572
FXUS66 KSEW 122245 AAC
AFDSEW
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE SEATTLE WA
345 PM PDT FRI JUN 12 2026
SYNOPSIS
A STRONG UPPER LEVEL RIDGE AND HIGH PRESSURE SYSTEM WILL
CONTINUE TO BUILD OFFSHORE FRIDAY, AND BEGIN TO MOVE INLAND THIS
WEEKEND INTO EARLY NEXT WEEK. A HEAT ADVISORY CONTINUES FOR MUCH
OF WESTERN WASHINGTON FOR WIDESPREAD MODERATE HEATRISK AS HIGHS
CLIMB INTO THE 80S AND 90S ON SUNDAY AND MONDAY. FIRE DANGER
WILL ALSO BECOME ELEVATED AS RELATIVE HUMIDITIES DIP WITH
OFFSHORE FLOW. THE HIGH WILL MOVE INLAND TUESDAY, WHICH WILL BE
FOLLOWED BY ONSHORE FLOW, AND LOWER TEMPERATURES.
SHORT TERM /TONIGHT THROUGH SUNDAY NIGHT/
IT'S A DRY AND MOSTLY SUNNY DAY ACROSS MUCH OF WESTERN
WASHINGTON THIS AFTERNOON. SATELLITE HAS A FEW AREAS OF CLOUDS
OVER THE CASCADES, AND OLYMPICS, AND SOME LOW STRATUS AROUND
NEAH BAY. QUITE A FEW PLACES IN THE LOWLANDS HAVE CLIMBED INTO
THE 70S THIS AFTERNOON. A FEW LOCATIONS WEST OF OLYMPIA/CHEHALIS
VALLEY MAY TRACK TOWARDS 80 THIS AFTERNOON. OTHERWISE, ONLY
MINOR HEATRISK TODAY WITH THE TEMPERATURES, WITH WINDS OUT OF
THE NORTH AROUND 5-10 MPH. LOWS TONIGHT DROP DOWN TO AROUND 50
TO 55.
THE MAIN STORY REMAINS WARM, AND DRY AIR GOING INTO THE WEEKEND,
AND INTO MONDAY ACROSS WESTERN WASHINGTON. AN UPPER LEVEL RIDGE
BUILDING OFFSHORE WILL BEGIN TO MOVE INLAND THIS WEEKEND, WITH
THE AXIS OVERHEAD BY SUNDAY EVENING. A THERMAL TROUGH IS ALSO
EXPECTED TO BUILD ALONG THE COAST, WHICH WILL IN TURN MAKE THE
FLOW MORE OFFSHORE IN THE OVERNIGHT PERIODS. WINDS WILL TURN
MORE OUT OF THE EAST, BUT MOST PLACES WILL SEE LIGHT WINDS
OVERNIGHT (WITH THE EXCEPTION OF THE WEST CASCADES AND OLYMPIC
SLOPES WHERE A FEW GUSTS UP TO 20 MPH MAY OCCUR). DURING THE
DAYS, THE WINDS WILL TURN TO THE NORTH/NORTHWEST 5 TO 10 MPH,
WITH SATURDAY BEING BREEZY IN MUCH OF PUGET SOUND AS WINDS PICK
UP TO 15-20 MPH IN THE AFTERNOON.
NOW FOR THE HEAT: SATURDAY WILL BE THE COOLER OF THE TWO WEEKEND
DAYS, BUT WILL STILL BE QUITE A BIT WARMER TO FRIDAY, AS HIGHS
APPROACH THE MID 70S INTO THE UPPER 80S (WITH A COUPLE LOW 90S
IN AREAS WEST OF OLYMPIA). HEATRISK INCREASES TO MODERATE FOR A
LARGE SWATH OF THE SOUTH/SOUTHWEST INTERIOR, BUT REMAINS MINOR
FOR THE REMAINDER OF THE LOWLANDS. LOWS WILL DROP INTO THE MID
AND UPPER 50S SATURDAY NIGHT INTO SUNDAY. SUNDAY WILL BE THE
WARMEST DAY OF THE WEEKEND, WITH HIGHS AROUND 80 TO NEAR 100 IN
THE SOUTHWEST INTERIOR. ALL OF THE LOWLANDS WILL SEE MODERATE
HEATRISK IMPACTS, WITH A FEW ISOLATED INSTANCES OF MAJOR
HEATRISK (BUT THIS HAS DECREASED SLIGHTLY TO 20-40% WITH THE
LATEST FORECAST UPDATE DUE TO LOW TEMPERATURES DROPPING A COUPLE
DEGREES TO AROUND 60). NEVERTHELESS, THE HEAT ADVISORY WILL
CONTINUE FOR THE EMPHASIS OF THOSE SPENDING TIME OUTSIDE (WHO
ARE SENSITIVE TO EXTREME HEAT) TO TAKE BREAKS IN THE AIR
CONDITIONING/SHADE, AND STAYING HYDRATED.
