066
FXUS66 KSEW 101032
AFDSEW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
332 AM PDT WED JUN 10 2026
SYNOPSIS
UPPER LEVEL TROUGH MOVING OUT OF THE AREA THIS MORNING. UPPER UPPER
LEVEL RIDGE BUILDING THIS AFTERNOON AND REMAINING THROUGH THURSDAY.
WEAK SYSTEM MOVING BY WELL TO THE NORTH THURSDAY NIGHT INTO
FRIDAY. STRONG UPPER LEVEL RIDGE BUILDING OFFSHORE FRIDAY WITH
THE RIDGE NOSING INTO BRITISH COLUMBIA SATURDAY. LOW LEVEL FLOW
GOING OFFSHORE SATURDAY NIGHT AS THERMALLY INDUCED SURFACE
TROUGH BUILDS ALONG THE COAST. UPPER LEVEL RIDGE WEAKENS MONDAY
NIGHT WITH THE LOW LEVEL FLOW TURNING ONSHORE TUESDAY. RIDGE
CONTINUES TO WEAKEN WEDNESDAY WITH STRONGER LOW LEVEL ONSHORE
FLOW.
SHORT TERM /TODAY THROUGH FRIDAY/
SATELLITE IMAGERY SHOWS CLOUDY SKIES FOR THE MOST PART OVER
WESTERN WASHINGTON EARLY THIS MORNING. WAVE CLOUDS PRESENT OVER
THE EAST SLOPES OF THE CASCADES INDICATING WE STILL HAVE STRONG
FLOW ALOFT. DOPPLER RADAR HAS CONVERGENCE ZONE OVER SNOHOMISH
COUNTY, RAIN SHADOW OVER THE CENTRAL PUGET SOUND AND SCATTERED
SHOWERS ELSEWHERE. TEMPERATURES AT 2 AM/09Z WERE IN THE UPPER
40S TO MID 50S.
UPPER LEVEL TROUGH EXITING THE AREA THIS MORNING. SURFACE
GRADIENTS WEAKENING WHICH COULD ALLOW THE CONVERGENCE ZONE TO
DRIFT SOUTH POSSIBLY INTO KING COUNTY THIS MORNING BEFORE
DISSIPATING. UPPER LEVEL RIDGE BUILDING THIS AFTERNOON WITH THE
LOW LEVEL FLOW TURNING NORTHERLY. THIS WILL HELP DRY OUT THE AIR
MASS GIVING THE AREA SOME SUNSHINE AFTER THE MORNING CLOUD
COVER. AIR MASS ALOFT STILL A LITTLE ON THE COOL SIDE SO EVEN
WITH THE SUNSHINE HIGHS A TOUCH BELOW NORMAL, IN THE 60S.
UPPER LEVEL RIDGE OVER THE AREA TONIGHT AND THURSDAY WITH LIGHT
OR NORTHERLY FLOW IN THE LOWER LEVELS. THIS WILL LIMIT THE CLOUD
COVER WEDNESDAY NIGHT/THURSDAY MORNING MAKING FOR A SUNNY DAY.
CLEARING TONIGHT LEADING TO A COOL MORNING THURSDAY WITH LOWS
MOSTLY IN THE 40S. COLDER LOCATIONS GETTING DOWN TO THE UPPER
30S. HIGHS WARMER THURSDAY, IN THE MID 60S TO MID 70S.
WEAK SYSTEM MOVING BY WELL TO THE NORTH THURSDAY NIGHT INTO
FRIDAY WILL FLATTEN THE UPPER LEVEL RIDGE AND INDUCE WEAK LOW
LEVEL ONSHORE FLOW. THIS WILL KEEP HIGHS IN THE MID 60S TO MID
70S FRIDAY. LOWS FRIDAY MORNING IN THE 40S AND LOWER 50S.
LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/
GOOD CONSISTENCY IN THE MODELS WITH A STRONG UPPER LEVEL RIDGE
BUILDING OFFSHORE FRIDAY NIGHT. THE RIDGE WILL MOVE EAST AND
NOSE INTO BRITISH COLUMBIA SATURDAY. 500 MB HEIGHTS RISING FROM
THE LOWER TO MID 570 DMS FRIDAY AFTERNOON TO THE LOWER TO MID
580 DMS SATURDAY AFTERNOON. NORTHWESTERLY FLOW IN THE LOWER
LEVELS WITH AFTERNOON SEABREEZES KNOCKING A COUPLE OF DEGREES
OFF THE HIGHS NEAR THE WATER. HIGHS SATURDAY IN THE MID 70S TO
MID 80S.
RIDGE REMAINING OVER THE AREA SUNDAY AND MONDAY. LOW LEVEL FLOW
TURNING OFFSHORE AS THERMALLY INDUCED SURFACE TROUGH DEVELOPS
ALONG THE COAST SATURDAY NIGHT. TEMPERATURES ALOFT CONTINUE TO
WARM WITH MODEL 850 MB TEMPERATURES PEAKING AROUND PLUS 20C
MONDAY. HIGH TEMPERATURES WARMING INTO THE 80S AND LOWER 90S
SUNDAY WITH THE WARMER LOCATIONS IN THE MID 90S MONDAY. RECORD
HIGHS ARE LIKELY SUNDAY AND VERY LIKELY MONDAY.
MODEL SOLUTIONS BECOMING A LITTLE INCONSISTENT TUESDAY.
