467
FXUS66 KPQR 211807
AFDPQR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
1100 AM PDT WED OCT 21 2026
SYNOPSIS
MAINLY DRY CONDITIONS WILL CONTINUE THROUGH EARLY
SATURDAY. LOW-LEVEL OFFSHORE FLOW AND ABUNDANT SUNSHINE WILL
RESULT IN AFTERNOON HIGH TEMPERATURES THAT ARE AROUND TEN
DEGREES ABOVE NORMAL FOR INLAND VALLEYS. WINDS TURN ONSHORE
LATER THIS AFTERNOON. TRENDING COOLER THURSDAY THROUGH TUESDAY
WITH WIDESPREAD MORNING FROST FRIDAY AND SATURDAY. CHANCES FOR
RAIN ARE MAINLY FOCUSED ON THE SATURDAY EVENING THROUGH SUNDAY
MORNING TIME FRAME WHEN CHANCES INCREASE TO 30-50%.
DISCUSSION...NOW THROUGH TUESDAY
DRY CONDITIONS FOR MOST OF
THE FORECAST AREA THROUGH EARLY SATURDAY. SHORTWAVE RIDGING
REMAINS IN PLACE TODAY, SUPPORTING ANOTHER DAY OF WELL ABOVE
AVERAGE TEMPERATURES WITH INTERIOR LOWLANDS PEAKING IN THE LOW
TO MID 70S AND 60S ALONG THE COAST. OFFSHORE WINDS CONTINUE
THROUGH THE MORNING ON THE EASTERN SLOPES OF THE CASCADES AND
THROUGH THE COLUMBIA RIVER GORGE. WIND GUSTS IN THE WESTERN
COLUMBIA RIVER GORGE COULD STILL REACH 20-30 MPH THROUGH AROUND
11 AM TODAY. WINDS WILL EVENTUALLY TURN ONSHORE AS A TROUGH
APPROACHES FROM THE NORTHWEST.
COOLER TEMPERATURES ARE EXPECTED THROUGH THE REST OF THE
FORECAST PERIOD AS SEVERAL TROUGHS MOVE OVER THE REGION.
TEMPERATURES IN THE 60S ARE EXPECTED OVER THE LOWLANDS AND 50S
AT THE COAST FROM THURSDAY ONWARD. ENSEMBLES CONTINUE TO TREND
DRIER WITH THE SYSTEM PASSING THROUGH ON THURSDAY WITH MOST OF
THE FORECAST AREA EXPECTED TO REMAIN DRY. THE BEST CHANCES FOR
PRECIPITATION WILL BE OVER THE CASCADES AND CASCADE FOOTHILLS,
MAINLY IN EASTERN LANE AND LINN COUNTIES WHERE POPS PEAK BETWEEN
20-40%. THE MAIN CONCERN DURING THIS TIME PERIOD WILL BE
WIDESPREAD MORNING FROST FRIDAY AND SATURDAY, BRINGING IMPACTS
TO THOSE WITH AGRICULTURAL INTERESTS. SATURDAY MORNING IS
SHAPING UP TO BE THE COLDEST MORNING, AS THIS IS WHEN SOME
LOCATIONS COULD FALL BELOW- FREEZING; THE NBM IS SHOWING A
25-50% CHANCE FOR LOWS OF 32 DEGREES OR COLDER IN THE SOUTHERN
WILLAMETTE VALLEY, EXCEPT HIGHER CHANCES GREATER THAN 80% FROM
CRESWELL TO COTTAGE GROVE AND NEAR 15% IN EUGENE.
DETAILS HEADING INTO THE WEEKEND REMAIN MURKY AS ENSEMBLES
SOLUTIONS CONTINUE TO VARY. THERE IS A MODERATE CHANCE (30-40%)
THAT A ROBUST SHORTWAVE DEVELOPS OVER THE GULF OF ALASKA AND
DROPS SOUTHWARD, SUPPORTING A SURFACE LOW AS IT APPROACHES THE
PACNW. ENSEMBLE MEMBERS CONTINUE TO TREND DRIER WITH MORE
SOLUTIONS FAVORING THE SURFACE LOW REMAINING OFFSHORE OR
TRACKING FARTHER NORTH INTO CANADA. THIS CURRENT TREND SIGNAL
LOWER POTENTIAL FOR MUCH NEEDED RAINFALL ACROSS THE AREA BUT
ALSO LOWER CHANCES FOR IMPACTFUL WINDS ACROSS THE REGION. THAT
BEING SAID, POPS HAVE DECREASED TO 30-50% LATE SATURDAY THROUGH
SUNDAY. CHANCES FOR 0.25 INCHES OF RAIN REMAIN AROUND 20-40% FOR
MOST LOCATIONS, SLIGHTLY HIGHER NEAR 40-50% ALONG THE COAST.
