STORM SUMMARY NUMBER 2 FOR WEST COAST ATMOSPHERIC RIVER AND HEAVY
RAIN
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
800 PM PDT FRI APR 06 2018

...HEAVY RAIN IS FALLING ACROSS NORTHERN CALIFORNIA AS AN
ATMOSPHERIC RIVER PROVIDES RECORD-BREAKING MOISTURE... 

FLOOD WATCHES ARE IN EFFECT FOR MUCH OF NORTHERN AND CENTRAL
CALIFORNIA PORTIONS OF SOUTHWESTERN OREGON AND PORTIONS OF IDAHO.

HIGH WIND WARNINGS ARE IN EFFECT FOR PORTIONS OF OREGON AND
WASHINGTON NORTHERN CALIFORNIA AND NORTHERN NEVADA.

FOR A DETAILED GRAPHICAL DEPICTION OF THE LATEST
WATCHES...WARNINGS AND ADVISORIES...PLEASE SEE WWW.WEATHER.GOV

AT 700 PM PDT...A SURFACE LOW WITH A CENTRAL PRESSURE OF 978
MB...28.88 INCHES...WAS CENTERED APPROXIMATELY 600 MILES WEST OF
THE OREGON COAST AND MOVING NORTHEASTWARD. AHEAD OF THE LOW
PRESSURE SYSTEM A BROAD ATMOSPHERIC RIVER WAS PROVIDING HIGH TO
RECORD-BREAKING AMOUNTS OF MOISTURE TO CALIFORNIA AND SOUTHERN
OREGON. NATIONAL WEATHER SERVICE DOPPLER RADARS AND SURFACE
OBSERVATIONS INDICATED THAT A BROAD AREA OF MODERATE TO HEAVY RAIN
WAS LOCATED ACROSS NORTHERN AND CENTRAL CALIFORNIA. LIGHT TO
MODERATE RAIN WAS FALLING IN SOUTHERN OREGON AND NORTH CENTRAL
NEVADA.

...SELECTED PRELIMINARY STORM TOTAL RAINFALL IN INCHES FROM 100 AM
PDT THU APR 05 THROUGH 700 PM PDT FRI APR 06...

...CALIFORNIA...
GUALALA                               4.69                    
COMPTCHE 9 W                          4.28                    
VENADO                                4.20                    
LEGGETT 1 NW                          4.04                    
LEGGETT                               4.00                    
ROCKPORT 3 N                          4.00                    
WHITEHORN 2 WNW                       3.88                    
SEBASTOPOL                            3.55                    
SODA CREEK                            3.52                    
DILLON BEACH                          3.50                    
MENDOCINO PASS                        3.41                    
RUTH                                  3.03                    
SHELTER COVE 1 WNW                    3.00                    
BLUE CANYON/NYACK ARPT                2.81                    
SANTA ROSA/SONOMA CO. ARPT            2.72                    
OAKLAND/METROPOLITAN INTL ARPT        1.40                    
SACRAMENTO METRO ARPT                 1.23                    


THE ATMOSPHERIC RIVER WILL CONTINUE TO SPREAD COPIOUS AMOUNTS OF
MOISTURE ONSHORE...PRODUCING HEAVY RAINFALL ALONG MUCH OF THE WEST
COAST INTO SATURDAY. BY SATURDAY AFTERNOON THE SURFACE LOW WILL
APPROACH BRITISH COLUMBIA WHILE THE COLD FRONT SWEEPS INLAND
ACROSS THE WEST COAST STATES...CUTTING OFF THE INFLOW OF DEEP
MOISTURE INTO THE WEST COAST. WHILE THE HEAVIEST RAINFALL RATES
SHOULD BEGIN TO WIND DOWN LATE SATURDAY...ONSHORE FLOW IN THE WAKE
OF THE COLD FRONT WILL KEEP SHOWERS IN PLACE INTO SUNDAY ACROSS
THE PACIFIC NORTHWEST. ADDITIONAL RAINFALL AMOUNTS OF 3 TO 5
INCHES ARE POSSIBLE THROUGH SUNDAY FROM WESTERN WASHINGTON AND
OREGON SOUTH TO CENTRAL CALIFORNIA...ESPECIALLY AT THE HIGHER
ELEVATIONS WHERE OROGRAPHIC LIFT WILL ENHANCE PRECIPITATION RATES.
1 TO 2 INCHES OF ADDITIONAL RAINFALL ARE EXPECTED AT LOWER
ELEVATION LOCATIONS.

THE NEXT STORM SUMMARY WILL BE ISSUED BY THE WEATHER PREDICTION
CENTER AT 200 AM PDT. PLEASE REFER TO YOUR LOCAL NATIONAL WEATHER
SERVICE OFFICE FOR ADDITIONAL INFORMATION ON THIS EVENT.

RYAN