000
FOUS30 KWBC 130630
QPFERD

EXCESSIVE RAINFALL DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
229 AM EDT THU JUN 13 2013

...VALID 06Z THU JUN 13 2013 - 12Z FRI JUN 14 2013...
...REFERENCE AWIPS GRAPHIC UNDER...DAY 1 EXCESSIVE RAINFALL...


SLIGHT RISK OF RAINFALL EXCEEDING FFG TO THE RIGHT OF A LINE FROM
15 E MKJ 15 ENE 6V3 20 SW I16 35 WNW I16 10 S HTS 20 W HTS
50 SE LUK 10 NNW CVG 25 ESE GEZ GEZ 20 NE EYE 20 ESE LAF
15 NE LAF 25 WNW GUS 10 NNW GUS 25 SSW FWA 35 ENE MIE 25 SSW AOH
OSU CMH VTA 20 N ZZV 15 WNW PHD 10 W CAK 10 SSE CGF 25 NE CGF
20 NNW HZY 15 W ERI 10 SW JHW ELZ 10 W ELM 20 S ITH 25 SE BGM
10 E MSV 15 SSE SWF HPN 10 NE JFK 25 S JFK NEL MIV 15 WSW WWD
10 S GED 10 SSW SBY 20 NNW MFV 15 SE FYJ 10 NE FYJ 15 WSW 2W6
NYG 15 WSW EZF 25 N FVX 15 NE LYH 25 S BCB 15 E MKJ.

MODERATE RISK OF RAINFALL EXCEEDING FFG TO THE RIGHT OF A LINE FROM
10 N ILG ILG APG BWI DAA 15 SSE CJR 10 E CHO 20 SSW CHO
30 NNE LYH 10 NE ROA 15 NNW ROA 15 E LWB 15 NE LWB 10 NNE CRW
15 SSE 3I2 45 WSW UNI 20 NE LUK 15 W WMO 30 NW WMO 20 W DAY DAY
15 SSW TZR 10 SSE LHQ 20 NNW PKB 25 NE PKB 35 NW CKB 25 SSW AFJ
10 W AFJ 15 NNW AFJ PIT 10 E BTP 30 ENE BTP DUJ 10 ESE DUJ
10 SSW FIG 25 NNW AOO 10 SSW JST 20 SSW JST 10 NNW 2G4
20 SSW 2G4 15 NNE W99 MRB 15 W FDK 20 NE FDK 20 ESE THV LNS
10 W UKT 10 SSW MPO 10 WSW MSV MSV 15 SE MSV 10 SW MGJ 15 S SWF
10 W HPN LGA 10 ESE EWR 15 WNW BLM 10 E PNE PHL 10 N ILG.


UPPER OH VALLEY INTO THE MID ATLANTIC

THE PREVIOUS EXCESSIVE RAINFALL POTENTIAL OUTLOOK AREA WAS SHIFTED
TO THE SOUTHEAST GIVEN CURRENT TRENDS WITH THE ORGANIZED
CONVECTION MOVING QUICKLY EAST SOUTHEASTWARD FROM THE LOWER GREAT
LAKES AND TOWARD THE UPPER OH VALLEY.  THE NORTHERN PORTION OF THE
CONVECTION IS BOWING WITH A FAST EASTWARD PUSH THROUGH THE
REMAINDER OF THE EARLY MORNING HOURS AS THE LINE PUSHES INTO
NORTHEAST OH AND NORTHERN PA.  WHILE CONVECTION IS VERY
PROGRESSIVE HERE---SHORT TERM PRECIPITATION AMOUNTS OF 1-1.5"+
POSSIBLE.

TRAINING AND OR BACK BUILDING OF CELLS IS LIKELY TO CONTINUE ON
THE SOUTHERN PORTION OF THE CONVECTION FROM EAST CENTRAL IN INTO
SOUTHERN OH AND POSSIBLY INTO CENTRAL TO NORTHERN WV WHERE THE LOW
LEVEL FLOW SOUTH SOUTH WESTERLY TO WESTERLY FLOW WILL CONTINUE TO
FEED MUCH ABOVE AVERAGE PW VALUES---1.5+ STANDARD DEVIATIONS ABOVE
THE MEAN---INTO THE CONVECTION.  IN AREAS OF TRAINING---SHORT TERM
PRECIPITATION AMOUNTS OF 2"+ POSSIBLE.

CONFIDENCE ON EVOLUTION OF THIS ORGANIZED CONVECTION IS LOW AFTER
1200 UTC.  HOWEVER---WITH FFG RELATIVELY LOW ACROSS THE MID
ATLANTIC FROM RECENT RAINS---A MODERATE RISK AREA WAS EXTENDED
FROM WESTERN VA---NORTHEASTWARD THROUGH THE METRO AREAS FROM
WASHINGTON---BALTIMORE---PHILADELPHIA TO WEST AND NORTHWEST OF
NYC.  THERE ARE SOME SIGNIFICANT MODEL DIFFERENCES WITH THE MAX
QPF AXES.  THE FARTHER SOUTHWARD AXES OF THE HI RES ARW AND ECMWF
WAS FAVORED OVER THE FARTHER NORTHWARD GFS---NAM--UKMET AND SREF
MEAN GIVEN POTENTIAL FOR ORGANIZED CONVECTION AND GENERAL MODEL
BIASES OF BEING TOO FAR NORTH WITH QPF IN THESE INSTANCES.  ACROSS
THESE AREAS--SHORT TERM PRECIPITATION AMOUNTS OF 1"+ POSSIBLE.

ORAVEC
$$