[MCD] SWOMCD

[MCD at goshenarc.org]

ACUS11 KWNS 191108
SWOMCD
SPC MCD 191108 
INZ000-MIZ000-OHZ000-191615-

MESOSCALE DISCUSSION 2544
NWS STORM PREDICTION CENTER NORMAN OK
0508 AM CST SUN DEC 19 2004

AREAS AFFECTED...NW IND AND SWRN MI...NERN OH

CONCERNING...HEAVY SNOW 

VALID 191108Z - 191615Z

HEAVIEST LAKE EFFECT SNOW WILL SHIFT SLOWLY OUT OF EXTREME SWRN MI
LATER THIS MORNING...WHILE GRADUALLY MOVING WWD OVER NWRN IND AND
INTENSIFYING THROUGH THE MORNING AND INTO EARLY AFTERNOON.

SNOW BANDS SHOULD BECOME INCREASINGLY ORGANIZED IN THE WAKE OF
ARCTIC FROPA ACROSS NERN OH. NLY FETCH ACROSS LH WILL BE FURTHER
ENHANCED BY SHORT FETCH ACROSS LE TO RESULT IN INCREASING POTENTIAL
FOR HEAVY SNOW ALONG THE SRN SHORE OF LE INTO THE AFTERNOON.

SNOWFALL RATES WITHIN THE CORE OF THE MOST INTENSE SNOW BANDS COULD
EXCEED 2 IN/HR.

LATEST MESOANALYSIS WAS SHOWING A THERMALLY-INDUCED SURFACE PRESSURE
TROUGH EXTENDING FROM THE SRN TIP OF LM NWD TO SRN LS. THIS FEATURE
HAS ENHANCED LOW LEVEL CONFLUENCE FROM THE U.P. OF MI SWD ACROSS THE
N-S FETCH OF LM WHERE A SINGLE LONG-FETCH SNOW BAND CONTINUES TO
EVOLVE EARLY TODAY. STRONG LOW LEVEL COLD AIR ADVECTION WILL BE
MAXIMIZED OVER SRN LM OVER THE NEXT FEW HOURS WITH LAKE SURFACE TO
850MB DELTA-T VALUES IN THE EXTREME RANGE AROUND 30C. THIS STRONG
LOW LEVEL INSTABILITY COUPLED WITH A RISING INVERSION AND LIMITED
DIRECTIONAL SHEAR IN THE CLOUD-BEARING LAYER WILL CONTINUE TO
SUPPORT INTENSE LAKE EFFECT SNOW OFF SRN LM. LATEST 4KM WRF WAS
FCSTG A WWD SHIFT TO THE SINGLE BAND ACROSS SRN LM AND RECENT RADAR
TRENDS ARE CONSISTENT WITH THIS FCST. THIS WWD SHIFT IS FURTHER
SUPPORTED BY SLOW WWD SHIFT TO THE THERMAL TROUGH AXIS...MORE TOWARD
THE MIDDLE OF LM OVER THE NEXT FEW HOURS. THIS WILL RESULT IN THE
HEAVIEST SNOW BECOMING INCREASINGLY FOCUSED ACROSS NWRN IND INTO
EARLY AFTERNOON.

FARTHER EAST...ACROSS NERN OH...SNOW BANDS ARE EXPECTED TO BECOME
BETTER DEFINED FROM LH SWD ACROSS LE OVER THE NEXT SEVERAL HOURS. AS
THERMODYNAMIC AND KINEMATIC ENVIRONMENT IN PLACE ACROSS LS AND LM
SHIFT EAST WITH THE LARGE SCALE UPPER TROUGH AND ASSOCIATED LOW
LEVEL ARCTIC AIRMASS...LAKE EFFECT SNOW OFF OF LAKE ERIE SHOULD
INTENSIFY INTO THE AFTERNOON.

..CARBIN.. 12/19/2004

...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 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...IWX...IND...LOT...CLE...

41618739 41298750 40988735 40898715 40738658 40718619
41248599 41548600 41718597 41968613 42088651 41788670 

41728144 41888076 41648081 41218132 41038161 41048181
41178229 41288239 41378246 41538189 

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