[MCD] SWOMCD

[MCD at goshenarc.org]

ACUS11 KWNS 062301
SWOMCD
SPC MCD 062301 
CAZ000-070300-

MESOSCALE DISCUSSION 2506
NWS STORM PREDICTION CENTER NORMAN OK
0501 PM CST MON DEC 06 2004

AREAS AFFECTED...THE MOUNTAINS OF NRN CA ABOVE 3500FT

CONCERNING...HEAVY SNOW 

VALID 062301Z - 070300Z

HEAVY SNOW WILL CONTINUE ACROSS THE SHASTA/SISKIYOUS REGION AND
SPREAD ESEWD INTO THE NRN SIERRA MTNS THROUGH 07/06Z. SNOW LEVELS
EXPECTED AROUND 3500 FT NEAR MT SHASTA AND AROUND 4000 FT IN THE NRN
SIERRA MTNS. SNOWFALL RATES UP TO 2"/HR PER HOUR POSSIBLE...
PARTICULARLY SWD/SWWD FACING SLOPES WITH OROGRAPHIC ENHANCEMENT. 

VORT MAX EMBEDDED IN STRONG ZONAL FLOW SOUTH OF STATIONARY UPPER LOW
OFF WA COAST WILL CONTINUE TO PROGRESS RAPIDLY EWD REACHING THE NRN
CA COAST BY 07/06Z. PRECIPITATION HAS ALREADY SPREAD EWD INTO THE
COASTAL RANGES AND MT SHASTA REGION ASSOCIATED WITH LOW-LEVEL WARM
ADVECTION INFERRED FROM RECENT EUREKA VAD WIND PROFILES. HVY SNOW
COMMENCED AT MT. SHASTA ASOS /MHS/ AT 20Z. VERY STRONG WIND
FIELDS...WITH SWLY 1KM FLOW AROUND 60KT...SHOULD FAVOR STRONG
OROGRAPHIC LIFT ALONG SOUTH/SW FACING SLOPES THROUGH THE FORECAST
PERIOD. 

COOLING CLOUD TOPS IN IR IMAGERY JUST IN ADVANCE OF VORT MAX 125 NM
WEST OF EKA SUGGEST STRONGEST LARGE-SCALE SUPPORT FOR ASCENT SHOULD
ARRIVE IN NRN COASTAL RANGES AND MT SHASTA AREA BETWEEN
01-04Z...WHEN 2"/HR RATES ARE MOST LIKELY. HEAVY SNOW WILL SPREAD
EWD INTO THE NRN SIERRA MTNS BETWEEN 03-06Z. SOME MINOR FLUCTUATION
IN FREEZING LEVELS ARE SUGGESTED BY HOURLY ETA THERMODYNAMIC
PROFILES THROUGH 06Z...HOWEVER SNOW LEVELS SHOULD HOLD BETWEEN
3500-4000FT ACROSS MOST OF THE DISCUSSION AREA...WITH LOWER LEVELS
FAVORED ACROSS NRN MOST SECTIONS OF DISCUSSION AREA.

..BANACOS.. 12/06/2004

...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 05-06 UTC...
11-12 UTC...17-18 UTC...AND 23-00 UTC AS SIGNIFICANT SHORT
RANGE WINTER WEATHER EVENTS UNFOLD.  THIS SCHEDULE WILL BE
USED FROM DECEMBER 1 THROUGH FEBRUARY 28 TO ALLOW PARTNERS
AND USERS TO BETTER ANTICIPATE THE TIMING OF SPC WINTER WEATHER
MESOSCALE DISCUSSIONS.

ATTN...WFO...REV...MFR...STO...EKA...

40372282 40132271 39712263 39492266 39452276 39592297
39982327 40252338 40662346 41612355 41742302 41762213
41742181 41632155 41442134 40872100 40282067 39682034
38992004 38932054 39162080 39492106 40222162 40662173
41012184 41122205 41112231 40812269 

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