000
FOUS30 KWBC 121325
QPFERD

EXCESSIVE RAINFALL DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
925 AM EDT WED JUN 12 2013

...VALID 15Z WED JUN 12 2013 - 12Z THU JUN 13 2013...
...REFERENCE AWIPS GRAPHIC UNDER...DAY 1 EXCESSIVE RAINFALL...


SLIGHT RISK OF RAINFALL EXCEEDING FFG TO THE RIGHT OF A LINE FROM
10 WSW ARR SFY DBQ 15 WSW MRJ 15 SE LNR 10 WSW RYV 20 E MKE
10 SSW GRR 10 W OZW 20 W CWAJ 10 WNW HZY 20 ESE YNG 10 W BVI
10 NE PHD 15 ESE MNN 10 SSE FWA 20 S VPZ 10 SE JOT 10 WSW ARR.

MODERATE RISK OF RAINFALL EXCEEDING FFG TO THE RIGHT OF A LINE FROM
GYY 15 WNW DPA RFD 15 SSW JVL 10 S JVL 15 ESE JVL 15 S BUU
25 WNW BEH 10 NE JYM 15 SSW CXHA 20 SE CXPT 15 NNW CLE CLE
15 SW CLE 25 NW MFD 25 WSW DFI GYY.


AFTER LOOKING AT THE 06Z MODEL GUIDANCE..12Z UPPER AIR DATA AND
RECENT RADAR/SATL IMAGERY AND TRENDS..SEE NO REASON TO GO AGAINST
EARLIER THINKING.  THE H5 S/WV TOPPING FLAT UPR RIDGE OVER THE
NCNTL STATES AT THIS TIME WILL SHARPEN ESEWD THIS PD TOWARD THE OH
VALLEY BY THUR MRNG.  AS IT DOES SO...IT SHOULD TRIGGER A FAIRLY
STG SFC LOW THAT WILL TRACK MORE OR LESS EWD ALONG DVLPG E/W
FRONTAL BNDRY WHILE DEEPENING TOWARD THE OH VALLEY BY THUR MRNG.
MODELS HAVE COME INTO FAIRLY GOOD AGREEMENT WITH THIS SCENARIO AND
ARE SUGGESTING A FAIRLY IMPRESSIVE RAINFALL SET-UP ALONG AND NORTH
OF THE LOW TRACK IN RESPONSE TO COMBINATION OF POOLING OF 1.75 TO
2 INCH PWS ALONG THE BNDRY..STG HEIGHT FALLS...AND STRENGTHENING
LOW LEVEL JET AND MSTR CONVERGENCE INTO THE BNDRY.  LATEST NAM
GUIDANCE SHOWS VERY UNSTABLE AIR DVLPG SOUTH OF THE BNDRY ACRS
PARTS OF THE MIDWEST/OH VALLEY WED AFTN WHICH SHOULD FUEL SOME
VERY STG TSTMS WITH HEAVY RAIN RATES.  SOMEWHAT BROAD ISENTROPIC
LIFT AND JET STRUCTURE SHOULD SUPPORT STG STORMS OUT AHEAD OF THE
MAIN LOW AND WITH MID LEVEL FLOW PARALLELING THE SFC BNDRY...SOME
TRAINING OF CELLS IS A GOOD PSBLTY OVER NRN SECTIONS OF IL..NRN
IN..NRN OH INTO SRN LOWER MI WHERE THE HEAVIEST RAINS ARE
EXPECTED.  STAYED ON THE SRN END OF GUIDANCE FOR THE HEAVIER
RAINS..AS POTNL COLD POOL DVLPMENT AND RESULTANT OUTFLOW BNDRIES
MAY SHIFT EFFECTIVE FRONT SOUTH OF FORECAST SYNOPTIC BNDRY.
OVERALL EXPECT WIDESPREAD 1 TO 3 INCH RAINS INVOF THE LOW TRACK
WITH ISOLD HEAVIER AMOUNTS CERTAINLY POSSIBLE..WITH A MDT RISK OF
EXCESSIVE RAINS DEPICTED WHERE GREATEST THREAT OF TRAINING IS
ANTICIPATED.

TERRY
$$