Severe Thunderstorm Warning 354, NWS St. Louis, MO

000 
WWUS53 KLSX 221753
SVSLSX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE ST LOUIS MO
1253 PM CDT THU JUN 22 2006

ILC121-221803-
/O.EXP.KLSX.SV.W.0354.000000T0000Z-060622T1745Z/
MARION IL-
1253 PM CDT THU JUN 22 2006

...THE SEVERE THUNDERSTORM WARNING FOR EASTERN MARION COUNTY EXPIRED
AT 1245 PM...

THE STORM WHICH PROMPTED THE WARNING HAS WEAKENED AND MOVED OUT OF
THE COUNTY.

ADDITIONAL STRONG THUNDERSTORMS ARE POSSIBLE...AND A SEVERE 
THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 7 PM.

LAT...LON 3882 8887 3846 8886 3845 8869 3884 8871

$$

TRUETT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ST LOUIS MO
700 AM CDT THU JUN 22 2006

.DISCUSSION...
THE QUASI-STATIONARY FRONT WEVE BEEN WATCHING FOR THE PAST COUPLE
OF DAYS IS TRYING TO MOVE AS OUTFLOW FROM CONVECTION OVER THE PLAINS
KICKS THE EFFECTIVE BOUNDARY ALONG.  FRONTAL POSITION IS QUITE
DIFFICULT TO DISCERN THIS MORNING SINCE THE MCS ACTIVITY OVER
KANSAS...NEBRASKA...AND IOWA IS MUDDYING THE WATERS.  HOWEVER...IT
LOOKS LIKE THE FRONT STRETCHES FROM NORTHEAST KANSAS THROUGH EXTREME
NORTHWEST MISSOURI...INTO SOUTHERN IOWA AND CONTINUING EAST THROUGH
NORTHERN ILLINOIS.  WITH LITTLE IN THE WAY OF UPPER LEVEL FORCING
DUE TO ZONAL FLOW ALOFT...SLOW SOUTHEAST PROGRESS IS CONTINUED TO BE
EXPECTED AS CONVECTIVE OUTFLOW SHOVES THE FRONT IN FITS AND STARTS
THROUGH FRIDAY MORNING.  TRYING TO TIME FROPA AT ANY GIVEN LOCATION
IS NEXT TO IMPOSSIBLE DUE TO THE FICKLE NATURE OF WHERE AND WHEN
THESE MCSS WILL FORM.

HAVE BASICALLY THROWN THE GFS IN THE TRASH DUE TO ITS CONTINUED
PROBLEMS WITH CONVECTIVE FEEDBACK.  THE NEW NAM/WRF MODEL SEEMS TO
HAVE AT LEAST A DECENT HANDLE ON WHATS GOING ON OVER THE PLAINS AND
WESTERN MISSOURI AT THIS TIME...SO IVE LEANED HEAVILY ON ITS
SOLUTION.  HAVE INCREASED POPS ACROSS THE AREA TO 60-70 PERCENT FOR
THE NEXT 36 HOURS OR SO AS THE FRONT MAKES ITS SLOW PROGRESS THROUGH
THE CWFA.  IM NOT CONFIDENT ENOUGH TO SAY CATEGORICALLY THAT IT
WILL RAIN AT ANY GIVEN LOCATION DURING THAT TIME-FRAME DUE TO THE
LACK OF STRONG FORCING...BUT IT SURE SEEMS LIKELY THAT A MAJORITY OF
THE AREA WILL SEE AT LEAST SOME RAIN.  SOME AREAS OVER CENTRAL OR
SOUTHEAST MISSOURI MAY RECEIVE LOCALLY HEAVY RAIN ESPECIALLY TONIGHT
AS THE FRONT INTERACTS WITH A WEAK LOW LEVEL JET AND SMALL SHORTWAVE
TROF ALOFT.  BUT AGAIN...SIGNALS ARE VERY WEAK...SO HAVENT
HIGHLIGHTED ANYTHING IN THE FORECAST JUST YET.  MAY MENTION
IT IN THE HWO LATER...

THE FRONT SHOULD FINALLY MOVE SOUTH OF THE AREA FRIDAY NIGHT OR
EARLY SATURDAY MORNING BRINGING AN END TO THE PRECIP CHANCES.  THIS
FINAL PUSH SEEMS TO BE AT LEAST PARTLY IN RESPONSE TO AN AMPLIFYING
UPPER PATTERN AS A STRONG RIDGE BUILDS OVER THE SOUTHWEST CONUS AND
A LOW DEEPENS OVER THE HUDSON BAY REGION.  THIS SHOULD PUT THE
MIDWEST BACK INTO NORTHWEST FLOW ALOFT AND ALLOW A CANADIAN AIRMASS
TO BUILD INTO THE GREAT LAKES REGION BRINGING OUR AREA RELATIVELY
COOLER AND DRIER WEATHER FOR SATURDAY AND SUNDAY.

