EXCESSIVE RAINFALL DISCUSSION NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD 251 PM EDT FRI APR 22 2011 ...VALID 18Z FRI APR 22 2011 - 00Z SUN APR 24 2011... ...REFERENCE AWIPS GRAPHIC UNDER...DAY 1 EXCESSIVE RAINFALL... SLIGHT RISK OF RAINFALL EXCEEDING FFG TO THE RIGHT OF A LINE FROM 15 NNE CRW 15 NW CRW HTS 25 S LEX 35 W HOP 25 NNE BVX 30 S HRO 25 ESE TQH TQH 15 ESE GMJ 30 SSW TBN 25 NNW FAM 15 NW 1H2 25 NNW EYE 10 ESE AOH 15 NE MNN MFD BJJ 10 ESE CAK 15 WNW BVI 10 ENE BVI BTP 20 E BTP 15 NW IDI 20 NNE IDI 20 SSW FIG 20 WSW UNV 25 SE UNV 25 W CXY 30 NE HGR 20 NE HGR 10 ENE HGR 10 SSE HGR MRB OKV 15 S OKV 25 SSW OKV 35 NE SHD 25 NE SHD 20 NNW SHD 30 SE EKN 30 SSE EKN 25 SSW EKN 15 E 48I 10 WNW 48I 15 NNE CRW. MODERATE RISK OF RAINFALL EXCEEDING FFG TO THE RIGHT OF A LINE FROM MGY 20 SSW TZR 25 NNE UNI 20 WSW PKB 15 NNE 3I2 25 W 3I2 40 WNW HTS 15 SSW FFT 10 ENE OWB 25 SSE HSB 15 ENE CGI 25 SSE FAM 10 ESE FAM SAR FOA 15 ENE RSV 20 W BAK WMO MGY. MID MS VALLEY THRU THE OH VALLEY... ONLY SOME SLIGHT CHANGES MADE TO THE PREVIOUS EXCESSIVE RAINFALL POTENTIAL OUTLOOK BASED ON LATEST RADAR TRENDS. LATEST GUIDANCE IS IN FAIRLY GOOD AGRMNT WITH A WIDESPREAD HVY TO EXCESSIVE PCPN EVENT THIS PERIOD FROM THE MID MS VALLEY..NEWD THRU THE OH VALLEY. LITTLE CHANGE EXPECTED TO THE AXIS OF ABOVE AVG PW VALUES...1-2+ STD ABOVE THE MEAN...ALONG THE MEAN FRONTAL BNDRY PSN BECOMING ESTABLISHED ACRS THESE AREAS. THE INITIAL BATCH OF ORGANIZED CONVECTION MOVG EWD TO THE NORTH OF THE OH RIVER IS EXPECTED TO BUILD SWD TONIGHT INTO THE MID TO UPR OH RIVER VALLEY IN A REGION OF ANOMALOUS MOISTURE FLUX AND FAVORABLE UPR DIFFLUENCE. WHILE THIS ACTIVITY MAY WEAKEN AFTER 1200 UTC SAT...ADDITIONAL CONVECTION EXPECTED TO FIRE SAT FARTHER TO THE SW OVR SRN MO/NRN AR AND BUILD NEWD INTO THE LOWER OH VALLEY AS UVVS ARE ENHANCED AHEAD OF ADDITIONAL NEWD MOVG SHRTWVS. THE QPF AXES AMONG THE LATEST GUIDANCE ARE SIMILAR ACRS THE OUTLOOK REGION. FOR QPF DETAILS THE SLIGHTLY HEAVIER HI RES ARW/NMM AMTS WERE FOLLOWED...WITH WIDESPREAD 1-3"+ TOTALS EXPECTED THIS PERIOD FROM NRN AR/SRN MO...ENEWD THRU THE OH VALLEY....WITH LOCALLY HEAVIER TOTALS POSSIBLE. ORAVEC !$$