479
FXUS66 KPQR 201034
AFDPQR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
334 AM PDT MON JUL 20 2026
SYNOPSIS
HOT WEATHER WILL INTENSIFY THROUGH MIDWEEK AS HIGH
PRESSURE STRENGTHENS OVER THE REGION. INLAND TEMPERATURES ARE
EXPECTED TO PEAK TUESDAY AND WEDNESDAY, WHEN MANY VALLEY
LOCATIONS RISE INTO THE MID TO UPPER 90S, WHILE COASTAL AREAS
REMAIN SUBSTANTIALLY COOLER. DRY CONDITIONS WILL CONTINUE, AND
HEAT IMPACTS WILL INCREASE ACROSS THE INTERIOR LOWLANDS BEFORE A
NOTICEABLE EASING OF TEMPERATURES ARRIVES LATER IN THE WEEK.
DISCUSSION...NOW THROUGH SATURDAY
THE EARLY MORNING PATTERN
REMAINS DOMINATED BY A BROAD RIDGE CENTERED OVER THE GREAT BASIN
AND EXTENDING NORTHWEST INTO THE PACIFIC NORTHWEST. THAT
FEATURE WILL CONTINUE TO SUPPORT A WARM AND DRY STRETCH THROUGH
AT LEAST WEDNESDAY, WITH ONLY WEAK MARINE INFLUENCE LINGERING
NEAR THE COAST. AS A RESULT, INLAND AREAS WILL KEEP WARMING DAY
BY DAY, WHILE COASTAL LOCATIONS STAY NOTICEABLY COOLER BUT STILL
EDGE UPWARD A FEW DEGREES.
FORECAST CONFIDENCE REMAINS HIGHEST IN THE BROADER TEMPERATURE
TREND AND SOMEWHAT LOWER IN THE DETAILS FOR THE MIDDLE OF THE
WEEK. ONE SOURCE OF UNCERTAINTY CONTINUES TO BE THE TIMING AND
NORTHWARD EXTENT OF MOISTURE ASSOCIATED WITH OFFSHORE LOW
PRESSURE AND SOUTHERLY FLOW ALOFT. CURRENT GUIDANCE SUGGESTS THE
BETTER POTENTIAL FOR DEEPER MOISTURE AND ANY ASSOCIATED
PRECIPITATION WOULD HOLD OFF UNTIL LATE WEDNESDAY INTO THURSDAY,
WHICH WOULD LESSEN ITS INFLUENCE ON DAYTIME HEATING TUESDAY AND
LIKELY MUCH OF WEDNESDAY AS WELL. EVEN SO, SOME INCREASE IN
HIGH CLOUDS, HAZE, OR SMOKE REMAINS POSSIBLE BEFORE THEN, AND
THAT COULD STILL HAVE A MODEST EFFECT ON TEMPERATURES. CLUSTER
GUIDANCE REMAINS LESS THAN IDEAL IN ITS AGREEMENT, SO WHILE THE
MOST LIKELY OUTCOME STILL FAVORS A HOTTER AND DRIER SOLUTION
THROUGH MIDWEEK, SOME FORECAST UNCERTAINTY REMAINS.
TODAY WILL MARK THE BEGINNING OF THE HOTTER STRETCH FOR THE
INTERIOR LOWLANDS, WITH WIDESPREAD UPPER 80S TO LOWER 90S
EXPECTED. THE COAST SHOULD REMAIN CONSIDERABLY COOLER, GENERALLY
IN THE 70S. THE HOTTEST CONDITIONS ARE STILL EXPECTED TUESDAY
AND WEDNESDAY, WHEN MANY INLAND VALLEYS REACH THE MID 90S AND
SOME OF THE TRADITIONALLY WARMER LOCATIONS MAY PUSH THE UPPER
90S. WHILE THERE REMAINS SOME SPREAD IN THE GUIDANCE, THE ODDS
CONTINUE TO SUPPORT WIDESPREAD MID TO UPPER 90S BOTH DAYS, AND
THERE IS STILL A LOWER-END CHANCE (15-30%) THAT A FEW SPOTS
APPROACH 100 DEGREES IF CLOUDS AND HAZE REMAIN LIMITED.
