635
FXUS66 KPQR 121027
AFDPQR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
327 AM PDT FRI JUN 12 2026
SYNOPSIS
UPPER LEVEL HIGH PRESSURE BUILDS OVER THE FAR
NORTHEAST PACIFIC INTO WESTERN WA/OR OVER THE NEXT SEVERAL
DAYS, USHERING IN A PROLONGED STRETCH OF DRY AND HOT
CONDITIONS. DAYTIME TEMPERATURES INCREASE SIGNIFICANTLY THIS
WEEKEND INTO EARLY NEXT WEEK, PEAKING SUNDAY AND MONDAY WITH
INTERIOR LOWLANDS IN THE UPPER 90S TO AROUND 100 DEGREES. LOW
TEMPERATURES WILL NOT PROVIDE MUCH RELIEF FROM THE HEAT. HEAT
RELATED IMPACTS ARE ANTICIPATED FOR MUCH OF THE REGION WITH
WIDESPREAD MODERATE TO HIGH HEATRISK. TEMPERATURES WILL TREND
COOLER FOR WEDNESDAY ONWARD WITH THE RETURN OF ONSHORE FLOW.
DISCUSSION...FRIDAY THROUGH THURSDAY
SATELLITE IMAGERY EARLY
FRIDAY MORNING SHOWS MOSTLY CLEAR SKIES OVER NW OR AND SW WA AS
HIGH PRESSURE BUILDS OVER THE E PACIFIC. THE EXCEPTION IS
POCKETS OF STRATUS ARE SEEN FORMING OVER THE N OR AND SW WA
COASTLINE AS LIGHT NW WINDS PUSH MOIST MARINE AIR INLAND. THIS
STRATUS SHOULD DISSIPATE BY LATE MORNING DUE TO SURFACE HEATING.
WEATHER CONDITIONS TODAY WILL BE SIMILAR TO THURSDAY WITH DRY
WEATHER AND INLAND HIGH TEMPERATURES PEAKING IN THE UPPER 70S
TO LOW 80S.
ATTENTION THEN SHIFTS TO THE SIGNIFICANT WARMING TREND THIS
WEEKEND INTO EARLY NEXT WEEK. ENSEMBLE GUIDANCE IS IN STRONG
AGREEMENT THAT UPPER LEVEL HIGH PRESSURE CONTINUES BUILDING
OVER THE E PACIFIC WITH THE AXIS SHIFTING CLOSER TO THE PACNW
SATURDAY THEN SHIFTING OVER THE COAST SUNDAY INTO MONDAY. AT THE
SURFACE, A THERMAL TROUGH CURRENTLY OVER THE N CA AND S OR COAST
WILL SPREAD NORTH INTO N OR WEST OF THE CASCADES SATURDAY INTO
MONDAY MORNING, INTRODUCING OFFSHORE FLOW ACROSS THE AREA, WHICH
WILL HAVE AN ADDITIONAL WARMING AND DRYING EFFECT FOR MANY
LOCATIONS.
DAYTIME TEMPERATURES ARE EXPECTED TO QUICKLY INCREASE INTO THE
UPPER 80S TO LOW 90S ON SATURDAY THEN TO THE MID TO UPPER 90S
FOR SUNDAY AND MONDAY FOR THE INTERIOR LOWLANDS AND PORTIONS OF
THE OR COAST RANGE. THE COAST WILL BE MUCH WARMER THAN NORMAL AS
WELL, PEAKING IN THE 70S EACH DAY AND NEAR 80 DEGREES ON SUNDAY.
THE OFFSHORE FLOW IS CONTRIBUTING TO THE WARMER TEMPERATURES
OVER THE COAST RANGE AND CASCADES. PROBABILITIES FOR
TEMPERATURES EXCEEDING 90 DEGREES ARE AROUND 60-90% BETWEEN
SALEM AND VANCOUVER ON SATURDAY, INCREASING TO OVER 90% FOR ALL
OF THE INTERIOR LOWLANDS AND PORTIONS OF THE COAST RANGE FOR
SUNDAY AND MONDAY. PROBABILITIES FOR TEMPERATURES EXCEEDING 95
DEGREES ARE AROUND 70-90% BETWEEN SALEM AND VANCOUVER AND 40-60%
FOR THE REST OF THE INTERIOR LOWLANDS ON SUNDAY, INCREASING TO
80-95% AND 60-75% RESPECTIVELY ON MONDAY. SOME LOCATIONS BETWEEN
SALEM AND VANCOUVER COULD ALSO REACH OR EXCEED 100 DEGREES,
ESPECIALLY ON MONDAY, WITH PROBABILITIES FOR SUNDAY 25-45% AND
MONDAY 45-75%.
