MESOSCALE PRECIPITATION DISCUSSION 0073
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
926 PM EST THU MAR 10 2016
 
AREAS AFFECTED...N CALIFORNIA 
 
CONCERNING...HEAVY RAINFALL 
 
VALID 110300Z - 111300Z
 
SUMMARY...SHIFTING ORIENTATION OF MOISTURE FEED WILL CHANGE BUT
REMAIN FOCUSED ON SMALL AREA OF COASTLINE OVER THE NEXT 6-12 HOURS.

DISCUSSION...HIGHLY ELONGATED N-S UPPER LOW NEAR 135W PROVIDING
ENOUGH ENERGETICS TO BEGIN AMPLIFYING LEADING TO BAROCLINIC LEAF
BUT ALSO INCREASING DIFFLUENCE BETWEEN THE POLAR AND SUBTROPICAL
JET STREAKS OVER THE SAN FRANCISCO BAY AREA AND NORTH.  IN THE LOW
LEVELS...A NARROW BUT CONCENTRATED MOISTURE PLUME CONNECTED TO THE
DEEP TROPIC TRACED BACK TO JUST EAST OF THE BIG ISLAND OF HAWAI'I
IS ORIENTED SW TO NE FOCUSED JUST SOUTH OF THE ENTRANCE TO THE BAY
AND SOUTH OF BEST UPPER LEVEL ASCENT...PRESENTED IN WV/IR AS SOLID
WITH SOME COLIFORM PRESENTATION IN THE ALTOSTRATUS DECK. 
CURRENTLY VWP AND RAP ANALYSIS SHOW 25-30 KT LOW LEVEL SWLY FLOW
BUT GIVEN HIEGHT FALLS AND SHORTWAVE RIDGING STARTING TO ENHANCE
SOUTH NEAR 32N 130W...LIFTING NORTH IN THE NEXT FEW HOURS...THE
LOW LEVEL FLOW WILL RESPOND AND BACK TOWARD THE DUE SOUTH LEADING
TO RESPITE OF HIGHEST RATES AND SEVERING THE RAINFALL ACROSS THE
NORTHERN VALLEY AND NORTHER SIERRAS.  THIS WILL ALSO LIMIT RAIN
RATES TO .1-.25" MAINLY NORTH OF THE BAY BY 06Z GIVEN THE
SHORT-TERM REDUCTION IN MOISTURE FLUX BEFORE THE MOISTURE AXIS
REORIENTS MORE FAVORABLY WITH A MORE SOUTHERLY ORIENTATION AS WELL
AS ENHANCING LOW LEVEL FLOW TO 30-40KTS BY 10Z. AS SUCH RATES WILL
BEGIN TO INCREASE TO .25-.4"/HR BUT FROM A DIFFERENT OROGRAPHIC
ASCENT PREFERENCE.  THIS LULL WILL STILL BE SUPPORTIVE OF 1-2"
TOTALS IN THE NEXT 6-12 HOURS HOURS PARTICULARLY OVER MARIN AND
SONOMA COUNTIES BEFORE INCREASING TOWARD EARLY MORNING AS THE WAVE
AND INCREASED FORCING/WIND FLOW APPROACHES IN THE MORNING TO
AFTERNOON HOURS.  

GALLINA

ATTN...WFO...EKA...MTR...STO...

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

LAT...LON   40272283 39392227 38172175 37742179 37542185 
            37382244 37892283 38692360 39712394