048
FXUS66 KPQR 111750 AAB
AFDPQR
AREA FORECAST DISCUSSION...UPDATE
NATIONAL WEATHER SERVICE PORTLAND OR
1050 AM PDT FRI SEP 11 2026
UPDATED AVIATION DISCUSSION
SYNOPSIS
A COOL AND UNSETTLED WEEKEND IS AHEAD AS AN UPPER-LEVEL
LOW MOVES ACROSS THE PACIFIC NORTHWEST. WIDESPREAD RAIN AND
SHOWERS WILL DEVELOP SATURDAY AND CONTINUE INTO SUNDAY, WITH
TEMPERATURES REMAINING BELOW SEASONAL AVERAGE. A MUCH WARMER AND
DRIER PATTERN THEN DEVELOPS EARLY NEXT WEEK AS HIGH PRESSURE
BUILDS OFFSHORE.
DISCUSSION...NOW THROUGH THURSDAY
TODAY WILL BE A RELATIVELY
QUIET DAY BETWEEN WEATHER SYSTEMS, BUT TEMPERATURES WILL REMAIN
COOL COMPARED TO YESTERDAY. INCREASING CLOUDS AHEAD OF THE NEXT
SYSTEM WILL LIMIT AFTERNOON WARMING, WITH HIGHS REACHING THE
UPPER 60S TO LOW 70S ACROSS THE INTERIOR AND LOW TO MID 60S NEAR
THE COAST. SOME INTERIOR VALLEYS COULD ALSO SEE PATCHY FOG OR
LOW CLOUDS THIS MORNING WHERE SKIES REMAIN CLEAR, ESPECIALLY IN
AREAS WITH LIGHT WINDS AND HIGHER SURFACE MOISTURE.
THE NEXT SYSTEM WILL BECOME THE MAIN WEATHER STORY THIS
WEEKEND. AN UPPER-LEVEL LOW WILL DEEPEN OFFSHORE TONIGHT BEFORE
MOVING ACROSS THE REGION SATURDAY. RECENT GUIDANCE CONTINUES TO
SUGGEST THAT RAIN WILL REACH THE COAST SATURDAY MORNING AND
SPREAD INLAND THROUGH THE AFTERNOON. RAIN AND SHOWERS WILL
CONTINUE SATURDAY NIGHT, FOLLOWED BY ADDITIONAL SHOWERS THROUGH
MOST OF SUNDAY. CONFIDENCE IS HIGH THAT MOST OF THE FORECAST
AREA WILL SEE MEASURABLE PRECIPITATION, WITH MOST ENSEMBLE
MEMBERS SUPPORTING RAIN SOMEWHERE ACROSS THE REGION.
SATURDAY THROUGH SUNDAY, TOTAL RAINFALL AMOUNTS SHOULD
GENERALLY REMAIN ON THE LIGHTER SIDE, WITH AROUND 0.10-0.50 INCH
EXPECTED FOR MOST LOCATIONS. THE CASCADES WILL LIKELY RECEIVE
MORE, WITH THE SOUTHWEST WASHINGTON AND NORTH OREGON CASCADES
CURRENTLY FAVORED FOR THE HIGHEST TOTALS AROUND 0.50-1.00 INCH
(HIGHEST VALUES IN THE SOUTHWEST WASHINGTON CASCADES). SHOWERS
WILL BECOME MORE SCATTERED SUNDAY AS THE SYSTEM MOVES EAST,
ALTHOUGH THE HIGHER TERRAIN WILL CONTINUE TO HAVE THE BEST
CHANCE FOR STRATIFORM RAIN.
THERE IS ALSO A SLIGHT CHANCE FOR THUNDERSTORMS (15-25% CHANCE)
SATURDAY AS THE COLD AIR ASSOCIATED WITH THE UPPER-LEVEL LOW
MOVES OVERHEAD. HOW MUCH INSTABILITY DEVELOPS WILL DEPEND PARTLY
ON THE TIMING OF THE SYSTEM. IF THE COLDEST AIR ARRIVES LATER
IN THE DAY, AFTER DAYTIME HEATING HAS WEAKENED, THUNDERSTORM
CHANCES WILL BE LOWER. AN ISOLATED THUNDERSTORM IS STILL
POSSIBLE, HOWEVER. COLD-CORE FUNNEL CLOUDS COULD ALSO DEVELOP
NEAR THE UPPER LOW. THESE ARE GENERALLY SHORT LIVED AND OFTEN
REMAIN ABOVE THE GROUND, BUT A FUNNEL REACHING THE SURFACE
CANNOT BE COMPLETELY RULED OUT.
THE WEEKEND SYSTEM WILL ALSO BRING ANOTHER NOTICEABLE DROP IN
TEMPERATURES. HIGHS SATURDAY AND SUNDAY WILL GENERALLY BE IN THE
LOW TO UPPER 60S ACROSS THE INTERIOR. CONDITIONS SHOULD
GRADUALLY IMPROVE SUNDAY NIGHT AS THE LOW MOVES EAST AND SHOWER
ACTIVITY DECREASES.