HPR
LONG TERM /MONDAY THROUGH FRIDAY/
SURFACE THERMAL TROUGH DEEPENS INLAND WITH HIGHEST SURFACE TEMPERATURES
ON MONDAY. WIDESPREAD MODERATE HEATRISK REMAINS LIKELY ON
MONDAY, WITH MORE HIGHS LIKELY TO BREAK 90 IN THE INTERIOR.
MONDAY EVENING, THIS THERMAL TROUGH WILL BEGIN TO WEAKEN AND
DISORGANIZE. OVERNIGHT TEMPERATURES HAVE COOLED A COUPLE
DEGREES, BUT WILL STILL LIKELY RANGE FROM THE UPPER 50S TO LOW
60S. TUESDAY WILL BE MUCH COOLER DUE TO THIS WEAKENING OF THE
THERMAL TROUGH, BRINGING WINDS WITH A NORTHWESTERLY COMPONENT. A
FEW GUSTY WINDS WILL BE POSSIBLE ON TUESDAY. THE UPPER LEVEL
RIDGE THAT HAD BUILT OVER WESTERN WASHINGTON SHIFTS INLAND ON
TUESDAY, CAUSING TEMPORARY ZONAL/ONSHORE FLOW UNTIL A UPPER
LEVEL TROUGH PUSHES IN ON THURSDAY, KEEPING TEMPERATURES COOL
THROUGH THE END OF THE WEEK.
HPR/NW
AVIATION
CLEAR SKIES AND VFR CONDITIONS ARE EXPECTED TO CONTINUE OVER THE
AREA THROUGH 00Z SUNDAY. CHANCES FOR CEILINGS BELOW 3000 FT ALONG
THE COAST PEAK BETWEEN 5-10% BETWEEN 12-16Z SATURDAY. WINDS REMAIN
OUT OF THE NORTH TO NORTHEAST AS OF 21Z FRIDAY, EXCEPT WEST TO
NORTHWEST AT THE COAST AND FROM KSEA TO KBFI. WINDS WILL BECOME CALM
AGAIN TONIGHT AFTER 04-06Z SATURDAY.
KSEA...VFR CONDITIONS WILL PREVAIL NOW THROUGH 00Z SUNDAY WITH
MOSTLY CLEAR SKIES CONTINUING. WNW TO NW WINDS AROUND 10 KT AS OF
21Z FRIDAY SHOULD BECOME N TO NNE LATE THIS EVENING INTO TONIGHT
WHILE WEAKENING TO 5-8 KT. WINDS ARE EXPECTED TO BECOME N TO NW
SATURDAY AFTERNOON, HOWEVER OCCASIONAL WIND SHIFTS TO WNW ARE
POSSIBLE (5-10% CHANCE). -23
MARINE
HIGH PRESSURE WILL GENERALLY REMAIN IN PLACE OVER THE NORTHEAST
PACIFIC AND COASTAL WATERS THROUGH NEXT FRIDAY. THIS WILL BRING
PERSISTENT NORTH TO NORTHWEST WINDS, EXCEPT FOR TWO PERIODS OF
NORTHEAST WINDS OVER THE INNER COASTAL WATERS SATURDAY MORNING AND
SATURDAY NIGHT THROUGH SUNDAY MORNING. HOWEVER, WINDS WILL GENERALLY
BE LIGHT DURING THOSE TWO TIME PERIODS AT AROUND 5-10 KT WITH
MINIMAL IMPACTS.
