MESOSCALE PRECIPITATION DISCUSSION 0053
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
307 AM EST THU FEB 16 2017

AREAS AFFECTED...N CALIFORNIA

CONCERNING...HEAVY RAINFALL

VALID 160805Z - 161501Z

SUMMARY...A SURGE OF HEAVY RAINFALL RATES POSSIBLY ECLIPSING 1
IN/HR ALONG COASTAL LOCATIONS INTO THE SHASTA CASCADE IS EXPECTED
OVER NRN CA THROUGH 12-15Z THIS MORNING. 2-3 INCHES OF RAIN WITH
LOCALLY HIGHER VALUES WILL BE POSSIBLE IN THESE LOCATIONS THROUGH
15Z.

DISCUSSION...LATEST WATER VAPOR IMAGERY SHOWING A VORTICITY MAXIMA
EMBEDDED WITHIN LARGE SCALE MID LEVEL TROUGH JUST OFFSHORE OF THE
NORTHERN CALIFORNIA COAST NEAR 35N 135W. SOUTH-SOUTHWEST LOW LEVEL
FLOW OF 60-80 KT WILL COMBINE WITH PRECIPITABLE WATER VALUES
MAXING OUT IN THE 1.0 TO 1.4 INCH RANGE ALONG THE NRN CA
COAST...TRANSPORTING A PLUME OF 1000+ KG/M/S INTEGRATED WATER
TRANSPORT ACROSS THE NORTHERN CALIFORNIA COASTAL RANGE INTO THE
SHASTA CASCADE.

WHEN COMBINED WITH STRONG UPPER LEVEL DIFFLUENCE AND APPROACHING
LEFT EXIT REGION JET DYNAMICS JUST OFFSHORE...RAINFALL RATES ARE
EXPECTED TO RANGE BETWEEN 0.75 AND 1.0 IN/HR AT TIMES WITHIN THE
MPD THREAT AREA...WITH THE POSSIBILITY OF RATES EXCEEDING 1.0
IN/HR ON A LOCALIZED BASIS...AND SHOULD BE CONCENTRATED FROM CURRY
TO NRN MENDOCINO COUNTIES WHERE SSW FACING TERRAIN INTERCEPTS THE
ROBUST MOISTURE FLUX.

MONTEFUSCO/OTTO

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

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

LAT...LON   41792373 41712314 41402196 40782175 39582190
            39262196 38602213 38422234 38452312 38602390
            39002433 40222437 40922443 41602414 41572416