ZCZC SPCSWOMCD ALL
ACUS11 KWNS 230958 
SPC MCD 230958 
INZ000-MIZ000-ILZ000-WIZ000-231430-

MESOSCALE DISCUSSION 0133
NWS STORM PREDICTION CENTER NORMAN OK
0458 AM CDT MON MAR 23 2015

AREAS AFFECTED...FAR SRN WI...NRN IL...NW IND

CONCERNING...HEAVY SNOW 

VALID 230958Z - 231430Z

SUMMARY...A BURST OF HEAVY SNOW WILL MOVE FROM SW WI ACROSS
N-CNTRL/NE IL INTO NWRN IND THROUGH MIDDAY. WHILE OVERALL INTENSITY
SHOULD GRADUALLY SUBSIDE LATE THIS MORNING...AROUND 1 TO LOCALLY 2
IN/HR RATES ARE EXPECTED DURING THE MORNING COMMUTE INCLUDING
CHICAGOLAND.

DISCUSSION...LATEST METARS CONFIRM A BAND OF HEAVY SNOW ACROSS SW WI
WHICH HAS BEEN COINCIDENT WITH SPORADIC LIGHTNING STRIKES DURING THE
PAST HOUR PER NLDN. AMDAR DATA INVOF CHICAGOLAND SUPPORTS AN ALL
BELOW-FREEZING THERMAL PROFILE ACROSS THE NRN/ERN PORTION OF THE
MIXED PRECIP SWATH IN ASSOCIATION WITH A SHORTWAVE IMPULSE SHIFTING
E/SE FROM THE UPPER MS VALLEY TOWARD THE MIDWEST. 40-50 KT LOW-LEVEL
S/SWLYS HAVE BEEN PREVALENT IN VWP DATA AT EAX/DMX/ILX YIELDING
STRONG WAA/FRONTOGENETICAL ASCENT. GUIDANCE IS CONSISTENT IN
WEAKENING WINDS SLOWLY AFTER DAYBREAK WHICH WILL EVENTUALLY RESULT
IN MORE MODERATE SNOWFALL RATES TOWARDS 18Z. UNTIL THAT
OCCURS...EXPECT THE BURST OF HEAVY SNOW TO SHIFT SEWD AND AFFECT THE
ROCKFORD/CHICAGO METRO AREAS DURING THE MORNING COMMUTE.

..GRAMS.. 03/23/2015

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

ATTN...WFO...IWX...IND...LOT...MKX...DVN...

LAT...LON   42639016 42908974 42738851 42398773 41718646 41208629
            40808637 40678665 40818720 41128783 41658912 42329008
            42639016 

NNNN