YESTERDAY'S RUNS FAVORED A MARINE PUSH. THERE ARE MORE ENSEMBLE
SOLUTIONS ON THE LATEST RUN GOING FOR A JUST A WEAK PUSH AS THE
UPPER LEVEL RIDGE HANGS ON A LITTLE LONGER AND THE THERMALLY
INDUCED TROUGH DOESN'T MOVE INLAND UNTIL AFTERNOON. TOUGH CALL
THIS FAR OUT. CURRENT BLEND FORECAST LEANING TOWARDS A STRONGER
PUSH, HIGH TEMPERATURES DROPPING 10-15 DEGREES VERSUS THE WEAKER
PUSH SCENARIO, A 5-10 DEGREE DROP.
MINOR HEATRISK SATURDAY BECOMING MODERATE SUNDAY AND MONDAY.
PROBABLY OF MAJOR HEATRISK MONDAY FROM SEATTLE SOUTHWARD
INCLUDING THE LOWER CHEHALIS VALLEY AND THE CASCADE FOOTHILLS
HAS DROPPED TO 20-40% FROM 40-60% YESTERDAY. IN ADDITION TO THE
HEATRISK THE CLOUDS AND RAIN RECENTLY HAS PREVENTED THE WATER
TEMPERATURES AROUND THE AREA FROM RISING. LAKE WASHINGTON AND
LAKE SAMMAMISH WATER TEMPERATURES CURRENTLY ONLY 62 DEGREES.
AREA RIVERS ARE EVEN COLDER. LETS PLAY IT SAFE AROUND THE WATER
DURING THIS SHORT WARM SPELL. FELTON
AVIATION
A MIX OF MVFR AND VFR CIGS EARLY THIS MORNING AS SCATTERED SHOWERS
CONTINUE TO MOVE ACROSS THE AREA. EXPECT SHOWER ACTIVITY TO
GRADUALLY DIMINISH THROUGHOUT THE MORNING HOURS. GUIDANCE CONTINUES
TO SUGGEST THAT MVFR CIGS COULD BE REINTRODUCED BETWEEN 15Z-19Z FOR
TERMINALS THAT HAVE MANAGED TO STAY VFR. IMPROVEMENT TO VFR FOR ALL
TERMINALS EXPECTED AFTER 18Z-20Z AND WILL PREVAIL THROUGHOUT THE
DAY. SOUTHERLY FLOW WILL SHIFT NORTHERLY ACROSS THE TERMINALS BY
THIS AFTERNOON AS HIGH PRESSURE BUILDS OVER THE REGION.
KSEA...MVFR CIGS EARLY THIS MORNING AT THE TERMINAL. IMPROVEMENT TO
VFR EXPECTED AFTER 18Z-19Z. ELEVATED SOUTHERLY WINDS WILL CONTINUE
TO DWINDLE THROUGHOUT THE MORNING HOURS. NORTHWESTERLY FLOW 4-6 KT
IN THE AFTERNOON AFTER 20Z-23Z, BECOMING NORTHEASTERLY AFTER 06Z.
29
MARINE
HIGH PRESSURE WILL CONTINUE TO REBUILD OVER THE COASTAL WATERS
TODAY. WINDS HAVE DECREASED BELOW GALE CRITERIA, AND THE GALE
WARNING HAS BEEN DOWNGRADED TO A SMALL CRAFT ADVISORY. ANOTHER
WESTERLY PUSH ACROSS THE STRAIT OF JUAN DE FUCA IS EXPECTED THIS
EVENING, WITH HIGH-RES GUIDANCE SUGGESTING AN 70-80% CHANCE OF WINDS
EXCEEDING 21 KT ACROSS THE CENTRAL AND EAST PORTIONS. IN ADDITION,
GUIDANCE IS SUGGESTING ANOTHER PUSH THROUGH THE CENTRAL STRAIT
THURSDAY EVENING. LATEST PROBABILITIES ARE AROUND 65-80% FOR SMALL
CRAFT THRESHOLDS. AS THE WEEK PROGRESSES, STRENGTHENING HIGH
PRESSURE WILL BUILD OVER THE INNER WATERS AS WELL, LEADING TO
INCREASED NORTHERLY SURFACE FLOW ACROSS AREA WATERS. LATEST GUIDANCE
SUGGESTS WINDS SHOULD REMAIN BELOW SMALL CRAFT THRESHOLDS (20-40%
CHANCE OVER THE COASTAL WATERS). SEAS WILL REMAIN BELOW 10 FT GOING
INTO THE WEEKEND AS HIGH PRESSURE PREVAILS OVER AREA WATERS.
29
FIRE WEATHER
WETTING RAINS THE LAST TWO DAYS SIGNIFICANTLY SLOWED THE DRYING
OF THE FUELS AROUND WESTERN WASHINGTON. WARMING TEMPERATURES
AND THE RETURN OF OFFSHORE FLOW SUNDAY AND MONDAY WILL DO A GOOD
JOB DRYING THE AREA ONCE AGAIN. MINIMUM RELATIVE HUMIDITY
VALUES AS LOW AS THE TEENS SUNDAY AND MONDAY. FINE FUELS HAVE
NOT REACHED CRITICAL THRESHOLDS BUT THE LOW LEVEL OFFSHORE FLOW
SUNDAY AND MONDAY WILL ALLOW THEM TO CURE PUTTING THEM CLOSE TO
CRITICAL LEVELS BY EARLY NEXT WEEK. LARGER FUELS ARE DRYING OUT
AS WELL. FIRE CONCERNS WILL BE ELEVATED OVER THE WEEKEND PEAKING
MONDAY. FELTON
SEW WATCHES/WARNINGS/ADVISORIES
WA...NONE.
PZ...SMALL CRAFT ADVISORY UNTIL 5 AM PDT EARLY THIS MORNING FOR
CENTRAL U.S. WATERS STRAIT OF JUAN DE FUCA.
SMALL CRAFT ADVISORY UNTIL 3 PM PDT THIS AFTERNOON FOR EAST
ENTRANCE U.S. WATERS STRAIT OF JUAN DE FUCA.
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