Tornado Watch 101

Issued

Mar 31, 2007, 1:47 PM CDT (18:47 UTC)

Expired

Mar 31, 2007, 8:43 PM CDT

In force

7 hr

Issued by

the Storm Prediction Center

Largest hail expected

2 in

Strongest gust expected

60 kt

The Des Moines radar (KDMX), 126 km from the middle of the area, began a volume at 18:50 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

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

70%

• Mesoscale Discussion 395Mar 31, 10:30 AM CDT
• Mesoscale Discussion 398Mar 31, 12:57 PM CDT
• Mesoscale Discussion 399Mar 31, 2:38 PM CDT

000
WWUS20 KWNS 311847
SEL1  
SPC WW 311847
IAZ000-ILZ000-MOZ000-010200-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 101
NWS STORM PREDICTION CENTER NORMAN OK
145 PM CDT SAT MAR 31 2007

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

       EASTERN IOWA
       PARTS OF WESTERN ILLINOIS
       PARTS OF NORTHEAST MISSOURI

EFFECTIVE THIS SATURDAY AFTERNOON AND EVENING FROM 145 PM UNTIL
900 PM CDT.

TORNADOES...HAIL TO 2 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 65 STATUTE
MILES EAST AND WEST OF A LINE FROM 60 MILES EAST NORTHEAST OF
MASON CITY IOWA TO 30 MILES SOUTHWEST OF QUINCY 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.

OTHER WATCH INFORMATION...CONTINUE...WW 99...WW 100...

DISCUSSION...AIR MASS CONTINUES TO DESTABILIZE AHEAD OF VIGOROUS
TROUGH AND 90KT MID LEVEL WIND MAX.  WITH MLCAPES TO NEAR 1000 J/KG
SUFFICIENT CAPE/SHEAR TO SUPPORT SUPERCELLS.  WARM FRONT SHIFTING
NWD ACROSS ERN IA WILL ALSO ENHANCE LOW LEVEL SHEAR AND TORNADO
POTENTIAL. THUNDERSTORMS NOW DEVELOPING ACROSS NRN MO/IA WILL
RAPIDLY INTENSIFY AND BECOME MORE WIDESPREAD THRU THE AFTERNOON.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 2 INCHES. EXTREME TURBULENCE AND SURFACE
WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
450. MEAN STORM MOTION VECTOR 22040.


...HALES

Tornado Watches in Iowa, 2007Tornado Watches in Missouri, 2007Tornado Watches in Illinois, 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.