LOW TEMPERATURES ARE NOT EXPECTED TO PROVIDE MUCH RELIEF FROM
THE DAYTIME HEAT SATURDAY NIGHT INTO SUNDAY MORNING THROUGH
MONDAY NIGHT INTO TUESDAY MORNING, ESPECIALLY SUNDAY NIGHT INTO
MONDAY MORNING. THERE'S ONLY A 15-35% CHANCE OF LOW TEMPERATURES
FALLING BELOW 60 DEGREES EACH NIGHT, WITH THE WARMEST CONDITIONS
EXPECTED FOR THE GREATER PORTLAND METRO AREA, COAST RANGE,
CASCADE FOOTHILLS, AND COLUMBIA RIVER GORGE. EVEN THE COAST IS
EXPECTED TO BE IMPACTED BY THESE WARMER LOW TEMPERATURES SUNDAY
MORNING AND MONDAY MORNING. LOW TEMPERATURES COULD EVEN REMAIN
ABOVE 70 DEGREES IN SOME LOCATIONS WITH A 5-15% CHANCE FOR THE
GREATER PORTLAND METRO AREA AND COAST RANGE SUNDAY NIGHT INTO
MONDAY MORNING AND 10-15% CHANCE FOR MUCH OF THE WILLAMETTE
VALLEY AND SW WA LOWLANDS, INCREASING TO 15-30% FOR THE GREATER
PORTLAND METRO AREA, ON MONDAY NIGHT INTO TUESDAY MORNING.
ENSEMBLE GUIDANCE INDICATES HIGH PRESSURE CONTINUES TUESDAY WITH
HEIGHTS BEGINNING TO LOWER ALONG WITH 850 MB TEMPERATURES, WHICH
WOULD ALLOW FOR LOWERING TEMPERATURES ON TUESDAY. HOWEVER,
THERE IS UNCERTAINTY IN THE FORECAST SPREAD OF BOTH OF THESE
ELEMENTS, LEADING TO UNCERTAINTY IN THE HIGH TEMPERATURE FOR
TUESDAY. ADDITIONALLY, IT IS NOT UNCOMMON FOR MODELS TO DEGRADE
HIGHLY AMPLIFIED RIDGES SUCH AS THIS ONE TOO EARLY IN THE
EXTENDED FORECAST PERIOD. THERE IS NO ROBUST WEATHER SYSTEM IN
THE MODELS THAT IS CAUSING THE LOWERING HEIGHTS, SO THERE IS THE
POTENTIAL THAT THE HIGH PRESSURE MAY NOT BREAK DOWN AS MUCH AS
ENSEMBLES INDICATE ON TUESDAY. NBM STILL INDICATES WARM DAYTIME
TEMPERATURES AT LEAST IN THE UPPER 80S FOR THE INTERIOR LOWLANDS
WITH A 30-50% CHANCE OF TEMPERATURES REACHING OR EXCEEDING 90
DEGREES SOUTH OF VANCOUVER. THE NBM 90TH PERCENTILE ALSO
INDICATES WIDESPREAD LOW TO MID 90S. ENSEMBLES ARE IN GOOD
AGREEMENT THAT THE SURFACE THERMAL TROUGH OVER OR WILL BREAK
DOWN SOMETIME MONDAY INTO TUESDAY, SO TUESDAY IS NOT EXPECTED TO
BE QUITE AS WARM FOR THE COAST AND COAST RANGE. EITHER WAY,
PAST HEAT EVENTS HAVE SHOWN THAT IMPACTS FROM THE HEAT CAN
CONTINUE DESPITE A COOL- DOWN, ESPECIALLY SINCE MORNING LOW
TEMPERATURES ARE EXPECTED TO REMAIN VERY WARM TUESDAY MORNING.
AN EXTREME HEAT WARNING HAS BEEN ISSUED FOR THE GREATER PORTLAND
METRO AREA AND HEAT ADVISORIES FOR THE REST OF THE REGION
BETWEEN THE COAST AND CASCADES FOR 11 AM SUNDAY THROUGH 11 PM
TUESDAY. THE COMBINATION OF VERY HOT DAYTIME TEMPERATURES AND
WARM OVERNIGHT TEMPERATURES WILL CREATE MODERATE TO MAJOR
HEATRISK ACROSS THE MAJORITY OF NW OR AND SW WA, EXCLUDING THE
CASCADES. THIS MEANS MOST OF THE GENERAL POPULATION WILL BE
SUSCEPTIBLE TO HEAT- RELATED ILLNESS, BUT ESPECIALLY THOSE
WITHOUT ACCESS TO AIR CONDITIONING AND THOSE SPENDING EXTENDED
TIME OUTDOORS. SOME FLUCTUATIONS IN THE MAJOR HEATRISK MAY BE
SEEN IN THE DETERMINISTIC FORECAST AS THE LOW TEMPERATURE
FORECASTS REMAIN RIGHT AROUND THE THRESHOLD AND FLUCTUATIONS OF
EVEN 1-3 DEGREES COULD CAUSE A DIFFERENCE BETWEEN MODERATE AND
MAJOR HEATRISK. HOWEVER, THERE IS A 60-80% CHANCE OF MAJOR
HEATRISK ACROSS MOST LOCATIONS BETWEEN THE COAST AND THE
CASCADES ON SUNDAY AND MONDAY, WHAT ARE EXPECTED TO BE THE
HOTTEST DAYS OF THIS HEAT EVENT. ADDITIONALLY, MANY HIGH AND LOW
TEMPERATURES COULD BREAK RECORDS WITH THIS EVENT. THOSE RECORDS
CAN BE SEEN IN THE "CLIMATE" SECTION BELOW.
