Severe Thunderstorm Watch 430

Issued

Jul 22, 2013, 3:08 PM CDT (20:08 UTC)

Expired

Jul 23, 2013, 12:00 AM CDT

In force

9 hr

Issued by

the Storm Prediction Center

Largest hail expected

2 in

Strongest gust expected

65 kt

The Des Moines radar (KDMX), 113 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

10%

One or more EF2 to EF5 tornadoes

2%

Ten or more severe wind reports

40%

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

30%

Six or more combined severe hail and wind reports

60%

• Mesoscale Discussion 1463Jul 22, 1:08 PM CDT
• Mesoscale Discussion 1464Jul 22, 3:34 PM CDT
• Mesoscale Discussion 1467Jul 22, 5:45 PM CDT
• Mesoscale Discussion 1470Jul 22, 7:42 PM CDT

537 
WWUS20 KWNS 222009
SEL0  
SPC WW 222009
IAZ000-NEZ000-230300-

URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 430
NWS STORM PREDICTION CENTER NORMAN OK
310 PM CDT MON JUL 22 2013

THE NWS STORM PREDICTION CENTER HAS ISSUED A

* SEVERE THUNDERSTORM WATCH FOR PORTIONS OF 
  NORTHWEST IOWA
  EASTERN NEBRASKA

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

* PRIMARY THREATS INCLUDE...
  SEVERAL DAMAGING WIND GUSTS WITH A FEW SIGNIFICANT GUSTS TO 75
    MPH POSSIBLE
  SEVERAL LARGE HAIL EVENTS WITH A FEW VERY LARGE HAIL EVENTS TO 2
    INCHES IN DIAMETER POSSIBLE

THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 45
STATUTE MILES NORTH AND SOUTH OF A LINE FROM 25 MILES SOUTHEAST
OF MASON CITY IOWA TO 30 MILES WEST OF TEKAMAH NEBRASKA.  FOR A
COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE
UPDATE (WOUS64 KWNS WOU0).

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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 429...

DISCUSSION...STORMS SHOULD INCREASE ALONG A COLD FRONT SETTLING
ACROSS THE REGION THOUGH THE REMAINDER OF THE AFTERNOON. A VERY HOT
AND UNSTABLE AIRMASS HAS DEVELOPED ALONG THE FRONTAL ZONE WITH
MLCAPE AROUND 3000 J/KG INDICATED IN LATEST ENVIRONMENT DATA. THIS
IN COMBINATION WITH CONTINUED LOW LEVEL LIFT ALONG THE FRONTAL
SEGMENT SHOULD SPUR ADDITIONAL INTENSE TSTM DEVELOPMENT. DEEP SHEAR
ACROSS THE REGION IS LIMITED AND MAY RESULT IN GENERALLY POOR STORM
ORGANIZATION WITH MULTICELL/PULSE CONVECTION POSING PRIMARILY A WIND
DAMAGE THREAT INTO THE EARLY EVENING.

AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT
TO 2 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 65
KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 550. MEAN STORM
MOTION VECTOR 29020.


...CARBIN

Severe Thunderstorm Watches in Iowa, 2013Severe Thunderstorm Watches in Nebraska, 2013Every severe thunderstorm watch in 2013

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.