Severe Thunderstorm Warning 57, NWS St. Louis, MO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ST LOUIS MO
300 PM CDT SUN MAY 13 2001

ELONGATED BAND OF SHRA/TSRA LCTD FM MID MO NWD CONTS TO REGENERATE
OVR SC IA.  THIS BAND OF PCPN OCCURING TO THE EAST OF THE SYNOPTIC
SCALE WRMFNT AND IN A RGN OF MODEST LOW LVL POS THETAE ADVCTN AT THE
NOSE OF THE ANTICYCLONICALLY CURVED LLJ.  MDLS DON'T APPEAR TO HV
THAT GREAT OF HANDLE ON THE SITN WITH EACH SHOWING A PIECE OR TWO OF
THE PUZZLE.  THEY ALL APPEAR TO BE A BIT FAST SHIFTING THIS WHOLE
LOW LVL THETAE ADVCTN/WAA ZN TO THE EAST THIS EVENING.  WL CARRY AT
LEAST DECENT CHC POPS OR AREAL COVERAGE MENTION FOR ALL BUT MAYBE
SRN SXNS OF THE CWFA.  AFOREMENTIONED N/S ZN OF LOW LVL FRCG PROGGED
TO BE OVR CNTRL IL BY 12Z MON AND THUS WL CONT WITH MRNG POPS TO THE
EAST OF THE MS RVR.  OTW SHUD SEE WRM FROPA OVR THESE LCTNS DURING
THE MRNG HRS AND S TO SW PBL FLOW SPREAD EAST FROM WRN MO.  THIS
SHUD ALLOW FOR GOOD WRMG.  MAV/FWC GUID TMPS ARE HARD TO ARGUE WITH
AND HV BEEN FOLLOWED.

WRM UP SHUD CONT INTO TUE AS HGTS RISE AND PATTERN FLATTENS OUT OVR
MOST OF THE CONUS.  QUESTION FOR TUE INTO WED IS WITH THE BACKDOOR
FRONT.  THE AVN HAS BEEN GETTING SLOWER EACH SUCCESSIVE RUN AND IS
THE AGRESSOR BRINGING A FNT THRU ON TUE NGT...WHICH EVENTUALLY GOES
STNRY OVR SRN SXNS WED MRNG.  THE ETA ON THE OTR HAND IS NOT NEARLY
AGRSV WITH A BACKDOOR FRONT...IF AT ALL.  MUCH OF THE AVN ARRISES FM
IT'S POTENT SHRTWV TROF DROPPING FM THE MIDWEST INTO THE WRN OH VLY
IN THE TUE-WED TIME FRAME.  THE PRVS FCST AND NCEP GUID BRINGS THE
FNT TO STL VCNTY AND WL FOLLOW THIS COURSE ATTM.  ONE THING WHICH
LOOKS PRETTY GOOD IS A VERY WRM DAY ON TUE.  DEEP W TO SW LOW TROP
FLOW IS PERFECT FOR THE RGN WITH THE H85 TMPS CURRENTLY PROGGED.
ALSO DRY GRND IN ALL BUT C/NE MO WL CREATE MORE FVRBL CONDS. FEEL
ALL THE MOS GUID IS A TOO COOL AND WL CONSERVATIVELY BOOST MOST RNGS
TO ARND 90.  NOTE THE ETA 2M TMPS ARE IN THE L90S.

IN THE EXTDD...THE BACKDOOR FNT SHUD PUSH BACK NWD INTO THURS.  A
PAC CDFNT WL THEN TRY TO MAKE IT THRU ON FRI AND MRF SUGGESTS IT MAY
WAVER WITH MID LVL WAVE PASSAGES INTO THE WEEKEND.  WL KP THE
WEEKENpD DRY FOR NOW AS MDLS HV SHOWN NO CONSISTENT TRENDS IN OUTER
PDS AS OF LATE.

.STL...NONE.
GLASS