MESOSCALE PRECIPITATION DISCUSSION 0796
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1021 PM EST WED DEC 14 2016
 
AREAS AFFECTED...NORTHERN CA...SOUTHWEST OR 
 
CONCERNING...HEAVY RAINFALL 
 
VALID 150320Z - 151000Z
 
SUMMARY...SHORT-TERM SURGE OF INCREASED RAINFALL AROUND 06Z
NEARING .5"/HR TO LOCALLY HIGHER AS FRONTAL ZONE/MST FLUX FOCUS
CONTINUES TO SLIP SLOWLY SOUTHWARD. 

DISCUSSION...GOES MOSAIC WV LOOP INDICATES MIDDLE LEVEL WAVE
LIFTING TOWARD THE MOUTH OF THE COLUMBIA RIVER ATTM WITH THE
TRAILING TROF CONTINUED TO SUPPORT NARROW/FOCUSED SWLY CHANNEL OF
HIGH MOISTURE FLUX ON 40-50KT 850/50-60KT 7H ACROSS THE SISKIYOU
AND SALMON RANGES OF N CALIFORNIA/S OREGON AT THIS TIME. THIS AREA
CONTINUES TO EXPERIENCE SOLID UPPER LEVEL SUPPORT WITH RIGHT
ENTRANCE DYNAMICS TO 120-130KT POLAR JET CROSSING THE CENTRAL OR
COAST.  THIS UL JET ASCENT WILL BE INCREASING THROUGH 06-07Z AS
SOME SHEARED MID-LEVEL VORTICITY DPVA (SEE EASTERN EXTENT OF WAVE
ALONG 40N WEST OF 130W) ALONG WITH INCREASE IN SUBTROPICAL LEFT
JET EXIT FOR DUAL JET SUPPORT FROM 06-10Z. 

LOW LEVEL MOISTURE PLUME APPEARS TO BE VERTICALLY ALIGNING PER
CIRA LAYERED TPW ANALYSIS AS WELL TO SUPPORT TOTAL TPW NEARING
1.4" ALONG THE NOSE OF THIS WAVE/DPVA.  THIS SHOULD SUPPORT
INCREASED SFC MOISTURE CONVERGENCE AT AND SOUTH OF THE FRONTAL
BOUNDARY THAT WILL BE SETTLING SOUTH OF CAPE MENDOCINO AROUND 07Z
WITH RATES OVER .5"/HR NEARING .75" POSSIBLE.  TOTALS...WITH
ENOUGH SUPPORT/MOISTURE FLUX THROUGH A DEEP DEPTH FOR .25-.4"/HR
RATES INTO TRINITY RANGE AND POINTS WEST. 

THIS MATCHES WELL WITHIN THE HI-RES MODELS (WITH EXCEPTION OF THE
SLOWER/NORTH RECENT HRRR SOLUTIONS) AND AS SUCH THE SSEO MEAN IS A
GOOD REPRESENTATION OVERALL.  STILL FAVORING THE THE 12Z WRF-ARW
AND NSSL-WRF  AS MOST FAVORED...BOTH SUGGESTING BROAD 2-3" TOTALS
FOR THE SW FACING OROGRAPHY OF NW CALIFORNIA WITH SOME 1-2" INTO
THE NORTH CENTRAL MOUNTAINS...AS MAXIMA JUST OVER 3" FOR S
HUMBOLDT AND NW MENDOCINO COUNTIES RANGES.  

GALLINA

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

ATTN...RFC...CNRFC...NWRFC...

LAT...LON   43042268 42722230 42442221 41902241 41582215 
            41212178 40552155 40212241 39392296 38922369 
            39802399 40082429 40442444 40812429 41372412 
            41732433 42162416 42662330