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The expiration time in the watch graphic is amended if the watch is
replaced, cancelled or extended.
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Watch Status Reports.
SEL9
URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 359
NWS STORM PREDICTION CENTER NORMAN OK
140 PM CDT TUE MAY 24 2011
THE NWS STORM PREDICTION CENTER HAS ISSUED A
SEVERE THUNDERSTORM WATCH FOR PORTIONS OF
WESTERN ILLINOIS
NORTHERN AND EASTERN MISSOURI
EFFECTIVE THIS TUESDAY AFTERNOON AND EVENING FROM 140 PM UNTIL
900 PM 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 60
STATUTE MILES NORTH AND SOUTH OF A LINE FROM 50 MILES NORTH OF
KNOB NOSTER MISSOURI TO 35 MILES NORTH OF SAINT LOUIS 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 354...WW 355...WW
356...WW 357...WW 358...
DISCUSSION...BOWING MCS OVER NWRN MO IS EXPECTED TO BECOME
PROGRESSIVELY SURFACE-BASED THIS AFTERNOON AS DOWNSTREAM AIR MASS
WARMS THROUGH THE 80S...CONTRIBUTING TO MLCAPE VALUES OF 1500-2500
J/KG. CURRENT EAX VAD SHOWS 50+ KT WSWLY WINDS ABOVE 5-6 KM AGL
WHICH WILL RESULT IN MODERATELY STRONG DEEP-LAYER SHEAR AND THE
POTENTIAL FOR FORWARD-PROPAGATION OF MCS. A CORRIDOR OF DAMAGING
WINDS WILL BE POSSIBLE ALONG SYSTEM TRACK AS WELL AS LARGE HAIL.
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 29035.
...MEAD
Note:
The Aviation Watch (SAW) product is an approximation to the watch area.
The actual watch is depicted by the shaded areas.
SAW9
WW 359 SEVERE TSTM IL MO 241840Z - 250200Z
AXIS..60 STATUTE MILES NORTH AND SOUTH OF LINE..
50N SZL/KNOB NOSTER MO/ - 35N STL/SAINT LOUIS MO/
..AVIATION COORDS.. 50NM N/S /49ENE MKC - 24NNE STL/
HAIL SURFACE AND ALOFT..2 INCHES. WIND GUSTS..60 KNOTS.
MAX TOPS TO 500. MEAN STORM MOTION VECTOR 29035.
LAT...LON 40319355 40119037 38389037 38589355
THIS IS AN APPROXIMATION TO THE WATCH AREA. FOR A
COMPLETE DEPICTION OF THE WATCH SEE WOUS64 KWNS
FOR WOU9.
Watch 359 Status Report Messages:
STATUS REPORT #3 ON WW 359
VALID 242230Z - 242340Z
SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 20 NNW VIH
TO 50 NE COU TO 10 SW UIN TO 15 NW UIN TO 25 NNW UIN AND 20 WSW
JEF TO 15 NNE COU TO 40 SE IRK TO 30 E IRK TO 35 ENE IRK.
..DEAN..05/24/11
ATTN...WFO...LSX...EAX...
&&
STATUS REPORT FOR WS 359
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
ILC001-009-013-061-083-117-119-133-149-163-242340-
IL
. ILLINOIS COUNTIES INCLUDED ARE
ADAMS BROWN CALHOUN
GREENE JERSEY MACOUPIN
MADISON MONROE PIKE
ST. CLAIR
$$
MOC071-073-099-113-139-151-163-183-189-219-510-242340-
MO
. MISSOURI COUNTIES INCLUDED ARE
FRANKLIN GASCONADE JEFFERSON
LINCOLN MONTGOMERY OSAGE
PIKE ST. CHARLES ST. LOUIS
WARREN
MISSOURI INDEPENDENT CITIES INCLUDED ARE
ST. LOUIS CITY
$$
THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE
REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL
INFORMATION ON COUNTIES...INDEPENDENT CITIES AND MARINE ZONES
CLEARED FROM SEVERE THUNDERSTORM AND TORNADO WATCHES.
$$
STATUS REPORT #2 ON WW 359
VALID 242150Z - 242240Z
SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 20 WSW JEF
TO 15 NNE COU TO 40 SE IRK TO 30 E IRK TO 35 ENE IRK.
..DEAN..05/24/11
ATTN...WFO...LSX...EAX...
&&
STATUS REPORT FOR WS 359
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
ILC001-009-013-061-083-117-119-133-149-163-242240-
IL
. ILLINOIS COUNTIES INCLUDED ARE
ADAMS BROWN CALHOUN
GREENE JERSEY MACOUPIN
MADISON MONROE PIKE
ST. CLAIR
$$
MOC007-027-051-071-073-099-111-113-127-137-139-151-163-173-183-
189-219-510-242240-
MO
. MISSOURI COUNTIES INCLUDED ARE
AUDRAIN CALLAWAY COLE
FRANKLIN GASCONADE JEFFERSON
LEWIS LINCOLN MARION
MONROE MONTGOMERY OSAGE
PIKE RALLS ST. CHARLES
ST. LOUIS WARREN
MISSOURI INDEPENDENT CITIES INCLUDED ARE
ST. LOUIS CITY
$$
THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE
REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL
INFORMATION ON COUNTIES...INDEPENDENT CITIES AND MARINE ZONES
CLEARED FROM SEVERE THUNDERSTORM AND TORNADO WATCHES.
$$
STATUS REPORT #1 ON WW 359
VALID 242015Z - 242140Z
SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 10 WSW SZL
TO 40 SSE CDJ TO 25 NW IRK.
..BROYLES..05/24/11
ATTN...WFO...LSX...EAX...
&&
STATUS REPORT FOR WS 359
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
ILC001-009-013-061-083-117-119-133-149-163-242140-
IL
. ILLINOIS COUNTIES INCLUDED ARE
ADAMS BROWN CALHOUN
GREENE JERSEY MACOUPIN
MADISON MONROE PIKE
ST. CLAIR
$$
MOC007-019-027-041-051-053-071-073-089-099-103-111-113-121-127-
135-137-139-151-159-163-173-175-183-189-195-205-219-510-
242140-
MO
. MISSOURI COUNTIES INCLUDED ARE
AUDRAIN BOONE CALLAWAY
CHARITON COLE COOPER
FRANKLIN GASCONADE HOWARD
JEFFERSON KNOX LEWIS
LINCOLN MACON MARION
MONITEAU MONROE MONTGOMERY
OSAGE PETTIS PIKE
RALLS RANDOLPH ST. CHARLES
ST. LOUIS SALINE SHELBY
WARREN
MISSOURI INDEPENDENT CITIES INCLUDED ARE
ST. LOUIS CITY
$$
THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE
REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL
INFORMATION ON COUNTIES...INDEPENDENT CITIES AND MARINE ZONES
CLEARED FROM SEVERE THUNDERSTORM AND TORNADO WATCHES.
$$
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 (60%)
|
Probability of 1 or more wind events > 65 knots
|
Mod (30%)
|
Hail
Probability of 10 or more severe hail events
|
Mod (30%)
|
Probability
of 1 or
more hailstones > 2 inches
|
Low (20%)
|
Combined Severe Hail/Wind
Probability of 6 or more combined severe hail/wind events
|
High (80%)
|
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 
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