Tornado Watch 561

Issued

Aug 3, 2007, 2:17 PM MDT (20:17 UTC)

Expired

Aug 3, 2007, 10:00 PM MDT

In force

8 hr

Issued by

the Storm Prediction Center

Largest hail expected

2 in

Strongest gust expected

60 kt

Counties Arthur County, NE, Blaine County, NE, Brown County, NE, Cherry County, NE, Custer County, NE, Garden County, NE, Grant County, NE, Hooker County, NE, Keya Paha County, NE, Logan County, NE, Loup County, NE, McPherson County, NE, Rock County, NE, Sheridan County, NE, Thomas County, NE, Bennett County, SD, Jackson County, SD, Mellette County, SD, Todd County, SD, Tripp County, SD

The North Platte radar (KLNX), 97 km from the middle of the area, began a volume at 20:19 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

70%

One or more EF2 to EF5 tornadoes

30%

Ten or more severe wind reports

70%

One or more gusts of 65 knots or more

50%

Ten or more severe hail reports

70%

One or more hailstones of 2 inches or more

60%

Six or more combined severe hail and wind reports

80%

• Mesoscale Discussion 1634Aug 3, 1:32 PM MDT
• Mesoscale Discussion 1637Aug 3, 4:49 PM MDT
• Mesoscale Discussion 1638Aug 3, 7:02 PM MDT

000
WWUS20 KWNS 032015
SEL1  
SPC WW 032015
NEZ000-SDZ000-040400-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 561
NWS STORM PREDICTION CENTER NORMAN OK
315 PM CDT FRI AUG 3 2007

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

       CENTRAL NEBRASKA
       SOUTH CENTRAL SOUTH DAKOTA

EFFECTIVE THIS FRIDAY AFTERNOON AND EVENING FROM 315 PM UNTIL
1100 PM CDT.

TORNADOES...HAIL TO 2 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 75 STATUTE
MILES EAST AND WEST OF A LINE FROM 60 MILES NORTHWEST OF
VALENTINE NEBRASKA TO 40 MILES WEST OF BROKEN BOW NEBRASKA.  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 560...

DISCUSSION...AIR MASS CONTINUES TO DESTABILIZE ACROSS THE REGION
WITH MLCAPES ACHIEVING 1500-2000 J/KG. IN ADDITION WITH BROAD
SHORTWAVE TROUGH APPROACHING AREA...THERE IS AN INCREASE IN LOW/MID
LEVEL FLOW SUFFICIENT FOR DEEP LAYER SHEAR VALUES TO BE 40-45 KT
NEAR A BOUNDARY THAT IS JUST NORTH OF THE SD/NEB BORDER.  THIS HAS
LEAD TO THE DEVELOPMENT OF SOME HP SUPERCELLS ACROSS PARTS OF SRN
SD/NRN NEB WHICH ARE MOVING INTO THE INSTABILITY AXIS.  THERE IS A
THREAT FOR TORNADOES...BUT WOULD EXPECT HAIL AND DAMAGING WINDS TO
BE PREVALENT ACROSS THE AREA.

AVIATION...TORNADOES AND 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 27035.


...MCCARTHY

Tornado Watches in Nebraska, 2007Tornado Watches in South Dakota, 2007Every tornado watch in 2007

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.