[MCD] SWOMCD

[MCD at goshenarc.org]

ACUS11 KWNS 050102
SWOMCD
SPC MCD 050102 
ILZ000-WIZ000-IAZ000-MOZ000-KSZ000-NEZ000-050700-

MESOSCALE DISCUSSION 0025
NWS STORM PREDICTION CENTER NORMAN OK
0702 PM CST TUE JAN 04 2005

AREAS AFFECTED...NERN KS...NW MO...SE IA...NRN IL...SRN WI

CONCERNING...WINTER MIXED PRECIPITATION 

VALID 050102Z - 050700Z

FREEZING RAIN WITH ACCUMULATION RATES OF UP TO 2 TENTHS OF AN INCH
IN ONE HOUR AND MODERATE SNOW WITH RATES APPROACHING ONE INCH AN
HOUR ARE EXPECTED TO SPREAD NORTHEASTWARD ACROSS THE THREAT AREA
THROUGH 06Z.  PREDOMINANTLY SNOW IS EXPECTED NORTH OF AN AXIS FROM
25MI NW TOP TO LWD TO 30MI N OF MLI AND 10MI S OF RFD.

INITIAL 500MB SHORTWAVE TROUGH LOCATED NEAR TOP WITH ITS ASSOCIATED
WARM ADVECTION WILL PROPAGATE NORTHEASTWARD AT 25KT AND CONTRIBUTE
TO NORTHEASTWARD EXPANSION OF AN AREA OF FREEZING RAIN AND SNOW. 
STRONG WARM ADVECTION LAYER BETWEEN 1KM AND 3KM IS EVIDENT IN 00Z
ETH WIND PROFILER OBSERVATION WITHIN THE MODERATE FREEZING RAIN AREA
. REINFORCEMENT OF COLD AIR AND ADIABATIC COOING WITH STRONGER
ASCENT ACROSS THE NORTHERN HALF OF THE THREAT AREA CONTRIBUTING TO A
TRANSITION FROM LIGHT FREEZING RAIN TO MODERATE SNOWFALL.  WARM
LAYER CURRENTLY SUPPORTING MODERATE FREEZING RAIN IS EVIDENT IN WARM
ADVECTION LAYER NEAR 850MB IN 00Z TOP SOUNDING.  A SHALLOW WARM
LAYER IS ALSO EVIDENT IN DVN SOUNDING NEAR 800MB WHERE STRONGER
ASCENT AND REINFORCEMENT OF COLD AIR AT LOW LEVELS MAY CONTRIBUTE TO
A GRADUAL TRANSITION TO SNOW.  SOUTHERN EDGE OF SURFACE FREEZING
LINE AND WET BULB ZERO IS EXPECTED TO REMAIN STATIONARY THROUGH 06Z
WITHIN A STEADY NORTHEAST SURFACE WIND FIELD.  EXPECT WARM LAKE
MICHIGAN TEMPERATURE TO LIMIT FROZEN ACCUMULATIONS IN EXTREME
NORTHEAST IL.

MODELS AGREE WITH A MINORING OUT OF THIS INITIAL SHORTWAVE AS IT
ENTERS THE CONFLUENT ZONE ACROSS THE UPPER MIDWEST AND FOCUS WILL
SHIFT SOUTHWESTWARD TO THE TRAILING SHORTWAVES LOCATED NEAR PUB AND
TUS.

..SCHNEIDER.. 01/05/2005

...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 00-01 UTC...
06-07 UTC...12-13 UTC...AND 18-19 UTC AS SIGNIFICANT SHORT
RANGE WINTER WEATHER EVENTS UNFOLD.  THIS SCHEDULE WILL BE
USED FROM DECEMBER 1 THROUGH FEBRUARY 28.

ATTN...WFO...LOT...ILX...MKX...LSX...DVN...ARX...DMX...EAX...OAX...TOP...

42268811 41868851 41318983 40709138 39669349 38719526
38979598 40229565 41319500 42019369 42319195 42639052
42788920 42838809 

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