[MCD] SWOMCD

[MCD at goshenarc.org]

ACUS11 KWNS 310047
SWOMCD
SPC MCD 310047 
CAZ000-NVZ000-310515-

MESOSCALE DISCUSSION 2595
NWS STORM PREDICTION CENTER NORMAN OK
0647 PM CST THU DEC 30 2004

AREAS AFFECTED...SIERRA MTNS OF NRN CA

CONCERNING...HEAVY SNOW 

VALID 310047Z - 310515Z

HEAVY SNOW /INCLUDING LOCALIZED BLIZZARD CONDITIONS/ WITH HOURLY
ACCUMULATIONS AS HIGH AS 2 IN/HR WILL CONTINUE THIS EVENING ACROSS
THE SIERRA NEVADAS OF CA.

LATEST IR/WV IMAGERY FEATURES UPPER LOW PERSISTING IMMEDIATELY OFF
THE ORE COAST. OWING TO QUASI-STATIONARY NATURE OF THIS
FEATURE...OBSERVATIONAL EVIDENCE SUGGESTS SWLY MOIST UPSLOPE
TRAJECTORIES/OROGRAPHIC LIFT INTO THE MOUNTAINOUS TERRAIN HAVE
FLUCTUATED LITTLE THIS AFTERNOON. ALTHOUGH A SLIGHT DECREASE IN WIND
SPEEDS IS EXPECTED INTO THE OVERNIGHT PER 21Z RUC GUIDANCE...
PERSISTENCE OF 40-70 KT SWLY WINDS IN 2 TO 5 KM LAYER /00Z OAK AND
REV RAOBS/ WILL CONTINUE TO SUPPORT HEAVY SNOW ACROSS MUCH OF THE
SIERRAS TONIGHT...NAMELY ON SW/W SLOPES.

OWING TO DEGREE OF COLD AIR ALOFT...PROXIMITY OF STEEP MID LEVEL
LAPSE RATES OF 7.0 C/KM OR GREATER WILL CONTINUE TO CONVECTIVELY
ENHANCE SNOW RATES TONIGHT...INSTABILITY AS FURTHER EVIDENCE BY
ISOLD LIGHTNING STRIKES ALONG THE ORE/NRN CA COAST THIS AFTERNOON.
21Z RUC SUGGESTS THERMODYNAMIC PROFILES WILL LARGELY REMAIN
UNCHANGED THROUGH 09Z...WITH SNOW LEVELS PERSISTING AROUND 3500 FT
ACROSS THE NRN SIERRAS...4000-4500 FT IN THE CNTRL SIERRAS...TO
AROUND 5000 FT IN THE FAR SRN SIERRAS.

..GUYER.. 12/31/2004

...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...HNX...STO...

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