MESOSCALE PRECIPITATION DISCUSSION 0220
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
716 PM EDT MON JUN 15 2015
 
AREAS AFFECTED...NORTHERN SECTIONS OF MO/IL/IN/OH AND LOWER MI... 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 152315Z - 160415Z
 
SUMMARY...STRONG VERTICAL MOTIONS IN THE PRESENCE OF ABOVE 2 INCH
PWATS HAS SPREAD A BROAD REGION OF DEEP CONVECTION FROM THE MIDDLE
MS VALLEY INTO THE UPPER GREAT LAKES. CONTINUED HEAVY RAINFALL ON
TOP OF ALREADY SATURATED GROUNDS SUPPORTS A FLASH FLOOD RISK INTO
THE OVERNIGHT HOURS.

DISCUSSION...ALONG AND AHEAD OF A FRONTAL ZONE ANALYZED FROM WEST
OF CHICAGO IL DOWN ACROSS THE MO/IA/IL TRI-STATE AREA AND INTO
NORTHERN MO...ANOMALOUS MOISTURE CONTENT REMAINS IN PLACE. THE 22Z
RAP OBJECTIVE ANALYSIS NOTES 2 TO 2.25 INCH PWATS ACROSS THE
REGION WHICH HAS SUPPORTED HEFTY HOURLY RAINFALL RATES IN THE 1 TO
2 INCH RANGE. MUCH OF THE ORGANIZED CONVECTION HAS BEGUN FOCUSING
ALONG THE ADVANCING BAROCLINIC ZONE AS WELL AS OVER THE MULTIPLE
OUTFLOW BOUNDARIES SETTING UP OVER THE REGION. PER 22Z RAP
FORECAST SOUNDINGS...THE THERMODYNAMIC PROFILES HAVE NOT CHANGED
SIGNIFICANTLY FROM THE 12Z RAOBS THIS MORNING. DEEP/MOIST
WEST-SOUTHWESTERLY UNIDIRECTIONAL FLOW REMAINS IN PLACE IN THE
PRESENCE OF TROPOSPHERIC MOISTURE CONTAINING ANOMALIES IN THE 2 TO
3 SIGMA RANGE. SUCH INGREDIENTS SUPPORT AN ENHANCED RISK FOR FLASH
FLOODING...PARTICULARLY OVER AREAS WHICH ARE ALREADY SATURATED
FROM PREVIOUS RAINFALL THIS AFTERNOON AND EVENING.

THE 22Z HRRR HAS A GENERAL HANDLE ON THE CURRENT
CONVECTION...ALBEIT WITH SOME SPATIO-TEMPORAL ERRORS. IT AGREES
WITH THE NOTION THAT THE ENHANCED CONVECTION ACROSS MO/IL WILL
SLOWLY DRAG EASTWARD WITH REPEAT CONVECTION LIKELY OVER AREAS OF
SIGNIFICANTLY DIMINISHED FFG VALUES. THE IDEA OF THE CONVECTION
SUSTAINING ITSELF SEEMS REASONABLE GIVEN SUFFICIENT BUOYANCY IS
SUGGESTED INTO THE OVERNIGHT HOURS WITH NO DISCERNIBLE CAPPING.
WILL LET NIGHT SHIFT RE-ASSESS THE SITUATION.



RUBIN-OSTER

ATTN...WFO...CLE...DTX...DVN...EAX...GRR...ILN...ILX...IND...
IWX...LOT...LSX...MKX...SGF...

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

LAT...LON   42738752 42088553 41898386 41648302 40658301 
            40248391 40268600 40098783 39748914 39149079 
            38529228 38459346 38849428 39619423 40199284 
            41249060 41658960 42348907 42728829