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000
FXUS66 KEKA 072305
AFDEKA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE EUREKA CA
305 PM PST FRI MAR 7 2014

.SYNOPSIS...HIGH PRESSURE WILL BRING MAINLY DRY WEATHER THROUGH
SATURDAY MORNING. A FRONT WILL PUSH IN FROM THE NORTHWEST AND
STALL OVER NORTHWEST CALIFORNIA SATURDAY NIGHT WITH MODERATE TO
HEAVY RAIN THROUGH SUNDAY.

&&

.DISCUSSION...HIGH PRESSURE IS BRINGING CLEAR SKIES ACROSS MUCH OF
THE AREA THIS AFTERNOON. THERE WAS FAIRLY WIDESPREAD LOW CLOUDS
AND FOG THIS MORNING...HOWEVER THE MAJORITY OF THIS CLEARED OUT BY
NOON. TONIGHT ADDITIONAL FOG AND LOW CLOUDS ARE POSSIBLE OVER
INLAND VALLEYS. SOUTHERLY WINDS WILL START TO PICK UP TOWARD MORNING
SO THE LOW CLOUDS MAY CLEAR OUT A BIT EARLIER...BUT AT THE SAME
TIME HIGH CLOUDS WILL START TO MOVE OVER THE AREA. VIS SAT SHOWS
SOME PATCHES OF LOW CLOUDS OFF THE COAST. AT THE COAST WIND WILL
BE OUT OF THE WEST FOR A PERIOD OF TIME THIS EVENING BEFORE THE
SOUTHERLY WINDS START TO KICK IN. THIS MAY ALLOW SOME OF THESE LOW
CLOUDS AND FOG TO MOVE ONTO THE REDWOOD COAST. THE CLOUDS WILL
LIKELY MOVE BACK OUT TO SEA ONCE THE SOUTHERLY WINDS KICK IN.
INLAND VALLEYS OF MENDOCINO COUNTY WERE IN THE MID TO UPPER 30S
THIS MORNING. WITH TEMPERATURES WARMING ALOFT AND PATCHY FOG
EXPECTED AGAIN...IT APPEARS THAT ANY FROST COVERAGE WILL BE FAIRLY
MINIMAL. SO WILL CONTINUE WITH FROST MENTIONED IN THE HWO AND A
FEW LOCAL AREAS IN THE GRIDS.

SATURDAY AFTERNOON THE FRONTAL BOUNDARY STARTS TO MAKE ITS WAY
ONSHORE. LATE AFTERNOON THE RAIN IS EXPECTED TO START IN CRESCENT
CITY AND SLOWLY MAKE ITS WAY SOUTH OVERNIGHT. IN THE EVENING
RAINFALL WILL LIKELY BE LIGHT IN THE HUMBOLDT BAY AREA DUE TO THE
DOWN-SLOPING....ALTHOUGH THE WINDS ARE NOT LOOKING PARTICULARLY
STRONG SO THERE SHOULD BE SOME RAIN. THE FRONT APPEARS TO RUN
INTO THE RIDGE AND STALL OUT OVER THE AREA FOR 12 TO 18 HOURS.
THIS SYSTEM LOOKS WARM WITH SNOW LEVELS UP AROUND 8000 FEET. THIS
SYSTEM ALSO HAS A NICE TROPICAL FEED AND MAINLY WARM RAIN
PROCESSES SO RAINFALL AMOUNTS MAY BE HIGHER IN FAVORED AREAS THAN
EXPECTED. THERE MAY BE SOME BREAKS IN THE RAIN AND PERIODS OF
HEAVIER RAIN AS DIFFERENT IMPULSES MOVE ALONG THE FRONT. RAINFALL
AMOUNTS THROUGH MONDAY MORNING WILL RANGE FROM TWO TO FOUR INCHES
OVER MOST OF NW CA. HIGHER AMOUNTS WILL BE FOUND IN DEL NORTE
COUNTY, AND THE W/SW- FACING RIDGES LIKE THE KING RANGE, SOUTH
FORK MTN, AND THE SISKIYOUS, WHERE THREE TO SIX INCHES CAN BE
EXPECTED. AMOUNTS OVER ERN TRINITY AND HUMBOLDT BAY WILL STRUGGLE
TO REACH 2 INCHES DUE TO DOWN-SLOPING, AND SRN MENDOCINO WILL SEE
CLOSER TO AN INCH.

SUNDAY NIGHT INTO MONDAY MORNING MODELS ARE STRUGGLING WITH THE
STRENGTH AND TIMING OF THE POST FRONTAL TROUGH. THE MOST RECENT
GFS AND ECMWF ARE FINALLY COMING INTO LINE WITH EACH OTHER. THIS
BRINGS A MODERATE TROUGH OVER THE AREA MONDAY MORNING. THERE IS
SOME MODERATE INSTABILITY WITH THIS TROUGH WHICH COULD GENERATE
SOME LIGHTNING STRIKES...ALTHOUGH AT THIS POINT CONFIDENCE IS TOO
LOW TO ADD THUNDERSTORMS TO THE FORECAST. TEMPERATURES AT 500 MB
LOOK MARGINAL AT BEST FOR SMALL HAIL...ALTHOUGH THE GFS HAS BEEN
TRENDING DEEPER AND COLDER WITH THIS TROUGH. THIS WILL NEED TO BE
MONITORED.

TUESDAY MODELS ARE IN DECENT AGREEMENT ON THE RIDGE BUILDING BACK
INTO THE AREA. MODELS ARE SLIGHTLY DIFFERENT IN THE STRENGTH...BUT
OVERALL THE IDEA OF A RIDGE IS FAIRLY CERTAIN. THIS WILL LIKELY
ALLOW GOOD RADIATIONAL COOLING AND POSSIBLY SOME FROST MONDAY NIGHT
INTO TUESDAY MORNING. THERE MAY BE WIDESPREAD LOW CLOUDS AND FOG
ACROSS THE VALLEYS AS WELL.

