Tornado Watch 521

Issued

Jun 26, 2009, 6:24 PM CDT (23:24 UTC)

Expired

Jun 26, 2009, 10:20 PM CDT

In force

4 hr

Issued by

the Storm Prediction Center

Largest hail expected

3 in

Strongest gust expected

60 kt

The Aberdeen radar (KABR), 190 km from the middle of the area, began a volume at 23:25 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

60%

One or more EF2 to EF5 tornadoes

20%

Ten or more severe wind reports

70%

One or more gusts of 65 knots or more

30%

Ten or more severe hail reports

70%

One or more hailstones of 2 inches or more

40%

Six or more combined severe hail and wind reports

90%

• Mesoscale Discussion 1343Jun 26, 6:05 PM CDT
• Mesoscale Discussion 1348Jun 26, 8:55 PM CDT

072 
WWUS20 KWNS 262324
SEL1  
SPC WW 262324
SDZ000-270700-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 521...RESENT
NWS STORM PREDICTION CENTER NORMAN OK
625 PM CDT FRI JUN 26 2009

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

       LARGE PART OF CENTRAL AND EASTERN SOUTH DAKOTA

EFFECTIVE THIS FRIDAY NIGHT AND SATURDAY MORNING FROM 625 PM
UNTIL 200 AM CDT.

TORNADOES...HAIL TO 3 INCHES IN DIAMETER...THUNDERSTORM WIND
GUSTS TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE
AREAS.

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 80 STATUTE
MILES EAST AND WEST OF A LINE FROM 75 MILES SOUTHWEST OF
CHAMBERLAIN SOUTH DAKOTA TO 40 MILES NORTH NORTHWEST OF ABERDEEN
SOUTH DAKOTA.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE
ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU1).

REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR
TORNADOES AND 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.

OTHER WATCH INFORMATION...CONTINUE...WW 517...WW 518...WW
519...WW 520...

DISCUSSION...A VERY MOIST/UNSTABLE AIR MASS CONTINUES TO MOVE NWD
THRU WATCH AREA AHEAD OF THE APPROACHING SEVERE THUNDERSTORMS TO THE
W.  MODEL FORECASTS ALL SUPPORT STRONG VEERING SHEAR PROFILES THRU
THE EVENING...WHICH SHOULD ENHANCE DEVELOPMENT OF SUPERCELLS
INCLUDING TORNADOES AND VERY LARGE HAIL.  ACTIVITY WILL MOVE
PROPAGATE NEWD ACROSS CENTRAL IN ERN SD DURING THE EVENING.

AVIATION...TORNADOES AND 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 24025.


...HALES

Tornado Watches in South Dakota, 2009Every tornado watch in 2009

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.