IN ADDITION TO THE HEAT, THERE WILL ALSO BE INCREASING FIRE
WEATHER CONCERNS IN AREAS WITH CURED GRASSES AND FINER FUELS
SATURDAY INTO MONDAY DUE TO HOT, DRY, AND BREEZY CONDITIONS.
THE THERMAL TROUGH WILL BRING BREEZY CONDITIONS WITHIN THE
WESTERN COLUMBIA RIVER GORGE/CASCADES GAPS AND THE WILLAMETTE
VALLEY SATURDAY THROUGH SUNDAY NIGHT. AS DAYTIME HIGHS INCREASE,
RELATIVE HUMIDITIES WILL ALSO DECREASE. BASED ON FEEDBACK FROM
AREA PARTNERS, FUELS ARE NOT QUITE CURED ENOUGH TO CONSIDER ANY
RED FLAG WARNINGS AT THIS POINT, BUT THERE IS UNCERTAINTY ON
HOW THE FUELS WILL BE IMPACTED BY THE CONTINUOUS DAYS OF DRY
AND HOT CONDITIONS. BE AWARE OF POTENTIAL IGNITION SOURCES SUCH
AS VEHICLE CHAINS DRAGGING ON THE PAVEMENT, HOT VEHICLE
COMPONENTS, SPARKS CREATED BY POWER TOOLS, AND CIGARETTE BUTTS
AS ALL OF THESE COULD EASILY RESULT IN THE IGNITION OF CURED
GRASSES AND DRY, FINE FUELS. LIVE VEGETATION AND LARGER FUELS
MAY NOT HAVE ENOUGH TIME TO DRY OUT PRIOR TO THE DRY AND BREEZY
CONDITIONS, BUT THIS IS A VARIABLE THAT IS BEING CLOSELY
MONITORED BY OUR STATE AND FEDERAL FIRE PARTNERS.
ENSEMBLE GUIDANCE INDICATES THE HIGH PRESSURE AXIS SHIFTS WEST
BACK OVER THE E PACIFIC WEDNESDAY AND THURSDAY AS A STRONG UPPER
TROUGH DIGS INTO THE MIDWEST. HOWEVER, UNCERTAINTY IN THE
STRENGTH OF THE TROUGH LEADS TO UNCERTAINTY IN THE HIGH PRESSURE
OVER THE WESTERN US/E PACIFIC. THERE IS HIGH CONFIDENCE THAT
TEMPERATURES WILL BE QUITE COOLER THAN SUNDAY AND MONDAY, BUT
50-60% OF ENSEMBLE MEMBERS STILL KEEP JUST ENOUGH HIGH PRESSURE
OVER THE REGION FOR HIGH TEMPERATURES TO REMAIN IN THE LOW TO
MID 80S FOR THE INTERIOR LOWLANDS. -HEC
AVIATION
VFR FLYING CONDITIONS BENEATH LARGELY CLEAR SKIES
EXPECTED FOR MOST TERMINALS THROUGHOUT THE TAF PERIOD. THE ONLY
EXCEPTION IS MVFR CIGS ALONG THE N OR AND S WA COAST, WHICH
WILL IMPROVE TO VFR BY 16-17Z FRI AS DAYTIME HEATING PROGRESSES.
HIGH PRESSURE OFFSHORE WILL MAINTAIN DIURNAL NORTH TO NORTHWEST
WINDS, LIGHT LESS THAN 6 KTS THEN INCREASING AFTER 18-20Z FRI TO
AROUND 8-11 KTS WITH GUSTS UP TO 20-22 KT ALONG THE COAST. WINDS
DECREASE AGAIN AFTER 04-06Z SAT.
KPDX AND APPROACHES...VFR WITH CLEAR SKIES THROUGH THE TAF PERIOD.
