Alert archive / Illinois / Severe Thunderstorm Warnings in 2008

Severe Thunderstorm Warning 304, NWS St. Louis, MO

June 21, 2008Monroe County, Illinois; Jefferson County, Missouri

NWS St. Louis, MO issued this severe thunderstorm warning at Jun 21, 2008, 3:21 PM CDT for Monroe County, Illinois; Jefferson County, Missouri. It was in force for 39 min. 1 report came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued: Jun 21, 2008, 3:21 PM CDT (20:21 UTC)
Expired: Jun 21, 2008, 4:00 PM CDT
In force: 39 min
Issued by: NWS St. Louis, MO
Area: Storm-based polygon

Counties Monroe County, IL, Jefferson County, MO

The radar

The St Louis radar (KLSX), 56 km from the middle of the area, began a volume at 20:23 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 was reported inside it

Time	Report	Where	Remark
Jun 21, 3:40 PM CDT	TSTM WND DMG	2 Sw Pevely, MO	TREES AND POWER LINES REPORTED DOWN IN THE PEVELY AND HORINE MISSOURI REGION.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

Did it verify

Verified. The Iowa Environmental Mesonet's Cow matched one storm report to this severe thunderstorm warning; the first came 19 minutes after it went out.

Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.

The nearest sounding before it

Lincoln, IL (KILX), launched 12:00Z, 8.4 hours before the alert went out and 261 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 996 J/kg
Mixed-layer CIN: -64 J/kg
Mixed-layer LCL: 1325 m above ground
0-6 km bulk shear: 17 kt
0-1 km storm-relative helicity: 36 m²/s²
0-3 km storm-relative helicity: 19 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.

000 
WUUS53 KLSX 212023
SVRLSX
ILC133-MOC099-212100-
/O.NEW.KLSX.SV.W.0304.080621T2021Z-080621T2100Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE ST LOUIS MO
321 PM CDT SAT JUN 21 2008

THE NATIONAL WEATHER SERVICE IN ST LOUIS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  EASTERN JEFFERSON COUNTY IN EAST CENTRAL MISSOURI
  SOUTHWESTERN MONROE COUNTY IN SOUTHWEST ILLINOIS

* UNTIL 400 PM CDT

* AT 318 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING PENNY SIZE HAIL...AND
  DAMAGING WINDS IN EXCESS OF 60 MPH. THIS STORM WAS LOCATED 3
  MILES WEST OF PEVELY...AND MOVING SOUTHEAST AT 23 MPH.

* LOCATIONS IMPACTED INCLUDE...
  PEVELY...
  HERCULANEUM...
  FESTUS...
  CRYSTAL CITY...
  
SEVERE THUNDERSTORMS PRODUCE DAMAGING WIND IN EXCESS OF 60 MPH...
DESTRUCTIVE HAIL...DEADLY LIGHTNING...AND VERY HEAVY RAIN. FOR YOUR
PROTECTION MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF YOUR HOME
OR BUSINESS. HEAVY RAINS FLOOD ROADS QUICKLY SO DO NOT DRIVE INTO
AREAS WHERE WATER COVERS THE ROAD.

LAT...LON 3834 9063 3846 9040 3841 9034 3839 9034
      3840 9033 3823 9020 3810 9029 3809 9031
      3810 9033 3807 9037 3806 9041
TIME...MOT...LOC 2021Z 327DEG 20KT 3827 9043

$$

BYRD

1 follow-up statement

000 
WWUS53 KLSX 212047
SVSLSX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE ST LOUIS MO
345 PM CDT SAT JUN 21 2008

ILC133-MOC099-212100-
/O.CON.KLSX.SV.W.0304.000000T0000Z-080621T2100Z/
MONROE IL-JEFFERSON MO-
345 PM CDT SAT JUN 21 2008

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 400 PM CDT
FOR EASTERN JEFFERSON AND WESTERN MONROE COUNTIES...

AT 343 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A SEVERE THUNDERSTORM CAPABLE OF PRODUCING PENNY SIZE
HAIL...AND DAMAGING WINDS IN EXCESS OF 60 MPH. THIS STORM WAS LOCATED
JUST NORTHWEST OF FESTUS...MOVING SOUTHEAST AT 18 MPH.

LOCATIONS NEAR THE PATH OF THE SEVERE THUNDERSTORM INCLUDE... 
FESTUS...CRYSTAL CITY...MONROE CITY...OLYMPIAN VILLAGE...CHALFIN 
BRIDGE AND MAEYSTOWN.

