Severe Thunderstorm Warning 123, NWS St. Louis, MO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ST LOUIS MO
240 PM CDT SAT MAY 11 2002

MAIN CONCERNS THIS PKG TO BE PLACEMENT AND TIMING ON HVY RAFL EVENT
FOR FA. MDLS INITIALIZED WELL WITH 50H HI OVR ERN GLF MEX AND S/WV
TROF FM NRN RCKY MTNS TO CTRL CA. LO CLOSES OFF OVR SRN RCKYS BY 24H
THEN OPENS AS TROF ACRS FA BY 48H. NWLY FLOW ALFT AS RDG BLDS OVR
RCKY MTNS. RDG MVS SLOLY E WITH DRY WX THRU MIDWK AND NXT PCPN IN
LATTER PART OF XTNDD.

AT LWR LVLS PLENTY OF MSTR ADVCTG INTO RGN FOR ANTHR HVY PCPN EVENT
TNGT INTO SUN. WMFNT AT 19Z LOCTD ALG NRN PTN OF FA WITH SFC DPS
QUICKLY RISING INTO MID 60S. SAT SHWG DCRG CLDS OVR CTRL AND SRN ZNS
WITH SFC TEMPS WRMG INTO MID AND UPR 70S. MDLS IN GD AGMT WITH
DVLPMT AND MVMT OF SFC LO BUT MINOR DIFFS IN PLACEMENT OF QPF MAXES
TNGT AND SUN. AVN HAS MAXES SLGTLY MORE N AND W FM ETA. WL CONT
FLOOD WATCH FOR ALL CTRL AND NRN ZNS FOR TNGT AND FOR ALL ZNS FOR
SUN. MDLS INDCTG ANTHR MCS TO DVLP SUN NGT ALG FNT AND WATCH FOR SRN
ZNS PROB BE XTNDD BUT WL LV FOR NXT PKG.

GOING FCSTS ON TEMPS AND POPS GOOD AND WL ONLY TWEAK. CATEGORICAL
POPS OVR ALL BUT SRN ZNS FOR TNGT AND EVERYWHERE TMRW. CFNT TO MV SE
ACRS RGN ON SUN CRSG KSTL RGN APPROX 20Z. PCPN MAINLY TO BE ALG AND
AHD OF CFNT BUT FNT SLOWS ACRS SE MO SUN NGT AND WL KP HI POPS IN
CTRL AND SRN ZNS FOR 3RD PD.

TEMPS IN GEN AGMT THRU 36H BUT FAN TRENDING A LTL COOL AFTWDS. WL GO
WITH BLEND AS FWC PROB TOO WRM GIVEN XPCTD PCPN.

IN XTNDD WL DROP POPS IN NRN ZNS BUT KP CHC FM THU THRU SAT IN CTRL
AND SRN ZNS. HI PRES OVR RGN THRU MIDWK TO KP TEMPS AT OR BLO NRML
THRU XTNDD PD.

.STL...FLASH FLOOD WATCH FOR CTRL AND NRN ZNS TNGT AND ENTIRE FCST
       AREA FOR SUN.

WDB