[MCD] SWOMCD

[Mesoscale Convective Discussions]

ACUS11 KWNS 171843
SWOMCD
SPC MCD 171843 
MIZ000-172345-

MESOSCALE DISCUSSION 0156
NWS STORM PREDICTION CENTER NORMAN OK
1243 PM CST FRI FEB 17 2006

AREAS AFFECTED...CNTRL AND ERN UPPER PENINSULA OF MI

CONCERNING...HEAVY SNOW 

VALID 171843Z - 172345Z

SNOWFALL RATES ARE EXPECTED TO INTENSIFY THIS AFTERNOON INTO THE
EVENING HOURS IN LAKE-EFFECT BANDS ALONG THE CNTRL AND ERN UPPER
PENINSULA OF MI. RATES WILL LIKELY REACH 1 IN/HR WITH LOCAL RATES
POSSIBLY UP TO 2 IN/HR TOWARDS EVENING.

ONGOING MULTIPLE BANDS OF LAKE-INDUCED SNOWFALL SHOULD BEGIN TO
FOCUS LATER TODAY WITH MORE ORGANIZED BANDING IN ASSOCIATION WITH A
MID-LEVEL SHORTWAVE NW OF LAKE SUPERIOR. THIS WAVE WILL SLIDE EAST
THIS AFTERNOON/EVENING AND HELP STRENGTHEN MID-LEVEL
CONVERGENCE/FRONTOGENETICAL FORCING ACROSS SRN LAKE SUPERIOR. BOTH
RUC/NAM INDICATE THE 700 TO 600 MB MAXIMUM CONVERGENCE/ISENTROPIC
LIFT ZONE TO SHIFT ESE FROM THE KEWEENAW PENINSULA TO THE ERN UPPER
PENINSULA BY 00Z.

CURRENT MESOANALYSIS/VIS SAT IMAGERY SHOWS A WEAK SURFACE
CONVERGENCE BOUNDARY ALONG SRN LAKE SUPERIOR WITH A WEAK MESOLOW
JUST E OF THE KEWEENAW PENINSULA. RUC/NAM INDICATE THIS BOUNDARY
SHIFTING SLOWLY SWD WITH TIME AND INCREASING CURVATURE IN THE
LOW-LEVEL FLOW. THIS WILL HELP SHIFT THE LOW-LEVEL FLOW TO THE NW
PROVIDING GREATER FETCH ALONG THE SRN LAKE SUPERIOR SHORELINE. EVEN
THOUGH DENDRITIC GROWTH WILL NOT BE OPTIMAL DUE TO THE VERY COLD
ARCTIC AIRMASS...HIGH SNOW RATIOS WILL LIKELY PROVIDE PERIODS OF
MODERATE TO OCCASIONALLY HEAVY SNOW ESPECIALLY FROM NRN MARQUETTE TO
CHIPPEWA COUNTIES.

..GRAMS.. 02/17/2006

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

ATTN...WFO...APX...MQT...

47088849 47498789 46828455 46038416 45938545 46258724 

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