[MCD] SWOMCD

Sun Dec 18 18:57:33 UTC 2005

ACUS11 KWNS 181855
SWOMCD
SPC MCD 181855 
NVZ000-IDZ000-ORZ000-CAZ000-190100-

MESOSCALE DISCUSSION 2580
NWS STORM PREDICTION CENTER NORMAN OK
1255 PM CST SUN DEC 18 2005

AREAS AFFECTED...CNTRL AND ERN ORE/SIERRA/NRN NV

CONCERNING...HEAVY SNOW 

VALID 181855Z - 190100Z

...MODERATE TO HEAVY SNOW WILL CONTINUE ACROSS THE NRN GREAT BASIN
THROUGH AFTN...WITH SNOW SPREADING INTO THE ERN SLOPES OF THE
CASCADES WITHIN A FEW HOURS. SNOW RATES ABOVE 4000 FEET MAY BE IN
THE 2-3 INCH PER HOUR RANGE...

LATEST IR SATELLITE IMAGERY SHOWS INCREASING MOISTURE/CLOUDS MOVING
ACROSS SRN ID/ORE WITH SOME COOLING CLOUD TOPS NOTED. ENHANCED BAND
OF CLOUDS SEEMS TO BE ASSOCIATED WITH DEFORMATION BAND NEAR 700MB.
HEAVIEST SNOW CURRENTLY OVER NRN PORTIONS OF NV FROM LOL/WMC/EKO.
MEANWHILE...SNOW HAS CHANGED OVER TO RAIN IN THE TAHOE/RENO
AREA...SUGGESTING FROM THE SFC OBSERVATIONS THAT THE FREEZING LEVEL
HAS RISEN ABOVE 6000 FEET. 

BAND OF SNOW IS EXPECTED TO INCREASE FROM DESCHUTES CO ORE INTO SW
ID AND NW UT...ASSOCIATED WITH FRONTOGENETIC FORCING WITHIN THE
750-650 MB LAYER AND UPWARD MOTION DUE TO VORTICITY ADVECTION. THIS
IS SUPPORTED BY THE ETA/RUC/GFS. SNOW RATES MAY RANGE FROM 1 TO 2
INCHES PER HOUR. SOME FZRA HAS BEEN OBSERVED NORTH OF MEDFORD
EARLIER...BUT MOST LOCATIONS HAVE TEMPS ABOVE FREEZING NOW.
EXCEPTION MAY BE IN VALLEY LOCATIONS WHERE STRONG INVERSION IS
HOLDING DOWN TEMPS. HEAVY SNOW WILL ALSO CONTINUE IN THE HIGHER
ELEVATIONS OF THE SIERRA

..TAYLOR.. 12/18/2005

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

ATTN...WFO...BOI...LKN...PDT...REV...MFR...PQR...

39391884 40252000 41862008 42232251 43122257 45402189
45511851 44741731 42231521 40151489 

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