[MCD] SWOMCD

Sun Jan 14 17:48:10 UTC 2007

ACUS11 KWNS 141751
SWOMCD
SPC MCD 141750 
MOZ000-IAZ000-OKZ000-KSZ000-NEZ000-142245-

MESOSCALE DISCUSSION 0062
NWS STORM PREDICTION CENTER NORMAN OK
1150 AM CST SUN JAN 14 2007

AREAS AFFECTED...ERN KS...NRN/WRN/CNTRL MO...SRN IA...EXTREME SERN
NEB

CONCERNING...WINTER MIXED PRECIPITATION 

VALID 141750Z - 142245Z

A MIX OF FREEZING RAIN...SLEET...AND SNOW WILL EXPAND E/NEWD THIS
AFTERNOON. PRECIPITATION RATES OF .05 TO .15 IN/HR WILL BE
COMMON...WITH LOCALLY HEAVIER RATES IN EXCESS OF .20 IN/HR IN
CONVECTIVE CELLS.

A SWATH OF MODERATE TO OCCASIONALLY HEAVY SLEET HAS BEEN ONGOING
ACROSS MUCH OF CNTRL INTO ERN KS THIS MORNING...WITH MODERATE TO
HEAVY SNOW RECENTLY DEVELOPING IN PORTIONS OF SRN NEB. RECENT SLEET
ACCUMULATIONS OF AROUND 0.5 TO 1.5 INCHES HAVE BEEN REPORTED IN THE
ICT AREA. BOTH THE 12Z GFS AND 15Z RUC HAVE GOOD QPF AGREEMENT WITH
THE ONGOING PRECIPITATION EVOLUTION WHEN COMPARED TO REGIONAL RADAR
IMAGERY...WHILE THE 12Z NAM HAS BEEN TOO SLOW/FARTHER WEST. BOTH LOW
AND MID-LEVEL ISENTROPIC LIFT WILL CONTINUE DOWNSTREAM OF THIS
PRECIPITATION REGION...AS A SHORTWAVE TROUGH EJECTS NEWD FROM CO.
PRECIPITATION IS EXPECTED TO RAPIDLY EXPAND E/NEWD INTO MUCH OF MO
AND FAR SRN IA THIS AFTERNOON. A MIX OF PRECIPITATION TYPES WILL
OCCUR ACROSS THIS REGION WITH A TIGHT SW TO NE ORIENTED LOW-LEVEL
THERMAL GRADIENT.

AT 17Z...THE SURFACE FREEZING LINE WAS LOCATED FROM NEAR FYV TO 30 W
STL TO BRL. THIS LINE SHOULD MAKE SLOW PROGRESS WWD THROUGH THE
AFTERNOON....AS WEAK ELY WINDS CONTINUE TO THE N OF A DEVELOPING
SURFACE LOW IN THE TEXARKANA REGION. JUST W OF THIS FREEZING
LINE...OVER MUCH OF CNTRL MO...FREEZING RAIN WILL BE THE PRIMARY
PTYPE AS EVIDENCED BY THE 12Z OBSERVED SGF SOUNDING. FURTHER
NW...SLEET WILL BE THE PREDOMINANT PTYPE ACROSS SERN KS THROUGH THE
KC METRO AREA. HERE...A SMALL WARM LAYER OF ABOVE FREEZING
TEMPERATURES REMAINS BETWEEN 700-850 MB RELATIVE TO A MUCH COLDER
SURFACE-BASED LAYER /PER 12Z TOP AND LAMONT OK SOUNDINGS/. ACROSS
PORTIONS OF NERN KS/FAR NWRN MO INTO SRN IA...THE PRIMARY PTYPE WILL
BECOME ALL SNOW...AS MORNING MODEL GUIDANCE IS INSISTENT ON COOLING
THE 700-850 MB LAYER TO AOB FREEZING. AS THIS OCCURS...SNOW RATES
SHOULD BRIEFLY REACH 1 IN/HR.

..GRAMS.. 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...LSX...DVN...SGF...DMX...EAX...TSA...OAX...TOP...ICT...

39429684 40359668 40979599 41359494 41139300 40799234
40159190 39629152 38899154 38169164 37609196 37229299
36639378 36519440 36699518 37099604 38289662 