Severe Storm Outlook Narrative (AC)
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000
ACUS11 KWNS 120927
SWOMCD
SPC MCD 120926
CAZ000-121530-

MESOSCALE DISCUSSION 1975
NWS STORM PREDICTION CENTER NORMAN OK
0326 AM CST FRI DEC 12 2014

AREAS AFFECTED...WESTERN SLOPES OF THE CENTRAL AND SOUTHERN SIERRA
MOUNTAINS

CONCERNING...HEAVY SNOW

VALID 120926Z - 121530Z

SUMMARY...GREATEST LIKELIHOOD FOR HEAVY SNOWFALL RATES EXCEEDING 2
IN/HR IS EXPECTED TO SHIFT SOUTHWARD ALONG THE WESTERN SLOPES OF THE
CENTRAL TO SOUTHERN SIERRA MOUNTAINS BETWEEN 09-15Z.  SNOW LEVELS
WILL BE FALLING TO AROUND 6000 FEET THIS MORNING.

DISCUSSION...MOSAIC RADAR IMAGERY SHOWED A SWATH OF PRECIPITATION
WITH EMBEDDED MODERATE TO HEAVY RATES EXTENDING FROM IN VICINITY AND
WEST OF A PACIFIC FRONT.  AT 09Z...THE NRN EXTENT OF THIS FRONT WAS
MOVING EAST TOWARD THE CENTRAL SIERRA MOUNTAINS.  MODELS REMAIN
CONSISTENT SHOWING THIS FRONT WILL ADVANCE ESEWD ACROSS THE REST OF
CENTRAL AND MUCH OF SRN CA THROUGH 15Z...WITH THIS BOUNDARY REACHING
SERN CA BY 18Z. GIVEN THE PROGRESSION OF THE FRONT...THE ATTENDANT
BAND OF PRECIPITATION WILL SHIFT SWD ALONG THE WRN SLOPES OF THE
CENTRAL AND SRN SIERRA MOUNTAINS.  03Z SREF SUGGESTED A HIGH
LIKELIHOOD FOR SNOWFALL RATES TO EXCEED 2 IN/HR IN THE HIGHER
TERRAIN FROM ERN TUOLUMNE/SWRN ALPINE COUNTIES TO FAR ERN TULARE
COUNTY.

THIS SNOWFALL RATE WILL BE SUPPORTED BY STRONG DEEP LAYER ASCENT
ATTENDANT TO 90-120-METER 500-MB HEIGHT FALLS AND DPVA SPREAD ACROSS
THE DISCUSSION AREA WITH A PROGRESSIVE SHORTWAVE TROUGH MOVING
INLAND THIS MORNING.  THIS ASCENT COUPLED WITH MOIST UPSLOPE FLOW
WILL FAVOR HIGH SNOWFALL RATES IN THE HIGHER TERRAIN.

..PETERS.. 12/12/2014

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

ATTN...WFO...VEF...REV...HNX...STO...

LAT...LON   38501993 38271951 37941934 37721917 37521889 37041850
            36741836 36311817 36041812 35991818 36101823 36311847
            36571879 36911900 37281939 37731962 37951979 38192014
            38442016 38592008 38501993



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