MESOSCALE PRECIPITATION DISCUSSION 0736
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
536 AM EDT FRI OCT 14 2016
 
AREAS AFFECTED...NRN CA 
 
CONCERNING...HEAVY RAINFALL 
 
VALID 140935Z - 142100Z
 
SUMMARY...STRONG INTEGRATED VAPOR TRANSPORT (IVT) WILL GRADUALLY
DIMINISH THROUGH THE REMAINDER OF THE MORNING...BUT CONTINUE TO
SUPPORT HEAVY RAINFALL RATES EARLY IN THE PERIOD. ADDITIONAL
RAINFALL TOTALS OF 4-6 INCHES WILL BE POSSIBLE ACROSS THE SRN
CASCADES/NRN SIERRA NEVADA MOUNTAINS.

DISCUSSION...INFRARED SATELLITE IMAGERY AND SURFACE OBSERVATIONS
AS OF 09Z SHOWED A MATURE CYCLONE CENTERED NEAR 47N 131W...WITH AN
OCCLUDED/COLD FRONT ANALYZED THROUGH CNTRL WASHINGTON/OREGON AND
NRN CALIFORNIA...CROSSING THE COAST IN NRN MENDOCINO COUNTY.
ALTHOUGH TRENDS HAVE SHOWN WEAKENING OVER THE PAST 6
HOURS...BLENDED TPW IMAGERY CONTINUED TO SHOW A HIGHLY ANOMALOUS
PLUME OF PRECIPITABLE WATER ALONG AND AHEAD OF THE COLD FRONT WITH
1.5 INCH VALUES REACHING THE NRN CA COASTLINE AS OF 09Z. VAD WIND
PLOTS AT KBHX AND KMAX CONFIRMED RAP ANALYSES OF 40-50 KT AT 850
MB JUST AHEAD OF THE COLD FRONT ALONG THE COAST...WITH 70 KT AT
700 MB FARTHER INLAND ACROSS NRN CA. STRONG MOISTURE TRANSPORT
CONTINUED TO SUPPORT OBSERVED RAINFALL RATES OF 0.6 TO 0.7 IN/HR
ACROSS WRN TRINITY COUNTY WITH HIGHER VALUES LIKELY NOT BEING
OBSERVED THROUGH 09Z. 

AS THE POWERFUL UPPER TROUGH CONTINUES TO MOVE INLAND ACROSS THE
PACIFIC NORTHWEST OVER THE NEXT 6-9 HOURS...SHORT TERM MODEL
FORECASTS CONTINUE THE OBSERVED WEAKENING TREND OF PRECIPITABLE
WATER...TO SOME DEGREE...ALONG THE NRN CA COAST AS THE COLD FRONT
MOVES SOUTH...WITH A SLIGHT INCREASE INTO THE NRN SACRAMENTO
VALLEY. BY 15Z...850 MB WIND SPEEDS ARE EXPECTED TO DIMINISH TO
30-40 KTS JUST AHEAD OF THE COLD FRONT WITH THE CORE OF 70 KT 700
MB WINDS SHRINKING. THIS GRADUAL DIMINISHING OF IVT WILL ALLOW
RAINFALL RATES TO DROP BELOW 0.50 IN/HR ALONG THE NRN CA COASTAL
RANGES SHORTLY AFTER 15Z...BUT MAINTAIN A WHILE LONGER INTO THE
HIGHER ELEVATIONS OF THE NRN SIERRA NEVADA. SOME ADDED LIFT WILL
BE POSSIBLE EARLY ON AS THE RIGHT ENTRANCE REGION OF A 140-160 KT
UPPER LEVEL JET CORE MOVES ACROSS THE OR/CA BORDER THROUGH 15Z. IT
IS ACROSS THE NRN SIERRA NEVADA MOUNTAINS THAT THE GREATEST
ADDITIONAL RAINFALL TOTALS ARE EXPECTED WITH 4-6 MORE INCHES OF
RAIN FORECAST THROUGH 21Z. ALONG THE NRN CA COASTAL
RANGES...ADDITIONAL RAINFALL TOTALS OF 2 TO 4 INCHES WILL BE
POSSIBLE.

OTTO

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

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

LAT...LON   41622127 41522082 41392058 41022041 40532052 
            40282044 39932019 39562014 39312009 38972021 
            38632059 38492110 38632135 39092150 39462173 
            39572206 39552224 39382235 39092224 38722202 
            38372195 38132204 37822233 37822260 37972299 
            38222322 39262380 40332384 41292274 41602187