Severe Thunderstorm Watch 366

Issued

Jun 9, 2012, 9:23 PM MDT (03:23 UTC)

Expired

Jun 10, 2012, 2:38 AM MDT

In force

5 hr

Issued by

the Storm Prediction Center

Largest hail expected

2 in

Strongest gust expected

60 kt

The Aberdeen radar (KABR), 184 km from the middle of the area, began a volume at 03:22 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

40%

One or more gusts of 65 knots or more

30%

Ten or more severe hail reports

50%

One or more hailstones of 2 inches or more

40%

Six or more combined severe hail and wind reports

80%

• Mesoscale Discussion 1108Jun 9, 9:08 PM MDT
• Mesoscale Discussion 1110Jun 9, 11:45 PM MDT

666 
WWUS20 KWNS 100322
SEL6
SPC WW 100322
SDZ000-101000-

URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 366
NWS STORM PREDICTION CENTER NORMAN OK
925 PM MDT SAT JUN 9 2012

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

       SOUTHWEST AND CENTRAL SOUTH DAKOTA

EFFECTIVE THIS SATURDAY NIGHT AND SUNDAY MORNING FROM 925 PM
UNTIL 400 AM MDT.

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 60
STATUTE MILES EAST AND WEST OF A LINE FROM 40 MILES NORTHWEST OF
ABERDEEN SOUTH DAKOTA TO 75 MILES SOUTH SOUTHWEST OF PHILIP SOUTH
DAKOTA.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED
WATCH OUTLINE UPDATE (WOUS64 KWNS WOU6).

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...STORMS WILL CONTINUE TO INCREASE IN COVERAGE/INTENSITY
THE NEXT FEW HOURS AS A BAND OF LOW-MIDLEVEL FRONTOGENESIS INTERACTS
WITH THE RICHER MOISTURE/INSTABILITY ACROSS CENTRAL SD.  DEEP-LAYER
VERTICAL SHEAR WILL BE FAVORABLE FOR BOTH SUPERCELLS AND ORGANIZED
BOWING SEGMENTS...WITH AN ATTENDANT RISK FOR LARGE HAIL AND DAMAGING
WINDS THROUGH THE OVERNIGHT HOURS.

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 500. MEAN STORM
MOTION VECTOR 24030.


...THOMPSON

Severe Thunderstorm Watches in South Dakota, 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.