MESOSCALE PRECIPITATION DISCUSSION 0806
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
212 PM EST MON DEC 26 2016
 
AREAS AFFECTED...NORTHEAST AR...SOUTHEAST MO...NORTHWEST
TN...NORTHWESTERN KY...SOUTHERN IND...SOUTHWEST OH 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 261915Z - 270015Z
 
SUMMARY...CONTINUED TRAINING SHOWERS WITH EMBEDDED CONVECTIVE
ELEMENTS MAY POSE LOCALIZED FLASH FLOODING CONCERNS MAINLY IN
URBAN AND PRONE LOW FFG AREAS.

DISCUSSION...WV LOOP SHOWS BEST DYNAMICS/DPVA WITH SUBTLE
SHORTWAVE LIFTING THROUGH IND ATTM WITH CONTINUED BROAD UVV ALONG
SOUTHERN SIDE UPPER LEVEL 135KT JET DIVERGENCE.  THIS SUPPORTS
STRONG SWLY FETCH OF ANOMALOUS MOISTURE WITH TPWS RANGING FROM
1.4" NEAR SE MO TO 1.25" AS FAR NORTH AS CENTRAL OH.  STILL 850MB
FLOW HAS BEEN SLACKING AS THE HEIGHT FALLS/WAVE LIFTS NORTHEAST
YET FLOW REMAINS IN THE 40-55KT RANGE FROM KNQA TO KILN VAD
PROFILES.  THOUGH FLOW WILL REDUCE IN TIME...THE ORIENTATION OF
THE FLOW BECOMES MORE VERTICALLY STACKED AND NARROWS ACROSS THE
OHIO RIVER VALLEY PARTICULARLY ACROSS THE OH/IND/KY TRI-STATE
WHERE FFG VALUES REMAIN LOWER.  

SFC ANALYSIS SHOWS REMARKABLY STRONG 20-25KT SFC FLOW THAT
CONTINUES TO VEER AS AS WELL ALIGNING WITH THE 85-7H FLOW ACROSS
NE AR.  THIS CONTINUES TO FOCUS STRONG MOISTURE CONVERGENCE AND
FLUX...AND GIVEN COINCIDENT INSTABILITY WITH MLCAPES OF 750-1000
J/KG AVAILABLE.  THIS SHOULD CONTINUE TO SPUR SOME CONVECTIVE
ELEMENTATION WITHIN THE NARROWING PLUME WITH RATES OF 1.0-1.5"/HR
POSSIBLE.  GIVEN TRAINING PROFILE...LOCALIZED TOTALS TO 2.5" ARE
POSSIBLE LEADING TO FLASH FLOODING THREAT HERE AS WELL.  18Z RAP 
SUPPORTS ENOUGH WAA/MST FLUX IN THE LOW LEVELS TO SUPPORT ELEVATED
MUCAPES OF 250-500 J/KG AS FAR NORTH AS THE CINCINNATI METRO
THROUGH 00Z. 

HI-RES GUIDANCE WAS SLOW TO DEVELOP THE CONVECTIVE ELEMENTS AND
THEREFORE CONTINUE TO DISPLACE THE CONVECTIVE CORES A BIT FURTHER
WEST THAN WHAT IS CURRENTLY BEING OBSERVED AND SHOULD BE SHIFTED
ACCORDINGLY.     

GALLINA

ATTN...WFO...ILN...IND...LMK...MEG...OHX...PAH...

ATTN...RFC...LMRFC...OHRFC...

LAT...LON   39458422 39058371 38288449 36588777 35388976 
            35409080 35989071 36369041 37138913 37918794 
            38738617 39358488