Severe Thunderstorm Watch 200

Issued

Apr 28, 2012, 6:33 PM CDT (23:33 UTC)

Expired

Apr 29, 2012, 2:00 AM CDT

In force

7 hr

Issued by

the Storm Prediction Center

Largest hail expected

3 in

Strongest gust expected

60 kt

The Altus AFB radar (KFDR), 82 km from the middle of the area, began a volume at 23:33 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

20%

Ten or more severe hail reports

80%

One or more hailstones of 2 inches or more

40%

Six or more combined severe hail and wind reports

95%

• Mesoscale Discussion 613Apr 28, 3:54 PM CDT
• Mesoscale Discussion 616Apr 28, 6:46 PM CDT
• Mesoscale Discussion 617 Severe thunderstorm watch 200Apr 28, 10:54 PM CDT
• Mesoscale Discussion 618Apr 29, 1:37 AM CDT
• Mesoscale Discussion 619Apr 29, 1:53 AM CDT

228 
WWUS20 KWNS 282342
SEL0
SPC WW 282342
OKZ000-TXZ000-290700-

URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 200
NWS STORM PREDICTION CENTER NORMAN OK
635 PM CDT SAT APR 28 2012

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

       WESTERN AND CENTRAL OKLAHOMA
       THE TEXAS SOUTH PLAINS AND WESTERN NORTH TEXAS

EFFECTIVE THIS SATURDAY NIGHT AND SUNDAY MORNING FROM 635 PM
UNTIL 200 AM CDT.

HAIL TO 3 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 50
STATUTE MILES EAST AND WEST OF A LINE FROM 55 MILES WEST
SOUTHWEST OF ABILENE TEXAS TO 10 MILES EAST NORTHEAST OF ENID
OKLAHOMA.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE
ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU0).

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 197...WW 198...WW 199...

DISCUSSION...TSTMS/SUPERCELLS EXPECTED TO FORM NEAR SW-NE
DRYLINE/FRONT MOVING NWWD ACROSS W CNTRL TX AND SW/CNTRL OK.
ACTIVITY WILL BE SUPPORTED BY WEAKENING OF EXISTING EML CAP
FOLLOWING DAYTIME HEATING...CONTINUED LOW LVL MOISTURE INFLOW...AND
INCREASING ASCENT ASSOCIATED WITH ENTRANCE REGION OF JET STREAM
CROSSING NM.  MAIN SVR THREAT SHOULD BE LARGE HAIL...ESPECIALLY FROM
POSSIBLE LEFT SPLIT STORMS ALONG WRN FRINGE OF WW.  SETUP ALSO MAY
SUPPORT A CONDITIONAL RISK FOR TORNADOES...MAINLY IN WRN N TX AND SW
OK...WHERE LOW LVL FLOW WILL REMAIN SLIGHTLY BACKED N OF NW TX SFC
WAVE AS LLJ STRENGTHENS THIS EVE.  DEPENDING UPON PREDOMINANT STORM
MODE/PATTERN OF DEVELOPMENT...THIS REGION MAY REQUIRE UPGRADE TO A
TORNADO WW LATER TNGT.  OTHERWISE...EXPECT EVENTUAL DEVELOPMENT OF
ONE OR MORE STORM COMPLEXES...WITH STORM INTERACTIONS/
FORWARD-PROPAGATING SEGMENTS EXTENDING THE SVR THREAT GENERALLY E/NE
WITH TIME.

AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT
TO 3 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60
KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 550. MEAN STORM
MOTION VECTOR 27020.


...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.