NORTHWEST WINDS AROUND 5 KT OR LESS OVERNIGHT, INCREASING NEAR 10 KT
IN THE AFTERNOON AS PRESSURE GRADIENTS TIGHTEN. WINDS DECREASE
AGAIN AFTER 04-06Z SAT. -03
MARINE
EXPECT A TYPICAL SUMMERTIME PATTERN PERSIST INTO NEXT
WEEK AS HIGH PRESSURE BUILDS OFFSHORE. DIURNAL NORTHERLY WINDS
WILL STRENGTHEN, PEAKING EACH AFTERNOON AND EVENING. EXPECT WINDS
OF 15-20 KT WITH GUSTS UP TO 25 KT SOUTH OF CAPE FALCON ON
FRIDAY, INCREASING TO 15-25 KTS WITH GUSTS UP TO 30 KTS ON
SATURDAY. WIND GUSTS MAY FALL BELOW 21 KTS (SMALL CRAFT ADVISORY)
IN THE LATE NIGHT AND EARLY MORNING HOURS AT BUOYS AS PRESSURE
GRADIENTS SLACKEN, BUT STILL EXPECT GUSTS OVER 21 KTS IN THE OUTER
WATERS DURING THIS TIME. SMALL CRAFT ADVISORIES HAVE BEEN
EXTENDED THROUGH 5 AM PDT SUNDAY FOR LOCATIONS SOUTH OF CAPE
FOULWEATHER. SEAS CONTINUE TO HOLD AROUND 4-7 FT AT 9-11 SECONDS
WITH A PERSISTENT WESTERLY SWELL. LONG- RANGE GUIDANCE BRINGS A
RETURN OF MORE ACTIVE WEATHER AND A HIGHER CHANCE OF ELEVATED SEAS
BY THE END OF NEXT WEEK, BUT CONFIDENCE IN THIS PATTERN CHANGE IS
LOW.
CLIMATE
RECORD HIGH TEMPERATURES AND WARM LOW TEMPERATURES FOR SUNDAY,
JUNE 14
HIGH TEMPERATURES: WARM LOW TEMPERATURES:
PORTLAND INT'L 89F (1988) 62F (1985)
VANCOUVER, WA 93F (1986) 61F (1931)
HILLSBORO 96F (1961) 60F (1963)
MCMINNVILLE 93F (1986) 59F (1936)
SALEM 92F (1961) 59F (1936)
EUGENE 92F (1914) 57F (1993)
ASTORIA 86F (1914) 58F (1972)
RECORD HIGH TEMPERATURES AND WARM LOW TEMPERATURES FOR MONDAY,
JUNE 15
HIGH TEMPERATURES: WARM LOW TEMPERATURES:
PORTLAND INT'L 95F (1966) 60F (1969)
VANCOUVER, WA 95F (1930, 1966) 62F (1961)
HILLSBORO 99F (1961) 60F (1963)
MCMINNVILLE 96F (1961) 59F (1936)
SALEM100F (1966) 59F (1931)
EUGENE 96F (1966) 60F (1961)
ASTORIA 91F (1966) 58F (1997)
RECORD HIGH TEMPERATURES AND WARM LOW TEMPERATURES FOR TUESDAY,
JUNE 16
HIGH TEMPERATURES: WARM LOW TEMPERATURES:
PORTLAND INT'L 95F (1958) 60F (2012)
VANCOUVER, WA 92F (1961) 67F (1966)
HILLSBORO100F (1961) 65F (1961)
MCMINNVILLE 98F (1961) 59F (1966)
SALEM 97F (1961) 61F (1961)
EUGENE 95F (1961) 62F (1961)
ASTORIA 87F (1958) 59F (1997)
PQR WATCHES/WARNINGS/ADVISORIES
OR...HEAT ADVISORY FROM 11 AM SUNDAY TO 11 PM PDT TUESDAY FOR
ORZ104>108-113>119-121>125.
EXTREME HEAT WARNING FROM 11 AM SUNDAY TO 11 PM PDT TUESDAY FOR
ORZ109>112-120.
WA...HEAT ADVISORY FROM 11 AM SUNDAY TO 11 PM PDT TUESDAY FOR
WAZ202>205-208-210.
EXTREME HEAT WARNING FROM 11 AM SUNDAY TO 11 PM PDT TUESDAY FOR
WAZ206-207-209.
PZ...SMALL CRAFT ADVISORY FROM 2 PM THIS AFTERNOON TO 5 AM PDT SUNDAY
FOR PZZ252-272.
SMALL CRAFT ADVISORY UNTIL 5 AM PDT SUNDAY FOR PZZ253-273.
WWW.WEATHER.GOV/PORTLAND
INTERACT WITH US VIA SOCIAL MEDIA:
WWW.FACEBOOK.COM/NWSPORTLAND
X.COM/NWSPORTLAND
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