[MCD] SWOMCD

Sun Jan 14 17:39:35 UTC 2007

ACUS11 KWNS 141742
SWOMCD
SPC MCD 141742 
MNZ000-IAZ000-NEZ000-SDZ000-142345-

MESOSCALE DISCUSSION 0061
NWS STORM PREDICTION CENTER NORMAN OK
1142 AM CST SUN JAN 14 2007

AREAS AFFECTED...NERN NEB...SERN SD...NWRN IA...SWRN MN

CONCERNING...HEAVY SNOW 

VALID 141742Z - 142345Z

MDT TO HVY SN ACROSS PORTIONS OF SERN/SCNTRL NEB WILL CONTINUE TO
EXPAND ACROSS THE MO RIVER VALLEY THROUGH THIS AFTERNOON. SNOWFALL
RATES WITHIN THE STRONGER BANDS WILL BE AROUND 1 INCH PER HOUR...
WITH LIGHTER HOURLY AMOUNTS OCCURRING IN BETWEEN THE BANDS.

THE ONGOING BANDING ACROSS NEB COINCIDES VERY WELL WITH A
INTENSIFYING AXIS OF 700-500MB LAYER FRONTOGENESIS DEPICTED IN
LATEST RUC AND NAM-WRF MODELS. THIS SW-NE ORIENTED AXIS OF MESOSCALE
ASCENT WAS DEVELOPING AHEAD OF A SHORT WAVE TROUGH EJECTING NEWD
FROM ERN CO AND LATEST GUIDANCE MAINTAINS STRONG ASCENT ACROSS THE
REGION THROUGH ABOUT 15/00Z. WITH MID LEVEL LIFT OCCURRING IN A
THERMODYNAMIC REGIME FAVORING EFFICIENT WATER VAPOR TO ICE TRANSPORT
/-12C TO -17C/...AND A DEEP DENDRITE GROWTH LAYER...SNOWFALL RATES
SHOULD EASILY REACH AN INCH PER HOUR AS LOW LEVEL SATURATION OCCURS
FROM SW TO NE.

SREF GUIDANCE DEPICTS THE HIGHEST PROBABILITY OF INCH PER HOUR
SNOWFALL RATES DEVELOPING FROM CNTRL NEB INTO SERN SD BY LATE THIS
AFTERNOON AND THROUGH EARLY EVENING. HOWEVER...LATEST RADAR TRENDS
WOULD SUGGEST THAT PERHAPS A SECONDARY AXIS OF HVY SN MAY BE
EVOLVING FARTHER SOUTH...ALONG A MCK-OFK-SUX LINE. GIVEN CLOSER
PROXIMITY OF THIS BAND TO LOW LEVEL MOISTURE INFLOW...THE SREF
GUIDANCE MAY BE DISPLACED SLIGHTLY NORTH OF GREATEST SNOWFALL RATE
POTENTIAL THROUGH LATE THIS AFTERNOON.

..CARBIN.. 01/14/2007

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

...NOTICE...
SPC WINTER WEATHER MESOSCALE DISCUSSIONS WILL BE ISSUED ON A
SCHEDULED BASIS FROM DECEMBER 1 THROUGH FEBRUARY 28...FOUR
TIMES A DAY...AROUND 00 UTC...06 UTC...12 UTC...AND 18 UTC
FOR SIGNIFICANT SHORT RANGE WINTER WEATHER EVENTS.

ATTN...WFO...DMX...FSD...OAX...GID...LBF...GLD...

43029919 43769637 43579501 42089557 41449564 41049606
40619655 40449783 40419819 40589885 40279963 40260050
41260044 41890070 42320042 42729991 