MESOSCALE PRECIPITATION DISCUSSION 0473
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
133 AM EDT MON JUL 18 2016
 
AREAS AFFECTED......NORTHEAST ILLINOIS...NORTHERN
INDIANA...NORTHWEST OHIO... 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 180526Z - 180926Z
 
SUMMARY...CONVECTION WILL CONTINUE TO GROW UPSCALE AND TRAIN ALONG
AN AXIS OF STRENGTHENING WSW-W LOW LEVEL INFLOW...STRONG AVAILABLE
DEEP LAYER INSTABILITY...AND HIGH PRECIPITABLE WATER AVAILABILITY.
 

DISCUSSION...AN UPPER LEVEL JET STREAK SLIDING ESE ACROSS THE
WI-LOWER MI IS CAUSING AN UPTICK IN FORCING ACROSS NORTHERN IL-IN
WITHIN THE RIGHT ENTRANCE REGION. CONVECTION CONTINUES TO BLOSSOM
AND GROW UPSCALE EARLY THIS MORNING AS A RESULT OF THE INCREASED
DYNAMICAL SUPPORT ALONG WITH A HIGHLY FAVORABLE THERMODYNAMIC
ENVIRONMENT. DEEP-LAYER INSTABILITY FEEDING INTO THIS DEVELOPING
MCS WERE QUITE ROBUST...WITH MUCAPES BETWEEN 2500-3500
J/KG...WHILE WSW LOW LEVEL INFLOW HAS INCREASED TO AROUND 35 KTS.
PRECIPITABLE WATER VALUES PER THE LATEST GPS ANALYSIS WERE BETWEEN
1.75-2.0 INCHES. 

OVER THE NEXT SEVERAL HOURS...THE VEERING LOW LEVEL JET WILL ALIGN
MORE PARALLEL TO THE WESTERLY 850-300 MB MEAN FLOW. THIS WILL
RESULT IN SLOW EAST TO SOUTHEAST PROPAGATION OF THE MCS EARLY THIS
MORNING...WITH THE HIGH LIKELIHOOD OF CONTINUED CELL TRAINING. THE
HIGHLY FAVORABLE THERMODYNAMIC PROFILE (DEEP-LAYER INSTABILITY AND
HIGH AVAILABLE MOISTURE...WITH SURFACE DEWPOINTS IN THE MID TO
UPPER 70S ALONG AND SOUTH OF THE MCS) WILL SUPPORT HOURLY RAINFALL
RATES BETWEEN 2-2.5 INCHES UNDERNEATH THE HEAVIEST CONVECTIVE
CLUSTERS. THE LATEST HRRR AND PARALLEL HRRR RUNS SHOW MAX 3-6
HOURLY RAINFALL BETWEEN 3 AND 6 INCHES...WHICH IS ALSO NOTED FROM
THE WRF-ARW... NMMB...AND NSSL-WRF. HOWEVER...IT SHOULD BE NOTED
THAT THE HIGH-RES CAM GUIDANCE CONTINUES TO STRUGGLE WITH
LATITUDINAL PLACEMENT OF THE AXIS OF HEAVIEST RAIN WITHIN THE MPD
AREA.

HURLEY

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

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

LAT...LON   41548753 41398555 40638435 39988453 39858577 
            40308880 40868946 41258896