Severe Thunderstorm Warning 51, NWS St. Louis, MO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ST LOUIS MO
440 PM CDT WED APR 30 2003

ENTIRE AREA IN THE WRM SECTOR ATTM WITH WRMFNT DRAPPED FM LOW IN NE
KS ALG THE MO/IA BRDR INTO THE NRN OH VLY.  TMPS IN THE LM80S ALG
WITH DPTS IN THE LM60S AND STEEP MID LVL LAPSE RATES HV RESULTED IN
A VRY UNSTBL AMS WITH CAPES AOA 3500 J/KG.  LTL IF ANY CAPPING LEFT
BUT ALSO NO SOURCE OF LIFT EITHER AND ONLY AN ISOLD TSRA OCCURING
ATTM.  THIS SHUD CHG THIS EVNG HOWEVER AS THE LLJ INTENSIFIES AND
LRG SCALE ASCENT SPRDS ACRS THE FNTL ZN IN ASSOCN WITH THE SHRTWV
MIGRATING FM THE PLAINS.  EXPECT WDSPRD DVLPMNT ALG THE FNTL ZN BTWN
00-03Z.  SHEAR AND INSTABILITY PROFILES SUPPORT GD SVR THREAT WITH
CELL TRAINING INVOF THE BNDRY PSBL BRINGING POTNTL OF LCLY HVY
RNFL.  CONTEMPLATED A FLOOD WATCH IN NE MO/WC IL BUT AFT
COORDINATING WITH SURROUNDING OFFICES WL HOLD OFF AND LET THE EVNG
SHIFT MONITOR.  IF THERE IS MUCH QUESTION TNGT IT IS THE EVOLUTION
OF ANY MCSS WHICH DUE DVLP AND HOW MUCH SEWD MVMNT WL OCCUR.  THE
12Z ETA AND GFS SHOW A DECIDED SWD MOTION TNGT AND INTO THURS BUT
IM NOT SURE HOW MUCH OF THIS IS FEEDBACK.  IT SEEMS WHENEVER THE
AMS IS VERY UNSTBL WITH STEEP MID LVL LAPSE RATES/DRY AIR...THE MDLS
DVLP SPURIOUS VORT CNTRS...BNDRYS AND TRY TO SINK EVERYTHING QUICKLY
SWD.  WHILE THE AMS WUD FAVOR GD COLD POOL DVLPMNT...I THINK THE 12Z
RUNS ARE A BIT AGRESSIVE.  THE 18Z ETA KPS THE PCPN MORE ANCHORED TO
THE FNT WITH SOME SWD DEVIATION AND THIS APPEARS MORE RSNBL GIVEN
THE MEAN WSW FLOW ALF...VEERING LLJ TNGT AND PROGGED CFM VECTORS.

HOW THE CNVCTV EVOLUTION PANS OUT TNGT WL HV BIG IMPACTS ON THE
TMPS AND SVR WX POTNTL ON THURS.  THE MORE NWD THE PSN OF THE MCS AT
DAYBREAK WL ALLOW MORE HTG/INSTABILITY AND POTNTL FOR A BUSY SVR WX
DAY.  SHEAR AND STABILITY PARAMETERS BORDER ON MULTICELL/SUPERCELL
MODES WITH BEST THREAT OF THE LATER NR ANY BNDRIES.

AFT THIS SYS EXITS EAST ON FRI...AND WK RDGG BLDS INTO THE AREA IN
ITS WAKE THE QUESTION THEN BCMS WHEN TO REINTRODUCE POPS.  QUALITY
MSTR NEVER GETS FAR RMVD AND SHUD RETURN QUICKLY ONCE PRES/HGTS BGN
FALLING ACRS THE PLAINS AND S/SE LOW LVL FLOW DVLPS.  THE ETA AND
GFS INDCT THAT ELEVATED MSTR/INSTABILITY AND ATTENDANT THUNDER CHCS
CUD OCCUR AS ERLY AS SAT AFT.  IN ORDER TO BLEND BTR WITH
NEIGHBORING OFFICES I HELD OFF ON INTRODUCING POPS UNTIL SAT
NGT...ALTHO WUDNT BE SURPRISED TO SEE THEM ERLYR.