LAT...LON 3818 9050 3825 9056 3836 9030 3823 9020
      3810 9029 3809 9031 3810 9033 3807 9037
      3806 9041
TIME...MOT...LOC 2045Z 332DEG 16KT 3822 9042

$$

BYRD

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS St. Louis, MO wrote its last area forecast discussion before this severe thunderstorm warning went out at Jun 21, 12:50 PM CDT, 2 hours 31 minutes earlier.

Area forecast discussion, Jun 21, 12:50 PM CDT, 2 hours 31 minutes before

AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
1250 PM CDT SAT JUN 21 2008

.DISCUSSION...
/345 AM CDT SAT JUN 21 2008/

THE WEAK SHORT WAVE TROF MOVING THROUGH THE UPPER MS VLY ATTM IS
FORECAST TO CONT MOVING ESEWD TODAY AND INTO THE GREAT LAKES BY
EVENING...WITH THE ATTENDANT SFC BNDRY ACROSS SRN IA MOVING INTO
SRN IL AND SE MO BY 00Z. AMPLE SUN/HEATING TODAY SHOULD RESULT IN
DECENT INSTABILITY AHEAD OF THE BNDRY WILL MLCAPES AROUND 2000
J/KG. CONVERGENCE ALONG THE BOUNDARY HOWEVER WILL BE RELATIVELY
WEAK AND DEEP LAYER SHEAR ONLY PROGGED TO BE AROUND 20-25 KTS...WHICH
WOULD SUPPORT ISOLD-SCT COVERAGE OF PULSE TO MULTICELL STORMS.
EXPECTING STORMS TO DEVELOP ALONG THE BOUNDARY THIS AFTERNOON WITH
GREATEST COVERAGE ACROSS INDIANA/ILLINOIS DECREASING SWWD INTO MO.
SOME MARGINALLY SEVERE HAIL AND WIND GUSTS COULD ACCOMPANY THE
MOST INTENSE CELLS. OVERALL COVERAGE AND INTENSITY SHOULD DIMINISH
THIS EVENING WITH LOSS OF HEATING AND AS THE STORMS MOVE SEWD AWAY
FROM THE CWA.

ATTENTION THEN TURNS TO THE POTENTIAL FOR ANOTHER ROUND OF STORMS
DURING THE LATE EVENING AND OVERNIGHT HOURS FOCUSED BACK TO THE
NORTH. A MUCH STRONGER SHRTWV TROF IS PROGGED TO DIG SEWD THRU THE
MS VLY REGION BEGINNING LATE TONIGHT INTO SUNDAY WITH AN ATTENDANT
COLD FRONT. A WESTERLY LLJ DEVELOPING AHEAD OF THE TROF/CDFNT TONIGHT
WILL FOCUS WAA/LIFT ACROSS THE MO VLY REGION SUPPORTING THUNDERSTORM
DEVELOPMENT. MODELS ARE SUGGESTING POTENTIAL FOR UPSCALE GROWTH
INTO AN ORGANIZED CONVECTIVE COMPLEX MOVING INTO NRN MO. NOT SURE
HOW FAR SOUTH THIS WILL GET BUT HAVE BUMPED UP POPS IN THE NORTH.
ALSO INCREASED POPS A BIT ACROSS THE ENTIRE AREA ON SUNDAY AS THE
MCS AND/OR RESIDUAL BNDRY AND CDFNT CONTS SEWD ACROSS THE REGION.
DEEP LAYER SHEAR WILL BE MUCH IMPROVED DUE TO STRENGTHENING MID
LEVEL FLOW ASSOCD WITH THE DIGG SHRTWV TROF AND THIS WOULD SUPPORT
MUCH GREATER CONVECTIVE ORGANIZATION/COVERAGE. HIGH PRESSURE
SHOULD THEN SETTLE INTO THE REGION ON MONDAY BRINGING A BRIEF
SPELL OF DRY AND TRANQUIL WEATHER.

