MESOSCALE PRECIPITATION DISCUSSION 0065
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
118 PM EST MON FEB 27 2017

AREAS AFFECTED...SOUTHWEST CALIFORNIA

CONCERNING...HEAVY RAINFALL

VALID 271817Z - 280217Z

SUMMARY...DEEP MOISTURE REACHING SW CA COAST WILL RESULT IN
INCREASING RAIN RATES OVER CENTRAL AND SOUTHERN SAN DIEGO COUNTY
THROUGH 02Z.

DISCUSSION...SYNOPTIC SETUP AND LATEST GOES-W WV IMAGERY DENOTES A
DEEP NORTHERN STREAM TROUGH DROPPING ACROSS S CA ATTM...TIGHTENING
THE GRADIENT ACROSS THE LOCAL AREA AND SERVING TO ENHANCE THE JET
TO 100-120 KTS IN FAVORABLE RIGHT ENTRANCE PLACED OVER AREA OF
CONCERN. AT THE SURFACE...BLENDED TPW AND 89GHZ IMAGERY DENOTE A
STATIONARY FRONT EXTENDING FROM JUST NORTH OF THE US/MEX BORDER
TOWARD A WEAK INFLECTION JUST OFFSHORE.

HI-RES GUIDANCE CONTINUES TO INDICATE RAIN RATES WILL INCREASE IN
THE NEXT FEW HOURS OVER CENTRAL/SOUTHERN SAN DIEGO COUNTY INTO THE
SAN JACINTO MOUNTAINS...AS SUBTROPICAL MOISTURE...1-1.25" PER
LATEST BLENDED TPW IMAGERY...IS SHUNTED NORTH ACROSS THE REGION. 

HRRR/HRRR-TLE/HREF PROBABILITIES IN GOOD AGREEMENT WITH DEPICTION
OF A DEVELOPING SWATH OF HEAVIER RAINFALL...INCLUDING RAINFALL
RATES IN EXCESS OF .4-.5"/HR NOW THROUGH 21-23Z...POSSIBLY
LINGERING TO AROUND 02Z OVER THE SANTA ANA MTNS. TOTAL RAINFALL
AMOUNTS BETWEEN 2-3" WILL BE POSSIBLE ACROSS THIS AREA...PRIMARILY
IN THE AFOREMENTIONED PENINSULAR RANGES THROUGH LATE TONIGHT. WILL
CONTINUE TO MONITOR AND UPDATE AS NECESSARY AS NEW DATA BECOMES
AVAILABLE. 

MONTEFUSCO

ATTN...WFO...SGX...

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

LAT...LON   33901684 33821655 33531642 33011640 32711624
            32401611 32381642 32531665 32661684 32961723
            33411729 33771704