EXCESSIVE RAINFALL DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
302 PM EDT MON APR 25 2011
 
...VALID 18Z MON APR 25 2011 - 00Z WED APR 27 2011...
...REFERENCE AWIPS GRAPHIC UNDER...DAY 1 EXCESSIVE RAINFALL...
 

SLIGHT RISK OF RAINFALL EXCEEDING FFG TO THE RIGHT OF A LINE FROM
15 WSW PRX 40 SE MLC 35 NE MLC 15 N MKO 10 E GCM 25 SE CFV
25 NW JLN 60 NNE JLN 20 SE DMO 15 ENE JEF 30 W SUS SET
25 SSW TAZ 20 ESE TAZ 15 S CMI 25 WSW ASW 20 SSE IRS 10 W ADG
ONZ 10 W CXPT 30 ESE TDZ 20 ESE FDY DAY CVG 20 SE LOU 15 NNW BWG
40 WSW BNA 35 NNW MSL 40 NE TUP TUP 35 WSW TUP 30 NNW GWO
15 N GLH 30 SW LLQ 30 WSW ELD 15 WSW PRX.

MODERATE RISK OF RAINFALL EXCEEDING FFG TO THE RIGHT OF A LINE
FROM
30 WSW M89 25 ESE DEQ DEQ 10 W DEQ 25 NW DEQ 35 SSW RKR
25 SW RKR 15 W RKR JSV 25 NNE TQH 10 N GMJ 15 NE JLN 45 NW SGF
35 W AIZ 20 SSW JEF 25 WSW SUS 15 N BLV 10 SSW MTO 15 S LAF GUS
15 NNW FWA 25 NE FWA 20 ENE FWA 20 SSE FWA MIE 10 WNW GEZ
10 SSW BMG 25 ESE LWV 25 ESE AJG EVV EHR 40 E M30 40 W HOP
40 NE MKL 15 NE MKL 20 SW MKL 10 N OLV M97 30 W UTA 10 SSW SGT
15 NNW PBF M89 30 WSW M89.

HIGH RISK OF RAINFALL EXCEEDING FFG TO THE RIGHT OF A LINE FROM
40 ENE DYR 20 SSE DYR 10 NE NQA 20 NW AWM 25 E SRC 10 N LRF
30 WNW LZK 20 NNW HOT 10 SW MWT 20 ENE DEQ 10 ENE DEQ 10 NNW DEQ
35 S RKR 10 SSE RKR 10 SSW FSM 15 NNW FSM 20 WSW FYV SLG
10 SSE GMJ 10 NE GMJ 20 SE JLN 30 E JLN 15 NW SGF 35 NNE SGF
15 S VIH 30 E VIH 30 NNW FAM 10 S BLV 10 NNW ENL 10 NNE SLO
10 S 1H2 15 E 1H2 OLY CUL 15 E PAH 40 ENE DYR.

 
THE VRY SIGNIFICANT/EXCESSIVE RNFL EVENT WL CONT THIS PD AND
BEYOND..AS A COUPLE OF ROUNDS OF ADDITIONAL HVY CNVCTN/RAINS
IMPACT MUCH OF THE OH VLY INTO THE MID MS VLY. TWO WELL DEFINED H5
S/WVS WL BE IMPACTING THE AREA DURG THIS PD..WITH THE 1ST SYS NOW
OVR THE SRN PLAINS FCST TO LIFT NNEWD AND CLOSE OFF OVR THE
MIDWEST LTR TUE..WHILE THE STG UPSTREAM S/WV NOW VCNTY OF THE PAC
NW DIVES/AMPLIFIES INTO THE SRN HI PLAINS TWDS THE END OF THE PD. 
COMBO OF LRG SCALE LIFT FM THESE S/WVS AND FOCUSING SFC BNDRYS IN
PLACE..A CONTD STG LOW LVL INFLO OF DEEPER GULF MSTR..AND A VRY
FAVORABLE COUPLED UPR JET STRUCTURE ASSOCTD WITH BOTH S/WVS..WL
LEAD TO THE DVLPMNT AND CONTINUATION OF THE VRY HVY TO EXCESSIVE
RAINS.  THE LATEST MDL MASS FIELD SOLNS ARE SHOWING SOME SLGT
TIMING DIFFS..AND MDL QPFS ARE SHOWING SOME DIFFS REGARDING THE
AXIS OF HVIEST RAIN..BUT IN GENL THEY ARE IN AGREEMENT ON IT BEING
A BIG RNFL EVENT..SO CONFIDENCE IS HIGH THAT THERE WL BE SOME VRY
HVY RAINS THIS PD.  MANUAL QPF AGAIN LEANED MORE HEAVILY TWDS A
CANADIAN GEM/GFS/IN-HOUSE BIAS CORRECTED BLEND..WITH THE ECMWF
HIRES QPF LOOKING TOO LGT WHILE THE NAM HVIER RNFL AXIS LOOKED TOO
FAR N TWDS THE LWR GTLKS.  A BAND OF 3-4 INCH RNFL AMTS LIKELY FM
CNTRL AR NNEWD INTO THE LWR OH RVR VLY..WITH SOME ISOLD GTR THAN 5
INCH TOTALS PSBL..GIVEN THIS REGION WL BE IMPACTED BY RAINS
ASSOCTD WITH EACH SYS.  WITH THE RECENT VRY HVY RAINS..HAVE
INDICATED A LRG HI RISK AREA WITH SIGNIFICANT ADDITIONAL FLOODING
LIKELY WITHIN THE THREAT AREA.

TERRY
$$