WEDNESDAY MORNING COULD BE ANOTHER CANDIDATE FOR FROST...ALTHOUGH
CONFIDENCE IS LOWER. THE GFS IS SHOWING A WEAK TROUGH MOVING INTO
THE PACIFIC NORTHWEST WHILE THE ECMWF IS KEEPING THE RIDGE OVER
NORTHWEST CALIFORNIA. THURSDAY AND FRIDAY BOTH MODELS FLATTEN THE
RIDGE A BIT...ALTHOUGH KEEP US MAINLY DRY. KEPT SOME SLIGHT
CHANCE POPS IN THE FAR NORTH IN CASE THESE SYSTEMS DEEPEN. THE
MODELS ARE STRUGGLING WITH THE PATTERN...BUT AT THIS POINT NO
SIGNIFICANT RAINFALL IS EXPECTED. MKK

&&

.AVIATION...VFR CONDITIONS ARE PRESENT ACROSS ALL OF NORTHWESTERN
CALIFORNIA THIS AFTERNOON AS UPPER LEVEL RIDGING DOMINATES THE
WEATHER PATTERN. HOWEVER...AS A STORM SYSTEM BEGINS TO BREAK DOWN
THE RIDGE OVERNIGHT SOME LOW CLOUDS MAY FORM ALONG THE COAST. THESE
CLOUDS SHOULD BE ISOLATED SO VFR HAS BEEN MAINTAINED IN THE TAFS.
ADDITIONALLY...RADIATIONAL COOLING WILL LIKELY ALLOW LOW CLOUDS TO
FORM IN INTERIOR VALLEYS RESULTING IN CONDITIONS POSSIBLY AS LOW AS
IFR.

AS SOUTHERLY WINDS INCREASE ALONG THE COAST SATURDAY MORNING ANY
COASTAL CLOUDS SHOULD DISSIPATE. RAIN WILL BEGIN TO APPROACH THE
COAST LATE SATURDAY AFTERNOON ACROSS THE NORTH BRINGING LOWERING
CIGS AND POSSIBLE VISIBILITY RESTRICTIONS. THE HEAVIEST RAIN AND
WORST CONDITIONS WILL HOLD OFF UNTIL SATURDAY NIGHT AND SUNDAY JUST
AHEAD OF THE COLD FRONTAL PASSAGE. RPA


&&

.MARINE...LIGHT WINDS AND SUBSIDING SEAS ARE PRESENT ACROSS THE
WATERS THIS AFTERNOON. THE WEST SWELL SHOULD SUBSIDE TO NEAR 6 FEET
OVERNIGHT BEFORE SOUTHERLY WINDS BEGIN TO INCREASE AHEAD OF THE NEXT
STORM SYSTEM. EXPECTING NEAR GALE CONDITIONS IN THE NORTHERN OUTER
WATERS JUST AHEAD OF A COLD FRONTAL PASSAGE SATURDAY NIGHT INTO
EARLY SUNDAY. MODEL 925 MB WINDS 45 TO 55 KT IN THE EXTREME NORTHERN
AND NORTHWESTERN PORTION OF THE WATERS MAY ALLOW SOME GUSTS OVER 35
KT...BUT IN GENERAL CONDITIONS SHOULD REMAIN BELOW GALE. THUS SMALL
CRAFT ADVISORIES HAVE BEEN RAISED FOR ALL ZONES EXCEPT THE SOUTHERN
INNER WATERS. A LARGE WESTERLY SWELL IS FORECAST TO BUILD INTO THE
WATERS SATURDAY NIGHT WITH THE ADVANCING FRONT WHICH WILL LIKELY
PUSH THE SOUTHERN INNER WATERS INTO SMALL CRAFT CRITERIA FOR A
PERIOD SATURDAY NIGHT INTO SUNDAY...BUT UNCERTAINTY WITH THE
MAGNITUDE AND TIMING OF THE SWELL PRECLUDES ISSUANCE OF A SMALL
CRAFT ADVISORY AT THIS TIME.

THE COLD FRONT WILL STALL OUT OVER THE WATERS SUNDAY ALLOWING A
SECONDARY LOW PRESSURE SYSTEM TO SLIDE UP THE FRONT INTO THE
WATERS. MODEL GUIDANCE INDICATES THE LOW WILL REMAIN RELATIVELY
WEAK LEAVING ONLY SMALL CRAFT WINDS OVER THE WATERS. THE FRONT
WILL FINALLY SLIDE SOUTH SUNDAY NIGHT INTO MONDAY ALLOWING
NORTHERLY WINDS TO INCREASE. MODELS ARE FAIRLY CONSISTENT NOW IN
STRONG NORTHERLIES DEVELOPING...ESPECIALLY OVER THE OUTER
WATERS...RESULTING FROM HIGH PRESSURE BUILDING OVER THE EASTERN
PACIFIC BEHIND THE FRONT AND LOW PRESSURE MOVING SLOWLY INLAND.
THUS THE SMALL CRAFT ADVISORY FOR THE SOUTHERN WATERS HAS BEEN
ISSUED ALL THE WAY THROUGH TUESDAY NIGHT WITH NO APPRECIABLE BREAK
IN SMALL CRAFT CONDITIONS EXPECTED BETWEEN THE WESTERLY SWELL AND
NORTHERLY WIND DEVELOPMENT. RPA


&&

.EKA WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
NORTHWEST CALIFORNIA COASTAL WATERS...NONE.
&&

$$

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