EXCESSIVE RAINFALL DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
201 AM EDT TUE AUG 25 2009
 
...VALID 06Z TUE AUG 25 2009 - 12Z WED AUG 26 2009...
...REFERENCE AWIPS GRAPHIC UNDER...DAY 1 EXCESSIVE RAINFALL...
 

 
...CNTRL PLNS...
TWO PART EXCESSIVE THIS PD. FFG IS FAIRLY HI THRU THE REGION SO
CAN'T JUSTIFY A SLGT AT THIS TIME.

ONGOING MCS ACRS NEB SHLD REMAIN IN PLC AND EXPAND FOR THE NEXT
SVRL HRS...THEN AS THE MIDLVL SHRTWV EJECTG FM THE CNTRL HI PLNS
REACHES THE REGION XPCT PCPN TO BEGIN TO ACCEL NEWD ALNG/AHD OF
THE SFC BNDRY...THEN WEAKEN LATER THIS MRNG AS THE LLJ WEAKENS.
MOIST TONGUE ACRS THE REGION REMAINS IMPRVS WITH SOME PWS ARND TWO
INCHES AND SFC DWPTS IN THE LWR 70S FEEDG INTO THE REGION. UPR
FLOW IS DIFL WITH AN UPR JET ENTRNC REGION PROVIDG DVRG. LATEST
NSSL RDR DERIVED RNFL RATES ARE 1-2 INCHES PER HR AND XPCT THESE
RATES TO CONT FOR THE NEXT SVRL HRS. ISOLD TOTALS OF 3-4 INCHES
ARE PSBL...ESPCLY OVR NERN NEB INTO NW IA.

LATER TDA...MDLS SHOW THE FNTL BNDRY (OR OUTFLOW FM TNGTS CNVCTN)
PSTND ACRS SRN NEB WITH DEEP MSTR POOLG ALNG THE BNDRY. ADDTNL
SHRTWV ENERGY IS FCST TO EJECT FM THE ROCKIES INTO THE PLNS LATER
TDA AND WL PROVIDE LRG SCALE ASCENT FOR CNVCTN OVR THE CNTRL HI
PLNS THAT SHLD CONGEAL INTO ANOTHER MCS TNGT ALNG THE KS/NEB
BORDER. MDLS ARE SHOWG DIFFERENT LAT PLACEMENT OF THE PCPN...WHICH
COULD BE DUE TO SOME FEEDBACK. ONE OTHER PRBLM IS WHETHER TO FOCUS
ALNG TNGTS OUTFLOW OR THE SYNOPTIC BNDRY. WOULD RATHER FOCUS ON
THE XPCTD OUTFLOW THAT WL BE S OF THE MAIN SYNOPTIC BNDRY. LATER
TNGT...CNVCTN SHLD BCM BETTER ALIGNED WITH THE 8H BNDRY...WHICH
DROPS INTO NERN KS...THEN EXTENDS INTO SRN IA. ALL GUID IS SHOWG A
STG...BUT NARROW RIBBON OF HI THETA-E AIR/MSTR THRU THIS
REGION...WHICH IS ALSO UNDER FAVORABLE UPR LVL DIFL AND THE ENTRNC
REGION OF ANOTHER UPR JET STREAK. PWS ARE FCST TO AGN BE ARND TWO
INCHES. XPCT RNFL RATES OF 1-2 INCHES PER HR WITH ISOLD 3-4 INCH
TOTALS BY WED MRNG.

ECKERT