FXUS66 KSTO 010530
AFDSTO
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
930 PM PST MON NOV 30 2009
.DISCUSSION...
UPPER LEVEL HIGH PRESS RIDGE OVER THE EASTERN PACIFIC AND WEST COAST
BRINGING FAIR SKIES TO THE REGION AND EXPECTED TO CONTINUE TO DO SO
FOR THE REMAINDER OF THE WORK WEEK. WEAK FRONTAL BAND DRAGGING
ACROSS THE NORTHEASTERN PORTION OF THE RIDGE AND THROUGH THE PACIFIC
NORTHWEST BRINGING SOME HIGH CLOUDINESS ACROSS THE NORTHERN ZONES
THIS EVENING BUT UNLIKELY TO HAVE SIGNIFICANT IMPACT ON OVERNIGHT
TEMPERATURES OR FOG CONDITIONS. HIGH TEMPERATURES TODAY RAN A FEW TO
SEVERAL DEGREES BELOW SUNDAY AND STILL RUNNING A FEW DEGREES BELOW
24 HOURS AGO. EXCEPTION IS THE NORTHERN SACRAMENTO VALLEY WHERE A
LIGHTER WIND AND LACK OF ADIABATIC WARMING ARE ALLOWING TEMPERATURES
IN REDDING AND RED BLUFF TO BE 19 AND 14 DEGREES COOLER RESPECTIVELY
THAN 24 HOURS AGO. BY THE EARLY MORNING HOURS THIS MORNING...WINDS
WERE FAIRLY LIGHT AND LIKELY TO BE SO AGAIN TONIGHT UNDER LIGHT
SURFACE GRADIENTS. WITH SLIGHTLY COOLER AIRMASS...SHOULD SEE
OVERNIGHT LOWS JUST A BIT BELOW THIS MORNINGS. OVERNIGHT MINS LOOK
OKAY AND NO UPDATES EXPECTED. MAIN OVERNIGHT CONCERN WILL BE PATCHY
FOG DEVELOPMENT. COOLER TEMPERATURES AND HIGHER DEW POINTS WILL
INCREASE LIKELIHOOD OF VALLEY FOG DEVELOPMENT. DEW POINT
TEMPERATURES IN THE CENTRAL VALLEY ARE MAINLY IN THE 30S SO NOT
EXPECTING DENSE FOG.
UPPER RIDGE BUILDS A BIT ON TUESDAY FOR A LITTLE WARMING. A SHORT
WAVE NEARING 35N/140W IS FORECAST TO DISSIPATE AS IT RUNS INTO THE
EASTERN PACIFIC RIDGE WEDNESDAY AND THURSDAY. THIS FIRST ATTEMPT AT
UNDERCUTTING THE RIDGE LOOKS TO BE A VERY UNSUCCESSFUL ATTEMPT. IN
FACT...MAX TEMPERATURES THESE DAYS AND FRIDAY ARE FORECAST TO
REMAIN RELATIVELY FLAT. THIS MAY NOT BE THE CASE FOR NEXT WEEKEND
AS BOTH THE GFS AND ECMWF SHOW BREAK DOWN OF THE RIDGE...BUT DIFFER
SIGNIFICANTLY ON HOW WET IT MAY BE IN NORCAL. WHILE THE GFS BRINGS A
COLD AIR LOW DOWN FROM THE ARCTIC...THE ECMWF BRINGS IT IN FROM THE
GULF OF AK...AND IS MUCH WETTER AS MOISTURE FROM TYPHOON NIDA
CURRENTLY NEAR 140E MAY BECOME ENTRAINED INTO THE UNDERCUTTING FLOW.
THEREFORE THERE IS A HIGH DEGREE OF UNCERTAINTY INVOLVED IN THE THE
FORECASTS FOR THE UPCOMING WEEKEND. SMITH
&&
.AVIATION...
UPR RDG CONTS OVR NORCAL WITH NWLY FLOW ALF. VFR CONDS OVR INTR
NORCAL EXC AREAS OF MVFR IN BR FM VCNTY KMYV SWD AFT 07Z TIL ARND
18-20Z WITH LCL LIFR POSS IN FOG BTWN 10Z-17Z FM SACRAMENTO AREA SWD
INTO PTNS OF NRN SAN JOAQUIN VLY.
&&
.STO WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
