670
FXUS66 KSEW 080328 CCA
AFDSEW
AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE SEATTLE WA
828 PM PDT THU AUG 7 2025
SYNOPSIS
LINGERING SHOWERS WILL CONTINUE TO DIMINISH THIS
AFTERNOON, WITH COOLER TEMPERATURES AND CLOUDS HANGING AROUND.
THE PATTERN CHANGES FRIDAY INTO EARLY NEXT WEEK AN UPPER LEVEL
RIDGE BUILDS ACROSS THE REGION. TEMPERATURES WILL INCREASE AND
CONDITIONS WILL DRY OUT AS A RESULT. CONDITIONS WILL COOL GOING
INTO THE MIDDLE OF THE WEEK AS THE RIDGE DEPARTS THE REGION,
WITH A TROUGH PATTERN MOVING IN.
SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/
FORECAST REMAINS
ON TRACK THIS EVENING WITH SOME LINGERING CLOUDS OVER THE
MOUNTAINS AND TEMPERATURES GENERALLY IN THE LOWER TO MID 60S
ACROSS THE REGION AS OF 8 PM. PREVIOUS DISCUSSION FOLLOWS.
ON FRIDAY, AN UPPER LEVEL HIGH OFFSHORE WILL INCH CLOSER TO THE
SHORE. FLOW WILL BECOME MERIDIONAL AS A THE DEPARTING TROUGH DIGS
SOUTHWARD OVER THE NORTHERN GREAT PLAINS (AND AS THE HIGH
AMPLIFIES AND BUILDS A RIDGE OVER THE HIGH UP TO ALASKA).
CONDITIONS WON'T WARM UP TOO MUCH ON FRIDAY (GIVEN SOME MARINE
AIR WILL BRING SOME CLOUDS IN THE MORNING), BUT SKIES WILL CLEAR
OUT OVER MUCH OF THE REGION IN THE AFTERNOON. WINDS WILL GENERALLY
BE LIGHT OUT OF THE NORTHWEST DURING THE DAY. HIGHS IN THE
INTERIOR WILL CLIMB INTO THE MID AND UPPER 70S (POTENTIAL FOR AN
80 IN THE SOUTH INTERIOR), BUT REMAIN IN THE 60S ALONG THE COAST.
SATURDAY WILL LIKELY BE A REPEAT OF FRIDAY, WITH MORE WIDESPREAD
CLEARING TAKING PLACE IN THE AFTERNOON/OVERNIGHT PERIOD AS THE
RIDGE AXIS TILTS OVER THE REGION. MID 70S TO LOW 80S ARE EXPECTED
IN THE INTERIOR, WITH MINOR (YELLOW) HEATRISK.
WITH THE RIDGE AXIS COMING OVER A LITTLE SOONER, TEMPERATURES ON
SUNDAY INCREASED QUITE A BIT WITH SKIES REMAINING CLEAR OVERNIGHT
(AND SKIES REMAINING CLEAR DURING THE DAY). SOME MODELS ALSO SHOW
A BRIEF THERMAL TROUGH ALONG THE COAST (TYPICALLY A GOOD SOURCE
FOR SOME INSTABILITY IN THE AIR AND AIDING IN WARMER
TEMPERATURES - FORECAST SOUNDINGS SHOW A CONDITIONALLY UNSTABLE
AIRMASS OVER THE REGION). TEMPERATURES NOW APPEAR TO PEAK SUNDAY
AFTERNOON, WITH HIGHS IN THE INTERIOR IN THE 80S (AND SOME LOW 90S
IN THE SOUTH INTERIOR). AN INCREASED AREA OF MODERATE (ORANGE)
HEATRISK NOW SPANS ACROSS THE SOUTH INTERIOR (AND SOME
CASCADE/OLYMPIC VALLEY AREAS). LOWS WILL ALSO CREEP UP INTO THE
UPPER 50S TO LOW 60S SUNDAY INTO MONDAY.
LONG TERM /SUNDAY THROUGH THURSDAY/
THE SUNDAY PATTERN IS
EXPECTED TO CONTINUE INTO MONDAY WITH HIGH TEMPERATURES LIKELY
REMAINING WARM IN THE 80S AND LOW 90S IN THE INTERIOR (WARMEST
TOWARDS THE SOUTH). THE TEMPERATURE SPREAD FOR TUESDAY REMAINS
LARGE AS THE ENSEMBLES STILL HAVE QUITE A BIT OF A TIMING ISSUE
WITH THE BREAKDOWN OF THE RIDGE. A COUPLE SOLUTIONS ALSO HAVE A
TROUGH POTENTIALLY DIGGING SOUTHWARD OVER THE REGION (THOUGH
SOME MODELS KEEP THIS UP INTO CANADA). NEVERTHELESS, HEATRISK
WILL DROP TO MINOR TUESDAY THROUGH MIDWEEK, TEMPERATURES WILL
COOL DOWN GRADUALLY WITH INCREASING ONSHORE FLOW, AND AT THIS
TIME CONDITIONS ARE EXPECTED TO REMAIN DRY.
