MESOSCALE PRECIPITATION DISCUSSION 0739
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
544 PM EDT SAT OCT 15 2016
 
AREAS AFFECTED...CENTRAL AND NORTHERN CALIFORNIA...SW OREGON 
 
CONCERNING...HEAVY RAINFALL 
 
VALID 152143Z - 160603Z
 
SUMMARY...A STRONG AND OCCLUDED SURFACE LOW WILL CONTINUE TRACKING
TOWARDS VANCOUVER ISLAND THIS EVENING, WITH A TRAILING COLD FRONT
APPROACHING CENTRAL AND NORTHERN CALIFORNIA.  AN ATMOSPHERIC RIVER
OF ENHANCED MOISTURE AHEAD OF THIS FRONT IS FORECAST TO BRING A
PERIOD OF MODERATE TO HEAVY RAINFALL RATES LASTING THROUGH 6Z FOR
PARTS OF SOUTHWEST OREGON, AND THE COASTAL AND MOUNTAINOUS AREAS
OF CENTRAL AND NORTHERN CALIFORNIA.  RAINFALL RATES ON THE ORDER
OF 0.3 TO 0.6 INCHES PER HOUR ARE LIKELY, WITH RAINFALL TOTALS OF
2 TO 4 INCHES POSSIBLE ACROSS THE FAVORED TERRAIN AREAS.

DISCUSSION...21Z WATER VAPOR AND INFRARED SATELLITE IMAGERY SHOWED
A PLUME OF DEEP MOISTURE AND COOLING CLOUD TOPS APPROACHING THE
NORTHERN CALIFORNIA COAST.  THIS IS CO-LOCATED WITHIN AN AXIS OF
300-MB DIVERGENCE WHICH SUPPORTS THE ASCENT SEEN IN SATELLITE
IMAGERY.  MODEL GUIDANCE CONTINUES TO BE IN GOOD AGREEMENT WITH
THE PROGRESSION OF THE MOISTURE PLUME TOWARDS THE SOUTH ACROSS THE
CALIFORNIA COAST OVER THE COURSE OF THE EVENING. THE GUIDANCE
SUGGESTS PRECIPITABLE WATER VALUES OF 1.0 TO 1.3 INCHES ARE
EXPECTED TO REACH THE NORTHWESTERN CA COAST ALONG WITH A 50-60 KT
LOW LEVEL JET FROM THE SW. THE STRONG MOISTURE FLUX WILL FOCUS THE
GREATEST MOISTURE INTO THE COASTAL RANGES, THE SISKIYOUS, AND THE
NORTHERN SIERRA RANGE.  THIS WILL BEGIN TO WEAKEN DURING THE
OVERNIGHT HOURS.  BEHIND THE COLD FRONT, INSTABILITY SHOWERS WILL
LIKELY AFFECT THE COASTAL REGIONS.

HAMRICK

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

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

LAT...LON   42722336 42722239 42422181 41972157 41412097 
            40062056 39332044 38191951 37411908 36961925 
            37182009 37692052 38622099 39462151 39972207 
            39482256 38702235 37972198 37312170 36922188 
            37282269 38382329 39002394 39932452 40492469 
            41132443 41632409 42382374