Severe Thunderstorm Watch 621

Issued

Aug 16, 2010, 3:08 PM CDT (20:08 UTC)

Expired

Aug 16, 2010, 7:10 PM CDT

In force

4 hr

Issued by

the Storm Prediction Center

Largest hail expected

1.5 in

Strongest gust expected

60 kt

Counties Antelope County, NE, Blaine County, NE, Boone County, NE, Brown County, NE, Cherry County, NE, Colfax County, NE, Cuming County, NE, Dodge County, NE, Garfield County, NE, Holt County, NE, Keya Paha County, NE, Loup County, NE, Madison County, NE, Pierce County, NE, Platte County, NE, Rock County, NE, Stanton County, NE, Thomas County, NE, Wayne County, NE, Wheeler County, NE

The North Platte radar (KLNX), 103 km from the middle of the area, began a volume at 20:08 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

30%

One or more gusts of 65 knots or more

30%

Ten or more severe hail reports

30%

One or more hailstones of 2 inches or more

20%

Six or more combined severe hail and wind reports

70%

• Mesoscale Discussion 1703Aug 16, 2:50 PM CDT
• Mesoscale Discussion 1704Aug 16, 5:32 PM CDT

357 
WWUS20 KWNS 162007
SEL1
SPC WW 162007
NEZ000-170300-

URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 621
NWS STORM PREDICTION CENTER NORMAN OK
310 PM CDT MON AUG 16 2010

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

       NORTHERN NEBRASKA

EFFECTIVE THIS MONDAY AFTERNOON AND EVENING FROM 310 PM UNTIL
1000 PM CDT.

HAIL TO 1.5 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 35
STATUTE MILES NORTH AND SOUTH OF A LINE FROM 40 MILES NORTH
NORTHWEST OF MULLEN NEBRASKA TO 45 MILES EAST NORTHEAST OF
COLUMBUS NEBRASKA.  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.

OTHER WATCH INFORMATION...CONTINUE...WW 619...WW 620...

DISCUSSION...A COUPLE OF SUPERCELLS HAVE DEVELOPED THIS AFTERNOON
ALONG A WNW-ESE ORIENTED LOW-LEVEL BAROCLINIC ZONE.  WHILE AMBIENT
AIR MASS IS NOT PARTICULARLY UNSTABLE...THE PRESENCE OF STEEP
LOW-LEVEL LAPSE RATES AND 40-50 KT OF DEEP NWLY SHEAR WILL REMAIN
SUPPORTIVE OF ORGANIZED SEVERE STORMS THROUGH THE REMAINDER OF THE
EVENING.

AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT
TO 1.5 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60
KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500. MEAN STORM
MOTION VECTOR 29030.


...MEAD

Severe Thunderstorm Watches in Nebraska, 2010Every severe thunderstorm watch in 2010

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.