Note:
The expiration time in the watch graphic is amended if the watch is
replaced, cancelled or extended.
Note: Click for
Watch Status Reports.
SEL9
URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 299
NWS STORM PREDICTION CENTER NORMAN OK
955 PM CDT WED MAY 13 2009
THE NWS STORM PREDICTION CENTER HAS ISSUED A
SEVERE THUNDERSTORM WATCH FOR PORTIONS OF
CENTRAL ILLINOIS
SOUTHERN AND EAST CENTRAL MISSOURI
EFFECTIVE THIS WEDNESDAY NIGHT AND THURSDAY MORNING FROM 955 PM
UNTIL 400 AM CDT.
HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 70
MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.
THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 100
STATUTE MILES EAST AND WEST OF A LINE FROM 55 MILES NORTH OF
SALEM ILLINOIS TO 40 MILES SOUTHEAST OF MONETT MISSOURI. FOR A
COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE
UPDATE (WOUS64 KWNS WOU9).
REMEMBER...A SEVERE THUNDERSTORM WATCH MEANS CONDITIONS ARE
FAVORABLE FOR 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. SEVERE THUNDERSTORMS CAN AND OCCASIONALLY
DO PRODUCE TORNADOES.
OTHER WATCH INFORMATION...CONTINUE...WW 293...WW 295...WW
296...WW 297...WW 298...
DISCUSSION...A BROKEN BAND OF SEVERE STORMS SHOULD GRADUALLY
CONSOLIDATE INTO A MORE SOLID LINE OF STORMS IN THE NEXT SEVERAL
HOURS ALONG THE COLD FRONT. SUFFICIENT INSTABILITY /PER THE 02Z SGF
SPECIAL SOUNDING/ AND VERTICAL SHEAR WILL REMAIN TO SUPPORT A
CONTINUING THREAT FOR LARGE HAIL AND DAMAGING WINDS INTO THE EARLY
MORNING HOURS.
AVIATION...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 500. MEAN STORM
MOTION VECTOR 28030.
...THOMPSON
Note:
The Aviation Watch (SAW) product is an approximation to the watch area.
The actual watch is depicted by the shaded areas.
SAW9
WW 299 SEVERE TSTM IL MO 140255Z - 140900Z
AXIS..100 STATUTE MILES EAST AND WEST OF LINE..
55N SLO/SALEM IL/ - 40SE UMN/MONETT MO/
..AVIATION COORDS.. 85NM E/W /18SSW DEC - 38ENE RZC/
HAIL SURFACE AND ALOFT..2 INCHES. WIND GUSTS..60 KNOTS.
MAX TOPS TO 500. MEAN STORM MOTION VECTOR 28030.
LAT...LON 39438709 36459158 36459519 39439083
THIS IS AN APPROXIMATION TO THE WATCH AREA. FOR A
COMPLETE DEPICTION OF THE WATCH SEE WOUS64 KWNS
FOR WOU9.
Watch 299 Status Report Message has not been issued yet.
Note:
Click for Complete Product Text.
Tornadoes
Probability of 2 or more tornadoes
|
Low (20%)
|
Probability of 1 or more strong (F2-F5) tornadoes
|
Low (5%)
|
Wind
Probability of 10 or more severe wind events
|
Mod (50%)
|
Probability of 1 or more wind events > 65 knots
|
Mod (40%)
|
Hail
Probability of 10 or more severe hail events
|
Mod (60%)
|
Probability
of 1 or
more hailstones > 2 inches
|
Mod (40%)
|
Combined Severe Hail/Wind
Probability of 6 or more combined severe hail/wind events
|
High (70%)
|
For each watch, probabilities for particular events inside the watch
(listed above in each table) are determined by the issuing forecaster.
The "Low" category contains probability values ranging from less than 2%
to 20% (F2-F5 tornadoes), less than 5% to 20% (all other probabilities),
"Moderate" from 30% to 60%, and "High" from 70% to greater than 95%.
High values are bolded and lighter in color to provide awareness of
an increased threat for a particular event.
weather.gov 
