801
FXUS66 KPQR 291746 AAA
AFDPQR
AREA FORECAST DISCUSSION...UPDATE
NATIONAL WEATHER SERVICE PORTLAND OR
1045 AM PDT TUE SEP 29 2026
UPDATED AVIATION DISCUSSION
SYNOPSIS
TODAY A DECAYING FRONTAL SYSTEM DROPS SOUTHWARD
CLIPPING THE REGION AND BRINGING CHANCES FOR RAIN THROUGH
TONIGHT WITH THE HIGHEST PROBABILITIES ALONG THE WASHINGTON AND
NORTH OREGON COAST AND COAST RANGE. DRY WEATHER IS FAVORED
AGAIN BY WEDNESDAY, LIKELY LASTING THROUGH THE WEEKEND, WITH
TEMPERATURES TRENDING WARMER DAY TO DAY AS WELL.
DISCUSSION...NOW THROUGH MONDAY NIGHT
CURRENT RADAR AND
SATELLITE IMAGERY EARLY THIS MORNING SHOWS PRECIPITATION/CLOUD
COVER ASSOCIATED WITH A FRONTAL SYSTEM SLOWLY SLIDING SOUTHWARD
INTO THE REGION. AS IT PROGRESSES THROUGHOUT THE DAY IT IS
EXPECTED TO CONTINUE WEAKENING BUT THERE SHOULD BE ENOUGH
LINGERING MOISTURE TO FACILITATE LIGHT RAINFALL OVER PORTIONS
OF THE OREGON COAST AND POSSIBLY THE PORTLAND METRO AREA AND
LOCATIONS NORTHWARD INTO SOUTHWEST WASHINGTON. THE LATEST NBM
SUGGESTS THERE IS STILL AROUND A 45-60% CHANCE FOR 0.25 INCH OF
RAINFALL FROM TILLAMOOK NORTHWARD, WITH A 50-60% CHANCE FOR A
0.50 INCH OF RAIN OR MORE IN THE WILLAPA HILLS. RAIN WILL BE
MORE SPOTTY WITH LIGHT AMOUNTS EXPECTED ACROSS PORTIONS OF
SOUTHWEST WA AND THE PORTLAND METRO, GENERALLY ONLY 20-25%
CHANCE FOR AMOUNTS TO EXCEED 0.10 INCH, WHILE CONDITIONS SALEM
SOUTHWARD REMAIN MOSTLY DRY.
THANKS TO THE QUICK-HITTING NATURE OF THIS FRONTAL SYSTEM,
CONFIDENCE IS HIGH WIDESPREAD DRY CONDITIONS RETURN WEDNESDAY
MORNING, AND FROM THIS POINT ONWARD DRY WEATHER LIKELY
CONTINUES THROUGH THE REMAINDER OF THE WEEK AND WEEKEND. THE
ONE CAVEAT INCLUDES A WEAK WEATHER SYSTEM POTENTIALLY BRUSHING
NORTHERN PORTIONS OF OUR FORECAST AREA AGAIN ON THURSDAY AND
THURSDAY NIGHT. BUT IN-LINE WITH PRIOR WEATHER MODEL CYCLES,
MOST 00Z ENSEMBLE MEMBERS ARE KEEPING THE RAIN PINNED FARTHER
NORTH, WITH ONLY 10% OR LESS SHOWING RAINFALL LOCALLY.
TEMPERATURES REMAIN FAIRLY SEASONABLE THROUGH THE END OF
SEPTEMBER INTO THE FIRST COUPLE OF DAYS OF OCTOBER WITH HIGHS
GENERALLY IN THE LOW TO MID 70S ACROSS THE INLAND VALLEYS.