LASTLY, CHANCES FOR IMPACTFUL WINDS HAVE ALSO DECREASED WITH THE
POTENTIAL SYSTEM THIS WEEKEND, WITH LESS THAN A 5% CHANCE FOR
WIND GUSTS OF 40-45 MPH OR STRONGER. THEREFORE, IMPACTS ARE
UNLIKELY TO OCCUR THIS WEEKEND AND THERE'S A NOTABLE CHANCE
CONDITIONS WILL REMAIN DRY. CHANCES FOR RAIN DECREASE EVEN MORE
ON MONDAY AND TUESDAY TO 10-15%. -19/23
AVIATION...THROUGH 18Z THURSDAY
HIGH PRESSURE OVER THE REGION
WILL LEAD TO PREDOMINANTLY LIGHT WINDS AND VFR CONDITIONS THROUGH
18Z THURSDAY. THE MAIN EXCEPTION TO THIS WILL BE BETWEEN 09-18Z
THURSDAY WHEN CLEAR SKIES, LIGHT WINDS AND LOW LEVEL MOISTURE WILL
LEAD TO POCKETS OF FOG AND LOW CLOUDS DEVELOPING AT SEVERAL TAF
SITES. THE HIGHEST PROBABILITIES FOR IFR CONDITIONS DEVELOPING ARE
AT KEUG AND KHIO BETWEEN 09-18Z THURSDAY WHERE THERE IS A 30-40%
CHANCE FOR THESE CONDITIONS OCCURRING AT ANY GIVEN HOUR DURING THAT
TIMEFRAME. THERE IS AROUND A 20% CHANCE OF IFR CONDITIONS DEVELOPING
AT ANY GIVEN HOUR AT OUR REMAINING TAF SITES DURING THIS TIME
PERIOD. IN ADDITION, THERE IS A SIGNAL THAT MARINE CLOUDS ALONG THE
COAST MAY RESULT IN A PERIOD OF IFR CONDITIONS ALONG THE CENTRAL
COAST OF OREGON THIS EVENING, PRIMARILY BETWEEN 00-05Z THURSDAY.
KPDX AND APPROACHES...HIGH PRESSURE OVER THE REGION WILL LEAD TO
LIGHT WINDS AND PREDOMINANTLY VFR CONDITIONS THROUGH 18Z
THURSDAY. THE MAIN EXCEPTION TO THIS WILL BE IN THE 12-18Z
THURSDAY TIME PERIOD WHEN THERE IS A 20-30% CHANCE FOR MVFR TO IFR
CONDITIONS DEVELOPING AT ANY GIVEN HOUR.
MARINE
NORTHERLY WINDS EXPECTED TO REMAIN BELOW 20 THROUGH
EARLY TONIGHT WITH SEAS 5-7 FEET AT 11-13 SECONDS. WINDS AND
SEAS ARE SET TO INCREASE AGAIN LATE TONIGHT THROUGH FRIDAY
MORNING WITH THE PASSAGE OF A DECAYING FRONT. WINDS WILL BE
STRONGEST OVER THE NORTHERN WATERS NORTH OF CAPE FALCON WHERE
WIND GUSTS OF 25-30 KT WILL BE POSSIBLE. ELSEWHERE, WINDS ARE
EXPECTED TO BE SLIGHTLY LOWER BUT STILL HAZARDOUS TO SMALL
CRAFT. THEREFORE, SMALL CRAFT ADVISORIES HAVE BEEN ISSUED FOR
LATE TONIGHT INTO THURSDAY EVENING. LATER THURSDAY EVENING,
A STEEP WESTERLY SWELL MAY PUSH WAVE HEIGHTS TO 10-12 FEET AT
9-11 SECONDS WHICH WOULD WARRANT A HAZARDOUS SEAS ADVISORY FOR
THE WATERS NORTH OF CAPE FALCON. DECIDED TO HOLD OFF ON ISSUING
HAZARDOUS SEAS HEADLINES IN CASE AN EXTENSION OF THE SMALL
CRAFT ADVISORIES SUFFICES.
THERE IS THE POTENTIAL FOR A STRONGER LOW PRESSURE SYSTEM OVER
THE UPCOMING WEEKEND, BRINGING A 10-30% CHANCE FOR GALE FORCE
WIND GUSTS AND SEAS OVER 10 FEET. OVERALL CONFIDENCE IN THE
EXACT TRACK AND STRENGTH OF THIS POTENTIAL LOW PRESSURE SYSTEM
REMAINS LOW AT THIS TIME. IT IS WORTH NOTING THAT CHANCES HAVE
DECREASED FOR SIGNIFICANT WINDS AND SEAS WITH TODAY'S FORECAST
UPDATE DUE TO A LESS FAVORABLE LOW TRACK. -19/23
PQR WATCHES/WARNINGS/ADVISORIES
DURING THAT
TIMEFRAME
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FROM 11 AM TO 8 PM PDT THURSDAY FOR
PZZ210-252-253-273.
SMALL CRAFT ADVISORY FROM 5 AM TO 8 PM PDT THURSDAY FOR PZZ251-
271-272.
WWW.WEATHER.GOV/PORTLAND
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