Tornado Watch 397

Issued

Jun 13, 2009, 1:56 PM MDT (19:56 UTC)

Expired

Jun 13, 2009, 11:00 PM MDT

In force

9 hr

Issued by

the Storm Prediction Center

Largest hail expected

2 in

Strongest gust expected

60 kt

The Cheyenne radar (KCYS), 42 km from the middle of the area, began a volume at 19:56 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

40%

One or more EF2 to EF5 tornadoes

20%

Ten or more severe wind reports

30%

One or more gusts of 65 knots or more

30%

Ten or more severe hail reports

60%

One or more hailstones of 2 inches or more

30%

Six or more combined severe hail and wind reports

80%

• Mesoscale Discussion 1093Jun 13, 12:41 PM MDT
• Mesoscale Discussion 1099Jun 13, 4:26 PM MDT
• Mesoscale Discussion 1101Jun 13, 6:42 PM MDT
• Mesoscale Discussion 1104Jun 13, 7:58 PM MDT

941 
WWUS20 KWNS 131957
SEL7  
SPC WW 131957
COZ000-NEZ000-WYZ000-140300-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 397
NWS STORM PREDICTION CENTER NORMAN OK
155 PM MDT SAT JUN 13 2009

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

       A LARGE PORTION OF EASTERN COLORADO
       MUCH OF NEBRASKA PANHANDLE
       PARTS OF EASTERN WYOMING

EFFECTIVE THIS SATURDAY AFTERNOON AND EVENING FROM 155 PM UNTIL
900 PM MDT.

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 80 STATUTE
MILES EAST AND WEST OF A LINE FROM 50 MILES NORTH OF DOUGLAS
WYOMING TO 50 MILES SOUTH OF LIMON COLORADO.  FOR A COMPLETE
DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE UPDATE
(WOUS64 KWNS WOU7).

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.

DISCUSSION...WITH APPROACH OF S/WV TROUGH FROM UT/WRN CO...SHEAR
PROFILES AND INSTABILITY ARE BECOMING FAVORABLE FOR DEVELOPMENT OF
SEVERE THUNDERSTORMS...PRIMARILY EAST OF MOUNTAINS.  WITH MLCAPES
AOA 1200 J/KG AND 40KT OF SHEAR...SUPERCELLS ARE ILKLEY WITH
POTENTIAL FOR LARGE HAIL AND TORNADOES.  ACTIVITY WILL GRADUALLY
DEVELOP EWD ACROSS THE WATCH INTO THE MORE FAVORABLE LOW LEVEL
SHEAR/INSTABILITY ENVIRONMENT.

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 24025.


...HALES

Tornado Watches in Colorado, 2009Tornado Watches in Nebraska, 2009Tornado Watches in Wyoming, 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.