FXUS66 KSEW 232219

AFDSEW



AREA FORECAST DISCUSSION

NATIONAL WEATHER SERVICE SEATTLE WA

220 PM PST FRI JAN 23 2015



.SYNOPSIS...EXPECT RAIN AT TIMES ACROSS WESTERN WASHINGTON TONIGHT 

AS A WARM FRONT MOVES ACROSS THE AREA. THE WARM FRONT WILL SHIFT 

NORTH INTO BRITISH COLUMBIA ON SATURDAY WITH RAIN TAPERING OFF. AN 

UPPER LEVEL RIDGE WILL GIVE DRY AND MILD WEATHER TO THE AREA SUNDAY 

AND MONDAY. LIGHT SHOWERS ARE LIKELY LATER TUESDAY INTO THURSDAY AS 

A COUPLE OF WEAK FRONTS MOVE ACROSS THE AREA. 



&&



.SHORT TERM...SATELLITE IMAGERY AND OBSERVATIONS SHOW A WARM FRONT 

OVER THE OFFSHORE WATERS. THIS FRONT WILL LIFT NE ACROSS WESTERN 

WASHINGTON THIS EVENING. ANOTHER WARM FRONT APPEARS FROM THE CENTRAL 

OREGON OFFSHORE WATERS TO A 999 MB LOW NEAR 41N 139W. THIS SECOND 

WARM FRONT WILL MOVE NE ACROSS THE EARLY SATURDAY MORNING. 



RAINFALL RATES WITH THE FIRST WARM FRONTAL FEATURE HAVE BEEN BETWEEN 

0.25 AND 0.35 INCHES PER HOUR OVER THE WESTERN OLYMPIC PENINSULA. 

KLGX RADAR SHOWS THE PRECIPITATION TAPERING OFF FROM THE WEST AS THE 

WARM FRONT MOVES INLAND LATE THIS AFTERNOON. POES AMSU RAINFALL 

RATES CENTERED NEAR THE TRIPLE POINT OF THE SECOND FRONT AT 42N 139W 

AT 20Z ARE BETWEEN 0.75 AND 1 INCH PER HOUR. THE 20Z HRRR MODEL 

BRINGS THIS BATCH OF SHOWERS TO THE SOUTHWEST FACING OLYMPICS 

BETWEEN 05Z AND 09Z AND GIVES ABOUT 1.5 INCHES OF RAIN DURING THAT 

PERIOD TO THE AREA WEST OF QUEETS. RAIN WILL GRADUALLY TAPER OFF 

THEN COME TO AN END FROM THE SOUTH ON SATURDAY AS THE SECOND WARM 

FRONT MOVES NORTH INTO BRITISH COLUMBIA AND STRONG UPPER LEVEL 

RIDGING DEVELOPS OVER WASHINGTON.



TEMPERATURES TONIGHT AND SATURDAY WILL BE MILD. DESPITE THE DRIPS OF 

PRECIPITATION AND THE CLOUDS HIGH TEMPERATURES WILL LIKELY RISE INTO 

THE MID AND UPPER 50S ACROSS THE AREA. AS CLOUDS DECREASE SATURDAY 

NIGHT...EXPECT SOME FOG TO FORM OVER THE VALLEYS OF THE SOUTH 

INTERIOR. THEN SUNDAY SHOULD BE A VERY NICE DAY FOR LATE JANUARY AS 

TEMPERATURES RISE TO AROUND 60 DEGREES UNDER PARTLY TO MOSTLY SUNNY 

SKIES. MONDAY MORNING WILL LIKELY SEE MORE FOG AROUND THE AREA. 

