Tornado Watch 90

Issued

Apr 10, 2013, 1:46 PM CDT (18:46 UTC)

Expired

Apr 10, 2013, 9:00 PM CDT

In force

7 hr

Issued by

the Storm Prediction Center

Largest hail expected

2.5 in

Strongest gust expected

60 kt

The St Louis radar (KLSX), 89 km from the middle of the area, began a volume at 18:47 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

70%

One or more EF2 to EF5 tornadoes

40%

Ten or more severe wind reports

50%

One or more gusts of 65 knots or more

30%

Ten or more severe hail reports

60%

One or more hailstones of 2 inches or more

50%

Six or more combined severe hail and wind reports

95%

• Mesoscale Discussion 426Apr 10, 12:36 PM CDT
• Mesoscale Discussion 427Apr 10, 1:03 PM CDT
• Mesoscale Discussion 429Apr 10, 3:01 PM CDT
• Mesoscale Discussion 432Apr 10, 6:09 PM CDT
• Mesoscale Discussion 434Apr 10, 7:55 PM CDT

148 
WWUS20 KWNS 101848
SEL0  
SPC WW 101848
ILZ000-MOZ000-110200-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 90
NWS STORM PREDICTION CENTER NORMAN OK
150 PM CDT WED APR 10 2013

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

       SOUTHERN ILLINOIS
       SOUTH CENTRAL AND SOUTHEAST MISSOURI

EFFECTIVE THIS WEDNESDAY AFTERNOON AND EVENING FROM 150 PM UNTIL
900 PM 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 80 STATUTE
MILES EAST AND WEST OF A LINE FROM 25 MILES NORTHEAST OF SCOTT
AFB ILLINOIS TO 35 MILES EAST SOUTHEAST OF WEST PLAINS MISSOURI. 
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 88...WW 89...

DISCUSSION...SURFACE HEATING/DESTABILIZATION ACROSS SRN/ERN MO IS
CONTRIBUTING TO MODERATE INSTABILITY IN THE WARM SECTOR...WITH A
WEAKENING CAP AND INCREASING PROBABILITY FOR THUNDERSTORM INITIATION
IN THE NEXT COUPLE OF HOURS.  GIVEN THE MODERATE INSTABILITY AND MID
60S BOUNDARY LAYER DEWPOINTS...AN INCREASE IN VERTICAL SHEAR
/ALREADY NOTED IN THE VWP FROM SAINT LOUIS/ WILL RESULT IN AN
INCREASING RISK FOR SUPERCELLS WITH TORNADOES AND LARGE HAIL.  LATER
THIS AFTERNOON/EVENING...CONVECTION SHOULD EVOLVE INTO MORE OF A
LINE ALONG THE COLD FRONT IN MO...WITH A CONTINUED RISK FOR EMBEDDED
CIRCULATIONS AND DAMAGING WINDS.

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 23040.


...THOMPSON

Tornado Watches in Missouri, 2013Tornado Watches in Illinois, 2013Every tornado watch in 2013

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.