004
FXUS66 KSEW 132314
AFDSEW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
414 PM PDT THU AUG 13 2026
SYNOPSIS
SHOWERS AND THUNDERSTORMS WILL CONTINUE OVER THE MOUNTAINS
THIS AFTERNOON AND FRIDAY AFTERNOON UNDER THE INFLUENCE OF AN
UPPER LEVEL TROUGH. SOUTHWEST FLOW ALOFT WILL DEVELOP OVER THE
WEEKEND, BRINGING SOME WARMING AHEAD OF ANOTHER WEAK TROUGH AT
THE BEGINNING OF NEXT WEEK THAT WILL LIKELY BRING SLIGHTLY
COOLER AND UNSETTLED CONDITIONS.
SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/
RECENT SATELLITE IMAGERY SHOWS SOMEWHAT HAZY SKIES OVER THE
REGION ALONG WITH DISSIPATING MARINE STRATUS OVER THE COAST. AN
UPPER LEVEL TROUGH WILL REMAIN IN PLACE OVER WESTERN WASHINGTON
INTO FRIDAY. THIS TROUGH WILL HELP THE AIR MASS BECOME UNSTABLE
THIS AFTERNOON AND EVENING OVER THE CASCADES AND THE OLYMPICS,
ESPECIALLY THE HIGHER TERRAIN. WE'LL CONTINUE TO SEE CHANCES
FOR SCATTERED CONVECTION THIS AFTERNOON AND EVENING, PRIMARILY
FOR AREAS IN THE CASCADES AND OLYMPICS. IN ANY THUNDERSTORM THAT
DEVELOPS, WE COULD SEE THE POTENTIAL FOR ABUNDANT LIGHTNING,
ERRATIC WIND GUSTS UP TO 40 MPH, AND LOCALIZED WETTING RAINS
THAT COULD PRODUCE AND ELEVATED RISK OF BURN SCAR DEBRIS FLOWS.
ADDITIONALLY, A RED FLAG WARNING REMAINS IN EFFECT THIS EVENING
FOR THOSE AFOREMENTIONED AREAS. FOR MORE INFORMATION ABOUT FIRE
WX CONDITIONS, SEE THE .FIRE WEATHER SECTION DOWN BELOW.
GENERALLY, WE'LL SEE HIGH TEMPERATURES THIS AFTERNOON IN THE
UPPER 70S TO LOWER 80S IN SPOTS WITH A MIX OF SUN AND HAZE.
ONSHORE FLOW WILL CONTINUE TONIGHT AND INTO FRIDAY MORNING, WITH
A SHALLOW MARINE LAYER MOVING INLAND BY THE MORNING. HIGH
TEMPERATURES ON FRIDAY WILL BE SLIGHTLY COOLER, IN THE UPPER 70S
FOR MOST LOCATIONS. THE ATMOSPHERE WILL CONTINUE TO REMAIN
UNSTABLE FRIDAY AFTERNOON - WHICH WILL LEAD TO ANOTHER CHANCE OF
SCATTERED THUNDERSTORMS, PRIMARILY IN THE CASCADES AND OLYMPICS.
A FIRE WEATHER WATCH IS IN EFFECT FOR THOSE AREAS - PRIMARILY
FOR LIGHTNING AND GUSTY OUTFLOW WINDS.
WEAK RIDGING WILL INFLUENCE THE AREA HEADING INTO SATURDAY,
WHICH WILL LEAD TO GENERALLY WARM AND DRY CONDITIONS. A FEW
SHOWERS MAY STILL BE POSSIBLE IN THE CASCADES, BUT OVERALL A
TYPICAL SUMMER DAY WITH HIGH TEMPERATURES IN THE LOW 80S.
LONG TERM /SUNDAY THROUGH THURSDAY/
WARM AND DRY CONDITIONS CONTINUING ON SUNDAY WITH HIGH
TEMPERATURES IN THE LOWER 80S. UPPER LEVEL TROUGHING LOOKS TO
MAINTAIN INFLUENCE OVER THE AREA THROUGH MIDWEEK, ALLOWING FOR
ONSHORE FLOW IN VARIABLE STRENGTHS THROUGHOUT THE WEEK.
UNSETTLED AND COOLER CONDITIONS THROUGH THE REMAINDER OF THE
WEEK, WITH HIGH TEMPERATURES IN THE MID 70S.
MAZURKIEWICZ
AN UPPER LEVEL TROUGH WILL REMAIN IN PLACE THROUGH THE TAF PERIOD,
WITH WEAK SOUTHWEST TO WEST FLOW ALOFT. MOST TERMINALS ARE VFR THIS
AFTERNOON, WITH THE EXCEPTION OF THE COAST WHERE STRATUS REMAINS.
SATELLITE AND RADAR HAS AREAS OF CONVECTION IN PROGRESS IN THE
CASCADES THIS AFTERNOON, AS WELL AS THE OLYMPICS. ACTIVITY IS
EXPECTED TO REMAIN AWAY FROM THE MAIN TERMINALS. ADDITIONALLY, SMOKE
FROM FIRES WILL PRIMARILY REMAIN ELEVATED OVER THE TERMINALS, BUT
AREAS NEAR FIRES WILL SEE POOR SURFACE VISIBILITIES (ESPECIALLY IN
THE CASCADES). ANOTHER MARINE PUSH IS EXPECTED FOR FRIDAY MORNING.
