MESOSCALE PRECIPITATION DISCUSSION 0048
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
534 AM EST MON MAR 07 2016
 
AREAS AFFECTED...CENTRAL AND SOUTHERN CA 
 
CONCERNING...HEAVY RAINFALL 
 
VALID 070930Z - 071500Z
 
SUMMARY...A LINE OF HEAVY SHOWERS AND A COUPLE OF THUNDERSTORMS
WILL CROSS DOWN THROUGH THE COASTAL RANGES OF CENTRAL AND SOUTHERN
CA THROUGH THE EARLY MORNING HOURS.

DISCUSSION...THE LATEST IR SATELLITE IMAGERY SHOWS A STRONG
SHORTWAVE AND ASSOCIATED VORT CENTER VERY QUICKLY APPROACHING
CENTRAL CA AS A COLD FRONT CONTINUES TO ADVANCE SOUTHEAST DOWN
ACROSS THE COASTAL RANGES.

RAINFALL RATES OF A 0.25" TO 0.50"/HR ARE NOTED ALONG THE COLD
FRONT JUST OFFSHORE AS PER THE LATEST MICROWAVE BLENDED RAIN RATE
IMAGERY...AND THIS IS BEING FACILITATED BY A STRONGLY DYNAMIC VORT
CENTER APPROACHING CENTRAL CA WITH IMPRESSIVE UPPER LEVEL
DIVERGENCE/LARGE SCALE ASCENT OVER THE REGION. MOISTURE IS NOT
NECESSARILY THAT IMPRESSIVE WITH PWATS OF 0.7 TO 0.9 INCHES ALONG
THE COAST AND JUST OFFSHORE...BUT STEEP MID LEVEL LAPSE RATES ARE
HELPING TO CONTRIBUTE TO OVER 500 J/KG OF SBCAPE JUST OFFSHORE
ALONG THE FRONT...AND THIS IS ALLOWING FOR LOCALLY INTENSE
CONVECTIVE RAIN RATES AS A RESULT.

SURFACE OBSERVATIONS OVER THE LAST FEW HOURS HAVE ALSO BEEN
SHOWING RAIN RATES INLAND OVER THE SANTA CRUZ MOUNTAINS AS HIGH AS
0.50" TO 0.60"/HR...AND THESE RATES ARE EXPECTED TO CONTINUE TO
MATERIALIZE JUST INLAND OVER THE IMMEDIATE COASTAL RANGES OVER THE
NEXT SEVERAL HOURS AS CONVECTION SHOULD REMAIN FOCUSED ALONG THE
FRONT WHILE SETTLING TO THE SOUTHEAST.

DESPITE THE PROGRESSIVE NATURE OF THE FRONT...THE LAST COUPLE RUNS
OF THE HRRR INSIST ON LOCALIZED RAIN RATES REACHING UP TO AROUND
OR LOCALLY EXCEEDING A 0.50"/HR WITH THE FRONT AND THESE RAINS
WILL BE FALLING IN A SHORT PERIOD OF TIME. CONSEQUENTLY...THERE
MAY BE A CONCERN FOR RUNOFF PROBLEMS OVER THE BURN SCAR AREAS WITH
ISOLATED FLASH FLOODING ALONG WITH MUDSLIDES AND DEBRIS FLOWS.

ORRISON

ATTN...WFO...HNX...LOX...MTR...

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

LAT...LON   36362098 36192059 35292001 34741904 34411850 
            33911849 33981924 34311984 34452069 35012097 
            35262110 35702141 36092142