FXUS66 KEKA 041159
AFDEKA
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE EUREKA CA
400 AM PST FRI DEC 4 2009
.SYNOPSIS...THE DRY AND WARM INLAND TEMPERATURES AS OF LATE WILL COME
TO AN ABRUPT END BY THIS WEEKEND. MUCH COOLER TEMPERATURES ARRIVE
THIS WEEKEND FOLLOWED BY A WETTER PATTERN RETURNING BY THE MIDDLE OF
NEXT WEEK.
&&
.DISCUSSION...SOME MID AND HIGH CLOUD COVER HAS TEMPERED MORNING
LOW TEMPERATURES ACROSS THE INTERIOR WHILE THE COAST REMAINS FAIRLY
CLEAR...EXCEPT FOR LOW CLOUDS AND FOG ONCE AGAIN FILLING IN AROUND
HUMBOLDT BAY. FORECAST MODELS STILL POINT TO SIGNIFICANT COOLING
BEGINNING AS EARLY AS TOMORROW MORNING. 850MB TEMPERATURES COOL AS
MUCH AS 5 DEGREES BY SATURDAY MORNING...FOLLOWED BY A MORE ABRUPT
DROP SUNDAY. THIS IS IN RESPONSE TO THE WELL ADVERTISED INSIDE
SLIDER TYPE OF LOW PRESSURE SYSTEM EXPECTED TO ARRIVE TO NORCAL
LATE THIS WEEKEND. BY MONDAY 850 TEMPS WILL NEAR -7C WHICH
TRANSLATES TO WELL BELOW FREEZING SURFACE TEMPS ACROSS MOST OF THE
INTERIOR WHILE THE COAST WILL SEE MORNING TEMPS IN THE MID TO HIGH
30S (OR LOWER)...FOLLOWED BY DAYTIME HIGHS NOT EXCEEDING THE HIGH
40S. HAVE DROPPED FORECAST TEMPS TO REFLECT THESE EXPECTED CHANGES.
FORECAST MODELS CONTINUE TO DOWNPLAY THE AMOUNT OF PRECIPITATION
ASSOCIATED WITH THIS SYSTEM HOWEVER CANNOT RULE OUT SOME SHOWER
ACTIVITY AS THE LOW PASSES OVERHEAD. SNOW LEVELS WILL FALL TO 2500
FT THIS WEEKEND WHILE DURING THE LATE NIGHT AND EARLY MORNING HOURS
SNOW LEVELS COULD FALL AS LOW AS 1000 FT. DO NOT ANTICIPATE ANY
SIGNIFICANT AMOUNTS SNOW BUT A DUSTING TO AN INCH OR TWO AT OR ABOVE
THESE ELEVATIONS WOULD NOT BE UNREASONABLE.
LATER ON MONDAY THE TROUGH AXIS SHIFTS SOUTH WITH A DRIER NORTHERLY
FLOW TAKING OVER. A SHORTWAVE RIDGE THEN MOVES OVERHEAD FOR TUE
WHILE A SERIES OF STORMS LINE UP IN THE CENTRAL PACIFIC. MORE
SEASONABLE TEMPERATURES ARE ANTICIPATED AS THE FLOW BECOMES MORE
WESTERLY. THESE STORMS MAY CONTRIBUTE COPIOUS AMOUNTS OF RAIN LATE
NEXT WEEK HOWEVER SNOW LEVELS SHOULD REMAIN FAIRLY HIGH (>4500 FEET).
&&
.MARINE...WINDS OVER THE WATERS WILL REMAIN LIGHT TODAY BUT WILL
BEGIN TO INCREASE FROM THE NORTH AS HIGH PRESSURE PUSHES TOWARD THE
PACIFIC NORTHWEST. SMALL CRAFT ADVISORY CONDITIONS ARE EXPECTED FOR
ALL AREAS BEGINNING SATURDAY MORNING...WITH WINDS SOLID 25 KT OVER
THE OUTER WATERS AND SHORTER PERIOD SEAS BUILDING TO NEAR 6 FT IN
THE NEARSHORE WATERS. MODEL UNCERTAINTY CONTINUES FOR THE PERIOD
BEGINNING EARLY NEXT WEEK...HOWEVER ALL INDICATE THAT A SERIES OF
LOW PRESSURE SYSTEMS WILL AFFECT THE WATERS THROUGH THE WEEK. THE
FIRST IS EXPECTED AROUND TUESDAY WITH A STRONGER SYSTEM POSSIBLE
LATER IN THE WEEK. CC
&&
.AVIATION...PATCHY STRATUS AND FOG CONTINUE TO PLAGUE COASTAL AREAS
THIS MORNING. CONDITIONS CURRENTLY RANGE FROM VFR TO MVFR...BUT
OCCASIONAL DIPS TO IFR ARE EXPECTED TO OCCUR THROUGH MID MORNING.
INCREASING N WINDS THIS EVENING WILL HELP TO MIX THE MARINE
LAYER...RESULTING IN FEWER COASTAL RESTRICTIONS IN CIGS/VSBY
TONIGHT. INLAND AREAS WILL REMAIN VFR.
&&
.EKA WATCHES/WARNINGS/ADVISORIES...
SCA PZZ470...PZZ475.
&&
$$
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