THE MAIN TIME PERIOD OF CONCERN IS ON TUESDAY, AS THIS IS WHEN THE
NEXT FRONTAL SYSTEM. THIS SYSTEM WILL BRING A DECENT PUSH OF ONSHORE
WINDS OVER THE WATERS AND THE STRAIT OF JUAN DE FUCA. THERE IS
INCREASING CONFIDENCE (70-80% CHANCE OR GREATER) FOR GALES THROUGH
THE STRAIT OF JUAN DE FUCA ON TUESDAY. SEAS WILL ALSO BUILD ON
TUESDAY, WITH GUIDANCE SUGGESTING SEAS BUILDING TO AROUND 10 FEET.
-23/29
FIRE WEATHER
DRYING TREND OVER THE AREA THE NEXT FEW DAYS WITH ELEVATED FIRE
WEATHER CONCERNS BEGINNING SATURDAY AND LASTING INTO TUESDAY.
UPPER LEVEL RIDGE BUILDING THIS WEEKEND WITH THE LOW LEVEL FLOW
TURNING OFFSHORE SATURDAY NIGHT. HIGHS WARMING INTO THE 80S
SATURDAY, 80S TO LOWER 90S SUNDAY AND FOR THE INTERIOR 80S TO
MID 90S MONDAY. RELATIVE HUMIDITY VALUES LOWERING IN THE DRIER
LOCATIONS, LIKE THE SOUTHWEST INTERIOR, INTO THE TEENS BOTH
SUNDAY AND MONDAY AFTERNOON. EVEN THOUGH FINE FUELS HAVE NOT
REACHED CRITICAL THRESHOLDS, THIS RAPID DRYING WILL CREATE
ELEVATED FIRE CONCERNS ESPECIALLY FOR DRY GRASSY/SHRUBBY AREAS,
AS WELL AS PILES OF DEAD FUELS. OFFSHORE FLOW SUNDAY INTO MONDAY
WILL PREVENT GOOD RELATIVE HUMIDITY RECOVERIES OVERNIGHT.
RELATIVE HUMIDITIES WILL IMPROVE WITH THE RETURN OF ONSHORE FLOW
TUESDAY. WINDS WILL BECOME PARTICULARLY GUSTY, WITH PORTIONS OF
THE COAST/MOUNTAINS/SOUTH INTERIOR SEEING WEST TO NORTHWEST
WIND GUSTS UP TO 20 TO 30 MPH. LOW LEVEL ONSHORE FLOW AND
COOLER TEMPERATURES WEDNESDAY AND THURSDAY WILL EASE FIRE
WEATHER CONCERNS THE MIDDLE OF NEXT WEEK. FELTON/HPR
SEW WATCHES/WARNINGS/ADVISORIES
WA...HEAT ADVISORY FROM 11 AM SUNDAY TO 5 AM PDT TUESDAY FOR CITY
OF SEATTLE-DOWNTOWN EVERETT / MARYSVILLE AREA-EASTERN
KITSAP COUNTY-EASTERN STRAIT OF JUAN DE FUCA-EASTSIDE-
FOOTHILLS AND VALLEYS OF CENTRAL KING COUNTY-FOOTHILLS
AND VALLEYS OF PIERCE AND SOUTHERN KING COUNTIES-
FOOTHILLS AND VALLEYS OF SNOHOMISH AND NORTHERN KING
COUNTIES-FOOTHILLS AND VALLEYS OF THURSTON AND LEWIS
COUNTIES-FOOTHILLS AND VALLEYS OF THE NORTH CASCADES-
FOOTHILLS OF THE WESTERN AND SOUTHERN OLYMPIC PENINSULA-
ISLAND COUNTY-LAKE CRESCENT AREA INCLUDING US 101-LOWER
CHEHALIS RIVER VALLEY-LOWLANDS OF LEWIS AND SOUTHERN
THURSTON COUNTIES-LOWLANDS OF PIERCE AND SOUTHERN KING
COUNTIES-LOWLANDS OF WESTERN SKAGIT AND NORTHWESTERN
SNOHOMISH COUNTIES-LOWLANDS OF WESTERN WHATCOM COUNTY-
MIDDLE CHEHALIS RIVER VALLEY-NORTHERN HOOD CANAL-OLYMPIA
AND SOUTHERN PUGET SOUND-PORT TOWNSEND AREA-SAN JUAN
COUNTY-SHORELINE / LYNNWOOD / SOUTH EVERETT AREA-SOUTHERN
HOOD CANAL-WILLAPA AND BLACK HILLS.
PZ...NONE.
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