ZCZC SPCSWOMCD ALL
ACUS11 KWNS 251748 
SPC MCD 251748 
MIZ000-251845-

MESOSCALE DISCUSSION 1589
NWS STORM PREDICTION CENTER NORMAN OK
1248 PM CDT THU AUG 25 2016

AREAS AFFECTED...SERN LOWER MICH

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 

VALID 251748Z - 251845Z

PROBABILITY OF WATCH ISSUANCE...20 PERCENT

SUMMARY...GRADUAL STORM INTENSIFICATION IS EXPECTED.  A FEW STRONG
STORMS CAPABLE OF A LOCALIZED WIND DAMAGE ARE POSSIBLE THIS
AFTERNOON.  THE DISCUSSION AREA WILL CONTINUE TO BE MONITORED FOR
CONVECTIVE TRENDS.

DISCUSSION...17Z SUBJECTIVE SURFACE MESOANALYSIS PLACES A COLD FRONT
FROM SAGINAW BAY SWWD THROUGH NWRN INDIANA WITH TEMPS IN THE LOWER
80S AND LOWER 70S DEWPOINTS.  MODIFYING THE 12Z DTX RAOB FOR EARLY
AFTERNOON SURFACE CONDITIONS YIELDS AROUND 2200 J/KG MLCAPE AND
NEGLIGIBLE CINH.  VISIBLE-SATELLITE IMAGERY SHOWS A BAND OF
SWELLING/DEEPENING CU FROM THE THUMB OF MICH SWWD INTO SWRN LOWER
MICH --WITH HEAVIER CONVECTIVE SHOWERS NOW EVIDENT.  

AN MCV WHICH TRACKED ACROSS THE SRN GREAT LAKES REGION THIS MORNING
IS CURRENTLY IN SWRN ONTARIO AND IMPLIED WEAK HEIGHT RISES/WEAK
DESCENT MAY BE OCCURRING IN WAKE OF THIS FEATURE --PERHAPS PLAYING A
ROLE IN SLOWING STORM DEVELOPMENT/VIGOR DURING THE MIDDAY. 
HOWEVER...AS THIS FEATURE MOVES EWD AND DEPARTS FROM THE REGION...AN
INCREASE IN STORM DEVELOPMENT WILL PROBABLY OCCUR.  

RAP HOURLY ANALYSIS COUPLED WITH SUBJECTIVE MORNING UPPER-AIR
ANALYSIS SUGGESTS A BELT OF STRONGER MID-LEVEL WSWLY FLOW /40 KT/
WILL REMAIN OVERHEAD.  THE DEEP-LAYER SHEAR WILL SUPPORT STORM
ORGANIZATION--MAINLY IN THE FORM OF MULTICELLS.  THE STRONGER STORMS
MAY BE CAPABLE OF A RISK FOR LOCALIZED DAMAGING WINDS ONCE STORM
MATURATION OCCURS.

..SMITH/WEISS.. 08/25/2016

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...DTX...IWX...GRR...

LAT...LON   42298502 43418338 43338229 42398255 41728332 41878514
            42298502 

NNNN