[MCD] SWOMCD

[MCD at goshenarc.org]

ACUS11 KWNS 031825
SWOMCD
SPC MCD 031825 
CAZ000-032330-

MESOSCALE DISCUSSION 0018
NWS STORM PREDICTION CENTER NORMAN OK
1225 PM CST MON JAN 03 2005

AREAS AFFECTED...MTN OF SRN CA...SRN SIERRA NEVADA

CONCERNING...PRECIPITATION TRENDS...WINTER PRECIPITATION 

VALID 031825Z - 032330Z

HVY SNOW OVER SAN GABRIEL MTNS OF SRN CA ABOVE 4000 FT WILL 
DIMINISH IN INTENSITY THROUGH 20Z...WITH HVY SNOW DIMINISHING OVER
THE SAN GABRIEL AND SAN DIEGO CTY MTNS ABOVE 5000 FT BETWEEN 20-22Z.
HRLY ACCUMULATIONS ABOVE 2 INCHES WILL REMAIN LIKELY THROUGH THESE
TIMES. FARTHER NORTH...HVY SNOW IS ANTICIPATED TO DEVELOP OVER THE
KERN COUNTY MTNS AND SRN SIERRA NEVADA THROUGH 00Z. HOURLY
ACCUMULATION ON SOUTH FACING SLOPES GREATER THAN 2 INCHES CAN BE
EXPECTED.

DOUBLE BARRELED UPPER LOW OFF THE CA COAST WILL CONTINUE TO SLOWLY
PROGRESS EWD THROUGH THE AFTERNOON. STRONG UPPER DIVERGENCE ON THE
ERN SIDE OF THE UPPER TROUGH COMBINED WITH LOW-MID LEVEL CONVERGENCE
AHEAD OF A LEAD TROUGH AXIS WILL MAINTAIN A WELL DEVELOPED
PRECIPITATION AREA OVER SRN AND PORTIONS OF CENTRAL CA. STRONG
CONVERGENCE AHEAD OF A LOW-MID LEVEL TROUGH WILL CONTINUE TO SUPPORT
HVY SNOWFALL OVER THE MTNS OF SRN CA THROUGH 20-22Z TIME.
PROGRESSIVE NATURE OF THIS TROUGH EVIDENT BY RECENT KVTX VWP DATA
AND SAT TRENDS INDICATE THAT FOCUSED CONVERGENCE WILL CONTINUE TO
SHIFT FURTHER INLAND OVER THE HIGH DESERT AND SRN SIERRA NEVADA.
SNOW LEVELS RANGING FROM AROUND 4000 FT IN THE NRN SAN GABRIEL MTNS
TO AROUND 5000 FT IN THE MTNS OF SAN DIEGO COUNTY SHOULD FALL
SLIGHTLY AFTER THE TROUGH PASSAGE.

FARTHER NORTH...AS THE LEAD MID LEVEL TROUGH PROGRESSES INTO THE
HIGH DESERT AND SRN SAN JOAQUIN VALLEY...EXPECT HVY SNOW TO CONTINUE
TO DEVELOP OVER THE SRN SIERRA NEVADA/KERN COUNTY MTNS ABOVE 4000
FT. DEEP/MODERATE SSELY FLOW WILL SUPPORT ADDITIONAL UPSLOPE
COMPONENT TO VERTICAL MOTION AND 2 IN/HR RATES ON S/SE FACING
SLOPES.  AS MAIN UPPER TROUGH CONTINUES TO DIG SLOWLY OFF THE CA
COAST...THE SRN SIERRA NV IS LIKELY TO BE THE LOCATION OF A
DEVELOPING MID LEVEL DEFORMATION ZONE. THUS...THERE EXIST THE
POTENTIAL FOR A PROLONGED 1-2 IN/HR HVY SNOW EVENT WELL INTO THE
EVENING HOURS.

..CROSBIE.. 01/03/2005

...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...SGX...HNX...LOX...

32891667 32861687 34081792 34491887 34711945 35041908
35581879 36361911 36881954 37201959 37561900 36721821
35521798 34911853 34371768 

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