[MCD] SWOMCD

Thu Dec 21 00:56:58 UTC 2006

ACUS11 KWNS 210057
SWOMCD
SPC MCD 210057 
NEZ000-SDZ000-COZ000-210700-

MESOSCALE DISCUSSION 2289
NWS STORM PREDICTION CENTER NORMAN OK
0657 PM CST WED DEC 20 2006

AREAS AFFECTED...CNTRL INTO N-CNTRL NEB

CONCERNING...HEAVY SNOW 

VALID 210057Z - 210700Z

HEAVY SNOW WITH HOURLY RATES OF 1-1.5 INCHES IS FORECAST TO BECOME
INCREASING COMMON ACROSS DISCUSSION AREA THROUGH 21/06Z.  EMBEDDED
POCKETS OF FREEZING RAIN WILL ALSO REMAIN POSSIBLE...MAINLY FROM BBW
NEWD THROUGH BUB AND ONL.

AS MENTIONED IN MCD 2288...A SECONDARY DEFORMATION
BAND/PRECIPITATION SHIELD APPEARS TO BE DEVELOPING FROM NEAR AKO
ENEWD THROUGH LBF/BBW WITH SOME REINTENSIFICATION NOTED WITHIN
INITIAL BAND OVER CHERRY COUNTY.  THIS ENHANCEMENT IN
CLOUDS/PRECIPITATION APPEARS TO BE ARISING FROM STRONG VORTICITY
MAXIMUM ROTATING NWD AROUND UPPER LOW OVER SWRN CO...COUPLED WITH
LOW-LEVEL WAA OCCURRING TO THE N OF SURFACE FRONTAL OCCLUSION.

CURRENTLY...SURFACE OBSERVATIONS INDICATE A NARROW CORRIDOR OF
FREEZING RAIN FROM LBF/BBW NEWD TOWARD ANW/ONL...WITH A CHANGE OVER
TO SNOW FORECAST THIS EVENING FROM W-E AS COLD AIR DEEPENS ON
BACKSIDE OF SYNOPTIC SYSTEM.  PERIODS OF FREEZING RAIN WITH HOURLY
RATES OF .01 TO .05 INCHES MAY PERSIST THROUGH 21/06Z FROM BBW TO
ONL.

OTHERWISE...EXPECT THAT THE STRENGTHENING LARGE SCALE FORCING AHEAD
OF VORTICITY MAXIMUM WILL SUPPORT AN INCREASE IN SNOW COVERAGE AND
INTENSITY IN A BAND FROM IML AND SNY EWD THROUGH LBF/MHN/ANW AREAS
WITH SNOW RATES APPROACHING 1-1.5 INCHES THROUGH MIDNIGHT CST.

..MEAD.. 12/21/2006

...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...GID...LBF...UNR...BOU...CYS...

41580285 42310279 42740218 42990115 43000044 42979885
42509836 41559842 41119930 40910063 40930230 41220255 