FXUS66 KSTO 011021
AFDSTO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
230 AM PST TUE DEC 1 2009
.DISCUSSION...
HIGH PRESSURE REMAINS ENTRENCHED OVER THE REGION. A WEAK SYSTEM NEAR
35N AND 137W WILL SPREAD SOME HIGH CLOUDS OVER THE REGION TODAY AND
TONIGHT. THE SYSTEM IS PROGGED TO FALL APART AS IT TRIES TO
UNDERCUT THE RIDGE OVER THE NEXT DAY OR SO. TEMPERATURES TODAY WILL
BE NEAR YESTERDAYS HIGHS IN THE MOUNTAINS AND FOOTHILLS WITH MOST
VALLEY LOCATIONS A DEGREE OR SO COOLER. EXPECT TEMPERATURES TO RANGE
FROM THE UPPER 50S TO LOWER 60S IN THE CENTRAL VALLEY.
COLD MORNINGS WILL CONTINUE THIS WEEK WITH MOST VALLEY TEMPERATURES
COOLING INTO THE 30S AT NIGHT. THIS MORNING LOOKS TO BE THE COLDEST
MORNING OF THE NEXT SEVERAL WITH SOME PATCHES OF FROST FORMING IN
THE VALLEY THIS MORNING. SOME RURAL AREAS INCLUDING PARTS OF THE
DELTA COULD SEE SOME FREEZING TEMPERATURES AGAIN TONIGHT. SOME
PATCHES OF FOG SHOULD FORM FROM AROUND MARYSVILLE SOUTHWARD THE NEXT
COUPLE OF MORNINGS. ISOLATED AREAS OF DENSE FOG WILL BE POSSIBLE THE
NEXT SEVERAL NIGHTS. A FEW PATCHES OF FROST MAY THE NEXT SEVERAL
MORNINGS BUT NOT MUCH IS EXPECTED TO FORM ON THE GROUND OUTSIDE OF
SOME ISOLATED PATCHES POSSIBLE IN THE DELTA AND OVER SOME RURAL
AREAS.
GFS IS THE ODD MODEL OUT THIS MORNING WITH THE CANADIAN AND EUROPEAN
MODELS IN BETTER AGREEMENT ON FRIDAY AND SATURDAY. THE GFS
KEEPS AN AMPLIFIED RIDGE ALONG THE COAST WHILE THE OTHER TWO MODELS
INDICATE A WEAK SYSTEM MOVING OVER THE PACIFIC NORTHWEST ON FRIDAY
AND THEN DROPPING DOWN OVER THE REGION ON SATURDAY TO BRING A CHANCE
OF SHOWERS FOR PORTIONS OF NORTHERN CALIFORNIA.
.EXTENDED DISCUSSION (SUNDAY THRU WEDNESDAY)...
STILL DIFFICULT TO NAIL DOWN DETAILS FOR THE EXTENDED. GFS AS
MENTIONED ABOVE HAS BECOME THE OUTLIER KEEPING A HIGH AMPLITUDE
RIDGE OVER THE WEST COAST AS A LOW PRESSURE SYSTEM SLIDES TOWARDS
THE GREAT BASIN ON SUNDAY. THIS WOULD KEEP OUR CWA ON THE DRIER
SIDE. HOWEVER...THE ECMWF AND GEM MODELS STILL INDICATE A WETTER
PATTERN FOR NORTHERN AND CENTRAL CALIFORNIA. LOW PRESSURE
UNDERCUTTING THE RIDGE EXPECTED TO DRAG SUB-TROPICAL MOISTURE INTO
THE STATE WITH LINGERING PRECIPITATION INTO TUESDAY. LEANED TOWARDS
THE WETTER SOLUTION IN THE EXTENDED. JBB
&&
.AVIATION...
PATCHY FOG WILL ONCE AGAIN AFFECT PORTIONS OF THE CENTRAL SAC AND
NORTHERN SAN JOAQUIN VALLEYS...EXPECT PERIODS OF MVFR/IFR CONDS
BETWEEN NOW AND 17Z FOR THE KSMF-KMOD VCNTY. WINDS WILL REMAIN VERY
LIGHT FOR THE NEXT 24 HOURS...ONE OF THE CONTRIBUTING FACTORS TO FOG
DEVELOPMENT THIS MORNING. JBB
&&
.STO WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
