Tornado Watch 321

Issued

Jun 1, 2007, 12:35 PM CDT (17:35 UTC)

Expired

Jun 1, 2007, 7:00 PM CDT

In force

6 hr

Issued by

the Storm Prediction Center

Largest hail expected

1.5 in

Strongest gust expected

60 kt

The Quad Cities radar (KDVN), 96 km from the middle of the area, began a volume at 17:38 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

60%

One or more EF2 to EF5 tornadoes

30%

Ten or more severe wind reports

30%

One or more gusts of 65 knots or more

30%

Ten or more severe hail reports

50%

One or more hailstones of 2 inches or more

30%

Six or more combined severe hail and wind reports

80%

• Mesoscale Discussion 949Jun 1, 11:09 AM CDT
• Mesoscale Discussion 951Jun 1, 2:35 PM CDT

000
WWUS20 KWNS 011736
SEL1  
SPC WW 011736
IAZ000-ILZ000-WIZ000-020000-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 321
NWS STORM PREDICTION CENTER NORMAN OK
1235 PM CDT FRI JUN 1 2007

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

       EASTERN IOWA
       NORTHWEST ILLINOIS
       SOUTHWEST WISCONSIN

EFFECTIVE THIS FRIDAY AFTERNOON AND EVENING FROM 1235 PM UNTIL
700 PM CDT.

TORNADOES...HAIL TO 1.5 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 70 STATUTE
MILES EAST AND WEST OF A LINE FROM 20 MILES NORTH OF LONEROCK
WISCONSIN TO 60 MILES SOUTHEAST OF MOLINE ILLINOIS.  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.

DISCUSSION...WELL-DEFINED MCV IN IA WILL LIFT NNEWD TOWARD WI THIS
AFTERNOON...WITH CONVECTIVE DEVELOPMENT EXPECTED TO INCREASE IN A
BROKEN ARC FROM NE TO SE OF THE MID LEVEL VORTICITY CENTER. 
BOUNDARY LAYER DEWPOINTS HAVE INCREASED INTO THE UPPER 60S NEAR THE
MS RIVER IN ADVANCE OF THE DEVELOPING STORMS...WHILE VERTICAL SHEAR
IS QUITE FAVORABLE FOR SUPERCELLS IN A SMALL AREA E/NE OF THE MCV. 
GIVEN THE INCREASING MOISTURE/MODERATE INSTABILITY AND STRONG
LOW-LEVEL SHEAR...ADDITIONAL SUPERCELLS AND TORNADOES CAN BE
EXPECTED THROUGH THE AFTERNOON.

AVIATION...TORNADOES AND 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 22035.


...THOMPSON

Tornado Watches in Illinois, 2007Tornado Watches in Wisconsin, 2007Tornado Watches in Iowa, 2007Every tornado watch in 2007

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.