CARNEY

&&

.AVIATION...
FOR THE 12Z TAFS...MCS CENTERED OVR SE IA IS MOVING TO THE EAST
WITH CONVECTION AS FAR SOUTH AS CNTRL MO ON ITS SW FLANK. THE
CELLS ON THE SW FLANK ARE MOVING TO THE NE. THIS MOTION ALG WITH
THE MOVEMENT OF THE MCS SHOULD BRING SHRA/TSRA INTO UIN THIS MRNG.
THE INITIAL QUESTION IS HOW FAR SOUTH ANY NEW DEVELOPMENT WILL
OCCUR ON THE SW FLANK OF THE MCS. THERE IS A RATHER PRONOUNCED
OUTFLOW BNDRY AND THE RUC SHOWS DECENT H85 MOISTURE CONVERGENCE
THRU CNTRL MO...SO HAVE OPTED TO INCLUDE A TEMPO GROUP THIS MRNG
IN THE COU TAF IN LIGHT OF THE POTENTIAL. THIS OUTFLOW IF IT LASTS
COULD MORE OR LESS BECOME THE EFFECTIVE FORCING MECHANISM FOR PCPN
TDA. OTHERWISE ANTICIPATING A THREAT OF SHRA/TSRA TO COME WITH THE
FRONTAL BNDRY. THE FRONT IS DIFFICULT TO DISCERN ATTM BUT STILL
APPEARED TO BE DRAPPED ACRS IA INTO NRN KS. THE MODELS ARE HAVING
A DIFFICULT TIME RESOLVING THE FRONT...BUT THE GREATEST CONSENSUS
WOULD BRING THE FRONT TO AROUND I-70 BY 00Z AND THEN SLOWLY SINK
IT SOUTH INTO THE OZARKS TONIGHT. I HAVE PROB OR TEMPO GROUP TO
ACCT FOR THE POSSIBILITY OF ANOTHER ORGANIZED THUNDERSTORM COMPLEX
WITH THE FRONT LATER THIS AFTERNOON INTO THE EVENING AND THEN
REMOVED THE PCPN CHANCES FEELING THE BEST CHANCES WILL SHIFT SOUTH
OF THE TAF SITES.

GLASS

&&

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

WFO LSX

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE ST LOUIS MO
1156 AM CDT THU JUN 22 2006

ILZ058>060-064-065-069-070-074-079-095>102-MOZ018-019-026-027-
034>036-041-042-047>052-059>065-072>075-084-085-099-231200-
ADAMS IL-AUDRAIN-BOND IL-BOONE-BROWN IL-CALHOUN IL-CALLAWAY-
CLINTON IL-COLE-CRAWFORD-FAYETTE IL-FRANKLIN-GASCONADE-GREENE IL-
IRON-JEFFERSON-JERSEY IL-KNOX-LEWIS-LINCOLN-MACOUPIN IL-MADISON-
MADISON IL-MARION-MARION IL-MONITEAU-MONROE-MONROE IL-MONTGOMERY-
MONTGOMERY IL-OSAGE-PIKE-PIKE IL-RALLS-RANDOLPH IL-REYNOLDS-
SHELBY-ST. CHARLES-ST. CLAIR IL-ST. FRANCOIS-ST. LOUIS-
ST. LOUIS CITY-STE. GENEVIEVE-WARREN-WASHINGTON-WASHINGTON IL-
1156 AM CDT THU JUN 22 2006

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

.DAY ONE...THIS AFTERNOON AND TONIGHT

THUNDERSTORMS WILL MOVE ACROSS MISSOURI AND ILLINOIS THIS
AFTERNOON AND TONIGHT. A FEW OF THESE STORMS WILL LIKELY BE
SEVERE...PARTICULARLY SOUTH OF INTERSTATE 70 IN ILLINOIS. THE
STRONGEST STORMS WILL PRODUCE HAIL UP TO THE SIZE OF GOLFBALLS...
WIND GUSTS IN EXCESS OF 70 MPH...FREQUENT LIGHTNING AND HEAVY
DOWNPOURS.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY

THERE IS A CONTINUED RISK OF THUNDERSTORMS ON FRIDAY AS THE COLD
FRONT MOVES THROUGH SOUTHERN ILLINOIS AND SOUTHERN MISSOURI.
SEVERE THUNDERSTORMS WITH DAMAGING WINDS AND LARGE HAIL ARE
POSSIBLE...PRIMARILY ALONG AND SOUTH OF THE INTERSTATE 44 CORRIDOR
IN MISSOURI...AND THE INTERSTATE 70 CORRIDOR IN ILLINOIS.

.SPOTTER INFORMATION STATEMENT...

STORM SPOTTER GROUPS AND AMATEUR RADIO OPERATORS SHOULD MONITOR THE
WEATHER CLOSELY THIS AFTERNOON AND TONIGHT...AND BE PREPARED FOR
IMMEDIATE ACTIVATION IF NECESSARY.

BRITT