EXCESSIVE RAINFALL DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
253 AM EDT TUE JUN 08 2010
 
...VALID 06Z TUE JUN 08 2010 - 12Z WED JUN 09 2010...
...REFERENCE AWIPS GRAPHIC UNDER...DAY 1 EXCESSIVE RAINFALL...
 

SLIGHT RISK OF RAINFALL EXCEEDING FFG TO THE RIGHT OF A LINE FROM
15 ESE UGN 15 W SBN 15 NW DNV PPQ 20 WNW SZL 10 W IXD 30 N MHK
10 SE MCK 25 SSW LBF 15 E ODX 20 NNW TQE 15 NNE CIN MRJ
15 ESE UGN.

MODERATE RISK OF RAINFALL EXCEEDING FFG TO THE RIGHT OF A LINE
FROM
15 ENE C75 20 SW PIA 25 WSW UIN 25 S CDJ 30 WSW STJ 20 W HJH
10 ESE HDE 20 NNE EAR FET 20 ESE MIW SQI 15 ENE C75.

 
SHRTWV DYNAMICS ASOCTD WITH A MID/UPR LVL TROF WILL BE RESPONSIBLE
FOR DRIVING THE DEVELOPMENT OF AN ACTIVE SFC LOW WARM FRONT FROM
NE/KS DOWNSTREAM TO THE LWR GRT LAKES/NRN OH VLY OVER THE NEXT 24
HRS. HEIGHT FALLS PUSHING OUT INTO THE PLAINS EARLY THIS MORNING
IS ALREADY TRIGGERING A WELL-ORGANIZED CONVECTIVE COMPLEX ACROSS
NE AND THIS IS IN GENERAL VICINITY OF THE AFOREMENTIONED SFC LOW
AND WELL-DEFINED WARM FRONT. JET DYNAMICS COUPLED WITH A
STRENGTHENING S/SWLY LLJ...40 TO 50 KTS... IS DRIVING A POOL OF
VERY UNSTABLE AIR INTO THE WARM FRONT...AND WITH PWATS
INCREASING/POOLING TO OVER 2 INCHES THIS WILL LIKELY ALLOW THIS
COMPLEX AND HEAVY RAINFALL TO PROCEED DOWNSTREAM. THE LATEST
THINKING AND MODEL CHOICE FROM HPC ON QPF AMOUNTS AND AXIS IS A
COMBO OF THE NAM/ECMWF ON MASS FIELDS/QPF AMOUNTS AND THESE TWO
SOLUTIONS WITH THE SREF MEAN/ENSBC QPF FOR AXIS/ALIGNMENT. THE
STRONGEST FORCING AND INSTABILITY/MSTR TRANSPORT WILL SET UP FROM
ERN NE/KS ENEWRD THROUGH IA/NRN MO INTO THE OH VLY/LWR GRT LAKES
REGION. THIS IS AN AREA FROM ERN NE THROUGH A GOOD PART OF IA/NRN
MO INTO THE WEST CENTRAL OH VLY WHERE VERY HEAVY RAIN IMPACTED THE
REGION AND AS A RESULT... FFG GUIDANCE IS RATHER LOW. 3 HRLY
NUMBERS FROM ERN NE THROUGH SRN IA/NRN MO INTO NORTH CENTRAL IL IS
AROUND AN INCH AND THIS COULD BE MET EASILY. ALL OF THIS SOUNDS
GREAT AND RATHER CERTAIN BUT ALREADY... THE ACTIVE
CONVECTION/HEAVY RAIN IS SOUTH OF MOST OF THE OPERATIONAL MODEL
GUIDANCE AND ENSEMBLE DATA. THUS THIS QPF  AND EXCESSIVE RAIN FCST
REMAINS HIGHLY VARIABLE AND THE ENTIRE AXIS OF ANTICIPATED HEAVY
QPF PERHAPS WILL BE FARTHER SOUTH THAN THE GUIDANCE. HPC WENT WITH
QPF AMOUNTS OF 2 TO 4 INCHES WITH LOCALLY HEAVIER AMOUNTS AND A
SLIGHT TO MDT THREAT FOR EXCESSIVE RAINS ON AN AXIS FROM SERN
NE/SRN IA/NRN MO INTO NRN/CENTRAL IL AND NRN IN. 

MUSHER
$$