EXCESSIVE RAINFALL DISCUSSION NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD 942 PM EDT SUN MAY 01 2011 ...VALID 03Z MON MAY 02 2011 - 00Z TUE MAY 03 2011... ...REFERENCE AWIPS GRAPHIC UNDER...DAY 1 EXCESSIVE RAINFALL... SLIGHT RISK OF RAINFALL EXCEEDING FFG TO THE RIGHT OF A LINE FROM 20 SSE HUF 20 NE BMG 10 NE BAK 35 NW CVG 20 WNW CVG 30 SW CVG 10 SSW FTK 45 SW HOP 20 SSW UTA 35 NNW GLH ELD 15 NE DTN 10 SSE 4F4 20 WNW TYR 15 ENE LNC 10 NNW LNC JWY GKY FWS FTW DTO 15 SSW GYI 20 S MLC 10 ESE ASG 30 SSE SGF 35 W FAM RSV 20 SSE HUF. MODERATE RISK OF RAINFALL EXCEEDING FFG TO THE RIGHT OF A LINE FROM 15 N FSM 25 NE HRO 45 NE UNO 20 S SAR MVN 10 WNW AJG LWV 15 SSW BMG 30 S BMG HNB 10 NNW OWB 30 NW HOP 15 SSE DYR 35 W UTA 25 NE ELD 25 S TXK 10 SE OSA 20 NE 3T1 15 SSW SLR GVT 10 ESE TKI TKI 15 NNW TKI 30 E AQR 15 WNW RKR 15 N FSM. HIGH RISK OF RAINFALL EXCEEDING FFG TO THE RIGHT OF A LINE FROM 35 NNE ELD 15 E TXK 30 ENE OSA 15 NNE OSA 20 SSW LBR 15 SSE PRX 10 WSW PRX 25 NNW PRX 40 SE MLC 35 SE FYV BPK 10 SSW UNO 35 NW POF 20 WNW CGI 15 SSW MDH 10 S MWA 10 SSE HSB 25 SE HSB 30 ENE M30 25 E M30 20 SE PAH 30 S PAH 20 WNW AWM 35 NNE ELD. TOTAL RAINFALL AMOUNTS OF FIVE INCHES WILL BE POSSIBLE TO THE RIGHT OF A LINE FROM 20 ESE LIT 10 SSE M89 30 NNE TXK 20 SSE DEQ 20 SW DEQ 25 W DEQ 30 WNW DEQ 35 NW DEQ 20 SE FSM 35 S HRO 25 ESE UNO 30 W POF 10 WNW POF 15 SSE POF 25 NW BYH JBR 30 ESE SRC 20 ESE LIT. UPDATE.. THE AXIS OF THE PREVIOUS EXCESSIVE RAINFALL POTENTIAL OUTLOOK...ALONG WITH THE AREA OF POTENTIAL 5"+ PCPN AMTS...WAS SHIFTED NWWD FROM CNTRL TO NWRN AR...ACRS SERN MO AND INTO THE LOWER OH VALLEY REGION. THIS IS TO REFLECT CURRENT RADAR TRENDS WHICH CONT TO SHOW MOST OF THE ORGANIZED PCPN REMAINING POST FRONTAL TO THE NORTH OF THE FRONTAL BNDRY STRETCHING FROM ERN TX...NEWD INTO SRN AR...WRN TN AND INTO WRN TO CNTRL KY. THE LATEST HI RES RUNS..ESPECIALLY DURG THE 0000-1200 TIME PERIOD APPEAR TO BE TOO FAR TO THE SOUTH WITH THE CONVECTION. THEY HAVE NOT BEEN VERIFYING VERY WELL WITH THIS EVENT...LEADING TO LOW CONFIDENCE WITH THEIR OVERALL FARTHER SWD SOLN. ASIDE FROM THE NWWD SHIFT IN THE THREAT AXIS...THERE IS NO SIGNIFICANT CHANGE IN THE OVERALL VERY FAVORABLE PATTERN FOR CONTINUED HEAVY TO EXCESSIVE RAINS ALONG AND TO THE NORTH OF THE ABOVE MENTIONED FRONTAL BNDRY. STRONG MOISTURE FLUX INTO THIS FRONT AND FAVORABLE UPR DYNAMICS FROM THE ERN PORTIONS OF THE SRN PLAINS INTO THE OH VALLEY WL CONT TO SUPPORT HVY TO EXCESSIVE RAINFALL AMTS ACRS THESE AREAS. TRAINING OF CELLS WL CONT IN THIS ORGANIZED PCPN AXIS...SUPPORTING PCPN AMTS OF 1-3"+ IN AN HR OR TWO...AND A BROAD AREA WHERE ADDITIONAL TOTAL PCPN AMTS THIS PERIOD WL LIKELY EXCEED 5". ORAVEC PREVIOUS DISCUSSION... ...ARKLATX NEWD INTO THE LWR OH VLY... NO MAJOR CHNGS TO EARLIER OUTLOOK AS THE PTRN REMAINS SOMEWHAT STAGNANT OVR THE REGION. LATEST SFC ANLYS SHOWS A FNTL BNDRY DRAPED THRU THE REGION WITH SVRL WEAK SFC WAVES RIDING UP THE BNDRY. MIDLVL SHRTWVS/IMPULSES ARE ALSO LIFTG NEWD...OVR THE BNDRY AND PROVIDING DEEP LYRD LIFT. THE CLOSED LOW OVR THE 4-CORNERS REGION WL MOVE VRY SLOWLY AND CONT TO DIRECT PIECES OF ENERGY OVR THE REGION...WITH SVRL MORE PDS OF HVY RNFL. MDLS CONT TO SHOW THE AIRMASS ALNG/S OF THE SFC BNDRY WL BCM SOMEWHAT UNSTBL...BUT THERE REMAINS A CAP THAT SHLD HELP LIMIT THE SRN/SERN EXTENT OF CNVCTV DVLPMENT. MID/UPR SPLIT FLOW WL REMAIN INTACT WITH STG UPR DIFL/DVRG THAT WL PROVIDE PERSISTENT DEEP LYRD ASCENT. DEEP MSTR IS ALRDY IN PLC AND WL CONT TO BE REPLENISHED BY A MOD/STG LLJ AND DEEP LYRD SRLY FLOW THAT WL CONT TO TAP INTO EPAC/GULF/CARIBBEAN MSTR. PWS IN THE 1.50-1.75 INCH RANGE WL BE COMMON....WHICH IS ARND TWO STDS ABV NRML. THE MOD/STG LLJ WL SUPPORT CONT MSTR FLUX/TRANSPORT INTO THE REGION...WITH 8H MSTR FLUX ANOMALIES 2-3 STDS ABV NRML THRU TNGT...THEN THEY BEGIN TO BACK OFF ON MON. MDL FCST SOUNDGS CONT TO SHOW VRY MOIST PROFILES WITH LAPSE RATES ARND 6 DEG C/KM...TALL/SKINNY CAPES AND NEARLY PARALLEL FLOW FM THE JUST ABV THE SFC INTO THE UPR LVLS. ADDTNL TRAING TWD THE NE WL CONT THIS PD...WITH ONLY A SLOW SEWD DROP OF THE MAIN AXIS OF HVY RNFL. XPCT LCL TWO INCH PER HR RATES WITH A RIBBON OF 4-6 INCH RNFL FM THE ARKLATX NEWD INTO THE LWR OH VLY REGION. ECKERT $$