Severe Thunderstorm Watch 183

Issued

Apr 19, 2012, 6:38 PM CDT (23:38 UTC)

Expired

Apr 20, 2012, 1:00 AM CDT

In force

6 hr

Issued by

the Storm Prediction Center

Largest hail expected

2.5 in

Strongest gust expected

60 kt

The Altus AFB radar (KFDR), 78 km from the middle of the area, began a volume at 23:39 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

80%

One or more hailstones of 2 inches or more

20%

Six or more combined severe hail and wind reports

95%

• Mesoscale Discussion 567Apr 19, 6:10 PM CDT
• Mesoscale Discussion 569Apr 19, 9:13 PM CDT
• Mesoscale Discussion 570Apr 19, 10:49 PM CDT

312 
WWUS20 KWNS 192338
SEL3
SPC WW 192338
OKZ000-TXZ000-200600-

URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 183
NWS STORM PREDICTION CENTER NORMAN OK
640 PM CDT THU APR 19 2012

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

       SOUTH CENTRAL OKLAHOMA
       WESTERN NORTH TEXAS

EFFECTIVE THIS THURSDAY NIGHT AND FRIDAY MORNING FROM 640 PM
UNTIL 100 AM CDT.

HAIL TO 2.5 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 EAST AND WEST OF A LINE FROM 35 MILES WEST OF
MINERAL WELLS TEXAS TO 20 MILES NORTHEAST OF OKLAHOMA CITY
OKLAHOMA.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE
ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU3).

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 ARE BEGINNING TO FORM ALONG SURFACE COLD
FRONT/DRYLINE OVER WESTERN NORTH TX...AND ARE EXPECTED TO FORM IN
THE NEXT 1-2 HOURS OVER PARTS OF SOUTHWEST OK.  THIS ACTIVITY WILL
BE IN A REGION OF RELATIVELY WEAK LOW LEVEL SHEAR.  BUT...SUFFICIENT
EFFECTIVE SHEAR VALUES AND MODERATE CAPE WILL PROMOTE SUPERCELL
STRUCTURES CAPABLE OF LARGE HAIL AND DAMAGING WINDS.  ACTIVITY MAY
PERSIST NEAR THE RED RIVER FOR MUCH OF THE EVENING.

AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT
TO 2.5 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60
KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500. MEAN STORM
MOTION VECTOR 27030.


...HART

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.