SAT NGT INTO MON CUD BE ANOTHER ACTV PD WITH PRIND SHWG A SVR PSBLTY
SUN AFT/EVNG...SHIFTING INTO THE ERN MS VLY AND OH VLY ON
MON.

.STL...NONE.
GLASS

ILZ058>060-064-065-069-070-074-079-095>102-MOZ018-019-026-027-
034>036-041-042-047>052-059>065-072>075-084-085-099-020200-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE ST LOUIS MO
855 PM CDT WED APR 30 2003

THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL AND EASTERN MISSOURI
AND WEST CENTRAL AND SOUTHWEST ILLINOIS.

.DAY ONE...TONIGHT

THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS FOR THE REST OF
TONIGHT OVER NORTHEAST MISSOURI AND WEST CENTRAL ILLINOIS...AND
PARTS OF CENTRAL MISSOURI.  THIS MODERATE RISK AREA IS ROUGHLY ALONG
AND WEST OF A JEFFERSON CITY...PITTSFIELD ILLINOIS LINE.  TO THE
SOUTH AND EAST OF THIS MODERATE RISK AREA...THERE IS A SLIGHT RISK
OF SEVERE THUNDERSTORMS TONIGHT.

THUNDERSTORMS ERUPTED WEDNESDAY EVENING FROM SOUTHEAST IOWA...ACROSS
NORTH CENTRAL AND WEST CENTRAL MISSOURI...INTO SOUTHEAST KANSAS.
THE WARM UNSTABLE AIRMASS OVER THE REGION WILL CONTINUE TO FUEL
THESE STORMS AS THE MOVE EAST OVERNIGHT...WHILE THE WIND PROFILE
ACROSS THE AREA WILL MEAN THAT SOME OF THESE STORMS MAY BE SEVERE.

IN ADDITION TO THE THREAT OF LARGE HAIL AND DAMAGING WINDS...HEAVY
RAINS WILL ALSO BE POSSIBLE.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY

THERE IS A CONTINUED RISK OF SEVERE THUNDERSTORMS ACROSS EASTERN
MISSOURI AND SOUTHWEST ILLINOIS ON THURSDAY AND THURSDAY EVENING AS
THE COLD FRONT CONTINUES TO MOVE SOUTHEAST THROUGH THE AREA.

THERE IS ALSO A CHANCE OF THUNDERSTORMS ON SUNDAY AND MONDAY AS THE
NEXT STORM SYSTEM MOVES THROUGH THE MIDWEST.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE REQUIRED OVERNIGHT.

&&

MORE INFORMATION MAY BE OBTAINED AT...
HTTP://WWW.CRH.NOAA.GOV/LSX (ALL LOWER CASE)

TRUETT

MOC103-111-010815-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE ST LOUIS MO
255 AM CDT THU MAY 1 2003

SEVERE THUNDERSTORM WATCH #193 IS NO LONGER IN EFFECT FOR
KNOX AND LEWIS COUNTIES IN MISSOURI.  OVER THE PAST FEW HOURS
THE MAIN THREAT OF SEVERE WEATHER HAS PUSHED OUT OF THIS AREA.

TRUETT

MOC135-010815-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE ST LOUIS MO
305 AM CDT THU MAY 1 2003

SEVERE THUNDERSTORM WATCH #192 IS NO LONGER IN EFFECT FOR
MONITEAU COUNTY.   WHILE SHOWERS AND THUNDERSTORMS WILL BE MOVING
THROUGH THE AREA EARLY TODAY...THEY ARE NOT EXPECTED TO BE SEVERE.

TRUETT