091
FXUS66 KPQR 171701 AAA
AFDPQR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
1000 AM PDT WED JUN 17 2026
UPDATED AVIATION DISCUSSION
SYNOPSIS
WARMER THAN NORMAL TEMPERATURES AND DRY WEATHER
WITH ONSHORE FLOW PERSIST THROUGH THE WEEKEND. SIGNAL IS
INCREASING FOR HOTTER TEMPERATURES RETURNING EARLY NEXT WEEK
WITH WIDESPREAD MODERATE TO LOCALLY MAJOR HEATRISK AS HIGH
PRESSURE BUILDS OVER THE WESTERN US, BUT UNCERTAINTY IN STRENGTH
AND LOCATION OF THE HIGH PRESSURE BRINGS UNCERTAINTY IN EXACT
TEMPERATURE FORECAST.
DISCUSSION...WEDNESDAY MORNING THROUGH TUESDAY
NW OR AND SW
WA REMAIN SITUATED BETWEEN UPPER LEVEL HIGH PRESSURE OVER THE
EASTERN PACIFIC AND LONGWAVE TROUGHING OVER THE MIDWEST AND
EASTERN US. UNDER THIS PATTERN, ONSHORE FLOW CONTINUES TODAY
WITH NORTH TO NORTHWESTERLY WINDS ACROSS THE REGION.
NORTHWESTERLY WINDS ALONG THE SOUTH WA AND NORTH OR COAST ARE
ALLOWING FOR ANOTHER PUSH OF MARINE STRATUS ALONG THE COAST
EARLY THIS MORNING. AS THIS MARINE INFLUENCE HAS CONTINUED FOR
THE PAST 24 HOURS OR SO, MODELS ARE INDICATING MARINE STRATUS
COULD FORM INLAND THIS MORNING WITH STRATUS SPREADING EAST/SOUTH
ALONG THE COLUMBIA RIVER AS WELL AS ALONG THE WESTERN CASCADES
AND BACK BUILDING INTO THE WILLAMETTE VALLEY. BEST CHANCES ARE
NORTH OF AURORA. STRATUS SHOULD DISSIPATE BY MIDDAY, LEADING TO
MOSTLY CLEAR SKIES AND HIGH TEMPERATURES IN THE UPPER 70S TO
LOW 80S ACROSS THE INTERIOR LOWLANDS AND 60S ALONG THE COAST.
THURSDAY INTO FRIDAY, THE MAJORITY OF 500MB ENSEMBLE MEMBERS
INDICATE WEAK YET BROAD TROUGHING DEVELOPING IN THE EASTERN
PACIFIC AS HIGH PRESSURE LINGERS OVER THE PACNW INTO THE DESERT
SW. HIGH TEMPERATURES WILL WARM BACK UP INTO THE MID TO UPPER
80S FOR THE INTERIOR LOWLANDS ON THURSDAY AND UPPER 80S TO LOW
90S FOR FRIDAY. CHANCES FOR REACHING OR EXCEEDING 90 DEGREES
REMAIN AROUND 20-45% FOR LOCATIONS BETWEEN CORVALLIS AND
VANCOUVER ON THURSDAY BUT HAVE INCREASED TO 45-75% ON FRIDAY.
THE WEAK TROUGHING IS SLATED TO MOVE INLAND SATURDAY, LOWERING
TEMPERATURES AGAIN TO THE UPPER 70S TO LOW 80S FOR THE INTERIOR
LOWLANDS. THERE IS NO PRECIPITATION SIGNAL WITH THIS TROUGH
EXCEPT FOR POSSIBLY DRIZZLE ALONG THE COAST DUE TO STRONGER
ONSHORE FLOW. ENSEMBLE MEMBERS ARE IN BETTER AGREEMENT THAT
TROUGHING WEAKENS AS IT MOVES EAST AND HIGH PRESSURE BEGINS
BUILDING OVER THE WESTERN US. THIS WOULD ALLOW FOR TEMPERATURES
TO RAISE A FEW DEGREES AGAIN BACK INTO THE MID TO UPPER 80S FOR
INLAND VALLEYS.
THE MAJORITY OF ENSEMBLE MEMBERS (75-85%) INDICATE HIGH PRESSURE
CONTINUING TO BUILD OVER THE WESTERN US MONDAY INTO TUESDAY,
POTENTIALLY BRINGING ANOTHER PERIOD OF WIDESPREAD INLAND
TEMPERATURES OVER 90 DEGREES. NBM INDICATES A 60-85% CHANCE OF
TEMPERATURES REACHING OR EXCEEDING 90 DEGREES BOTH DAYS FOR THE
INTERIOR LOWLANDS. NBM HAS MODERATE PROBABILITIES FOR REACHING
OR EXCEEDING 95 DEGREES AS WELL WITH A 50-70% CHANCE BETWEEN
VANCOUVER AND SALEM AND A 25-45% CHANCE FOR THE REST OF THE
INTERIOR LOWLANDS. HOWEVER, THE NBM 10TH-90TH PERCENTILE
TEMPERATURE SPREAD IS STILL AROUND 15 DEGREES RANGING FROM THE
THE MID TO UPPER 80S TO LOW 100S. THIS IS DUE TO A COMBINATION
OF UNCERTAINTY IN THE STRENGTH OF THE HIGH PRESSURE AS WELL AS
EXACTLY WHERE THE AXIS WILL SET UP. SOME GUIDANCE SUGGESTS THE
AXIS WILL BE CLOSER TO THE PACNW, WHICH WILL LEAD TO HOTTER
SOLUTIONS, WHERE OTHER GUIDANCE HAS THE AXIS A BIT MORE EAST,
LEADING TO THE SLIGHTLY COOLER SOLUTIONS. ALSO, NOTE THAT THIS
OVERALL TEMPERATURE SPREAD HAS WARMED FROM THE PREVIOUS TWO
FORECASTS, LEADING TO INCREASING CONFIDENCE IN HOTTER
TEMPERATURE SOLUTIONS.
