[MCD] SWOMCD

[MCD at goshenarc.org]

ACUS11 KWNS 011845
SWOMCD
SPC MCD 011845 
ILZ000-WIZ000-IAZ000-MNZ000-012245-

MESOSCALE DISCUSSION 0004
NWS STORM PREDICTION CENTER NORMAN OK
1245 PM CST SAT JAN 01 2005

AREAS AFFECTED...CENTRAL/ERN IA...SRN WI AND PORTIONS OF NRN IL

CONCERNING...FREEZING RAIN AND SLEET 

VALID 011845Z - 012245Z

A MIX OF FREEZING RAIN AND SLEET WILL CONTINUE ACROSS THE REGION
THROUGH AFTERNOON...WITH DEVELOPMENT INTO SCENTRAL WI AND NRN IL
THROUGH 21Z. HRLY ACCUMULATIONS OF ICE FROM 0.05-0.10 INCHES WILL BE
POSSIBLE WITH THE HEAVIER CONVECTIVE SHOWERS.

LOW LEVEL ADVECTIVE COMPONENT WILL REMAIN WEAKER THAN FARTHER NORTH
THUS EXPECT OVERALL LIGHTER ACCUMULATIONS OF FREEZING RAIN/SLEET
THAN ACROSS FAR NRN IA/MN AND CENTRAL WI. HOWEVER...ISENTROPIC LIFT
NORTH OF SFC FRONT WILL REMAIN MODERATE AND COMBINED WITH ELEVATED
INSTABILITY...MUCAPES FROM 50-150 J/KG ...WILL SUPPORT HEAVIER
CONVECTIVE FREEZING RAIN/SLEET SHOWERS ACROSS THE AREA THROUGH 00Z.
AN EARLIER BAND OF PRECIPITATION THAT MOVED ACROSS CENTRAL/ERN IA
INTO SWRN WI HAS ALLOWED FOR SUFFICIENT SATURATION SO THAT ANY
ADDITIONAL PRECIPITATION WILL BE EFFICIENT IN REACHING THE GROUND.
LOW LEVEL WAA WILL LEAD TO NWD MOVEMENT OF THE SFC FREEZING LINE
THROUGH THE AFTERNOON...BUT SINCE SFC LOW MVMNT WILL BE ENEWD INTO
SERN NEB AND WET-BULB EFFECTS WILL BE OCCURRING...IT IS NOT
ANTICIPATED THAT THE SFC FREEZING LINE WILL MOVE MUCH NORTH OF I-80
THROUGH 00Z.

OVER SCENTRAL WI/NRN IL WHERE PRECIPITATION HAS NOT FALLEN MUCH
TODAY...A DELAY IN LOW-MID LEVEL SATURATION SHOULD PROVIDE FOR 
SLEET AS THE PREDOMINATE PTYPE FOR THE FIRST HOUR OR SO OF ONSET OF
PRECIP. PRECIP IS NOT ANTICIPATED TO CHANGE OVER TO FREEZING RAIN
OVER THE IMMEDIATE CHI METRO AREA...WHERE NELY WINDS OFF LK MI
SHOULD KEEP TEMPERATURES ABOVE FREEZING.

..CROSBIE.. 01/01/2005

...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...DVN...ARX...DMX...

43689076 42909326 42199377 41679346 41259186 41119084
41118952 41298867 41818767 43488808 

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