[MCD] SWOMCD

[MCD at goshenarc.org]

ACUS11 KWNS 300617
SWOMCD
SPC MCD 300617 
CAZ000-301015-

MESOSCALE DISCUSSION 2589
NWS STORM PREDICTION CENTER NORMAN OK
1217 AM CST THU DEC 30 2004

AREAS AFFECTED...MTNS OF NRN CA ABOVE 3000 FT

CONCERNING...HEAVY SNOW 

VALID 300617Z - 301015Z

HEAVY SNOW WILL CONTINUE TO SPREAD INLAND AFFECTING THE MT SHASTA
AREA SEWD ACROSS THE NRN SIERRA NEVADA THROUGH 12Z. HEAVY SNOW WITH
RATES OF 2"/HR ARE EXPECTED WITH SNOW LEVELS RANGING FROM NEAR 3000
FT ACROSS FAR NRN CA TO 3500 FT ACROSS THE NRN SIERRA MTNS. 

AT 06Z...IR IMAGERY REVEALS A POTENT MID-LEVEL VORT CENTER JUST OFF
THE SWRN ORE COAST...AND NEGATIVE TILT TROUGH AXIS WITH FRONTAL
PRECIPITATION BAND EXTENDING SEWD ACROSS NWRN CA INTO THE CENTRAL
VALLEYS. STRONG COLD ADVECTION REGIME IS INFERRED OFF THE CA COAST
WITH 500MB TEMPERATURES BETWEEN -28 AND -30C. SCATTERED LIGHTNING
STRIKES HAVE BEEN OBSERVED ACROSS NWRN CA AND THE OFFSHORE WATERS
WHERE ETA MODEL SOUNDINGS INDICATE 700-500MB LAPSE RATES AROUND 7.5
C/KM. HEAVY SNOW SHOWERS WILL INCREASINGLY AFFECT THE COASTAL RANGE
AND MT SHASTA AREA ABOVE 3000 FT THROUGH 12Z. PRIMARY FRONTAL
PRECIPITATION BAND WILL TRANSLATE EWD ACROSS THE NRN SIERRA MTNS
DURING THE NEXT SEVERAL HOURS. THE 00Z ETA INDICATES INCREASING SWLY
2-3KM FLOW TO 60KT ACROSS THE NRN SIERRAS THROUGH THE NEXT SEVERAL
HOURS...SUGGESTING STRONG OROGRAPHIC ENHANCEMENT AND POTENTIAL FOR
SNOW RATES UP TO 2"/HR...GENERALLY 3500 FT AND ABOVE.

..BANACOS.. 12/30/2004

...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...REV...MFR...STO...EKA...

40362277 40042272 39882279 39882304 40152327 40472343
40982351 41332338 41562298 41692255 41752206 41642156
41402139 41102111 40382063 39432015 39092000 38912000
38712014 38752043 39342081 40002119 40322148 40552168
40972183 41132201 41012256 40772277 

WWWW