Severe Thunderstorm Watch 111

Issued

Mar 26, 2012, 5:28 PM MDT (23:28 UTC)

Expired

Mar 27, 2012, 12:09 AM MDT

In force

7 hr

Issued by

the Storm Prediction Center

Largest hail expected

1.5 in

Strongest gust expected

70 kt

The Rapid City radar (KUDX), 78 km from the middle of the area, began a volume at 23:30 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

2%

Ten or more severe wind reports

60%

One or more gusts of 65 knots or more

30%

Ten or more severe hail reports

20%

One or more hailstones of 2 inches or more

5%

Six or more combined severe hail and wind reports

90%

• Mesoscale Discussion 363Mar 26, 2:56 PM MDT
• Mesoscale Discussion 365Mar 26, 8:17 PM MDT
• Mesoscale Discussion 366Mar 26, 10:38 PM MDT

210 
WWUS20 KWNS 262333
SEL1
SPC WW 262333
NDZ000-SDZ000-270700-

URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 111
NWS STORM PREDICTION CENTER NORMAN OK
530 PM MDT MON MAR 26 2012

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

       SOUTHERN NORTH DAKOTA
       WESTERN AND CENTRAL SOUTH DAKOTA

EFFECTIVE THIS MONDAY AFTERNOON AND TUESDAY MORNING FROM 530 PM
UNTIL 100 AM MDT.

HAIL TO 1.5 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 80
MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 85
STATUTE MILES EAST AND WEST OF A LINE FROM 75 MILES SOUTH
SOUTHWEST OF PHILIP SOUTH DAKOTA TO 20 MILES WEST NORTHWEST OF
BISMARCK NORTH DAKOTA.  FOR A COMPLETE DEPICTION OF THE WATCH SEE
THE ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU1).

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...TSTMS ARE NOW FORMING ALONG SSW-NNE CONFLUENCE AXIS ON
SW SD/FAR NW NEB.  OTHER STORMS MAY FORM LATER THIS EVE ALONG
NE-MOVING DEEP WIND SHIFT NOW CROSSING NE WY.  DEVELOPMENT WILL BE
ASSISTED BY UPR DIVERGENCE/DCVA ASSOCIATED WITH POTENT UPR VORT
MOVING STEADILY ENE FROM CNTRL WY.  WHILE THE CURRENT CONVECTION IS
WITHIN DRY/DEEPLY MIXED ENVIRONMENT SPREADING NE FROM THE CNTRL/NRN
HI PLNS...POTENTIAL WILL EXIST FOR THE STORMS TO BECOME ROOTED
WITHIN ZONE OF RELATIVELY MORE MOIST AIR STREAMING NWWD ALONG
SHALLOW WARM FRONT BISECTING SD.  IF THIS OCCURS...UPSCALE
DEVELOPMENT INTO ONE OR TWO SMALL MCSS MAY OCCUR.  50+ KT LWR
TROPOSPHERIC FLOW MAY YIELD EMBEDDED BOWING SEGMENTS WITH HIGH
WIND...MARGINALLY SVR HAIL...AND POSSIBLY A BRIEF TORNADO THROUGH
LATE TNGT/EARLY TUE.

AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT
TO 1.5 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 70
KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 400. MEAN STORM
MOTION VECTOR 23045.


...CORFIDI

Severe Thunderstorm Watches in South Dakota, 2012Severe Thunderstorm Watches in North 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.