INTERIOR TERMINALS ARE STILL HOLDING ONTO A 10-20% CHANCE OF
IFR/LIFR CONDITIONS (WITH MVFR BEING MORE LIKELY), AND THE
LIKELIHOOD INCREASES SIGNIFICANTLY FROM THE KITSAP PENINSULA OUT TO
THE COAST. SOME AREAS OF FOG CAN'T BE RULED OUT WITHIN THE MARINE
PUSH. NORTHWEST WINDS AT 5-10 KT THIS AFTERNOON WILL DROP TO 5 KT OR
LESS (OR BECOME CALM) OUT OF THE WEST FOR MOST AREAS, INCREASING OUT
OF THE WEST/SOUTHWEST FRIDAY.
KSEA...VFR THROUGH THIS AFTERNOON AND EVENING. SIMILAR PROBABILITIES
REMAIN FOR FRIDAY MORNING AS OF THIS MORNING - 40% CHANCE OF MVFR
CEILINGS BETWEEN 12 AND 18Z, WITH A 20-30% CHANCE OF IFR, AND A 10-
20% CHANCE OF LIFR CONDITIONS. IF LIFR DOES MAKE IT INTO THE
TERMINAL, CAN'T RULE OUT THE POSSIBILITY OF BRIEF FOG (BUT THIS
REMAINS A LESS THAN 10% RISK FOR VISIBILITIES UNDER 1 NM). NW WINDS
AT 5-10 KT WILL DIMINISH TO 5 KT OR LESS OUT OF THE WEST TONIGHT,
SHIFTING TO THE SOUTHWEST FOR FRIDAY.
HPR
MARINE
HIGH PRESSURE REMAINS IN THE NORTHEAST PACIFIC THROUGH FRIDAY. AN
UPPER LEVEL LOW WILL CUT SOUTHWARD OVER THE WATERS THIS WEEKEND
WHICH WILL PUSH THE HIGH TOWARDS THE SOUTH. THE HIGH PRESSURE WILL
REBUILD AGAIN OVER THE COASTAL WATERS EARLY NEXT WEEK. MAIN CONCERN
REMAINS THE DIURNAL WESTERLY PUSHES THROUGH THE STRAIT OF JUAN DE
FUCA, WITH PROBABILITIES FOR WINDS AND/OR GUSTS OVER 20 KT REMAINING
LOW UNTIL FRIDAY AND SATURDAY EVENING.
SEAS NEXT 7 DAYS WILL REMAIN AT 3-6 FT.
HPR
FIRE WEATHER
FIRE WEATHER CONCERNS REMAIN ELEVATED TO CRITICAL AT TIMES
THROUGH FRIDAY NIGHT. AIR MASS HAS ALREADY BECAME UNSTABLE OVER
THE HIGHER TERRAIN THIS AFTERNOON AND WILL CONTINUE THROUGH THE
EARLY EVENING HOURS WITH CHANCES OF THUNDERSTORMS AND SHOWERS
LIKELY, PRIMARILY IN THE CASCADES AND OLYMPICS. A RED FLAG
WARNING IS IN EFFECT THROUGH 9PM. IN ANY THUNDERSTORM THAT
DEVELOPS, WE COULD SEE THE POTENTIAL FOR ABUNDANT LIGHTNING,
ERRATIC WIND GUSTS UP TO 40 MPH, AND LOCALIZED WETTING RAINS.
ADDITIONALLY, A FIRE WEATHER WATCH HAS BEEN ISSUED FOR FRIDAY
AFTERNOON AND EVENING, FOR ANOTHER ROUND OF CONVECTION ACROSS
THE CASCADES AND OLYMPICS - PRIMARILY FOR LIGHTNING AND GUSTY
OUTFLOW WINDS.
UPPER LEVEL TROUGH REPLACED BY AN UPPER LEVEL RIDGE OVER THE
WEEKEND LESSENING BUT NOT ELIMINATING THE CHANCES FOR CONVECTION
OVER THE MOUNTAINS ESPECIALLY THE CASCADES. ANOTHER UPPER LEVEL
TROUGH MOVING INTO THE AREA NEXT WEEK WILL ONCE AGAIN INCREASE
FIRE WEATHER CONCERNS.
FELTON/MAZURKIEWICZ
SEW WATCHES/WARNINGS/ADVISORIES
WA...RED FLAG WARNING UNTIL 9 PM PDT THIS EVENING FOR EAST PORTION
OF THE OLYMPIC MOUNTAINS-WEST PORTION OF THE OLYMPIC
MOUNTAINS-WEST SLOPES OF THE CENTRAL CASCADES GENERALLY
ABOVE 1500 FEET-WEST SLOPES OF THE NORTH CASCADES
GENERALLY ABOVE 1500 FEET.
FIRE WEATHER WATCH FROM FRIDAY AFTERNOON THROUGH FRIDAY
EVENING FOR EAST PORTION OF THE OLYMPIC MOUNTAINS-WEST
PORTION OF THE OLYMPIC MOUNTAINS-WEST SLOPES OF THE
CENTRAL CASCADES GENERALLY ABOVE 1500 FEET-WEST SLOPES OF
THE NORTH CASCADES GENERALLY ABOVE 1500 FEET.
PZ...NONE.
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