Tornado Watch 180

Issued

Apr 15, 2012, 4:42 PM CDT (21:42 UTC)

Expired

Apr 15, 2012, 10:20 PM CDT

In force

6 hr

Issued by

the Storm Prediction Center

Largest hail expected

1.5 in

Strongest gust expected

60 kt

The St Louis radar (KLSX), 97 km from the middle of the area, began a volume at 21:44 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

20%

Ten or more severe wind reports

30%

One or more gusts of 65 knots or more

30%

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 549Apr 15, 1:38 PM CDT
• Mesoscale Discussion 552Apr 15, 4:22 PM CDT
• Mesoscale Discussion 556Apr 15, 7:28 PM CDT

384 
WWUS20 KWNS 152143
SEL0
SPC WW 152143
ILZ000-MOZ000-160500-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 180
NWS STORM PREDICTION CENTER NORMAN OK
445 PM CDT SUN APR 15 2012

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

       WESTERN ILLINOIS
       EASTERN MISSOURI

EFFECTIVE THIS SUNDAY AFTERNOON FROM 445 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 60 STATUTE
MILES EAST AND WEST OF A LINE FROM 40 MILES EAST SOUTHEAST OF
WEST PLAINS MISSOURI TO 20 MILES NORTH NORTHEAST OF QUINCY
ILLINOIS.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE
ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU0).

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 177...WW 178...WW 179...

DISCUSSION...TSTMS IN PROGRESS OVER CNTRL MO ARE EXPECTED TO
INTENSIFY AS LARGE-SCALE FORCING FOR ASCENT INCREASES ACROSS THE
REGION THIS EVENING.  WHILE INSTABILITY WILL REMAIN MARGINAL WITH
MLCAPE OF GENERALLY LESS 500 J/KG...THE PRESENCE OF STRONG VERTICAL
SHEAR AND INCREASED FORCING FOR ASCENT INDICATE A RISK OF EMBEDDED
SUPERCELLS AND BOWING STRUCTURES CAPABLE OF DAMAGING WINDS AND A
COUPLE OF TORNADOES.

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.


...MEAD

Tornado Watches in Missouri, 2012Tornado Watches in Illinois, 2012Every tornado watch in 2012

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.