OVERALL, THE FORECAST OVER THE NEXT 7 DAYS REMAINS ON THE DRY
AND WARM SIDE WITH MODERATE HEATRISK FOR PORTIONS OF THE
INTERIOR THURSDAY AND FRIDAY, BECOMING WIDESPREAD WITH SPECKS OF
MAJOR HEATRISK ON SUNDAY AND MONDAY. THOSE SENSITIVE TO THE
HEAT, ESPECIALLY THOSE WITHOUT ADEQUATE ACCESS TO AIR
CONDITIONING OR HYDRATION, SHOULD TAKE STEPS TO PRIORITIZE HEAT
SAFETY AND KEEP AN EYE ON THE RISING FORECAST FOR EARLY NEXT
WEEK. ALSO, REMEMBER THAT RIVERS AND LAKES REMAIN COLD DESPITE
THE WARM WEATHER, INCREASING THE RISK OF COLD- WATER SHOCK FOR
ANYONE SEEKING RELIEF NEAR THE WATER. -03
AVIATION
HIGH PRESSURE OVER THE REGION WILL LEAD TO PERSISTENT
NORTHWESTERLY FLOW ALOFT THROUGH THE PERIOD. MARINE STRATUS WITH
MVFR CIGS REMAINS ALONG THE NORTH OR AND SOUTH WA COAST. INLAND,
MVFR STRATUS PERSISTS THROUGH THE LOWER COLUMBIA RIVER VALLEY AND
INTO THE WESTERN CASCADE FOOTHILLS, INCLUDING PORTIONS OF THE
NORTHERN WILLAMETTE VALLEY. EXPECT MVFR CIGS AT PORTLAND AREA
TERMINALS TO PERSIST THROUGH 18Z. CONDITIONS ACROSS ALL TERMINALS
ARE EXPECTED TO IMPROVE TO VFR AFTER 18-21Z WED AS LOWER CLOUDS
SCATTER OUT. HIGH PRESSURE STRENGTHENS LATER TONIGHT INTO THU
WHICH WILL LEAD TO DRIER CONDITIONS AND THUS CLOUD COVER WILL BE
MORE CHALLENGING TO OBSERVE OUTSIDE OF THE COASTAL LOCATIONS.
WINDS ALONG THE COAST ARE EXPECTED TO INCREASE TO 12-15 KTS WITH
GUSTS TO AROUND 25 KTS THIS AFTERNOON. INLAND, WINDS INCREASE
AFTER 20Z TO 8-12 KTS WITH GUSTS UP TO 20 KTS. WINDS EXPECTED TO
DECREASE AFTER 06-08Z THU.
KPDX AND APPROACHES...BROKEN STRATUS WITH MVFR CIGS AROUND FL025
IS EXPECTED TO SCATTER OUT THIS AFTERNOON AS CONDITIONS IMPROVE TO
VFR BY 18-19Z. NORTHWEST WINDS INCREASE THIS AFTERNOON TO 8-11 KT
WITH GUSTS UP TO 18-20 KT, EASING AGAIN BY 07Z THU. /DH
MARINE
HIGH PRESSURE OFFSHORE WILL MAINTAIN A SUMMERTIME
PATTERN THROUGH THIS WEEK. DIURNALLY DRIVEN NORTHERLIES ARE
EXPECTED TO PEAK EACH AFTERNOON AND EVENING THROUGH THE WEEKEND.
WINDS EXPECTED TO PEAK EACH AFTERNOON AND EVENING WITH GUSTS TO
25-30 KTS, DECREASING A BIT IN THE LATE OVERNIGHT TO MORNING HOURS.
SEAS AROUND 7 TO 8 FT AT 8-10 SECONDS ARE EXPECTED TO BUILD TO
AROUND 8 TO 9 FT TONIGHT THEN BUILD TO 8-11 FT FRIDAY INTO
SATURDAY AS A FRESH NORTHWESTERLY SWELL BUILDS ACROSS THE WATERS.
/DH/03
PQR WATCHES/WARNINGS/ADVISORIES
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY UNTIL 5 AM PDT FRIDAY FOR PZZ251>253-
271>273.
WWW.WEATHER.GOV/PORTLAND
INTERACT WITH US VIA SOCIAL MEDIA:
WWW.FACEBOOK.COM/NWSPORTLAND
X.COM/NWSPORTLAND
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