320 
FXUS66 KSTO 190424
AFDSTO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
924 PM PDT MON MAR 18 2013

.SHORT TERM DISCUSSION...

OVERNIGHT CLOUDY SKIES WITH MOISTURE STREAMING IN FROM THE WEST
MAY PRODUCE A FEW FLURRIES IN THE MOUNTAINS. THE APPROACHING WARM
SYSTEM MAY START TO SPREAD SOME RAIN OVER THE FAR NORTHERN PARTS
OF THE SACRAMENTO VALLEY AND SURROUND MOUNTAINS AND FOOTHILLS
TUESDAY MORNING WITH THE BULK OF THE SYSTEM STILL EXPECTED TUESDAY
NIGHT FOR ALL AREAS...EXCEPT CONTINUING THROUGH WEDNESDAY MORNING
FOR THE WESTERN SLOPES. THE RAIN SHOULD BE CHANGING TO SHOWERS BY
WEDNESDAY MORNING IN THE VALLEY AND BY LATE MORNING TO EARLY
AFTERNOON FOR THE SIERRA NEVADA. THERE IS STILL SOME DISAGREEMENT
WITH THE TIMING OF THE ONSET OF PRECIPITATION AND AMOUNTS WITH THE
GFS CONTINUING TO BE THE WETTER ONE. IN GENERAL THEY DO PAINT A
WET PICTURE FOR TUESDAY NIGHT TAPERING TO SHOWERS EITHER BY OR
DURING THE DAY ON WEDNESDAY.

THE RAINFALL AMOUNTS ARE NOT LOOKING THAT GREAT WITH THIS SYSTEM
FOR THE VALLEY WITH AMOUNTS AROUND A QUARTER TO HALF AND INCH.
SNOW LEVELS LOOK HIGH BUT RESORT AREAS ABOVE 8000 FEET MAY BE
ABLE TO GET SOME DECENT AMOUNTS. NEAR PASS LEVELS IN THE SIERRA
NEVADA WE ARE EXPECTING BETWEEN 3 AND 6 INCHES OUT OF THIS
TAPERING TO ONLY MINOR ACCUMULATIONS DOWN TO NEAR 6000 FEET FOR
THE SIERRA NEVADA AND TO AROUND 5500 FEET OVER SHASTA COUNTY.

THE SHOWERS WILL BE ENDING WEDNESDAY EVENING FOR MOST AREAS WITH
ONLY LINGERING SHOWERS OVER THE SIERRA NEVADA INTO THE LATE NIGHT
HOURS. NORTHERLY WINDS WILL DEVELOP BEHIND THE SYSTEM FOR THURSDAY
AND FRIDAY. AT THIS TIME THEY DO NOT LOOK THAT STRONG FOR THURSDAY
BUT CONDITIONS IN THE VALLEY COULD BECOME BREEZY ON FRIDAY.

.EXTENDED DISCUSSION (FRIDAY THROUGH MONDAY)

NORTHERN CALIFORNIA WILL RESIDE IN NORTHWESTERLY FLOW ALOFT FOR
THE LATTER HALF OF NEXT WEEK BETWEEN AN EASTERN PACIFIC RIDGE AND
A MEAN TROUGH ACROSS THE ROCKIES. THIS WILL BRING MILD AND DRY
WEATHER THIS WEEKEND. LOOK FOR HIGH TEMPERATURES ROUGHLY 10
DEGREES ABOVE NORMAL...WITH 70S ACROSS THE VALLEY AND 50S AND 60S
OVER THE MOUNTAINS.

THE 12Z GFS AND EC HINT AT A 'DIRTY RIDGE' SETUP LATE SAT WITH A
WEAK SHORTWAVE AND SOME MOISTURE MOVING THROUGH THE
RIDGE...HOWEVER RUN-TO-RUN CONSISTENCY IS POOR WITH THIS FEATURE
AND THIS IS NOT A GOOD PRECIP-GENERATING PATTERN. HAVE LEFT SOME
SLIGHT CHANCE SHOWERS SAT NIGHT OVER THE SHASTA CO MOUNTAINS.

THE GFS ENSEMBLE HINTS AT A TROUGH NEARING THE COAST SOMETIME
NEXT WEEK. THE 12Z EC MEANWHILE HOLDS ONTO A WEST COAST RIDGE.
WITH UNCERTAINTY IN THE FORECAST HAVE TRENDED TOWARDS CLIMO POPS
EARLY NEXT WEEK. -DVC


&&

.AVIATION...

GENERALLY VFR CONDITIONS WITH MID AND HIGH CLOUDS AS A WEAK WAVE
MOVES THROUGH TONIGHT AND A STRONGER SYSTEM APPROACHES DURING THE
DAY TUESDAY. CEILINGS WILL LOWER BY THE AFTERNOON AS THE NEXT
WEATHER SYSTEM APPROACHES THE AREA POSSIBLY BRINGING MVFR
CONDITIONS TO THE NORTHERN SACRAMENTO VALLEY AFT 20Z. A SLIGHT
CHANCE OF SHOWERS TONIGHT OVER THE SIERRA WITH THE WEAK WAVE
MOVING THROUGH. WIDESPREAD PRECIPITATION THREAT INCREASES DURING
THE DAY TUESDAY FOR AREAS NORTH OF INTERSTATE 80. SOUTHERLY WINDS WILL
ALSO INCREASE TUESDAY AFTERNOON AND EVENING.


&&

.STO WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$