Tornado Watch 157

Issued

Apr 19, 2011, 6:46 PM CDT (23:46 UTC)

Expired

Apr 20, 2011, 3:47 AM CDT

In force

9 hr

Issued by

the Storm Prediction Center

Largest hail expected

2.5 in

Strongest gust expected

60 kt

The Paducah radar (KPAH), 67 km from the middle of the area, began a volume at 23:50 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

95%

One or more gusts of 65 knots or more

70%

Ten or more severe hail reports

80%

One or more hailstones of 2 inches or more

50%

Six or more combined severe hail and wind reports

95%

• Mesoscale Discussion 476Apr 19, 6:24 PM CDT
• Mesoscale Discussion 477Apr 19, 6:32 PM CDT
• Mesoscale Discussion 478Apr 19, 7:47 PM CDT
• Mesoscale Discussion 479Apr 19, 8:07 PM CDT
• Mesoscale Discussion 484Apr 19, 11:17 PM CDT
• Mesoscale Discussion 485Apr 19, 11:56 PM CDT

492 
WWUS20 KWNS 192348
SEL7
SPC WW 192348
ARZ000-ILZ000-INZ000-KYZ000-MOZ000-MSZ000-TNZ000-200700-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 157
NWS STORM PREDICTION CENTER NORMAN OK
650 PM CDT TUE APR 19 2011

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

       EASTERN ARKANSAS
       SOUTHERN ILLINOIS
       CENTRAL AND SOUTHWEST INDIANA
       WESTERN KENTUCKY
       SOUTHEAST MISSOURI
       EXTREME NORTHWEST MISSISSIPPI
       NORTHWEST TENNESSEE

EFFECTIVE THIS TUESDAY NIGHT AND WEDNESDAY MORNING FROM 650 PM
UNTIL 200 AM CDT.

TORNADOES...HAIL TO 2.5 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 75 STATUTE
MILES EAST AND WEST OF A LINE FROM 20 MILES WEST NORTHWEST OF
MUNCIE INDIANA TO 50 MILES WEST OF MONTICELLO ARKANSAS.  FOR A
COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE
UPDATE (WOUS64 KWNS WOU7).

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 154...WW 155...WW 156...

DISCUSSION...THUNDERSTORMS CONTINUE TO INCREASE IN COVERAGE IN
SEVERAL CLUSTERS/BANDS ALONG AND E OF A COLD FRONT MOVING INTO NW AR
AND CENTRAL MO...AND SURFACE LOW IN CENTRAL IL.  STRONG INSTABILITY
REMAINS IN ADVANCE OF THE BROKEN LINE TO THE S OF THE WARM FRONT IN
INDIANA...AND CONVECTION IS EXPECTED TO GROW UPSCALE INTO A LARGER
SQUALL LINE THROUGH THE EARLY OVERNIGHT HOURS.  DAMAGING WINDS WILL
BECOME THE MOST COMMON THREAT...THOUGH LARGE HAIL AND A FEW
TORNADOES WILL REMAIN POSSIBLE...ESPECIALLY THIS EVENING WITH THE
MORE DISCRETE SUPERCELL STRUCTURES.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 2.5 INCHES. EXTREME TURBULENCE AND SURFACE
WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
550. MEAN STORM MOTION VECTOR 27030.


...THOMPSON

Tornado Watches in Indiana, 2011Tornado Watches in Arkansas, 2011Tornado Watches in Kentucky, 2011Every tornado watch in 2011

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.