MESOSCALE PRECIPITATION DISCUSSION 0709
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
300 AM EST SUN DEC 27 2015
 
AREAS AFFECTED...EASTERN IL...CENTRAL IN...WESTERN OH 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 270755Z - 271000Z
 
SUMMARY...LOCALLY HEAVY RAINS WILL TEND TO BE REPEATING OVER THE
REGION THE NEXT COUPLE OF HOURS. THE RELATIVELY WET ANTECEDENT
CONDITIONS MAY BEGIN TO RESULT IN SOME LOCALIZED RUNOFF OR FLASH
FLOODING CONCERNS.

DISCUSSION...THE DEEP LAYER FETCH OF MOISTURE ROUNDING THE WESTERN
AND NORTHERN PERIPHERY OF THE SUBTROPICAL RIDGE OVER THE SOUTHEAST
CONTINUE TO STREAM EAST AND NORTHEAST ALONG A STRONG FRONTAL ZONE
WHERE THE LATEST SURFACE ANALYSIS SUGGESTS MULTIPLE WAVES OF LOW
PRESSURE RIDING ALONG IT.

THE IR SATELLITE IMAGERY SHOWS SOME POCKETS OF COLDER TOP
CONVECTION IN A SOMEWHAT ELEVATED FASHION MOVING ACROSS SOUTHERN
IL AND THEN EASTWARD INTO CENTRAL IN WHICH IS FOCUSING SOME
HEAVIER RAINFALL. IN FACT...THE LATEST GOES OTD ALGORITHM DEPICTS
A COUPLE OF OVERSHOOTING TOPS OVER SOUTHEAST IL NEAR THE BORDER
WITH IN AND THUS SOME ENHANCE RAINFALL RATES ARE LIKELY WITHIN
THESE CORES.

STRONGER DEEP LAYER ASCENT WITH H25 RIGHT-ENTRANCE REGION JET
DYNAMICS SHOULD CONTINUE TO FOCUS NUMEROUS SHOWERS AND SOME
THUNDERSTORMS ALONG AND NORTH OF THE FRONT. GIVEN ANOMALOUS
MOISTURE TRANSPORT INTERACTING WITH THE FRONT...WITH H85/H7
MOISTURE FLUX ANOMALIES OF 4 STD DEV ABOVE NORMAL...RAINFALL RATES
SHOULD TEND TO REMAIN RATHER HIGH.

WILL BE MONITORING CONVECTIVE TRENDS OVER THE NEXT COUPLE OF
HOURS...AND ADDITIONAL RAINFALL AMOUNTS THROUGH THE EARLY MORNING
HOURS OF 1 TO 2 INCHES WILL BE POSSIBLE. THIS MAY RESULT IN SOME
RUNOFF AND ISOLATED FLASH FLOODING CONCERNS GIVEN RELATIVELY LOW
FFG VALUES AND WET ANTECEDENT CONDITIONS.

ORRISON

ATTN...WFO...CLE...ILN...ILX...IND...IWX...LOT...

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

LAT...LON   41188429 41138308 40608290 40028380 39668441 
            39368520 39178584 39198672 39408729 39828792 
            40198854 40968588