[MCD] SWOMCD

[Mesoscale Convective Discussions]

ACUS11 KWNS 140621
SWOMCD
SPC MCD 140621 
OHZ000-MIZ000-INZ000-ILZ000-WIZ000-141145-

MESOSCALE DISCUSSION 0056
NWS STORM PREDICTION CENTER NORMAN OK
1221 AM CST SUN JAN 14 2007

AREAS AFFECTED...FAR SERN WI/NRN IL...NRN IN...SRN LOWER MI AND FAR
NWRN OH

CONCERNING...WINTER MIXED PRECIPITATION 

VALID 140621Z - 141145Z

LIGHT FREEZING RAIN AND SLEET SHOWERS WILL CONTINUE TO DEVELOP NORTH
OF THE SFC FREEZING LINE EXTENDING FROM NCENTRAL IL /PIA/ INTO NWRN
OH /TOL/ OVER THE NEXT 6 HOURS. AVERAGE HRLY LIQUID EQUIVALENT
ACCUMULATION RATES FROM 0.01 TO 0.05 INCH CAN BE EXPECTED.

LATEST RADAR IMAGERY INDICATES THAT PRECIPITATION CONTINUES TO
EXPAND OVER PORTIONS OF THE MID MS VALLEY AND WRN GREAT LAKES. THIS
PRECIPITATION WAS DEVELOPING IN RESPONSE TO STRENGTHENING ISENTROPIC
LIFT OVER THE SFC-850 MB FRONTAL BOUNDARY AND MID LEVEL VERTICAL
MOTION BOTH ASSOCIATED WITH AN APPROACHING SHORTWAVE TROUGH OVER
MISSOURI. FORECAST AND OBSERVED SOUNDINGS INDICATE THAT PRECIP TYPE
WILL RANGE FROM FREEZING RAIN OVER PORTIONS OF NERN IL/FAR NRN IND
AND FAR SRN MI/NWRN OH WHERE THE COLD AIR WAS SHALLOWER. SLEET IS
EXPECTED OVER FAR NERN IL AND PORTIONS OF SRN LOWER MI /GENERALLY
NORTH OF I-94/ WHERE THE DEPTH OF THE SUB-FREEZING LAYER WAS
GREATER. STEEP MID LEVEL LAPSE RATES WILL SUPPORT CONVECTIVE NATURE
OF PRECIP WITH OCCASIONAL BURSTS OF ACCUMULATIONS RATES UP TO
0.10/HR.

..CROSBIE.. 01/14/2007

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

...NOTICE...
SPC WINTER WEATHER MESOSCALE DISCUSSIONS WILL BE ISSUED ON A
SCHEDULED BASIS FROM DECEMBER 1 THROUGH FEBRUARY 28...FOUR
TIMES A DAY...AROUND 00 UTC...06 UTC...12 UTC...AND 18 UTC
FOR SIGNIFICANT SHORT RANGE WINTER WEATHER EVENTS.

ATTN...WFO...CLE...DTX...IWX...GRR...LOT...ILX...MKX...DVN...

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