severe Thunderstorm Watches in Oklahoma, 2012Severe Thunderstorm Watches in Texas, 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.