Area Forecast Discussion
Issued by NWS Seattle/Tacoma, WA

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000
FXUS66 KSEW 141730
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
930 AM PST SUN FEB 14 2016

.SYNOPSIS...MILD AND WET WESTERLY FLOW ALOFT WILL PERSIST OVER THE
AREA THROUGH TUESDAY FOR LOCALLY HEAVY RAIN AT TIMES. TEMPERATURES
WILL BE ABOVE NORMAL.

&&

.SHORT TERM...STRONG MOIST WESTERLY FLOW CONTINUES ACROSS WESTERN
WASHINGTON TODAY FOR MORE RAIN ACROSS THE CWA. BUT THERE WILL BE A
FEW BREAKS AS WELL...BOTH SEEN IN THE RADAR AND IN THE IR. THE AIR
MASS IS MILD AND TEMPS WILL RISE A FEW DEGREES WITH HIGHS IN THE
LOWER TO MID 50S. SNOW LEVELS ARE RISING TO 5000-7000 FT FOR RAIN IN
THE PASSES.

RAIN WILL INCREASE TONIGHT INTO MONDAY AS THE NEXT WAVE
ARRIVES...CURRENTLY BACK OF 140W. A DEEP MOISTURE PLUME AND STRONG
WESTERLY UPSLOPE FLOW WILL LEAD TO HEAVY RAIN ACROSS THE WEST SLOPES
OF THE MOUNTAINS...ESPECIALLY THE CENTRAL AND NORTHERN CASCADES.
RIVERS WILL BE RISING AND A FEW RIVERS WILL BE CLOSE TO FLOOD STAGE.
MODELS SHOW THE WARM FRONTAL BAND WAVERING BETWEEN SOUTHERN B.C. AND
WESTERN WA MONDAY NIGHT...SHIFTING THE HEAVY QPF BULLSEYES. THE GFS
REMAINS THE WETTEST SOLUTION WITH 6-8 INCHES POSSIBLE...3-5 IN THE
NAM AND ONLY 1-2 IN THE EURO...WHICH SEEMS WAY TOO LOW. GIVEN THE
UNCERTAINTY WILL LIKELY ISSUE A FLOOD WATCH OVER THIS PERIOD. AN
UPPER LEVEL TROUGH OVER THE NE PAC MAY BREAK THE MOISTURE TAP ON
TUESDAY WITH STEADY HEAVY RAIN ENDING. 33

.LONG TERM...PREVIOUS DISCUSSION...EXTENDED RANGE MODELS COMING INTO
AGREEMENT WITH BREAK IN THE DELUGE TUESDAY AFTERNOON CONTINUING INTO
WEDNESDAY BEFORE AN UPPER LEVEL TROUGH WILL START TO MOVE ONSHORE
WEDNESDAY NIGHT FOR YET ANOTHER ROUND OF PRECIP AND COOLING
TEMPERATURES. THIS SYSTEM WILL EXIT LATE THURSDAY WHILE A SECONDARY
SYSTEM WILL PUSH IN FRIDAY WITH NO REAL BREAK IN THE PRECIP AND THUS
A WET FINISH TO THE WEEK AHEAD. MODELS REMAIN CONSISTENT REGARDING A
RIDGE FOLLOWING THAT SECONDARY SYSTEM...BRINING DRIER CONDITIONS FOR
NEXT WEEKEND AND POSSIBLY A DAY OR TWO BEYOND. SMR

&&

.HYDROLOGY... THE SKOKOMISH RIVER IS RIGHT BELOW FLOOD STAGE THIS
MORNING AND SLOWLY RECEDING. HOWEVER WITH MORE RAIN IN THE FORECAST
THE RIVER IS EXPECTED TO RISE BACK OVER FLOOD STAGE TONIGHT.

EXPECT THE FOCUS OF THE HEAVY RAIN TO BE OVER THE FAR SOUTHERN PART
OF THE FORECAST AREA TODAY...SHIFTING NORTHWARD TONIGHT. ON
MON...THE HEAVIEST RAIN WILL LIKELY BE AIMED AT THE CENTRAL AND
NORTHERN CASCADES BEFORE THE FRONT SHIFTS SOUTHWARD AGAIN MON NIGHT.
MODELS STILL SHOW SEVERAL INCHES OF RAIN ACROSS THE WEST SLOPES OF
THE CASCADES WITH A FEW RIVERS CLOSE TO FLOOD STAGE. FLOODING MAY
START AS EARLY AS MONDAY MORNING AND A FLOOD WATCH WILL BE ISSUED.

&&

.AVIATION...DEEP-LAYER MOISTURE AND CLOUDS TODAY AND TONIGHT...AS
WARMER AND MOIST AIR STREAMS IN ON STRONG W-NW WINDS ALOFT AROUND
THE PERIPHERY OF A FLAT UPPER RIDGE. IFR CIGS BELOW 020 WILL BE MOST
COMMON OVER THE NEXT 24 HOURS...WITH PERIODS OF CIGS BELOW 010.
WIDESPREAD MOUNTAIN OBSCURATION EXPECTED.

KSEA...CIGS WILL REMAIN BELOW 020 FOR THE NEXT 30 HOURS...EVEN
FALLING BELOW 010 OVER THE NEXT FEW HOURS AND POSSIBLY AGAIN FOR A
TIME ON MON MORNING DURING A PERIOD WHEN RAIN IS EXPECTED TO PICK
UP. S/SW SFC WINDS PICKING UP ARND 03Z-04Z THIS EVNG AND BECOMING
GUSTY...WITH GUSTINESS CONTINUING OVERNIGHT. MEANWHILE...WINDS IN
THE 020-050 LAYER WILL BE W/SW ARND 35-45 KT THIS EVNG AND
OVERNIGHT.HANER

&&

.MARINE...FRONT LIFTING NORTH THROUGH THE WATERS LATER TODAY
STALLING OVER THE NORTHERN PORTION OF THE AREA TONIGHT. SOUTHWEST
WINDS WILL PICK UP SOUTH OF THE FRONT AND PEAK TONIGHT WITH SOME
WESTERLIES DOWN THE STRAIT. FRONT STALLED NORTH OF THE AREA MONDAY
WILL KEEP SOUTHERLY GRADIENTS INTACT OVER THE WATERS. ANOTHER FRONT
WILL MOVE THROUGH THE WATERS MONDAY NIGHT WITH HIGH PRESSURE
BUILDING BEHIND THE FRONT ON TUESDAY ALONG THE COAST.

WESTERLY SWELLS WILL BE FLIRTING WITH THE 10-FOOT CUTOFF OVER THE
COASTAL WATERS THROUGH MONDAY. HANER

&&

.SEW WATCHES/WARNINGS/ADVISORIES...

WA...NONE.

PZ...SMALL CRAFT ADVISORY ALL WATERS EXCEPT FOR THE NORTHERN INLAND
     WATERS.

     SMALL CRAFT ADVISORY FOR ROUGH BAR UNTIL MIDNIGHT PST TONIGHT
     FOR GRAYS HARBOR BAR.

&&

$$

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