Tornado Watch 491

Issued

Jun 8, 2008, 4:43 PM CDT (21:43 UTC)

Expired

Jun 8, 2008, 10:54 PM CDT

In force

6 hr

Issued by

the Storm Prediction Center

Largest hail expected

2.5 in

Strongest gust expected

70 kt

The Quad Cities radar (KDVN), 75 km from the middle of the area, began a volume at 21:42 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

50%

One or more EF2 to EF5 tornadoes

20%

Ten or more severe wind reports

50%

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 1285Jun 8, 4:32 PM CDT
• Mesoscale Discussion 1291Jun 8, 10:01 PM CDT

000
WWUS20 KWNS 082143
SEL1  
SPC WW 082143
IAZ000-ILZ000-WIZ000-090400-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 491
NWS STORM PREDICTION CENTER NORMAN OK
445 PM CDT SUN JUN 8 2008

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

       MUCH OF EASTERN IOWA
       PARTS OF NORTHWEST ILLINOIS
       SMALL PART OF SOUTHWEST WISCONSIN

EFFECTIVE THIS SUNDAY AFTERNOON AND EVENING FROM 445 PM UNTIL
1100 PM CDT.

TORNADOES...HAIL TO 2.5 INCHES IN DIAMETER...THUNDERSTORM WIND
GUSTS TO 80 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE
AREAS.

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 70 STATUTE
MILES EAST AND WEST OF A LINE FROM 40 MILES SOUTHEAST OF OTTUMWA
IOWA TO 40 MILES NORTHEAST OF DUBUQUE 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 486...WW 487...WW
488...WW 489...WW 490...

DISCUSSION...SEVERE THUNDERSTORMS DEVELOPING ACROSS CENTRAL/NRN IA
WILL BE MOVING ENEWD INTO A FAVORABLE SHEAR AND INSTABILITY
ENVIRONMENT FOR SUPERCELLS. WITH E/W BOUNDARY SHIFTING NWD THRU ERN
IA/NWRN IL...POTENTIAL FOR TORNADOES WILL BE ENHANCED VICINITY OF
THE BOUNDARY.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 2.5 INCHES. EXTREME TURBULENCE AND SURFACE
WIND GUSTS TO 70 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
600. MEAN STORM MOTION VECTOR 24040.


...HALES

Tornado Watches in Iowa, 2008Tornado Watches in Illinois, 2008Tornado Watches in Wisconsin, 2008Every tornado watch in 2008

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.