[MCD] SWOMCD

[MCD at goshenarc.org]

ACUS11 KWNS 201129
SWOMCD
SPC MCD 201128 
WIZ000-MNZ000-IAZ000-201630-

MESOSCALE DISCUSSION 2549
NWS STORM PREDICTION CENTER NORMAN OK
0528 AM CST MON DEC 20 2004

AREAS AFFECTED...NRN IA...SRN MN...WRN WI

CONCERNING...PRECIPITATION TRENDS...WINTER PRECIPITATION 

VALID 201128Z - 201630Z

WINTER WEATHER HAZARDS INCLUDING ICE PELLETS AND MDT TO HVY SNOW ARE
EXPECTED TO INCREASE ACROSS PARTS OF NRN IA...SRN MN...AND WRN WI
FROM LATE MORNING INTO THE AFTERNOON. ICE PELLETS APPEAR TO BE
PRIMARY THREAT OVER WRN MN THIS MORNING WHILE A NARROW AXIS OF
HEAVIER SNOWFALL...WITH RATES APPROACHING 1 INCH PER HOUR...MAY
DEVELOP FROM SERN MN INTO WRN WI BY AFTERNOON.

LATEST IR SATELLITE IMAGERY WAS DEPICTING COOLING CLOUD TOPS WITHIN
A DEVELOPING SMALL-SCALE BAROCLINIC LEAF ACROSS NERN SD AND CNTRL
MN. THIS FEATURE APPEARS TO BE DEVELOPING IN RESPONSE TO STRONG
IMPULSE AND MID/UPPER LEVEL JET STREAK SPREADING EAST FROM ERN WY
THIS MORNING. LATEST RUC AND 06Z ETA ARE IN GOOD AGREEMENT SHOWING
UPWARD VERTICAL MOTION INCREASING FROM ERN SD INTO SRN MN OVER THE
NEXT SEVERAL HOURS. VERY STRONG LOW LEVEL WARM AIR ADVECTION WAS
ALREADY OCCURRING ACROSS THIS AREA WITH INITIAL ROUND OF ISENTROPIC
ASCENT-INDUCED MDT/HVY SNOW NOW MOVING EAST ACROSS WI. CONTINUED
MOISTENING/WARMING WITHIN TRAILING ZONE OF LOW LEVEL ISENTROPIC LIFT
ACROSS SRN MN...COUPLED WITH INTENSIFYING SYNOPTIC SCALE FORCING FOR
DEEP ASCENT...SHOULD RESULT IN AN INCREASE IN WINTER PRECIPITATION
ACROSS THE AREA.

FORECAST THERMODYNAMIC PROFILES SUPPORT SNOW FROM SERN MN ACROSS WI.
HOWEVER...ACROSS WRN MN AND PARTS OF NWRN IA...PRONOUNCED WARM NOSE
WITH 850MB WET BULB TEMPERATURES 4-6C SHOULD RESULT IN A MIXTURE OF
ICE PELLETS ACROSS THESE AREAS...POSSIBLY CHANGING BACK TO SNOW
LATER TODAY.

..CARBIN.. 12/20/2004

...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...GRB...ARX...MPX...DMX...FSD...

45379065 44438957 43819044 43379486 43729610 44659604
45299351 

WWWW