TEMPERATURES MONDAY WILL LIKELY BE WARM AGAIN...HOW WARM WILL DEPEND 

ON WHEN FOG BURNS OFF MIDDAY. BUT ANOTHER DAY NEAR 60 LOOKS LIKELY 

ACROSS MOST OF THE AREA. ALBRECHT 



.LONG TERM...A VERY WEAK FRONT AND ASSOCIATED WEAK SHORT WAVE TROUGH 

ALOFT WILL MOVE THROUGH THE AREA LATE TUESDAY INTO WEDNESDAY AND 

WILL LIKELY BE FOLLOWED BY ANOTHER WEAK FRONT WEDNESDAY NIGHT INTO 

THURSDAY. TEMPERATURES ALOFT WILL BE WARM THROUGH THE PERIOD...SO 

SNOW LEVELS IN THE MOUNTAINS WILL REMAIN RATHER HIGH...6000 FEET ON 

TUESDAY FALLING TO AROUND 4000 FEET BY THURSDAY. IF YOU LIKE RIDGES 

AND MILD WEATHER THIS TIME OF YEAR...THE PATTERN APPEARS TO BE 

SETTING UP FOR A REDEVELOPING RIDGE LATE NEXT WEEK INTO NEXT WEEKEND 

WITH LIGHT LOW LEVEL OFFSHORE FLOW AND QUITE MILD CONDITIONS FOR 

LATE JANUARY. ALBRECHT



&&



.HYDROLOGY...THERE IS ONLY A LOW CHANCE OF MINOR FLOODING ON THE 

SKOKOMISH RIVER NEAR POTLATCH TONIGHT INTO SATURDAY MORNING. BUT AT 

THIS TIME IT APPEARS THAT RAINFALL AMOUNTS WILL BE INSUFFICIENT TO 

DRIVE THE RIVER ABOVE FLOOD STAGE. ELSEWHERE...FLOODING IS NOT 

EXPECTED OVER THE NEXT 7 DAYS. ALBRECHT    



&&



.AVIATION...WESTERLY FLOW ALOFT WILL CONTINUE TONIGHT. A WARM FRONT 

OVER THE AREA WILL WEAKEN TONIGHT THEN MOVE NORTH ON SATURDAY AS AN 

UPPER RIDGE BUILDS. AT THE SURFACE MODERATE SOUTHEAST FLOW WILL 

WEAKEN SLOWLY TONIGHT AND SATURDAY. AIR MASS MOIST AND STABLE. 



FRONT IS ALREADY VISIBLY WEAKENING ON RADAR. CEILINGS HAVE IMPROVED 

SLIGHTLY FROM LATE THIS MORNING WITH MOST CEILINGS 2-3K FT AND 

MOSTLY VFR VISIBILITIES. MORE CLOUD DECKS EXIST BOTH ABOVE AND 

BELOW. EXCURSIONS INTO BOTH IFR AND VFR ARE LIKELY THIS EVENING. 

MODELS SHOW A SECONDARY IMPULSE 06Z-12Z THAT WILL LIKELY BRING LOWER 

CEILINGS AND VISIBILITIES...PROBABLY 1-2K FT WITH 3-5SM IN RAIN. 

SIGNIFICANT IMPROVEMENT WILL OCCUR ON SATURDAY AS THE FRONT MOVES 

NORTH.



KSEA...DISCUSSION ABOVE APPLIES. MAINLY MVFR TONIGHT WITH POTENTIAL 

FOR VFR SATURDAY. SOUTHERLY WIND 4-8 KT WILL INCREASE TO 8-12 KT 

THIS EVENING. CHB



&&



.MARINE...A WARM FRONT WILL WEAKEN OVER THE AREA TONIGHT THEN MOVE 

NORTH ON SATURDAY. SURFACE HIGH PRESSURE WILL BUILD FROM THE SOUTH 

SATURDAY AND SATURDAY NIGHT WITH THE LOW LEVEL FLOW BECOMING LIGHT 

OFFSHORE ON SUNDAY. THE LIGHT OFFSHORE FLOW PATTERN WILL CONTINUE 

INTO MONDAY. SMALL CRAFT ADVISORY WINDS WILL OCCUR AT TIMES OVER ALL 

WATERS EXCEPT THE CENTRAL STRAIT THROUGH SATURDAY AFTERNOON. WINDS 

WILL EASE ACROSS THE WATERS SATURDAY NIGHT WITH LIGHT WINDS SUNDAY. 

A WEAK FRONT MAY MOVE INTO THE AREA TUESDAY.



KING TIDES...THE HIGHEST HIGH TIDES OF THE YEAR...ARE OCCURRING. THE 

FORECAST HIGH TIDES FOR SEATTLE THIS MORNING AND SATURDAY MORNING 

ARE 13.2 FEET. MINOR TIDAL OVERFLOW STARTS AT 13.5 FEET. SEA LEVEL 

PRESSURE WAS QUITE HIGH THIS MORNING...AROUND 1030 MB...WITH LIGHT 

WINDS. THIS GAVE A NEGATIVE TIDAL ANOMALY OF 0.8 FEET DURING THE 

TIME OF HIGH TIDE AT 710 AM THIS MORNING. THE HIGH TIDE ENDED UP 

BEING ONLY 12.4 FEET. 



SIMILAR METEOROLOGICAL CONDITIONS ARE EXPECTED DURING THE SATURDAY 

MORNING HIGH TIDE AT 750 AM. THERE WILL BE A NEGATIVE TIDAL ANOMALY 

AND THE UPSHOT IS MINOR TIDAL OVERFLOW IS NOT EXPECTED ON SATURDAY 

EITHER. CHB



&&



.SEW WATCHES/WARNINGS/ADVISORIES...

WA...NONE.

PZ...SMALL CRAFT ADVISORY ALL WATERS EXCEPT THE CENTRAL STRAIT.   

     SMALL CRAFT ADVISORY FOR ROUGH BAR CONDITIONS GRAYS HARBOR BAR. 



&&



$$



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