Alert archive / Missouri / Severe Thunderstorm Watches in 2009

Severe Thunderstorm Watch 430

June 16, 200919 counties in Illinois; 28 counties in Missouri

The Storm Prediction Center issued this severe thunderstorm watch at Jun 16, 2009, 12:41 AM CDT for 19 counties in Illinois; 28 counties in Missouri. It was in force for 4 hr.

The area

The outline as issued.

The facts

Issued
Jun 16, 2009, 12:41 AM CDT (05:41 UTC)
Expired
Jun 16, 2009, 4:48 AM CDT
In force
4 hr
Issued by
the Storm Prediction Center
Largest hail expected
2 in
Strongest gust expected
70 kt
All 47 counties

Alexander County, IL, Bond County, IL, Calhoun County, IL, Clinton County, IL, Franklin County, IL, Jackson County, IL, Jefferson County, IL, Jersey County, IL, Johnson County, IL, Madison County, IL, Marion County, IL, Monroe County, IL, Perry County, IL, Pulaski County, IL, Randolph County, IL, Saint Clair County, IL, Union County, IL, Washington County, IL, Williamson County, IL, Audrain County, MO, Bollinger County, MO, Boone County, MO, Callaway County, MO, Cape Girardeau County, MO, City of Saint Louis, MO, Cole County, MO, Crawford County, MO, Franklin County, MO, Gasconade County, MO, Iron County, MO, Jefferson County, MO, Lincoln County, MO, Madison County, MO, Moniteau County, MO, Montgomery County, MO, Osage County, MO, Perry County, MO, Pike County, MO, Reynolds County, MO, Saint Charles County, MO, Saint Francois County, MO, Saint Louis County, MO, Sainte Genevieve County, MO, Scott County, MO, Warren County, MO, Washington County, MO, Wayne County, MO

The radar

The St Louis radar (KLSX), 42 km from the middle of the area, began a volume at 05:44 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.

What SPC expected

The probabilities SPC published with the watch, for the watch area over its life.

Two or more tornadoes
20%
One or more EF2 to EF5 tornadoes
5%
Ten or more severe wind reports
70%
One or more gusts of 65 knots or more
40%
Ten or more severe hail reports
30%
One or more hailstones of 2 inches or more
20%
Six or more combined severe hail and wind reports
90%

Warnings issued inside it

5 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

IssuedProductOfficeCountiesLasted
Jun 16, 12:42 AM CDTFlash Flood WarningLSXBoone, Cole, Moniteau7 hr
Jun 16, 12:49 AM CDTSevere Thunderstorm WarningLSXBoone, Callaway, Cole, Moniteau, Osage56 min
Jun 16, 1:09 AM CDTFlash Flood WarningLSXAudrain, Callaway, Monroe, Montgomery8 hr
Jun 16, 4:14 AM CDTSevere Thunderstorm WarningPAHJohnson, Massac, Union46 min
Jun 16, 4:18 AM CDTFlash Flood WarningLSXSaint Louis, City of Saint Louis6 hr

Discussions around it

SPC mesoscale discussions over the same counties from four hours before the watch to its end.

The nearest sounding before it

Lincoln, IL (KILX), launched 00:00Z, 5.7 hours before the alert went out and 283 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Lincoln, IL at 00:00Z on 2009-06-16Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 27 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Lincoln, IL at 00:00Z on 2009-06-16The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -3 square meters per square second.19395878Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
27 J/kg
Mixed-layer CIN
-18 J/kg
Mixed-layer LCL
1076 m above ground
0-6 km bulk shear
37 kt
0-1 km storm-relative helicity
-3 m²/s²
0-3 km storm-relative helicity
51 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

371 
WWUS20 KWNS 160538
SEL0  
SPC WW 160538
ILZ000-MOZ000-161100-

URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 430
NWS STORM PREDICTION CENTER NORMAN OK
1240 AM CDT TUE JUN 16 2009

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

       SOUTHWEST ILLINOIS
       EAST CENTRAL AND SOUTHEAST MISSOURI

EFFECTIVE THIS TUESDAY MORNING FROM 1240 AM UNTIL 600 AM CDT.

HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 80
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 25 MILES SOUTHWEST
OF JEFFERSON CITY MISSOURI TO 20 MILES SOUTH SOUTHEAST OF MOUNT
VERNON ILLINOIS.  FOR A COMPLETE DEPICTION OF THE WATCH SEE THE
ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU0).

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 427...WW 428...WW 429...

DISCUSSION...INTENSE BOW ECHO OVER CENTRAL MO WILL TRACK EASTWARD AT
OVER 40 KNOTS ACROSS EASTERN MO INTO WESTERN IL OVERNIGHT.  EASTERN
EXTENT OF DAMAGING WIND THREAT IS UNCERTAIN DUE TO TIME OF DAY AND
LESS INSTABILITY AHEAD OF STORMS.  HOWEVER...POTENTIAL EXISTS FOR
WIDESPREAD DAMAGING WINDS FOR SEVERAL MORE HOURS.

AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT
TO 2 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 70
KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500. MEAN STORM
MOTION VECTOR 27040.


...HART

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 16, 3:53 AM CDTMesoscale DiscussionSPCBond, Clinton, Franklin, Jackson, Jefferson, Jersey and 12 more67 min
Jun 16, 9:38 AM CDTMesoscale DiscussionSPCAlexander, Gallatin, Hardin, Johnson, Massac, Pope and 3 more67 min
Jun 16, 10:40 AM CDTSevere Thunderstorm WatchSPCAlexander, Edwards, Franklin, Gallatin, Hamilton, Hardin and 10 more5 hr
Jun 16, 1:10 PM CDTMesoscale DiscussionSPCEdwards, Gallatin, Wabash, Wayne, White35 min
Jun 15, 7:33 PM CDTMesoscale DiscussionSPCAndrew, Atchison, Bates, Buchanan, Caldwell, Carroll and 23 more87 min
Jun 15, 8:14 PM CDTSevere Thunderstorm WatchSPCAndrew, Atchison, Bates, Buchanan, Caldwell, Carroll and 20 more6 hr
Jun 15, 9:32 PM CDTMesoscale DiscussionSPCAndrew, Atchison, Buchanan, Caldwell, Clay, Clinton and 8 more88 min
Jun 15, 10:49 PM CDTSevere Thunderstorm WatchSPCBarton, Benton, Camden, Cedar, Dade, Dallas and 18 more5 hr
Jun 15, 11:18 PM CDTMesoscale DiscussionSPCAdair, Andrew, Atchison, Audrain, Boone, Buchanan and 44 more87 min
Jun 16, 2:30 AM CDTMesoscale DiscussionSPCAndrew, Atchison, Barton, Bates, Benton, Buchanan and 43 more60 min
Jun 16, 4:52 AM CDTSevere Thunderstorm WatchSPCBarton, Benton, Camden, Cedar, Dade, Dallas and 18 more4 hr
Jun 16, 6:02 AM CDTMesoscale DiscussionSPCBarton, Benton, Camden, Cedar, Dade, Dallas and 18 more118 min
Jun 16, 4:51 PM CDTMesoscale DiscussionSPCBarry, Barton, Bates, Benton, Camden, Cass and 19 more84 min

Nearby

Severe Thunderstorm Watches in Missouri, 2009Severe Thunderstorm Watches in Illinois, 2009Every severe thunderstorm watch in 2009

Sources

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.