MESOSCALE PRECIPITATION DISCUSSION 0190
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
418 PM EDT SAT JUL 12 2014
 
AREAS AFFECTED...NORTHEAST IA...WI...NORTHWEST IL...U.P. OF MI 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 122010Z - 130000Z
 
SUMMARY...NUMEROUS SLOW-MOVING HEAVY SHOWERS AND THUNDERSTORMS
MOVING ACROSS NORTHEAST IA AND WI...MAY CONTINUE TO ORGANIZE
FURTHER OVER THE NEXT FEW HOURS. INTENSE RAINFALL RATES WILL
PROMOTE SOME SHORT-TERM FLASH FLOODING POTENTIAL.

DISCUSSION...THE LATEST IR/WV IMAGERY SHOWS A WELL-DEFINED
BAROCLINIC LEAF PATTERN OVER THE UPR MIDWEST ATTM WITH A FAIRLY
LARGE AREA OF MODERATE RAIN AND EMBEDDED AND FAIRLY WELL ORGANIZED
CLUSTERS OF HEAVY SHOWERS/THUNDERSTORMS. ON THE LARGER
SCALE...STRONG HEIGHT FALLS/JET DYNAMICS DIVING SOUTHWARD FROM
SOUTHERN CANADA IS SEEN PROVIDING DEEPER LYR ASCENT WITH AN
ENHANCING AREA OF UPR LVL JET DIVERGENCE.

THIS COUPLED WITH INCREASING SWLY LOW LVL WARM AIR/MOISTURE
TRANSPORT AND A DESTABILIZING BOUNDARY LAYER OVER ESP CNTRL/ERN IA
AHEAD OF A COLD FRONT SHOULD FOSTER AN EXPANSIVE AREA OF HEAVY
SHOWERS/THUNDERSTORMS WITH SOME UPSCALE ORGANIZATION POSSIBLE
THROUGH THE AFTERNOON. SBCAPE VALUES OF 3000 J/KG TO 4000 J/KG ARE
NOTED OVER CNTRL/ERN IA...AND WITH SWLY 850 MB FLOW PROGGED TO
INCREASE TO 30 TO 40 KTS...THIS INSTABILITY WILL BE INTERACTING
WITH THE LARGER SCALE HEIGHT FALLS/JET FORCING...AND THEREFORE
SUSTAINABLE CONVECTION CAN BE EXPECTED.

THE 12Z ECMWF AND 12Z GFS MODELS TEND TO HAVE A SOMEWHAT BETTER
HANDLE FOR THE TIME BEING ON THE EXPECTED AXIS OF
CONVECTION...WITH THE 12Z NAM...12Z ARW AND 12Z NMMB ALL LIKELY
TOO FAR SOUTH AT LEAST IN THE SHORT TERM.

BASED ON THE LATEST SAT/RADAR TRENDS...EXPECT THERE TO BE SOME
POTENTIAL FOR FLASH FLOODING. RAINFALL RATES OF 1 TO 2 INCHES/HR
CAN BE EXPECTED...AND WITH RELATIVELY SLOW MOVEMENT...THERE IS
POTENTIAL FOR SHORT TERM AMTS OF SEVERAL INCHES THROUGH 00Z.

ORRISON

ATTN...WFO...MQT...GRB...LOT...MKX...DVN...DLH...ARX...MPX...
DMX...

ATTN...RFC...NCRFC...

LAT...LON   44128747 42738837 41999011 41979161 42229260 42799261
            44079228 45219223 45769179 45959075 45948929 46138799
            45968695 45588668 44798707 44128747