Small Craft Advisory 38, NWS Seattle, WA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
330 AM PST MON FEB 15 2016

.SYNOPSIS...MILD AND WET WESTERLY FLOW ALOFT WILL CONTINUE OVER THE
AREA THROUGH TONIGHT ALLOWING RAIN TO PERSIST WITH LOCALLY HEAVY
RAIN AT TIMES. THE HEAVY RAIN THREAT WILL END ON TUESDAY. EXPECT A
WEAK WARM FRONT TO LIFT NORTH ACROSS THE REGION TUESDAY NIGHT WITH A
LOW PRESSURE SYSTEM APPROACHING THE AREA FOR WEDNESDAY.

&&

.SHORT TERM...CURRENT RADAR SHOWS RAIN BEING MAINLY A CONCERN FOR
THE OLYMPIC PENINSULA AND FROM CENTRAL SNOHOMISH COUNTY NORTH. RADAR
ESTIMATED RAINFALL AMOUNTS ARE GENERALLY LIGHT...ALTHOUGH THERE ARE
AREAS ENTERING INTO THREE TENTHS TO HALF AN INCH PER HOUR. GIVEN THE
STRONGER REFLECTIVITY ECHOES ENTERING NORTHWEST SNOHOMISH AND
WESTERN SKAGIT COUNTIES AT THE TIME OF THIS WRITING...CAN LIKELY
START TO SEE SIMILAR RATES THERE.

MODELS SUGGEST THAT PRECIP WILL STAY GENERALLY NORTH OF THE SOUND OR
ALONG THE CASCADES FOR MUCH OF THE DAY...ALTHOUGH SOME MOISTURE WILL
LINGER OVER SOUTHERN PORTIONS OF THE CWA SO AS NOT TO COMPLETELY
RULE OUT PRECIP THERE EITHER...BUT LIKELY TO A LESSER DEGREE. THIS
WILL CHANGE THIS EVENING AND INTO TONIGHT AS A SHORTWAVE IMPULSE
WILL HELP TO PUSH PRECIP SOUTHWARD.

UPPER LEVEL RIDGING OVER THE AREA MAY RESULT IN A BIT OF A BREAK
FROM THE RAIN FOR TUESDAY AFTERNOON AND EVEN POSSIBLY INTO
WEDNESDAY. THE GFS SEEMS TO BE MORE OPTIMISTIC ABOUT THE CHANCES OF
SOME DRYING COMPARED TO THE ECMWF. STILL...MOST LOCATIONS SHOULD
ONLY SEE CHANCE POPS IN THIS TIME FRAME AS OPPOSED TO THE LIKELY TO
CATEGORICAL THAT HAVE BEEN SO PREVALENT IN RECENT FORECASTS. SMR

.LONG TERM...MIDWEEK GETS TO BE A BIT OF A CONUNDRUM AS MODELS ARE
TRYING TO SLOW DOWN THE NEXT UPPER LEVEL LOW TO ENTER THE REGION.
CURRENT SOLUTIONS ARE ABOUT 6 HOURS SLOWER THAN PREVIOUS
RUNS...WHICH WOULD ALLOW MINOR RAINLESS STREAK INTO WEDNESDAY
MORNING FOR THE COAST...INTO WEDNESDAY AFTERNOON INLAND. BUT ONCE IT
GETS HERE...YET ANOTHER ROUND OF RAIN IS EXPECTED INTO THURSDAY WITH
A SECONDARY SYSTEM BRINGING EVEN MORE FOR FRIDAY. GFS REMAINS
CONSISTENT IN THAT THERE SHOULD BE SOME DRYING FOR SATURDAY WHILE
THE ECMWF IS ABOUT 6 TO 12 HOURS LATER WITH THE REPRIEVE. SMR

&&

.AVIATION...WESTERLY FLOW ALOFT CONTINUING THROUGH TODAY. WARM FRONT
STALLED OVER THE NORTHERN PORTION OF THE AREA TODAY WILL SHIFT EAST
TONIGHT WITH THE TRAILING COLD FRONT MOVE THROUGH WESTERN WASHINGTON.

CEILINGS MOSTLY IN THE 1000-2000 FOOT RANGE WITH AREAS OF CEILINGS
BELOW 1000 FEET AND VISIBILITIES 3-5 SM. LITTLE CHANGE IN THE
CONDITIONS THROUGH TODAY.

