AGUS76 KRSA 241551
HMDRSA

HYDROMETEOROLOGICAL DISCUSSION
NATIONAL WEATHER SERVICE / CALIFORNIA NEVADA RFC / SACRAMENTO CA
930 AM PST TUE NOV 24 2009

...FRONT WILL BRING RAIN TO NRN CA/SRN OREGON THUR AFTERNOON...

.24 HOUR PRECIPITATION TOTALS (ENDING NOV 24 AT 400 AM PST)...

NO PRECIPITATION WAS OBSERVED DURING THE PERIOD.

.METEOROLOGICAL CONDITIONS...

RIDGING BUILDING ALONG THE WEST COAST WILL CONTINUE DRY CONDITIONS 
THROUGH THURSDAY MORNING ACROSS THE FORECAST AREA.  A WEAK SHORTWAVE 
NEAR THE ALEUTIAN ISLANDS THIS MORNING IS EXPECTED TO DEVELOP OVER 
THE NEXT 48 HOURS AS IT ROUNDS THE BASE OF A GULF OF ALASKA LOW AND 
PUSHES THE RIDGE TO THE EAST OVER THE HIGH PLAINS.  BY THURSDAY 
AFTERNOON...THE SYSTEM AND ASSOCIATED FRONT ARE EXPECTED TO BE JUST 
OFF THE NRN CA COAST.  RECENT MODELS RUNS HAVE SLOWED THIS SYSTEM 
DOWN A BIT...AND IT LOOKS LIKE PRECIP WILL INITIATE ON THE NORTH 
COAST OF CA AROUND 00 UTC FRI.  THE 00-06 UTC FRI PERIOD SHOULD BE 
THE HEAVIEST IN NW CA WITH THE FRONT BEGINNING TO MOVE ONSHORE AND 
WITH PW VALUES AROUND 0.6-0.8" AND H85 WINDS OF 30-40 KNOTS AHEAD OF 
THE FRONT.  THE FINAL PERIOD SHOULD SEE PRECIP PUSHING INLAND INTO 
NE CA WITH SHOWERS ONGOING IN NW CA AS THE TROUGH AXIS SWINGS 
THROUGH THE REGION.  MAIN DIFFERENCES FROM HPC GUIDANCE WERE TO SLOW 
DOWN THE ONSET OF PRECIP IN THE 18 UTC THUR-00 UTC FRI PERIOD...BUMP 
UP RAIN AMOUNTS IN NW CA A BIT THUR NIGHT...AND SPREAD PRECIP 
FURTHER INLAND EARLY FRI MORNING.


DAY 1 QPF (TUE 24/12Z TO WED 25/12Z): DRY.

DAY 2 QPF (WED 25/12Z TO THU 26/12Z): DRY.

DAY 3 QPF (THU 26/12Z TO FRI 27/12Z): UP TO 0.25" MENDOCINO COAST... 
0.25-0.5" VAN DUZEN AND EEL BASINS...0.8-1.5" SMITH BASIN. 0.1-0.25" 
SRN CASCADES. A FEW HUNDREDTHS WEST SLOPES FAR NRN SIERRAS AND NE 
CA. VERY LIGHT AMOUNTS NORTH END OF SAC VALLEY.


.HYDROLOGICAL CONDITIONS...
LITTLE CHANGE ON THE RIVERS AND STREAMS IS EXPECTED THROUGH THE WEEK 
AS THE DRIER WEATHER PREVAILS.  ALL RIVER LEVELS ARE EXPECTED TO 
REMAIN BELOW MONITOR LEVELS THROUGH THE NEXT SEVERAL DAYS.

MORE INFORMATION ON THE CNRFC WEBSITE AT HTTP://WWW.CNRFC.NOAA.GOV

ME/KL/TLM

$$