MESOSCALE PRECIPITATION DISCUSSION 0459
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
454 PM EDT SUN JUL 15 2018

AREAS AFFECTED...SOUTHERN IL...SOUTHEAST MO

CONCERNING...HEAVY RAINFALL...FLASH FLOODING LIKELY

VALID 152050Z - 160100Z

SUMMARY...CONCENTRATED AXIS OF HEAVY RAINFALL EXPECTED IN
ASSOCIATION WITH COMPACT LOW CENTER. FLASH FLOODING WILL BE LIKELY
GIVEN THE LOCALLY WET ANTECEDENT CONDITIONS.

DISCUSSION...THE LATEST GOES-16 VISIBLE SATELLITE IMAGERY AND
SURFACE OBSERVATIONS SHOW A COMPACT LOW PRESSURE CENTER MOVING
ACROSS SOUTHERN IL WHICH IS INTERACTING WITH A NARROW AXIS OF
STRONG INSTABILITY LIFTING NORTHEAST AHEAD OF THE WAVE. THIS IS
DRIVING AN AREA OF DEEP CONVECTION OVER SOUTHWEST IL WITH COLD
TOPS REACHING OVER -65C.

MLCAPE VALUES OF 2000 TO 2500 J/KG ARE IN PLACE...AND WITH PWATS
ACROSS THE REGION OF 1.75 TO 2.0 INCHES WHICH WILL BE CONDUCIVE
FOR ENHANCED RAINFALL RATES OF 2.5 INCHES/HR. EXPECT AS MUCH AS 3
TO 4 INCHES OF RAINFALL TO BE POSSIBLE ALONG AND NEAR THE TRACK OF
THE LOW CENTER OVER THE NEXT FEW HOURS AS IT MOVES SLOWLY OFF TO
THE EAST. THE CONVECTIVE THREAT WILL ALSO INVOLVE PORTIONS OF
SOUTHEAST MO WHERE STRONG INSTABILITY IS NOTED AHEAD OF A SURFACE
TROUGH.

THE INTENSE RAINFALL RATES AND RELATIVELY WET ANTECEDENT
CONDITIONS WILL PROMOTE A LIKELIHOOD OF FLASH FLOODING.

ORRISON

ATTN...WFO...LSX...PAH...

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

LAT...LON   38618922 38358827 37938801 37628809 37108870
            36658957 36689029 36949060 37539018 38099015
            38509001