MESOSCALE PRECIPITATION DISCUSSION 0718
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
930 AM EST MON DEC 28 2015
 
AREAS AFFECTED...SE MISSOURI...S ILLINOIS...SW INDIANA...W
KENTUCKY...EXT NW TENNESSEE 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 281430Z - 282030Z
 
SUMMARY...STRONG LARGE SCALE ASCENT WILL KEEP MODERATE TO
SOMETIMES HEAVY RAINFALL PRODUCTION ACROSS ALREADY SATURATED
GROUNDS.

DISCUSSION...SYNOPTIC SETUP IDEAL FOR CONTINUED MODERATE RAINFALL
THAT WILL LEAD TO AN ADDITIONAL 1-2" OF RAIN ACROSS THE LOWER
OHIO/CENT MS RIVER VALLEYS THROUGH THE LATE MORNING INTO EARLY
AFTERNOON.

WV LOOP AND SATELLITE DERIVED WINDS INDICATE 110+ KT JET STREAK
ROUNDING THE EASTERN SIDE OF NEGATIVELY TILTED/TIGHTLY WOUND UP
UPPER LOW EXITING OK...ALONG WITH RIGHT ENTRANCE OF STRONG 80-90
KT JET STREAKING ACROSS THE GREAT LAKES LEAVES THE DISCUSSION AREA
IN A LARGE AREA OF ASCENT...ADDITIONALLY THE UPPER LOW WILL
TIGHTEN/ELONGATE WITH INCREASING DPVA...THIS IS ALREADY BEING
REFLECTED IN THE INCREASE/EXPANSION OF CONVECTIVE BAND ACROSS S
MO...BEGINNING TO CONNECT UP WITH MAIN SQUALL ACROSS W TN INTO E
MS.   DEEP WARM CONVEYOR IS DRAWING A NARROWING BUT STILL POTENT
MOISTURE PLUME WITH 1.5" TPWS AS FAR NORTH AS THE BOOTHEEL OF MO. 
LIMITED INSTABILITIES TO 100 J/KG IN MUCAPES SHOULD SUPPORT
ENHANCED CONVECTION WITH RATES UP TO 1.0"/HR BUT LIKELY RATES IN
THE .5-.75"/HR RANGE WILL OCCUR THOUGH MUCH OF SE MO INTO S IL AND
W KY.  EXPECTATIONS FOR ADDITIONAL 1-2" TOTALS IS WELL SUPPORTED
IN MUCH OF THE HI-RES GUIDANCE...THOUGH WELL PERFORMING MODELS
SUCH AS THE ARW HINT AT STREAKS OF 2+" WHICH SEEM LIKELY GIVEN
ATMOSPHERIC SETUP.

GALLINA

ATTN...WFO...ILX...IND...LMK...LSX...MEG...OHX...PAH...SGF...

ATTN...RFC...LMRFC...MBRFC...NCRFC...OHRFC...

LAT...LON   40038784 39378671 38208643 37618650 37128719 
            36648790 36098872 35988929 35908980 36649061 
            37599265 38909197 39939019