[MCD] SWOMCD

[MCD at goshenarc.org]

ACUS11 KWNS 281836
SWOMCD
SPC MCD 281836 
CAZ000-282230-

MESOSCALE DISCUSSION 2585
NWS STORM PREDICTION CENTER NORMAN OK
1236 PM CST TUE DEC 28 2004

AREAS AFFECTED...SRN SIERRA NEVADA OF CA ABOVE 5000 FT

CONCERNING...HEAVY SNOW 

VALID 281836Z - 282230Z

HEAVY SNOW WITH RATES AS HIGH AS 2 IN/HR WILL BE POSSIBLE THIS
AFTERNOON ACROSS THE SRN SIERRA NEVADA OF CA...WITH SNOW LEVELS
GRADUALLY LOWERING TO 5000 FT BY LATE AFTERNOON.

LATEST WV IMAGERY DEPICTS UPPER TROUGH CENTERED OFF THE CA COAST
AROUND 35N/130W...WITH LEADING VORT MAXIMA NEARING THE CA COAST
INVOF CHANNEL ISLANDS. STRONGLY DIFFLUENT REGIME/EXIT REGION OF
UPPER JET OVERSPREADING CA...WITH MOIST PLUME ADVECTING NEWD ACROSS
SRN CA. AS PORTRAYED IN RUC SOUNDINGS/REGIONAL VWPS...MID LEVEL SSW
WINDS OF 50 KTS OR GREATER ARE CONTRIBUTING TO STRONG
UPSLOPE/OROGRAPHIC FORCING FOR HEAVY SNOW ACROSS THE SRN SIERRA
NEVADA OF CA.

IN ADDITION TO OROGRAPHIC ENHANCEMENT...UPSTREAM STEEP MID LEVEL
LAPSE RATES OF 7.0 C/KM -- AS EVIDENT IN 12Z VBG RAOB -- AND
PROXIMITY OF OBSERVED LIGHTNING SUGGEST CONVECTIVE PRESENCE WILL
LIKELY LOCALLY ENHANCE SNOW RATES THIS AFTERNOON. IN ACCORDANCE WITH
OBSERVATIONAL TRENDS...12Z ETA/15Z RUC GUIDANCE SUGGESTS SNOW LEVELS
WILL GRADUALLY LOWER TO NEAR 5000 FT THROUGH 00Z.

..GUYER.. 12/28/2004

...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...VEF...REV...HNX...STO...

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