EXCESSIVE RAINFALL DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
258 PM EDT FRI JUN 11 2010
 
...VALID 18Z FRI JUN 11 2010 - 00Z SUN JUN 13 2010...
...REFERENCE AWIPS GRAPHIC UNDER...DAY 1 EXCESSIVE RAINFALL...
 

SLIGHT RISK OF RAINFALL EXCEEDING FFG TO THE RIGHT OF A LINE FROM
15 SW CDJ 15 NE TOP 15 WSW CNK 30 NE HLC 45 SSW MCK 25 NNE ITR
30 SSW AKO 30 E DEN 20 N DEN 15 ESE PUM 25 E ARL 35 WSW SIB
25 NE SIB 25 S IEN 35 SW VTN 30 E ANW 25 S YKN 25 SE LRJ SLB
25 SSW FOD IKV 15 ESE CNC 25 N CDJ 15 SW CDJ.

SLIGHT RISK OF RAINFALL EXCEEDING FFG TO THE RIGHT OF A LINE FROM
25 NNW SME 20 NE BWG 20 NW BWG 25 NNE HOP 20 SE PAH 10 WSW CIR
30 NNE POF 40 SW FAM 20 SSE VIH 15 NW VIH 20 E JEF 35 E COU
35 WNW SUS 10 WNW STL 15 NW SLO 20 NE SLO 15 ENE OLY 25 E RSV
10 WSW BMG 15 W BAK 30 WNW WMO 10 SE LCK 20 SSE ZZV 25 SE PKB
10 WNW CRW 25 NNE JKL 35 NNE SME 25 NNW SME.

 
OH VALLEY...

THE PREVIOUS EXCESSIVE RAINFALL POTENTIAL OUTLOOK WAS EXPANDED EWD
THRU MOST OF THE OH RIVER VALLEY TO ACCOUNT FOR THE CONTINUED
ENEWD MOVEMENT OF THE WELL DEFINED MID LEVEL VORT. THIS SYSTEM
SHOULD CONT TO PROGRESSIVE TO THE ENE THIS PERIOD...WITH THE
DETAILS OF THE ECMWF HANDLING OF THE VORT PREFERRED GIVEN BETTER
CONTINUITY OVR THE PAST FEW DAYS.   MUCH ABOVE AVG PW VALUES
ACCOMPANYING THIS FEATURE WL SUPPORT CONTINUED THREAT OF ORGANIZED
CONVECTION INVOF THE SYSTEM.  AS IN PAST DAYS..ACTIVITY MAY
CONTRACT NEAR THE CNTR OVERNIGHT INTO THE EARLY HOURS OF SAT
MORNING AND THEN EXPAND OUTWARD DURG THE DAY SAT.  WITH THE
INCREASED PROGRESSION...PCPN AMTS WL LIKELY NOT BE AS HIGH AS
POINTS UPSTREAM OVR THE SRN PLAINS/LOWER MS VALLEY.  STILL..WITH
POTENTIAL FOR CONVECTION TO FLARE NEAR THE CNTR
OVERNIGHT..ISOLATED PCPN AMTS OF 1-2" IN AN HR AND ISOLATED TOTALS
OF 3-5" MAY PRODUCE SOME RUNOFF PROBLEMS.

LEE OF THE CNTRL ROCKIES EWD INTO THE CNTRL PLAINS...

THERE IS POTENTIAL FOR ANOTHER ROUND OF ORGANIZED CONVECTION TO
PUSH EWD TONIGHT INTO THE EARLY HOURS OF SAT FROM THE LEE OF THE
CNTRL ROCKIES EWD INTO THE CNTRL PLAINS.  LOW LEVEL INFLOW
EXPECTED TO STRENGTHEN INTO THE W-E ORIENTED SFC BNDRY ACRS THE
CNTRL PLAINS.  THIS AND FAVORABLE UPR DIFFLUENCE ON THE ERN SIDE
OF THE WRN U.S. UPR TROF WL SUPPORT THE HEAVY RAIN THREAT.  THERE
IS STILL A LOT OF MODEL DIFFS WITH RESPECT TO THE AXIS THAT THIS
NEXT ORGANIZED CONVECTIVE COMPLEX WL TRACK. THE GFS AND GFSP ARE
ON THE NRN EDGE OF THE GUIDANCE AND APPEAR TO HAVE GRID SCALE
ISSUES WHICH TEND TO PUSH THE PCPN TOO FAR TO THE NORTH IN
OVERRUNNING CONVECTIVE SITUATIONS.  WE LEANED TOWARD A FARTHER SWD
AXIS AS PER THE 12Z HI RES HWRF ARW AND THE 12Z NAM.  THE LATEST
12Z ECMWF HAS TRENDED SWD BY APPROX 100 NM WITH ITS QPF AXIS FROM
THE 00Z RUN AND IS MORE IN LINE WITH THE FARTHER SWD HI RES HWRF
ARW AND NAM.   ONE LIMITING FACTOR FOR PCPN AMTS MAY BE THE
OVERALL PROGRESSIVE NATURE OF ANY MCC.  STILL...GIVEN THE OVERALL
FAVORABLE PATTERN FOR ORGANIZED CONVECTION...SHRT TERM PCPN AMTS
OF 1-1.5"+..WITH ISOLATED HEAVIER TOTALS IN THE 2-3"+ RANGE
POSSIBLE.

ORAVEC



$$