[MCD] SWOMCD

[MCD at goshenarc.org]

ACUS11 KWNS 140022
SWOMCD
SPC MCD 140022 
MIZ000-140615-

MESOSCALE DISCUSSION 0161
NWS STORM PREDICTION CENTER NORMAN OK
0622 PM CST SUN FEB 13 2005

AREAS AFFECTED...CENTRAL AND NRN LOWER MI

CONCERNING...WINTER MIXED PRECIPITATION 

VALID 140022Z - 140615Z

MIXED WINTER PRECIPITATION IS EXPECTED TO DEVELOP FROM SOUTH TO
NORTH ACROSS CENTRAL AND NRN LOWER MI THROUGH 03Z. PRIMARY THREAT
WILL BE FREEZING RAIN RATES OF 0.05-0.1 IN/HR LATE THIS EVENING INTO
THE OVERNIGHT PERIOD ACROSS CENTRAL AND ESPECIALLY NRN SECTIONS OF
LOWER MI. FREEZING RAIN SHOULD TRANSITION TO RAIN ACROSS SRN LOWER
MI BY 06Z...AND INTO CENTRAL SECTIONS BY 09Z.

VERTICALLY STACKED LOW PRESSURE SYSTEM CENTERED OVER NERN MO AT
14/00Z WILL TRACK NEWD TO NEAR CHICAGO BY 14/09Z. A SURFACE WARM
FRONT EXTENDS EWD FROM THE LOW ACROSS CENTRAL IL TO CENTRAL OH.
DISTRIBUTION OF PRECIPITATION CONTINUES TO BE MARKED BY A LEADING
DEFORMATION ZONE PROGRESSING SLOWLY NNEWD THROUGH THE CENTRAL GREAT
LAKES AREA AT 10-15 KT. MORE WIDESPREAD PRECIPITATION ACROSS NRN
IL...NRN IND...AND SRN LOWER MI IS ASSOCIATED WITH STRONG 850-700MB
WARM ADVECTION AND ISENTROPIC LIFT. VAD WIND PROFILES AT  GRR AND
IWX INDICATE STRONG VEERING AND SLY 1 KM FLOW OF 45-50 KT. THE
STRONG SYNOPTIC ASCENT WILL TRANSLATE NEWD ACROSS CENTRAL AND NRN
LOWER MI THROUGH THE LATE EVENING AND OVERNIGHT HOURS.

WHILE MUCH OF THE RESULTING PRECIPITATION WITH THIS SYSTEM HAS BEEN
RAIN...BOUNDARY LAYER CONDITIONS ACROSS CENTRAL AND ESPECIALLY NRN
LOWER MI ARE COLDER AND CONSIDERABLY DRIER. THIS APPEARS TO BE THE
RESULT OF ARCTIC HIGH PRESSURE CENTERED ACROSS ERN ONTARIO AND WRN
QUEBEC. NAM SOUNDINGS SUGGEST PRECIPITATION MAY BEGIN AS SNOW OR
SLEET DURING THE NEXT FEW HOURS OVER CENTRAL/NRN LOWER MI.
HOWEVER...INCREASING ABOVE-FREEZING LAYER BETWEEN 900-750MB SHOULD
RESULT IN A TRANSITION TO FREEZING RAIN FOR THE MAJORITY OF THE
OVERNIGHT HOURS. SURFACE DEWPOINT DEPRESSIONS INITIALLY BETWEEN
10-15F SHOULD ALLOW FOR AMPLE DIABATIC COOLING AND A SHALLOW LAYER
OF SUBFREEZING AIR NEAR THE SURFACE. ICING MAY BE LIMITED TO
ELEVATED SURFACES ACROSS CENTRAL MI WHERE TEMPERATURES WILL BE NEAR
FREEZING BUT WILL LIKELY INCLUDE GROUND SURFACES ACROSS NRN LOWER MI
WHERE THE COLDEST ANTECEDENT CONDITIONS EXIST /TEMPERATURES IN THE
MID TO UPPER 20S/. GUIDANCE FROM RUC AND NAM GENERALLY SUPPORT
HOURLY FREEZING RAIN RATES UP TO 0.1".

..BANACOS.. 02/14/2005

...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...DTX...APX...GRR...

42788460 43188628 43798657 45018606 45698501 45508401
45138328 44238287 43668256 42918254 42688283 42668358 

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