469 
FXUS63 KLSX 102203
AFDSTL

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ST LOUIS MO
350 PM CST MON MAR 10 2003

WX WL TAKE BIG CHG OVR THE NEXT 30H AS THE COLD RDG FINALLY GIVES 
WAY AND WRM AIR AND MSTR BGNS TO SPRD INTO THE RGN.  HOW QUICK THIS 
PROCESS TAKES PLACE IS ONE OF THE BIG QUESTIONS.  TNGT WL STILL BE 
ON THE COLD SIDE AS THE RDG SLOWLY RETREATS.  LOW CLDS SPRDG ACRS 
SRN MO/IL WL HELP KP TMPS UP THERE...OTW WENT ON THE COLDER END OF 
GUID TNGT WITH SFC FLOW GRDLY BCMG SELY.

THE RDG WL CONT TO RETREAT ON TUE WITH INCRSG S TO SW LOW LVL FLOW.  
WHILE THIS WL LEAD TO A BIG WRMUP OVR READINGS THE LAST FEW DAYS BUT 
IM NOT READY TO JUMP ON THE FWC BANDWAGON AND HV KEPT HIS CLOSER 
TO THE COOLER MAV.  LOW LVL MSTR WL ALSO BE ON THE INCRS BUT THIS 
KPS TRENDING SLOWER WITH EACH MDL RUN...MDLS FINALLY GET 6 DEG H85 
DPTS INTO SW MO BY ERLY EVNG.  I HV KEPT A LOW POP FOR SHRA IN MID 
MO FOR LATE AFT...THIS MAY BE A TAD FAST BUT THIS IS NR INCRSG MCON 
ON THE NOSE OF THE LLJ.

DIFS WRT TO FRONT PSN CONT FOR THE TUE NGT INTO WED AND BYD TIME 
FRAME.  THE 12Z ETA AND GFS HV REVERSED PSNS FM YDAS 12Z RUNS WITH 
THE ETA NOW SHWG THE FURTHEST SWD PENETRATION TO NR I-70 BY 12Z 
WED.  GFS AND UKMET NEVER BRING THE FNT INTO MO.  NOTEWORTHY IS THE 
18Z ETA HAS TRENDED FURTHER NORTH WITH THE FNT AS WELL.  MY FCST WAS 
INTIALLY A COMPROMISE AND NOW IS CLOSE TO THE NEW 18Z ETA BRINGING 
THE FNT NORTH OF I-70 BY WED MRNG.  THE LLJ WL CONT TO ADVECT MSTR 
ACRS THE RGN TMW NGT IN ADVANCE OF THE FNT AND THIS COMBINED WITH WK 
LRG SCALE ASCENT SUPPORTS CONTD THREAT OF SHRA.  BROUGHT A THREAT OF 
THUNDER INTO THE FAR SOUTH WHERE THE MDLS ARE INDCTG THE BEST BUT WK 
ELEVATED INSTABILITY.  

ON WED THE FNT SHUD LIFT BACK NWD IS RSPNS TO THE NEXT UPSTRM SHRTWV 
AND RESULTANT FALLING SFC PRES.  THE HARD PART WAS HOW WARM TO GO 
AND PRETTY MUCH STUCK NR THE CLUSTERED MOS GUID.  THE AVN 2M TMPS 
HOWEVER ARE ALOT MORE ROBUST WITH WRMG.  I HV ALSO HELD OFF ON POPS 
TIL WED NGT.  ATTM INCRSG LLM AND STEEPENING LAPSE RATES SHUD RESULT 
IN WK INSTABILITY ACRS MOST OF THE CWFA WED AFT INTO NGT.  AS THE 
NRN STRM SHRTWV DIGS ACRS THE LWR GRTLKS RGN THIS WL SWING THE NEXT 
CDFNT ACRS THE AREA WED NGT INTO ERLY THURS INTERACTING WITH THE 
LLM/INSTAB AND BRINGING A CD CHC OF SHRA/TSRA.  HI PRES WL BLD IN 
BHD THE FNT ON THURS AND THEN RETREAT BY ERLY FRI LEADING TO A NICE 
WRM-UP INTO THE WKND.     

.STL...NONE
GLASS