MESOSCALE PRECIPITATION DISCUSSION 0649
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
223 AM EDT WED SEP 07 2016
 
AREAS AFFECTED...SOUTHEAST SD...NORTHWEST IA...EXT NORTHEAST NEB 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 070622Z - 071100Z
 
SUMMARY...CONVECTION ALONG LOW LEVEL CONVERGENCE BAND MAY TRACK
FAVORABLY FOR SOME REPEATING AND TOTALS NEARING LOWER FFG VALUES
IN THE AREA.  ISOLATED THREAT FOR FLASH FLOODING POSSIBLE. 

DISCUSSION...GOES WV LOOP INDICATES A MODERATELY AMPLIFIED
SHORTWAVE IN THE PROXIMITY OF SW NEB SHIFTING NORTHEAST SUPPORTING
DEEPER WAVE DEVELOPMENT ALONG NW TILTED (WITH HEIGHT) BAROCLINIC
ZONE ACROSS NEB INTO N IA.  STRONG SW TO NE LLJ STREAKS ACROSS
CENTRAL KS TO CENTRAL IA WITH SOME BACKING NORTH OF THE FRONTAL
BOUNDARY SUPPORTING SOME MST FLUX CONVERGENCE NEAR THE ELEVATED
INSTABILITY FOR DEEPER CONVECTIVE DEVELOPMENT FROM NW IA TOWARD
APEX OF 850MB WAVE NEAR BBW.  CONVERGENCE BEING AS IT
IS...CONVECTION IS A BIT BROKEN PRECURSORY TO BETTER SIGNAL NEARER
THE LOW. HOWEVER...THE ORIENTATION OF THE BAND IS FAIRLY CLOSE TO
MEAN CELL MOTIONS ACROSS NE NEB INTO NW IA...SUPPORTING CELLS TO
REPEAT OVER SIMILAR AREAS.  CONVECTIVE VIGOR HAS BEEN INCREASING
THROUGH THE LAST FEW HOURS MOISTURE WILL CONTINUE TO POOL AND
INCREASE RAINFALL EFFICIENCY AS TPWS INCREASE FROM 1.75 TOWARD
2.0" BY 10Z.  RATES OF 1.25-1.75"/HR WITH THE POSSIBILITY OF
TRAINING SUPPORTS RAINFALL TOTALS IN THE 2-3" RANGE.  THIS WOULD
NEAR OR EXCEED SUB 2.5"/3HR FFG VALUES ACROSS THE CONCERNED
AREA...WARRANTING A THREAT FOR ISOLATED FLASH FLOODING
PARTICULARLY IN URBAN CENTERS.  

HI-RES CAMS SUCH AS THE ARW/NMMB ARE A BIT MORE BULLISH THAN
RECENT HRRR RUNS, AS WELL AS BEING A BIT FURTHER NORTH THAN WHAT
IS BEING OBSERVED VIA RADAR MOSAIC AND OBSERVATIONS.  HOWEVER
THESE MODELS ARE GENERALLY SUPPORTIVE OF THIS SETUP PROVIDING SOME
CONFIDENCE. 

GALLINA

ATTN...WFO...DMX...FSD...OAX...

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

LAT...LON   43439468 43229347 42699380 42319513 42139664 
            42129704 42339775 42809781 43259655