BY THE WEEKEND, MODELS AND THEIR ENSEMBLES ARE IN FAIRLY GOOD
AGREEMENT OF A MORE PRONOUNCED RIDGE OF HIGH PRESSURE BUILDING OVER
THE REGION. THIS WOULD MAINTAIN DRY WEATHER AND POTENTIALLY TREND
AFTERNOON TEMPERATURES AROUND 5-10 DEGREES ABOVE NORMAL FOR EARLY
OCTOBER. CLUSTERS HINT AT MORE UNCERTAINTY THOUGH HEADING INTO EARLY
NEXT WEEK AS ENSEMBLES STRUGGLE TO HANDLE THE POTENTIAL BREAKDOWN
AND PROGRESSION OF THIS UPPER-LEVEL RIDGE. -99/DH
AVIATION...THROUGH 18Z WEDNESDAY
WESTERLY FLOW ALOFT CONTINUES
WITH MOIST ONSHORE FLOW IN THE LOWER LEVELS. THIS WILL MAINTAIN
MOSTLY CLOUDY SKIES WITH IFR TO MVFR STRATUS AT THE COAST, AND A
MIX OF MVFR AND LOW-END VFR INLAND. PROBABILITIES FOR WIDESPREAD
VFR INLAND INCREASE AFTER 00-02Z WED. BUT, CIGS ARE EXPECTED TO
LOWER AGAIN LATE TONIGHT INTO THU MORNING WITH AROUND A 60-70%
CHANCE OF MVFR AFTER 09-14Z THU. AT THE COAST, IFR CONDITIONS ARE
FAVORED THROUGH 00Z THU WITH MORE UNCERTAINTY IN THE FORECAST
AFTER THE COLD FRONT PUSHES INLAND, AS SOME GUIDANCE SUGGESTS
CONDITIONS IMPROVE WHILE OTHERS SUGGEST CONDITIONS WORSEN.
SOUTHERLY WINDS WILL BE STRONGEST ALONG THE NORTH OREGON COAST
TODAY WITH GUSTS TO AROUND 25 KT THROUGH THIS AFTERNOON NEAR
KAST. WINDS BECOME LIGHT BEHIND THE FRONT AND OVERNIGHT.
KPDX AND APPROACHES...CLOUDY SKIES WITH CIGS JUMPING BETWEEN MVFR
AND LOW-END VFR THIS MORNING, LIKELY BECOMING PREDOMINATELY MVFR
THIS AFTERNOON. THEN CIGS ARE EXPECTED TO LIFT BACK TO VFR BY
00-01Z THU. CHANCES FOR MVFR CIGS AGAIN INCREASE TO ABOVE 60%
AFTER 10Z THU AS THE FRONT SAGS THROUGH THE AREA. SOUTHERLY WINDS
AROUND 5-9 KT BECOME LIGHT LATER THIS EVENING. /DH
MARINE
THIS MORNING A FRONTAL BOUNDARY QUICKLY APPROACHES THE
WATERS WITH SOUTHERLY WIND GUSTS IN THE 20-30 KNOT RANGE PEAKING
NORTH OF CAPE FALCON, ESPECIALLY RIGHT ALONG THE COASTLINE. A
SMALL CRAFT ADVISORY REMAINS IN EFFECT FOR COASTAL WATERS NORTH
OF CAPE FOULWEATHER, INCLUDING THE COLUMBIA RIVER BAR, INTO THE
LATE AFTERNOON AND EARLY EVENING HOURS. BEHIND THE FRONT, WINDS
ARE EXPECTED TO ABRUPTLY SHIFT TO THE NORTHWEST, TRANSITIONING TO
A SOMEWHAT LIGHTER NORTHERLY WIND PATTERN WEDNESDAY. ANOTHER WEAK
SYSTEM MAY APPROACH THE NORTHERN WATERS FROM THE WEST ON
THURSDAY, BUT IT LIKELY HOLDS NORTH AS IT MOVES TOWARD THE
WASHINGTON COAST THEN OUT OF THE REGION TO THE EAST. NORTHERLY
WINDS THEN RETURN FRIDAY, LIKELY PERSISTING OVER THE WEEKEND.
A MID-PERIOD WEST-NORTHWESTERLY SWELL OF 6 TO 8 FT AT 13-15
SECONDS WILL MOVE THROUGH THE COASTAL WATERS TODAY THROUGH TONIGHT,
INCREASING SIGNIFICANT WAVE HEIGHTS INTO THE 8 TO 10 FT RANGE.
SEAS THEN GRADUALLY SUBSIDE TO AROUND 4 TO 6 FT LATER IN THE WEEK
WITH NO OTHER PROMINENT SWELLS OF NOTE AT THIS TIME. -99/DH
PQR WATCHES/WARNINGS/ADVISORIES
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY UNTIL 11 PM PDT THIS EVENING FOR PZZ210.
SMALL CRAFT ADVISORY UNTIL 5 PM PDT THIS AFTERNOON FOR PZZ251-
252-271-272.
WWW.WEATHER.GOV/PORTLAND
INTERACT WITH US VIA SOCIAL MEDIA:
WWW.FACEBOOK.COM/NWSPORTLAND
X.COM/NWSPORTLAND
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