524
FXUS66 KPQR 180901
AFDPQR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
201 AM PDT THU JUN 18 2026
SYNOPSIS
WARMER THAN NORMAL AND DRY CONDITIONS ARE EXPECTED
TO CONTINUE THROUGH THE MIDDLE OF NEXT WEEK. CONFIDENCE IS
INCREASING THAT HOT TEMPERATURES PEAKING MONDAY AND TUESDAY WILL
SUPPORT MODERATE TO MAJOR HEATRISK, HOWEVER THERE REMAINS
UNCERTAINTY IN THE TEMPERATURE FORECAST AT THIS LEAD TIME.
DISCUSSION...THURSDAY MORNING THROUGH WEDNESDAY
THERE HAS
BEEN VERY LITTLE CHANGE IN THE FORECAST SINCE THE LAST PACKAGE.
AN UPPER- LEVEL RIDGE AXIS CURRENTLY CENTERED OVER THE
NORTHEASTERN PACIFIC WILL SHIFT EASTWARD AND INLAND THROUGH THE
END OF THE WORKWEEK, BRINGING WARMER TEMPERATURES WITH A
TYPICAL SUMMERTIME NORTHERLY WIND PATTERN. TEMPERATURES WILL
PEAK ON THURSDAY AT THE COAST AND ON FRIDAY INLAND AS TROUGHING
ALOFT SUPPORTS A RETURN TO STRONGER ONSHORE FLOW FRIDAY INTO
SATURDAY. TEMPERATURES NEAR 70 DEGREES ON THE COAST WILL YIELD
MINOR HEATRISK ON THURSDAY, WHILE INLAND TEMPERATURES CLIMB INTO
THE 80S TO NEAR 90 DEGREES BOTH THURSDAY AND FRIDAY, YIELDING
WIDESPREAD MINOR HEATRISK AND LOCALLY MODERATE HEATRISK FROM
SALEM NORTH TO KELSO/LONGVIEW AND PORTLAND EAST THROUGH THE
COLUMBIA GORGE. THE CHANCES TO EXCEED 90 DEGREES ON THURSDAY ARE
ONLY AROUND 20-35% FROM HILLSBORO TO NORTHERN MARION COUNTY AND
5-15% ELSEWHERE FOR THE INTERIOR LOWLANDS. THESE CHANCES
INCREASE ON FRIDAY TO 35-55% FROM PORTLAND/VANCOUVER SOUTH TO
NORTHERN MARION COUNTY, 15-25% IN THE CENTRAL WILLAMETTE VALLEY,
AND 5-15% ELSEWHERE ALONG THE I-5 CORRIDOR. AFOREMENTIONED
TROUGHING AND ONSHORE FLOW WILL YIELD COOLER TEMPERATURES NEAR
60 DEGREES STARTING FRIDAY ON THE COAST, AND UPPER 70S TO LOW
80S WITHIN INLAND VALLEYS ON SATURDAY.
ENSEMBLE GUIDANCE REMAINS IN GOOD AGREEMENT THAT RENEWED RIDGING
WILL DEVELOP FROM SUNDAY INTO EARLY NEXT WEEK, RAISING THE
CHANCES FOR ANOTHER PERIOD OF HOT TEMPERATURES PEAKING MONDAY
AND TUESDAY. UNCERTAINTY IN THE POSITION AND AMPLITUDE OF THE
RIDGE AXIS REMAIN, LEADING TO UNCERTAINTY IN THE TEMPERATURE
FORECAST, BUT GIVEN THE MODEL CONSENSUS, THERE ARE 70-95%
CHANCES FOR TEMPERATURES TO EXCEED 90 DEGREES THROUGHOUT INLAND
VALLEYS ON MONDAY, AND SLIGHTLY LOWER CHANCES, 65-85%, ON
TUESDAY. THE CHANCES TO EXCEED 95 DEGREES SIMILARLY PEAK AT
GENERALLY 30-80% EACH OF MONDAY AND TUESDAY AFTERNOON, WHILE
THE CHANCES TO REACH 100 DEGREES REACH 15-35% ONLY FROM SALEM
NORTH TO VANCOUVER. THESE DAYTIME TEMPERATURES COMBINED WITH
OVERNIGHT LOWS IN THE UPPER 50S TO LOW 60S SUPPORT WIDESPREAD
MODERATE HEATRISK INLAND BOTH MONDAY AND TUESDAY, WITH THE
COVERAGE OF MAJOR HEATRISK LARGELY DEPENDENT ON THE OCCURRENCE
OF OVERNIGHT TEMPERATURES FALLING TO LOWS ONLY IN THE MID 60S.
