Tornado Watch 601

Issued

Jul 5, 2011, 6:10 PM CDT (23:10 UTC)

Expired

Jul 5, 2011, 9:49 PM CDT

In force

4 hr

Issued by

the Storm Prediction Center

Largest hail expected

2.5 in

Strongest gust expected

60 kt

The Des Moines radar (KDMX), 37 km from the middle of the area, began a volume at 23:10 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

30%

Ten or more severe wind reports

30%

One or more gusts of 65 knots or more

10%

Ten or more severe hail reports

40%

One or more hailstones of 2 inches or more

30%

Six or more combined severe hail and wind reports

70%

• Mesoscale Discussion 1511Jul 5, 3:32 PM CDT
• Mesoscale Discussion 1516Jul 5, 7:49 PM CDT

077 
WWUS20 KWNS 052315
SEL1
SPC WW 052315
IAZ000-060400-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 601
NWS STORM PREDICTION CENTER NORMAN OK
610 PM CDT TUE JUL 5 2011

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

       CENTRAL AND SOUTHERN IOWA

EFFECTIVE THIS TUESDAY EVENING FROM 610 PM UNTIL 1100 PM CDT.

TORNADOES...HAIL TO 2.5 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 55 STATUTE
MILES EAST AND WEST OF A LINE FROM 65 MILES NORTH NORTHWEST OF
DES MOINES IOWA TO 15 MILES EAST OF LAMONI IOWA.  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 600...

DISCUSSION...ISOLD SUPERCELL HAS FORMED IN CNTRL IA...ALONG
INFLECTION IN BOUNDARY ARCING ESE FROM NEAR SLB TO S OF FOD TO E OF
DSM.  OTHER STORMS MAY FORM A BIT LATER THIS EVE ALONG THAT PART OF
BOUNDARY W OF CURRENT STORM.  LOW LVL WIND FIELD IS WEAK.  BUT
ORIENTATION OF BOUNDARY AND LOW LVL INSTABILITY AXIS...IN
CONJUNCTION WITH 40+ KT NWLY 500 MB FLOW...IS RESULTING IN
SIGNIFICANT DEVIATE STORM MOTION.  COUPLED WITH MOIST LOW LVL
ENVIRONMENT...THIS MAY CONTINUE TO SUPPORT EPISODES OF ENHANCED LOW
LVL ROTATION AND POSSIBLY A COUPLE TORNADOES GIVEN SUPERCELLULAR
NATURE OF STORM/S/.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 2.5 INCHES. EXTREME TURBULENCE AND SURFACE
WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
500. MEAN STORM MOTION VECTOR 34025.


...CORFIDI

Tornado Watches in Iowa, 2011Every tornado watch in 2011

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.