GLASS
&&

.AVIATION...
/1239 PM CDT SAT JUN 21 2008/
FOR THE 18Z TAFS...A COLD FRONT THAT EXTENDS FROM NORTHEASTERN
INDIANA THROUGH SOUTH CENTRAL ILLINOIS THEN INTO CENTRAL MISSOURI
WILL SLIDE SOUTH THROUGH THE REST OF THE AREA BY THIS EVENING.
THUNDERSTORMS ARE STILL EXPECTED TO DEVELOP ALONG AND BEHIND THE
FRONT AS IT MOVES SOUTH. HOWEVER...THUNDERSTORMS ARE EXPECTED TO
BE SCATTERED AND CHANCES OF THEM IMPACTING A TERMINAL ARE TOO
REMOTE TO INCLUDE IN TAFS. OTHERWISE...WINDS ARE EXPECTED TO BE
WESTERLY JUST AHEAD OF THE FRONT AND BECOME NORTHWEST TO NORTH
BEHIND THE FRONT. MCS DEVELOPMENT STILL A POSSIBILITY OVER WESTERN
IOWA TONIGHT WITH IT SLIDING SOUTHEAST TOWARDS TAF SITES...SO
ADDED VCTS/VCSH TO SITES BEGINNING AROUND 09Z FOR KUIN...10Z FOR
KCOU AND AROUND 12Z FOR KSUS/KSTL.

BYRD
&&

.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&

WFO LSX

Hazardous weather outlook, Jun 21, 5:53 AM CDT, 9 hours 28 minutes before

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE ST LOUIS MO
553 AM CDT SAT JUN 21 2008

ILZ058>060-064-065-069-070-074-079-095>102-MOZ018-019-026-027-
034>036-041-042-047>052-059>065-072>075-084-085-099-221100-
GREENE IL-MACOUPIN IL-MONTGOMERY IL-BOND IL-FAYETTE IL-CLINTON IL-
MARION IL-WASHINGTON IL-RANDOLPH IL-ADAMS IL-BROWN IL-PIKE IL-
CALHOUN IL-JERSEY IL-MADISON IL-ST. CLAIR IL-MONROE IL-KNOX-LEWIS-
SHELBY-MARION-MONROE-RALLS-PIKE-BOONE-AUDRAIN-MONITEAU-COLE-OSAGE-
CALLAWAY-MONTGOMERY-LINCOLN-GASCONADE-WARREN-ST. CHARLES-FRANKLIN-
ST. LOUIS-ST. LOUIS CITY-JEFFERSON-CRAWFORD-WASHINGTON-
ST. FRANCOIS-STE. GENEVIEVE-IRON-MADISON-REYNOLDS-
553 AM CDT SAT JUN 21 2008

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF EASTERN AND
CENTRAL MISSOURI AS WELL AS WEST CENTRAL AND SOUTHWEST ILLINOIS.

.DAY ONE...TODAY AND TONIGHT

ISOLATED TO SCATTERED THUNDERSTORMS ARE EXPECTED TO DEVELOP ALONG A
COLD FRONT THIS AFTERNOON AND PERSIST INTO THE EARLY EVENING. A
FEW OF THE STORMS COULD BE SEVERE WITH HAIL UP TO ONE INCH IN
DIAMETER AND DAMAGING WINDS TO 60 MPH.

ADDITIONAL THUNDERSTORMS ARE POSSIBLE LATE THIS EVENING AND
OVERNIGHT ACROSS MAINLY CENTRAL AND NORTHEAST MISSOURI AND WEST
CENTRAL ILLINOIS. SOME OF THESE STORMS COULD BE SEVERE WITH LARGE
HAIL AS THE PRIMARY THREAT.

MODERATE TO MAJOR RIVER FLOODING IS OCCURRING ALONG PARTS OF THE
MISSISSIPPI AND ILLINOIS RIVERS. SEE THE APPROPRIATE FLOOD
STATEMENT FOR SPECIFIC DETAILS.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY

THERE IS A CHANCE OF THUNDERSTORMS ON SUNDAY AND SUNDAY EVENING AS
AN UPPER LEVEL DISTURBANCE AND ANOTHER COLD FRONT MOVES ACROSS
THE REGION. SOME OF THESE STORMS COULD BE SEVERE.

THE CHANCE FOR THUNDERSTORMS WILL CONTINUE ACROSS MUCH OF THE AREA
FROM TUESDAY THROUGH FRIDAY.

MODERATE TO MAJOR RIVER FLOODING WILL CONTINUE ALONG PARTS OF THE
MISSISSIPPI AND ILLINOIS RIVERS. SEE THE APPROPRIATE FLOOD
STATEMENT FOR SPECIFIC DETAILS.

.SPOTTER INFORMATION STATEMENT...

LIMITED SPOTTER ACTIVATION IS POSSIBLE THIS AFTERNOON AND TONIGHT.

