Tornado Watch 102

Issued

Mar 31, 2007, 5:11 PM CDT (22:11 UTC)

Expired

Mar 31, 2007, 11:31 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), 74 km from the middle of the area, began a volume at 22:11 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

30%

One or more EF2 to EF5 tornadoes

20%

Ten or more severe wind reports

50%

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

5%

Six or more combined severe hail and wind reports

90%

• Mesoscale Discussion 400Mar 31, 4:25 PM CDT
• Mesoscale Discussion 403Mar 31, 7:25 PM CDT
• Mesoscale Discussion 404Mar 31, 9:17 PM CDT

000
WWUS20 KWNS 312216
SEL2  
SPC WW 312216
ILZ000-WIZ000-010500-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 102
NWS STORM PREDICTION CENTER NORMAN OK
515 PM CDT SAT MAR 31 2007

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

       CENTRAL AND NORTHERN ILLINOIS
       SOUTHERN WISCONSIN

EFFECTIVE THIS SATURDAY AFTERNOON FROM 515 PM UNTIL MIDNIGHT 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 55 STATUTE
MILES EAST AND WEST OF A LINE FROM 35 MILES NORTH NORTHEAST OF
LONEROCK WISCONSIN TO 30 MILES SOUTHWEST OF DECATUR ILLINOIS. 
FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH
OUTLINE UPDATE (WOUS64 KWNS WOU2).

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 100...WW 101...

DISCUSSION...ERN IA/NE MO SQLN WITH EMBEDDED SUPERCELLS SHOULD
CONTINUE SLOWLY E AS STORMS MOVE RAPIDLY NNE ALONG IT.  AS POTENT
NEG TILT UPR VORT NOW NEAR OMA CONTINUES TO EJECT NEWD...EXPECT
STRONG...LARGELY UNIDIRECTIONAL WIND PROFILES TO SPREAD E ACROSS
IL/SRN WI IN TANDEM WITH SQLN.  WHILE SFC-BASED INSTABILITY WILL
DECREASE WITH NIGHTFALL...SUFFICIENT CAPE SHOULD REMAIN PRESENT TO
SUPPORT ADDITIONAL STORM  DEVELOPMENT ALONG LINE.  ENHANCED
POTENTIAL FOR LOW LEVEL ROTATION/SPIN-UP TORNADOES WILL EXIST NEAR
LEWPS/CUSPS ALONG LINE...AND WITH ANY ISOLATED CELLS FORMING ALONG
STRENGTHENING LLJ AHEAD OF IT.

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
450. MEAN STORM MOTION VECTOR 22040.


...CORFIDI

Tornado Watches in Illinois, 2007Tornado Watches in Wisconsin, 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.