.KSEA...CEILINGS BOUNCING AROUND BETWEEN 500 AND 1500 FEET WITH
VISIBILITIES 2-4SM AT TIMES. SOUTHERLY WINDS 8 TO 14 KNOTS WITH
OCCASIONAL GUSTS 20-25 KNOTS. FELTON

&&

.MARINE...WARM FRONT STALLED OVER THE NORTHERN PORTION OF THE WATERS
TODAY WITH SMALL CRAFT ADVISORY WINDS OVER THE COASTAL WATERS AND
PUGET SOUND AND HOOD CANAL. WARM FRONT MOVING EAST WITH TRAILING
COLD FRONT MOVING ACROSS THE WATERS TONIGHT. WINDS QUICKLY COME DOWN
LATE TONIGHT AS A BRIEF HIGH PRES RIDGE BUILDS ALONG THE COAST TUE.
A LARGE SURFACE LOW WILL DEVELOP OFF THE COAST ON WEDNESDAY WITH A
SERIES OF SYSTEMS SPINNING OUT OF THE LOW MOVING ACROSS THE WATERS
WEDNESDAY NIGHT THROUGH FRIDAY. FELTON

&&

.HYDROLOGY...CURRENTLY...THE SNOQUALMIE...STILLAGUAMISH...AND SKAGIT
RIVERS ARE FORECAST TO REACH FLOOD STAGE ON MONDAY. OTHER RIVERS TO
KEEP AN EYE ON ARE THE NOOKSACK...SNOHOMISH...AND SKYKOMISH AS THEY
ARE FORECAST TO COME CLOSE TO FLOOD STAGE EITHER MONDAY OR
TUESDAY.THE TOLT HAS ALREADY COME CLOSE TO FLOOD STAGE...HENCE THE
CURRENT WARNING...BUT BEGAN TO RECEDE. ALTHOUGH IT REMAINS BELOW
FLOOD STAGE AT THE TIME OF THIS WRITING...THE FACT THAT THERE IS
MORE PRECIPITATION ON THE WAY MEANS THAT IT IS ONLY A MATTER OF TIME
BEFORE LEVELS START TO RISE ONCE MORE. THAT SAID...THE FLOOD WARNING
REMAINS IN EFFECT AS DOES THE FLOOD WATCH FOR WHATCOM...SKAGIT...
SNOHOMISH...KING...PIERCE...AND LEWIS COUNTIES.

THE HEAVIEST RAIN IS EXPECTED TO FALL IN THE CASCADES FROM NORTHERN
KING COUNTY NORTHWARD. A COUPLE OF THE HIGHER RESOLUTION MODELS SUCH
AS THE ARW INDICATED RAINFALL AMOUNTS OF 4.5 TO 6.5 INCHES IN THE
CASCADES FROM NORTHERN KING COUNTY NORTHWARD IN THE 30-HOUR PERIOD
ENDING 4 AM PST TUE.

THE UNIQUELY FLOOD-PRONE SKOKOMISH RIVER CONTINUES TO RECEDE BUT IS
FORECAST TO RISE VERY CLOSE TO FLOOD STAGE BY THIS AFTERNOON. GIVEN
THAT IT DOES NOT TAKE MUCH RAIN FOR THIS RIVER TO FLOOD...THE FLOOD
WATCH FOR MASON COUNTY WILL REMAIN IN EFFECT.

THE THREAT OF RIVER FLOODING SHOULD COME TO AN END THURSDAY...WITH
FLOODING NOT EXPECTED FRIDAY THROUGH THIS WEEKEND.

&&

.SEW WATCHES/WARNINGS/ADVISORIES...

WA...FLOOD WARNINGS ARE IN EFFECT FOR MULTIPLE RIVERS IN WESTERN
     WASHINGTON. PLEASE REFER TO THE LATEST FLOOD BULLETIN FOR
     DETAILS.

     FLOOD WATCH IN EFFECT THROUGH TUESDAY MORNING FOR WHATCOM...
	 SKAGIT...SNOHOMISH...KING...PIERCE...LEWIS...AND MASON
	 COUNTIES.

PZ...PZ...SMALL CRAFT ADVISORY ALL WATERS EXCEPT WEST ENTRANCE TO THE
     STRAIT.

&&

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