Severe Thunderstorm Warning 112, NWS St. Louis, MO

000 
WWUS53 KLSX 100349
SVSLSX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE ST LOUIS MO
1049 PM CDT WED MAY 9 2007

MOC093-123-100359-
/O.CAN.KLSX.SV.W.0112.000000T0000Z-070510T0400Z/
MADISON MO-IRON MO-
1049 PM CDT WED MAY 9 2007

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHERN IRON AND MADISON 
COUNTIES IS CANCELLED...

THE STORM WHICH PROMPTED THE WARNING HAS WEAKENED AND NO LONGER 
APPEARED TO BE SEVERE.

LAT...LON 3748 9068 3727 9066 3743 9029 3765 9042

$$

TRUETT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ST LOUIS MO
930 PM CDT WED MAY 9 2007

.UPDATE...
CNVTN OVR S AND W CNTRL MO WENT THRU A BIT OF WKNG AND A SLGT DCR
IN CVG SHORTLY BFR SNST...BUT OVR THE LAST HR NEW CELLS HV FORMED
OVR SE MO...AND NR KDMO. 00Z SFC ANALYSIS MAKES IT APR THAT RMNTS
OF SFC FNTL BNDRY IS DRAPED FROM JUST N OF KJLN TO NR KFAM. WITH
LGT S FLO FCST ACR THIS BNDRY PRODUCING WK LFT OF SLGTLY UNSTBL
AMS OVRNGT...CONTG CHC POPS OVR SW HLF OF CWA CERTAINLY APRS
WARRANTED. IF LO LVL FLOW WAS A BIT STGR WULD BE WORRIED ABT
CNVTN DVLPG FURTHER N...BUT GIVEN THAT THE 925 AND 850MB FLOW IS
FCST TO RMN IN THE 5-10 KT RANGE...AND VIRTUALLY NO UPR LVL
FORCING IS INDICATED ACR AREA...DONT BLV PCPN THRT WL GET ANY
FURTHER N THAN A MEXICO...JERSEYVILLE LN...WHICH IS THE NWD EXTENT
IN THE GOING FCSTS.

TRUETT

&&

.DISCUSSION...
WEAK FRONTAL BOUNDARY REMAINS TO THE SOUTH OF CWA THIS AFTERNOON
WITH DIURNAL CU POPPING UP MAINLY ALONG AND SOUTH OF I-70. RWS AND
TRWS THAT WERE OVER SWRN MO THIS MORNING...LIFTED N CLOSE TO
CWA...BUT DIMINISHED AS THEY HIT THE DRIER AIR BEHIND BOUNDARY.

FOR TONIGHT...COULD STILL SEE SOME ISOLATED TO SCATTERED RWS/TRWS
FOR SWRN HALF OF CWA...BUT MOST OF AREA TO REMAIN DRY AND MILD. LOW
TEMPS WILL BE IN THE UPPER 50S TO LOWER 60S.

IN THE MEANTIME...NEXT SIGNIFICANT SHORTWAVE OVER SERN NEW MEXICO TO
SLIDE EAST INTO CENTRAL TEXAS...SO COULD SEE AN INCREASE IN ACTIVITY
FOR SOUTHERN SECTIONS OF CWA ON THURSDAY AS MOISTURE AND INSTABILITY
ARE LIFTED NORTH OVER STALLED FRONTAL BOUNDARY. OUR BEST CHANCES OF
PCPN WILL BE ALONG AND SOUTH OF I-70 ONCE AGAIN. HIGH TEMPS ON
THURSDAY WILL BE IN THE UPPER 70S TO LOWER 80S...AS THERE WILL BE
MORE CLOUD COVER KEEPING TEMPS JUST SLIGHTLY COOLER THAN TODAY.

BY THURSDAY NIGHT AND FRIDAY...UPPER LOW TO SLIDE INTO THE GULF OF
MEXICO AS STRONG SURFACE RIDGE BUILDS IN OVER THE MIDWEST. WILL SEE
SOME LINGERING RWS/TRWS THURSDAY NIGHT AND FRIDAY WITH BEST CHANCES
REMAINING ALONG AND SOUTH OF I-70.

FINALLY WITH RIDGE OVERHEAD WILL SEE DRY AND MILD CONDITIONS THROUGH
THE WEEKEND AND INTO EARLY NEXT WEEK. NEXT CHANCE FOR RAIN WILL BE
MOVING IN LATE MONDAY NIGHT AND PERSIST THROUGH THE REST OF THE
FORECAST PERIOD. STILL SOME UNCERTAINTY WITH THIS SYSTEM...SO ONLY
HAVE LOW CHANCE POPS MONDAY NIGHT AND TUESDAY...THEN JUST SILENT 20S
FOR REST OF PERIOD. EXTENDED MODELS TENDING TO STALL THIS NEXT
FRONTAL BOUNDARY OVER AREA...SIMILAR TO CURRENT WEATHER PATTERN...SO
WILL PROBABLY NEED TO ADJUST GRIDS AS MODELS GET A BETTER HANDLE ON
THIS SYSTEM.

BYRD

&&

.AVIATION...
FOR THE 00Z TAFS...VFR CONDITIONS AND LGT SFC WNDS WILL PREVAIL
AREAWIDE THRU THE VALID TAF PERIOD. TWO CHANCES FOR PCPN OVER THE
NEXT 24 HOURS...WITH THE FIRST COMING THIS EVENING FROM AN UPPER
LEVEL DISTURBANCE AS IT DRIFTS SLOWLY NEWD TOWARDS CNTRL MO. HAVE
ADDED IN VCSH INTO THE KCOU TAF. THE NEXT CHANCE FOR RAIN WILL
OCCUR OVER A WIDER AREA AS LO PRES DEVELOPS ALONG THE QSTNRY FRONT
TO OUR S AND FORCES IT TO BUCKLE NWD...WITH THESE FEATURES MOVING
THRU THE AREA ON THURSDAY. THIS WILL RESULT IN A CHANCE FOR RAIN
OVER A LARGER AREA FROM MID MORNING THRU THE AFTERNOON. PROB30
GROUPS HAVE BEEN ADDED IN FOR ALL TAF SITES FOR THIS.

TES

&&

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

WFO LSX

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE ST LOUIS MO
341 PM CDT WED MAY 9 2007

ILZ058>060-064-065-069-070-074-079-095>102-MOZ018-019-026-027-
034>036-041-042-047>052-059>065-072>075-084-085-099-101200-
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-
341 PM CDT WED MAY 9 2007

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

.DAY ONE...TONIGHT

THERE IS A CHANCE OF THUNDERSTORMS FOR AREAS ALONG AND SOUTH OF
INTERSTATE 70 TONIGHT AS UPPER LEVEL DISTURBANCES INTERACT WITH THE
WARM...MOIST AND UNSTABLE AIR ACROSS THE BI-STATE REGION. THESE
STORMS ARE NOT EXPECTED TO BE SEVERE.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY

THE CHANCE OF THUNDERSTORMS WILL CONTINUE OVER THE AREA THROUGH
FRIDAY.

THE MISSOURI RIVER IS ABOVE FLOOD STAGE FROM JEFFERSON CITY TO
ST. CHARLES. MAJOR FLOODING IS FORECAST LATER THIS WEEK INTO
EARLY NEXT WEEK ALONG PARTS OF THE MISSOURI RIVER. PLEASE REFER TO
FLOOD SPECIFIC PRODUCTS FOR FURTHER INFORMATION.

THERE IS ANOTHER CHANCE FOR THUNDERSTORMS LATE MONDAY NIGHT AND
TUESDAY.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT ANTICIPATED TONIGHT.

BYRD