THE CHANCES OF MAJOR HEATRISK VERY NEARLY MIRROR THOSE OF
NIGHTTIME LOWS OF 65 DEGREES OR WARMER MONDAY NIGHT: 15-20%
FOR THE CENTRAL WILLAMETTE VALLEY, INCREASING NORTHWARD TO 50%
IN THE INNER PORTLAND/VANCOUVER METRO, THEN DECREASING TO 20%
NEAR KELSO/LONGVIEW. LONG-RANGE GUIDANCE FAVORS A COOLING TREND
BEGINNING TUESDAY NIGHT AND CONTINUING INTO LATER NEXT WEEK,
BUT THERE'S STILL A 20-40% CHANCE FOR TEMPERATURES ABOVE 90
DEGREES TO PERSIST INTO A THIRD DAY ON WEDNESDAY. -36/03
AVIATION
VFR AND DRY OVER THE NEXT 24 HOURS WITH WEAK ONSHORE
FLOW. OVERNIGHT COOLING WITH ONSHORE FLOW WILL LEAD TO MARINE
STRATUS ALONG THE NORTH OR AND SOUTH WA COAST. THERE'S A 40-60%
CHANCE OF MVFR CEILINGS CONTINUING AT ANY GIVEN TIME THROUGH AT
LEAST 14Z THU, DISSIPATING BY 16Z THU. FOR COASTAL LOCATIONS SOUTH
OF CLATSOP COUNTY AND PORTLAND METRO AREA TERMINALS, CHANCES OF
MVFR CIGS ARE ONLY AROUND 20-30%. IF ANY STRATUS FORMS, CONDITIONS
WILL IMPROVE TO VFR BY 17Z THU. LIGHT OVERNIGHT WINDS WILL YIELD
TO ANOTHER BREEZY DAY WITH NORTHERLY TO NORTHWESTERLY WINDS.
HIGHEST WIND SPEEDS WILL BE ALONG THE CENTRAL OREGON COAST AROUND
KONP WITH GUSTS UP TO 20-25 KTS AFTER 17Z THU. GUSTY CONDITIONS
INCREASE THROUGH THE WILLAMETTE VALLEY BETWEEN 20Z THU AND 02Z
FRI, THOUGH CONFIDENCE IN THE DURATION IS A LITTLE LESS CERTAIN.
KPDX AND APPROACHES...VFR THROUGH THE NEXT 24 HRS WITH A 20-30%
CHANCE OF BRIEF MVFR STRATUS AROUND SUNRISE THU. NORTHWEST WINDS
INCREASE AFTER 20Z THU TO 8-11 KT WITH GUSTS UP TO 18-20 KT,
EASING AGAIN BY 03-06Z FRI. -03
MARINE
HIGH PRESSURE OFFSHORE WILL MAINTAIN A SUMMERTIME
PATTERN THROUGH THIS WEEK. DIURNALLY DRIVEN NORTHERLIES ARE
EXPECTED TO PEAK EACH AFTERNOON AND EVENING THROUGH AT LEAST
FRIDAY. WINDS ARE EXPECTED TO PEAK EACH AFTERNOON AND EVENING
WITH GUSTS TO 25-30 KTS, DECREASING A BIT IN THE LATE OVERNIGHT TO
MORNING HOURS. WINDS WILL LIKELY EASE OVER THE WEEKEND AS HIGH
PRESSURE WEAKENS AND LOW PRESSURE MOVES INTO NORTHWEST WA, TURNING
WINDS MORE NORTHWESTERLY ON SATURDAY. SEAS AROUND 7 TO 9 FT AT
8-9 SECONDS ARE EXPECTED TO BUILD TO 9 TO 11 FT AT 9-10 SECONDS
LATER THURSDAY INTO EARLY SATURDAY AS A FRESH NORTHWESTERLY SWELL
PERSISTS ACROSS THE COASTAL WATERS. SEAS ARE EXPECTED TO SUBSIDE
LATER SATURDAY INTO SUNDAY. /DH/03
PQR WATCHES/WARNINGS/ADVISORIES
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FROM 5 AM TO 10 AM PDT THIS MORNING FOR
PZZ210.
SMALL CRAFT ADVISORY UNTIL 5 AM PDT FRIDAY FOR PZZ251>253.
SMALL CRAFT ADVISORY UNTIL 5 AM PDT SATURDAY FOR PZZ271>273.
WWW.WEATHER.GOV/PORTLAND
INTERACT WITH US VIA SOCIAL MEDIA:
WWW.FACEBOOK.COM/NWSPORTLAND
X.COM/NWSPORTLAND
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