FOUS30 KWBC 111830 QPFERD EXCESSIVE RAINFALL POTENTIAL OUTLOOK NATIONAL CENTERS FOR ENVIRONMENTAL PREDICTION HYDROMETEOROLOGICAL PREDICTION CENTER...NWS...CAMP SPRINGS MD 158 PM EDT MON SEP 11 2000 PRIOR TO SEP 13/0000 UTC HVY TO EXCESSIVE RAINFALL IS EXPECTED ACROSS PORTIONS OF EXTREME SRN WI AND NRN IL. AM CONCERNED ABOUT THE BAND OF CONVECTION THAT IS TAKING ON AN E-W ORIENTATION ACROSS SRN WI AND NRN IL INTO ERN IA FOR THE POTENTIAL FOR TRAINING OF CELLS AND HEAVY TO EXCESSIVE RAINFALL DURING THE NEXT 6 TO 9 HRS. AN OUTFLOW BOUNDARY HAS SET UP VICINITY OF THE WI/IL BORDER...CONVECTION CONTINUES TO DEVELOP ALONG IT. MORE IMPORTANTLY THE LATEST RADAR IMAGERY INDICATES THERE ARE NEW CELLS STARTING TO FORM UPSTREAM OVER ERN IA. SATELLITE IMAGERY INDICATES THERE IS A STRONG SHORTWAVE MOVING EWD ACROSS THE NRN PLAINS. CURRENT CONVECTION WILL PROBABLY NOT SHIFT EWD UNTIL THIS SHORTWAVE SHIFTS CLOSE ENOUGH TO FORCE THE SURFACE COLD FRONT EWD PAST THE CURRENT CONVECTION. GOES SOUNDER DATA SHOWS THAT PWS SOUTH OF THE OUTFLOW BOUNDARY ARE IN THE 1.60 TO 1.70 INCH RANGE. THE SOUNDER DATA ALSO INDICATES THAT THE AIRMASS TO THE WEST ACROSS IL IS CONTINUING TO DESTABILIZE. ALL THE ABOVE ARGUE FOR THE POTENTIAL FOR ISOLD 3 TO 5 INCH RAINFALL BEFORE THE SYSTEM STARTS SHIFTING EWD. [...] Back to the 11 September 2000 LI/PW Axis page