THE HYDROMETEOROLOGICAL PREDICTION CENTER

CAMP SPRINGS, MD


STORM SUMMARY MESSAGE



 
STORM SUMMARY NUMBER 1 FOR HEAVY RAIN EVENT OVER NORTHERN
CALIFORNIA AND SOUTHWESTERN OREGON
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
1 AM PST TUE DEC 27 2005

...A MULTI-DAY HEAVY RAINFALL EVENT ON TAP FOR NORTHERN CALIFORNIA
INTO SOUTHWESTERN OREGON...

A MULTI-DAY HEAVY RAINFALL EVENT IS BEGINNING ACROSS NORTHERN
CALIFORNIA AND WESTERN OREGON.  THE LATEST NATIONAL WEATHER
SERVICE RADAR IS SHOWING INCREASING COVERAGE TO RAINFALL OVER
NORTHERN CALIFORNIA AND WESTERN OREGON...WHILE THE LATEST NOAA
SATELLITE DATA IS SHOWING ABUNDANT UPSTREAM MOISTURE OVER THE
NORTHEASTERN PACIFIC...PUSHING EASTWARD TOWARD NORTHERN CALIFORNIA
AND WESTERN OREGON.   

AT 1 AM PST...THE CENTER OF STORM IS LOCATED NEAR 51.7N
149.0W...OR APPROXIMATELY 1050 NAUTICAL MILES WEST NORTHWEST OF
SEATTLE WASHINGTON.  WHILE THE CENTER OF THE STORM IS FAR FROM THE
WEST COAST...THE STRONGEST ONSHORE FLOW IS LOCATED WELL TO THE
SOUTHEAST OF THE STORM AND WILL BE IMPACTING INTO NORTHERN
CALIFORNIA AND WESTERN OREGON.  THIS ONSHORE FLOW OF MOIST AIR
INTO NORTHERN CALIFORNIAN AND WESTERN OREGON IS EXPECTED TO BE
ANOMALOUSLY STRONG OVER THE NEXT 24 HOURS.  THE PERSISTENT NATURE
OF THE MOIST ONSHORE UPSLOPE FLOW WILL BRING THE POTENTIAL OF VERY
HEAVY RAINFALL AMOUNTS FOR NORTHERN CALIFORNIA INTO WESTERN OREGON
OVER THE NEXT 24 HOURS.  THE HEAVY PRECIPITATION THREAT WILL OCCUR
IN WAVES. THE FIRST WAVE OF HEAVY PRECIPITATION IS EXPECTED TUE
INTO EARLY WEDNESDAY.  THIS WILL BE FOLLOWED BY ANOTHER ROUND OF
HEAVY PRECIPITATION FRIDAY INTO EARLY SATURDAY AND A THIRD ROUND
OF HEAVY PRECIPITATION POTENTIAL ON SUNDAY.  

OVER THE NEXT 24 HOURS THERE IS THE POTENTIAL FOR PRECIPITATION
AMOUNTS OF 4 TO 8 INCHES OVER NORTHERN CALIFORNIA INTO
SOUTHWESTERN OREGON...WITH ISOLATED MAXIMUM VALUES OF 10 INCHES
OVER NORTHWESTERN CALIFORNIA WHERE THE UPSLOPE FLOW INTO THE
HIGHER TERRAIN WILL BE THE GREATEST.  EACH SUCCESSIVE WAVE OF
HEAVY PRECIPITATION HAS THE POTENTIAL TO BRING SEVERAL INCHES OF
PRECIPITATION FOR NORTHERN CALIFORNIA INTO SOUTHWESTERN OREGON.

FLOOD WATCHES ARE CURRENTLY IN EFFECT FOR PORTIONS OF NORTHERN
CALIFORNIA.  WINTER STORM WATCHES ARE IN EFFECT FOR PORTIONS OF
THE NORTHERN SIERRA NEVADA RANGE.

HIGH WIND WATCHES AND WARNINGS HAVE BEEN ISSUED FOR THIS INTENSE
LOW PRESSURE SYSTEM. SUSTAINED WINDS IN EXCESS OF 40 MPH HAVE BEEN
FORECAST FOR THE PACIFIC NORTHWEST. HIGH WIND WARNINGS ARE
CURRENTLY IN EFFECT FOR PORTIONS OF SOUTHERN WASHINGTON AND
OREGON. A WIND ADVISORY IS IN EFFECT FOR THE NORTHERN CALIFORNIA
COAST.

THE NEXT STORM SUMMARY WILL BE ISSUED BY THE HYDROMETEOROLOGICAL
PREDICTION CENTER AT 7 AM PST FOR THIS SYSTEM.  PLEASE REFER TO
STATEMENTS ISSUED BY LOCAL NATIONAL WEATHER SERVICE OFFICES FOR
FURTHER INFORMATION ON THIS STORM.

ORAVEC/SZATANEK








Last Updated: 358 AM EST TUE DEC 27 2005