EXCESSIVE RAINFALL DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
926 PM EDT SUN APR 24 2011
 
...VALID 03Z MON APR 25 2011 - 00Z TUE APR 26 2011...
...REFERENCE AWIPS GRAPHIC UNDER...DAY 1 EXCESSIVE RAINFALL...
 

SLIGHT RISK OF RAINFALL EXCEEDING FFG TO THE RIGHT OF A LINE FROM
10 WSW HOT LBR 30 NNW PRX 10 ESE AQR 15 NE PVJ 10 N SNL BVO
50 SSW SZL SUS IND 10 NNW 4I3 20 SW PHD 20 SSE ZZV 20 NNE PKB
30 S HLG 15 NNW MGW 2G4 15 NNW CBE 15 ENE CBE 20 SSE CBE
20 ENE W99 10 SE W99 25 S W99 25 SE EKN 10 ESE EKN 10 NW EKN
10 SW W22 48I 30 NNE CRW 25 W CRW 20 SSW HTS 15 NNW JKL
25 NNE SME 40 SE FTK 35 WNW BWG 25 SSE M19 10 ENE LRF 10 WSW HOT.

MODERATE RISK OF RAINFALL EXCEEDING FFG TO THE RIGHT OF A LINE
FROM
RSV 10 N BMG 10 SE FFO 10 WSW ILN LUK 20 SW CVG 30 NNE LEX
10 ENE LEX 20 SSW FFT 10 ENE FTK 20 NNW FTK 15 SE HNB OWB
20 S PAH 20 NNW DYR SRC MWT 30 W DEQ 30 E AQR ADH 10 SE SNL
20 ENE CQB 15 E BVO 50 NW SGF VIH CPS 20 SW 1H2 RSV.

HIGH RISK OF RAINFALL EXCEEDING FFG TO THE RIGHT OF A LINE FROM
20 NW BYH 20 WNW SRC 25 ESE RUE 20 WNW MWT 30 SSE RKR 15 SE MLC
20 ENE ADH 20 ESE SNL 15 WSW RVS 20 ESE CFV 25 NNE JLN
35 NNW SGF 15 S AIZ 20 E TBN FAM 15 NNE MDH CUL EHR 35 SW EHR
10 ESE PAH 20 NW BYH.

TOTAL RAINFALL AMOUNTS OF FIVE INCHES WILL BE POSSIBLE TO THE
RIGHT OF A LINE FROM 40 WNW SRC RUE 25 E RKR 30 ENE MLC
30 NW MLC OKM 15 ESE TUL 20 NE GCM 20 S JLN 10 W SGF 15 E SGF
35 E SGF 45 NW UNO 25 NW UNO 15 NW UNO 15 E UNO 30 WSW POF
15 NNE ARG BVX 40 WNW SRC.

 
ERN OK...NRN AR...SRN MO INTO THE OH VALLEY...

VERY LITTLE CHANGE TO THE PREVIOUS REASONING AND THE EXCESSIVE
RAINFALL AREAS FROM 24/18Z...INCLUDING THE 5-INCH AREA WHERE
HEALTHY RAINFALL RATES OF 1-2 INCHES PER HOUR HAVE BEEN RECORDED
AT MUSKOGEE AND MCALESTER OKLAHOMA AND FORT SMITH ARKANSAS DURING
THE PAST 3 HOURS. IN FACT...MUSKOGEE PICKED UP 3.26 IN THEIR LAST
6-HR SYNOPTIC OB AT 25/00Z. THIS LINE OF HEAVY RAINFALL WILL
CONTINUE TO DRIFT VERY SLOWLY ACROSS I-40 INTO WEST CENTRAL
ARKANSAS DURING THE NEXT 3-6 HOURS AND APPEARS TO BE THE LEADING
EDGE OF A SQUALL LINE EMERGING AS OUTFLOW FROM A RATHER LARGE MCS
OVER NORTHEAST OKLAHOMA. ALONG THE STATIONARY FRONT...A SECOND MCS
FORMING OVER NORTH CENTRAL OKLAHOMA AND IS ATTEMPTING TO MERGE
WITH THE SYSTEM IN NORTHEAST OKLAHOMA. FROM THE 00Z RAOBS...THE
BETTER INFLOW AND LIFT REMAINS TUCKED IN ACROSS SOUTHERN
ARKANSAS...EAST TEXAS...AND WESTERN TENNESSEE...TO THE SOUTH AND
EAST OF THE TWO THUNDERSTORM COMPLEXES AND THE SYNOPTIC-SCALE
LOW-LEVEL BOUNDARY. WINDS ALOFT AT H5 AND ABOVE SUPPORT
BROAD-SCALE DIFFLUENCE AND GOOD OUTFLOW FOR SUSTAINING CONVECTION
FROM NORTH CENTRAL TEXAS INTO EASTERN KENTUCKY...WHILE TO THE
NORTH OF THE STATIONARY FRONT...PER ROABS FROM TOP/SGF...H7 FLOW
IS WESTERLY AND A STABLE... MID-LEVEL CAPPING INVERSION IS SETTING
UP. THESE INITIAL CONDITIONS...ALONG WITH SATELLITE..RADAR AND
SURFACE DATA...SUGGEST THE HPC RAINFALL FORECAST IS A VAST
IMPROVEMENT OVER THE GLOBAL MODEL OUTPUT. EVEN THE QPF OUTPUT FROM
THE HI-RES RUNS CONTINUE TO VERIFY POORLY...AND ADD CONFIDENCE TO
THE CURRENT EXCESSIVE RAINFALL OUTLOOK CALLING FOR
PERSISTENCE...WITH TRAINING ECHOES...AND WIDESPREAD 2-4 INCH
RAINS...ACROSS PORTIONS OF EASTERN OKLAHOMA...NORTHERN
ARKANSAS...SOUTHERN MISSOURI...WITH UP TO 5-INCH AMOUNTS...ALONG
I-40 AND FROM JUST EAST OF OKC TO LRF AND POINTS NORTH ALONG THE
I-44 CORRIDOR FROM OKC TO SGF. DOWNSTREAM ACROSS THE LOWER OHIO
VALLEY...OVER RUNNING SHOULD CONTINUE OVERNIGHT ALONG THE
STATIONARY FRONT...WITH WIDESPREAD 1-2 INCH AMOUNTS ACROSS
PORTIONS OF NORTHERN KENTUCKY...SOUTHERN ILLINOIS...SOUTHERN
INDIANA AND SOUTHERN OHIO.

VOJTESAK
$$