HPR
AVIATION
NORTHWESTERLY WINDS WILL CONTINUE ACROSS THE AREA IN
THE WAKE OF AN UPPER LEVEL LOW.
MOST OF THE INTERIOR AND THE COAST IS NOW UNDER CLEAR SKIES, BUT THE
MOUNTAINS AND PORTIONS OF THE SOUTHWEST INTERIOR (INCLUDING OLM)
REMAIN UNDER SOME CLOUD COVER. VFR CONDITIONS AREA WIDE THIS
EVENING. STRATUS IS EXPECTED TO REDEVELOP EARLY FRIDAY MORNING, BUT
THE TREND IN THE GUIDANCE HAS BEEN LESS AND LESS DEVELOPMENT. NBM
PROBABILITIES HAVE DROPPED TO AROUND 15-25% FOR THE SEATTLE METRO
TERMINALS FOR SEEING MVFR OR LOWER. MUCH HIGHER CONFIDENCE ALONG THE
COAST AND THE STRAIT OF JUAN DE FUCA. DESPITE THAT, WILL KEEP AT
LEAST THE MENTION OF POTENTIAL FOR LOWER CEILINGS IN THE TAF AND
WILL MONITOR HOW CONDITIONS EVOLVE OVERNIGHT. MOSTLY CLEAR SKIES ARE
EXPECTED FOR MOST OF FRIDAY AFTER ANY STRATUS EVAPORATES. NORTHWEST
WINDS WILL BECOME LIGHT AND VARIABLE OVERNIGHT. WINDS WILL BE WEST TO
NORTHWEST AGAIN TOMORROW, BUT A BIT WEAKER THAN TODAY.
KSEA...VFR CONDITIONS THROUGH THIS EVENING AND EARLY OVERNIGHT.
STRATUS MAY REDEVELOP OVER THE TERMINAL FOR A FEW HOURS MONDAY
MORNING, THOUGH PROBABILITIES HAVE DROPPED TO 15-20% FOR MVFR BETWEEN
13-17Z FRI. AFTER, MOSTLY CLEAR SKIES ARE EXPECTED FOR MUCH OF
FRIDAY. NORTHWEST WINDS AROUND 5 KT BECOMING LIGHT NORTHEASTERLY
OVERNIGHT. WINDS TOMORROW WILL BE NORTHWESTERLY 5-7 KT.
62
MARINE
A WEAK FRONTAL SYSTEM WELL OFFSHORE WILL DISSIPATE NEAR
THE AREA WATERS ON FRIDAY, THEN, HIGH PRESSURE WILL SLOWLY REBUILD
OVER THE NORTHEAST PACIFIC THIS WEEKEND INTO NEXT WEEK. A DIURNALLY
DRIVEN WESTERLY PUSH DOWN THE STRAIT OF JUAN DE FUCA WILL BRING LOW-
END SMALL CRAFT ADVISORY WINDS TONIGHT, WITH ONE MORE WEAKER PUSH
FRIDAY EVENING THAT WILL REMAIN BELOW THRESHOLDS.
AS HIGH PRESSURE BUILDS OVER THE WATERS, WITH A WEAK THERMAL TROUGH
ALONG THE COASTLINE, NORTHWESTERLY WINDS WILL BUILD ALONG THE COAST
STARTING SUNDAY INTO NEXT WEEK.
SEAS 4 TO 6 FT WILL EASE A BIT TOMORROW, BEFORE RISING UP TO 6 TO 8
FT BY SUNDAY. DEPENDING ON THE STRENGTH OF THE NORTHWEST WINDS,
WAVES MAY GET UP TO 10-12 FT THROUGH THE OUTER COASTAL WATERS EARLY
NEXT WEEK.
62
FIRE WEATHER
COOLER AND CLOUDIER CONDITIONS WILL CONTINUE
TODAY, HELPING TO MODERATE TEMPERATURES WITH GOOD OVERNIGHT RH
RECOVERIES. THE NEXT ELEVATED FIRE WEATHER CONCERN IS THE HOT
AND DRY PATTERN EXPECTED LATE THIS WEEKEND INTO EARLY NEXT WEEK
AS RIDGING BUILDS IN OVER THE AREA FROM THE PACIFIC. WARMING
TEMPERATURES, WITH HIGHS IN THE 80S TO LOW 90S AND MINIMUM
RELATIVE HUMIDITIES DIPPING DOWN INTO THE 20S AND 30S BY EARLY
NEXT WEEK WILL ELEVATE FIRE WEATHER CONCERNS ACROSS PORTIONS OF
THE INTERIOR. ENSEMBLES THEN SUGGEST TROUGHING REDEVELOPING
ACROSS THE REGION AGAIN BY MIDWEEK, WHICH WOULD HELP MODERATE
TEMPERATURES AND INCREASE ONSHORE FLOW.
14/MAZURKIEWICZ
SEW WATCHES/WARNINGS/ADVISORIES
WA...NONE.
PZ...SMALL CRAFT ADVISORY UNTIL 5 AM PDT FRIDAY FOR CENTRAL U.S.
WATERS STRAIT OF JUAN DE FUCA-EAST ENTRANCE U.S. WATERS
STRAIT OF JUAN DE FUCA.
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