[MCD] SWOMCD

[MCD at goshenarc.org]

ACUS11 KWNS 060452
SWOMCD
SPC MCD 060452 
MIZ000-061045-

MESOSCALE DISCUSSION 2499
NWS STORM PREDICTION CENTER NORMAN OK
1052 PM CST SUN DEC 05 2004

AREAS AFFECTED...PORTIONS OF CNTRL/ERN LOWER MI

CONCERNING...WINTER MIXED PRECIPITATION 

VALID 060452Z - 061045Z

A MIX OF LIGHT FREEZING RAIN AND LIGHT TO MDT SNOW WILL DEVELOP OVER
WCENTRAL LOWER MI BETWEEN 06-09Z AND OVER CENTRAL-SERN LOWER MI
BETWEEN 09-12Z. OVERALL ACCUMULATIONS WILL BE LIGHT DUE TO THE
PROGRESSIVE EWD MOVEMENT AND WEAKENING TREND IN THE MID/UPPER LEVEL
FEATURES.

STRONG WAA NOTED IN THE 2-4 KM LAYER OVER THE MID MS RIVER
VALLEY/WRN GREAT LAKES VWP AND PROFILER DATA HAS AIDED IN HOURLY
PRECIPITATION AMTS FROM 0.2-0.3 INCHES. THIS FORCING WILL GRADUALLY
SHIFT ENEWD INTO THE REGION OVERNIGHT. AS THE UPPER TROUGH CONTINUES
TO DE-AMPLIFY...A WEAKENING TREND IN UPPER LEVEL FORCING AND
PRECIPITATION AMTS IS ANTICIPATED TO OCCUR. 04Z SFC ANALYSIS
INDICATES THE 0 DEG C ISOTHERM WAS LOCATED FROM NEAR MKG TO NEAR
PTK...WITH THE WBZ LINE LOCATED ABOUT 40 MILES SOUTH OF THIS LINE.
LOW LEVEL WARM ADVECTION AND SATURATING/MELTING EFFECTS SHOULD
COUNTER EACH OTHER AND LEAVE LIMITED NWD MOVEMENT OF THE FREEZING
LINE WHEN PRECIPITATION MOVES INTO THE REGION LATER TONIGHT. SHALLOW
ELEVATED NOSE OF ABOVE FREEZING AIR WILL CONTINUE TO SHIFT NEWD
TONIGHT NORTH OF THIS FREEZING LINE. WITH THE ONSET OF STRONGEST MID
LEVEL LIFT...LIGHT FREEZING RAIN WILL BE POSSIBLE JUST NORTH OF THE
SFC FREEZING ISOTHERM FROM WCENTRAL INTO SERN LOWER MI...WITH A
TRANSITION OVER TO SNOW EXPECTED WITHIN AN HOUR OR TWO OF
PRECIPITATION DEVELOPMENT AS SATURATION AND WET BULB COOLING ENSUES.
DESPITE WEAKENING MID LEVEL WARM ADVECTION...STRONG REMNANT
FRONTOGENETIC CIRCULATION WILL OVERSPREAD THE AREA AND MAY LEAD TO
ONE OR SEVERAL BANDS OF MODERATE SNOWFALL MOVING EWD ACROSS THE AREA
IN THE 09-12Z TIME FRAME.

..CROSBIE.. 12/06/2004

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

...NOTICE...
SPC WINTER WEATHER MESOSCALE DISCUSSIONS WILL BE ISSUED ON A 
SCHEDULED BASIS...FOUR TIMES A DAY...BETWEEN 05-06 UTC...
11-12 UTC...17-18 UTC...AND 23-00 UTC AS SIGNIFICANT SHORT
RANGE WINTER WEATHER EVENTS UNFOLD.  THIS SCHEDULE WILL BE
USED FROM DECEMBER 1 THROUGH FEBRUARY 28 TO ALLOW PARTNERS
AND USERS TO BETTER ANTICIPATE THE TIMING OF SPC WINTER WEATHER
MESOSCALE DISCUSSIONS.

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

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