&&

FOR A GRAPHICAL VERSION OF THIS INFORMATION SEE OUR
WEBPAGE AT (LOWERCASE)... HTTP://WWW.WEATHER.GOV/LSX/?N=HWO1

GLASS

In the hours before

Local storm report, Jun 21, 10:57 AM CDT, 4 hours 24 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE ST LOUIS MO
1057 AM CDT SAT JUN 21 2008

..TIME..    ...EVENT...     ...CITY LOCATION...      ...LAT.LON...
..DATE..    ....MAG....     ..COUNTY LOCATION.. ST.. ...SOURCE....
            ..REMARKS..

0410 PM     HEAVY RAIN       DES PERES               38.60N  90.45W
06/20/2008  E1.90 INCH       ST. LOUIS          MO   TRAINED SPOTTER

            RAINFALL BETWEEN 200 AND 410 PM.

&&

EVENT NUMBER 00487

TES

Local storm report, Jun 21, 2:17 PM CDT, 1 hour 4 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE ST LOUIS MO
217 PM CDT SAT JUN 21 2008

..TIME..    ...EVENT...     ...CITY LOCATION...      ...LAT.LON...
..DATE..    ....MAG....     ..COUNTY LOCATION.. ST.. ...SOURCE....
            ..REMARKS..

0210 PM     HAIL             2 S CREVE COEUR         38.63N  90.44W
06/21/2008  E0.50 INCH       ST. LOUIS          MO   NWS EMPLOYEE

            INTERSECTION OF LADUE AND I 270

&&

EVENT NUMBER 00488

MILLER

Local storm report, Jun 21, 2:49 PM CDT, 32 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE ST LOUIS MO
249 PM CDT SAT JUN 21 2008

..TIME..    ...EVENT...     ...CITY LOCATION...      ...LAT.LON...
..DATE..    ....MAG....     ..COUNTY LOCATION.. ST.. ...SOURCE....
            ..REMARKS..

0235 PM     HAIL             KIRKWOOD                38.58N  90.42W
06/21/2008  E0.75 INCH       ST. LOUIS          MO   TRAINED SPOTTER

            AT INTERSECTION OF GUYER AND MANCHESTER ROAD.

&&

EVENT NUMBER 00489

SIPPRELL

Local storm report, Jun 21, 3:11 PM CDT, 10 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE ST LOUIS MO
311 PM CDT SAT JUN 21 2008

..TIME..    ...EVENT...     ...CITY LOCATION...      ...LAT.LON...
..DATE..    ....MAG....     ..COUNTY LOCATION.. ST.. ...SOURCE....
            ..REMARKS..

0305 PM     HAIL             COLUMBIA                38.46N  90.23W
06/21/2008  E0.75 INCH       MONROE             IL   TRAINED SPOTTER

            AT INTERSECTION OF MAIN AND LEPP.

&&

EVENT NUMBER 00490

SIPPRELL

Local storm report, Jun 21, 3:19 PM CDT, 2 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE ST LOUIS MO
319 PM CDT SAT JUN 21 2008

..TIME..    ...EVENT...     ...CITY LOCATION...      ...LAT.LON...
..DATE..    ....MAG....     ..COUNTY LOCATION.. ST.. ...SOURCE....
            ..REMARKS..

0252 PM     HAIL             ST. LOUIS               38.64N  90.24W
06/21/2008  E0.70 INCH       ST. LOUIS CITY     MO   EMERGENCY MNGR

            NEAR THE INTERSECTION OF I 55 AND LOUGHBOROUGH

&&

EVENT NUMBER 00492

MILLER

The office that day

Everything else NWS St. Louis, MO issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jun 21, 3:04 PM CDT	Severe Thunderstorm Warning	LSX	Monroe, Saint Clair	41 min
Jun 21, 3:54 PM CDT	Severe Thunderstorm Warning	LSX	Monroe	51 min
Jun 21, 2:35 PM CDT	Severe Thunderstorm Warning	LSX	Saint Louis, City of Saint Louis	40 min
Jun 21, 3:13 PM CDT	Severe Thunderstorm Warning	LSX	Saint Louis, City of Saint Louis	47 min
Jun 21, 5:21 PM CDT	Severe Thunderstorm Warning	LSX	Washington	39 min
Jun 21, 5:54 PM CDT	Severe Thunderstorm Warning	LSX	Washington	51 min
Jun 21, 6:21 PM CDT	Severe Thunderstorm Warning	LSX	Crawford, Iron, Washington	39 min

Nearby

Severe Thunderstorm Warnings in Illinois, 2008 Severe Thunderstorm Warnings in Missouri, 2008 Every severe thunderstorm warning in 2008

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.