Graphic for MPD #0531

MESOSCALE PRECIPITATION DISCUSSION 0531
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
230 AM EDT SAT JUL 22 2017

AREAS AFFECTED...ERN IA INTO NRN IL

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

VALID 220626Z - 221130Z

SUMMARY...ALTHOUGH THE ONGOING HEAVY RAIN AXIS IS EXPECTED TO
SHIFT SOUTH...A SIGNIFICANT FLASH FLOOD THREAT WILL CONTINUE FOR
PORTIONS OF ERN IA INTO NRN IL THROUGH 11Z. MAXIMUM ADDITIONAL
RAINFALL OF 3-5 INCHES IS EXPECTED.

DISCUSSION...AN ONGOING AXIS OF TRAINING HEAVY RAIN...EXTENDING
FROM NERN IA INTO NRN IL AS OF 06Z...HAS BEGUN TO ADJUST SOUTH
OVER THE PAST HOUR. THE REGENERATION POINT OVER N-CNTRL IA WAS
NOTED IN REGIONAL RADAR IMAGERY TO BE PUSHING SOUTH FROM HANCOCK
INTO WRIGHT COUNTY BETWEEN 05Z AND 06Z. VEERING OF THE 700 MB FLOW
NOTED IN THE KARX VAD WIND PLOT IS REPRESENTATIVE OF AN
APPROACHING 700 MB TROUGH AXIS AND INFUSION OF DRIER AIR FROM THE
NORTH...NOTED BETWEEN PWATS OF ROUGHLY 2 INCHES OVER IA AND NEARER
TO 1.6 INCHES OVER SERN MN VIA RECENT GPS SITE VALUES.

ONGOING STRONG 850 MB CONVERGENCE HAS BEEN NOTED ALONG THE HEAVY
RAINFALL AXIS BUT CONVERGENCE IS FORECAST TO SUBSIDE VIA THE RAP
BETWEEN 08-09Z WHEN THE AXIS IS FORECAST TO EXTEND FROM E-CNTRL IA
INTO NRN IL. NONETHELESS...A POOL OF HIGH CAPE REMAINS OVER CNTRL
IA WITH 2000-3000 J/KG MUCAPE ESTIMATED VIA THE LATEST SPC
MESOANALYSIS PAGE AND 35-45 KT 850-700 MB WLY FLOW AMID PWATS NEAR
2 INCHES FEEDING INTO THE CLUSTER OF ONGOING CONVECTION.

THE ONGOING AXIS OF HEAVY RAINFALL IS EXPECTED TO BROADEN A BIT
OVER THE NEXT 2-3 HOURS AND BECOME LESS FOCUSED...HOWEVER HEAVY
RAINFALL WILL CONTINUE TO TRAIN WITH MEAN FLOW PARALLEL TO A
STATIONARY BOUNDARY EXTENDING WEST TO EAST THROUGH IA AND NRN IL.
RAINFALL RATES OF GENERALLY 1-2 IN/HR BUT LOCALLY AS HIGH AS 3
IN/HR WILL MOVE INTO PORTIONS OF E-CNTRL IA AND NRN IL THROUGH THE
MORNING HOURS. GIVEN ANTECEDENT WET GROUND...ESPECIALLY OVER NRN
IL... RUNOFF/FLASH FLOODING APPEARS LIKELY...SOME OF WHICH COULD
BE SIGNIFICANT.

OTTO

ATTN...WFO...ARX...DMX...DVN...ILX...LOT...MKX...

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

LAT...LON   43159286 43069217 42819142 42659061 42478921
            42298809 42108774 41558759 40998777 40748870
            41129093 41489262 41999357 42779376 43049351
            43069348


Last Updated: 230 AM EDT SAT JUL 22 2017