A MUCH WARMER PATTERN IS THEN EXPECTED TO DEVELOP EARLY NEXT
WEEK AS HIGH PRESSURE STRENGTHENS OVER THE EASTERN PACIFIC. SOME
LINGERING TROUGHING COULD KEEP TUESDAY FROM BECOMING COMPLETELY
CLEAR AND WARM, BUT THE OVERALL TREND IS TOWARD DRIER WEATHER
AND RISING TEMPERATURES. INTERIOR HIGHS SHOULD CLIMB INTO THE
MID TO UPPER 70S BY TUESDAY.
BY WEDNESDAY, ENSEMBLE GUIDANCE FAVORS THE OFFSHORE RIDGE
MOVING CLOSER TO THE PACIFIC NORTHWEST, WITH ABOUT A 75% CHANCE
OF THIS SCENARIO. IF THE RIDGE CONTINUES TO BUILD AS EXPECTED,
TEMPERATURES COULD REACH THE LOW TO MID 80S ACROSS THE INTERIOR
LOWLANDS. THE OTHER 25% OF THE GUIDANCE KEEPS SOME TROUGHING
NEAR THE REGION AND WOULD RESULT IN COOLER TEMPERATURES.
INCREASING EASTERLY FLOW IS ALSO POSSIBLE BY MIDWEEK AS THE
RIDGE STRENGTHENS. CURRENT GUIDANCE SUGGESTS THE STRONGEST WINDS
FROM WEDNESDAY NIGHT INTO THURSDAY MORNING, WITH SUSTAINED
WINDS OF 15-20 MPH AND GUSTS 25-30 MPH (ISOLATED GUSTS UP 35
MPH). WITH RISING TEMPERATURES AND LOWERING RELATIVE HUMIDITY
TUESDAY THROUGH THURSDAY AND INCREASED WINDS ON WEDNESDAY, THIS
WILL DEFINITELY BE SOMETHING TO MONITOR AS THE WARMER PATTERN
DEVELOPS NEXT WEEK. ~12
AVIATION...THROUGH 12Z SATURDAY
WEST TO SOUTHWESTERLY FLOW
ALOFT TODAY AS A LOW PRESSURE SYSTEM REMAINS OFFSHORE AS IT DROPS
SOUTH OUT OF FAR WESTERN CANADA. PREDOMINATELY VFR CONDITIONS ARE
EXPECTED THROUGH THE TAF PERIOD, ALTHOUGH LOW STRATUS ALONG THE
NORTH OREGON COAST WILL BRING LOW VFR TO MVFR CIGS INTO EARLY THIS
AFTERNOON NEAR KAST. ELSEWHERE EXPECT SCATTERED TO BROKEN HIGH
LEVEL CLOUDS TO STREAM ACROSS THE AREA. WINDS ARE EXPECTED TO
REMAIN RELATIVELY LIGHT AND VARIABLE.
KPDX AND APPROACHES...VFR CONDITIONS EXPECTED THROUGH THE PERIOD.
SCATTERED TO BROKEN HIGH LEVEL CLOUDS INCREASING TONIGHT INTO
SATURDAY. LIGHT WINDS BECOMING NORTHWEST AROUND 4-6 KT THIS
AFTERNOON. /DH
MARINE
HIGH PRESSURE WILL MAINTAIN NORTHERLY WINDS ACROSS ALL
WATERS THROUGH AT LEAST FRIDAY. BREEZY NORTH WINDS WITH GUSTS
REACHING 20-25 KT WILL CONTINUE THROUGH THIS EVENING. MARGINALLY
STEEP SEAS OF 6-8 FT AT 9 SECONDS WILL ALSO CONTINUE TO POSE A
HAZARD TO SMALL CRAFT BEYOND 10 NM THROUGH TONIGHT BEFORE EASING.
THEREFORE, SMALL CRAFT ADVISORIES REMAIN IN EFFECT THROUGH 8 PM
PDT THIS EVENING ACROSS THE INNER WATER (WITHIN 10 NM) AND ACROSS
THE OUTER WATERS (BEYOND 10 NM) THROUGH 8 AM PDT FRIDAY.
ANOTHER WEAKER SYSTEM IS EXPECTED TO APPROACH THE COASTAL WATERS
FROM THE NORTH LATE FRIDAY INTO SATURDAY. THIS WILL RESULT IN A
SOUTHERLY WIND SHIFT ALONG WITH SEAS SUBSIDING TOWARDS 4 TO 6 FT
AND GUSTS BELOW 20 KTS. A MORE ACTIVE PATTERN IS EXPECTED TO
RETURN NEXT TUESDAY. THIS SYSTEM LOOKS TO BRING NORTHERLY WINDS
BACK INTO THE FORECAST WITH GUSTS APPROACHING 20 KT. SEAS ARE
ALSO EXPECTED TO BUILD TOWARDS 5 TO 7 FT. -42/03
PQR WATCHES/WARNINGS/ADVISORIES
OR...NONE.
WA...NONE.
PZ...NONE.
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