HEAT-RELATED IMPACTS WILL BECOME MORE OF A CONCERN AS THIS
STRETCH CONTINUES. MULTIPLE DAYS OF ABOVE NORMAL HEAT COMBINED
WITH LIMITED OVERNIGHT RELIEF WILL SUPPORT WIDESPREAD MODERATE
HEATRISK ACROSS MUCH OF THE INTERIOR. THE GREATEST CONCERN
REMAINS CENTERED ON THE PORTLAND/VANCOUVER METRO, THE COLUMBIA
RIVER GORGE INCLUDING HOOD RIVER COUNTY, AND THE KELSO/LONGVIEW
AREA, WHERE A HEAT ADVISORY IS IN EFFECT FROM TUESDAY MORNING
THROUGH AT LEAST WEDNESDAY EVENING. WITHIN THOSE AREAS, MAJOR
HEATRISK APPEARS INCREASINGLY LIKELY TUESDAY AND WEDNESDAY,
ESPECIALLY IN LOCATIONS THAT SEE THE WARMEST AFTERNOONS AND THE
LEAST NIGHTTIME COOLING. THOSE WITH OUTDOOR PLANS OR WITHOUT
EFFECTIVE COOLING SHOULD BE PREPARED FOR ELEVATED HEAT IMPACTS.
SO, DRINK PLENTY OF FLUIDS, STAY IN A COOL PLACE DURING THE
HEAT OF THE DAY, STAY OUT OF THE SUNSHINE, AND CHECK UP ON
RELATIVES AND NEIGHBORS.
BY THURSDAY AND FRIDAY, THE RIDGE IS EXPECTED TO WEAKEN SOMEWHAT
AS A BROADER TROUGH BEGINS TO PRESS INTO THE PACIFIC NORTHWEST.
THAT SHOULD ALLOW TEMPERATURES TO EASE A FEW DEGREES LATE IN THE
WEEK, THOUGH VALUES MAY STILL REMAIN SOMEWHAT ABOVE AVERAGE FOR
LATE JULY. BEYOND FRIDAY, THERE IS CURRENTLY NO STRONG SIGNAL
FOR MEANINGFUL PRECIPITATION. ~12
AVIATION
CURRENTLY AS OF 11Z MON, MARINE STRATUS MAINTAINS LIFR
CONDITIONS AT COASTAL TERMINALS WHILE INLAND TERMINALS REMAIN
VFR. THROUGH THE TAF PERIOD FOR COASTAL TERMINALS, GUIDANCE
SUGGESTS LIFR/IFR CONDITIONS UNTIL 17-19Z MON, POTENTIAL VFR
CONDITIONS AFTERWARD, THEN MORE LIFR/IFR CONDITIONS BY 01-03Z
TUE. WHILE GUIDANCE SUGGESTS A 70-90% CHANCE TO IMPROVE TO VFR
AT KAST BETWEEN 19Z MON AND 01Z TUE, KONP ONLY HAS A 50-70%
CHANCE TO IMPROVE TO VFR. IN OTHER WORDS, THERE IS A 10-30%
CHANCE FOR COASTAL TERMINALS TO MAINTAIN IFR CIGS BETWEEN 19Z
MON AND 01Z TUE. INLAND TERMINALS WILL MAINTAIN VFR CONDITIONS
THROUGH THE TAF PERIOD, ESPECIALLY WITH DRIER CONDITIONS
EXPECTED THROUGH THE TAF PERIOD. OTHERWISE, EXPECT NORTHWESTERLY
WINDS BETWEEN 5-10 KT AT ALL TERMINALS.
KPDX AND APPROACHES...VFR CONDITIONS WITH NORTHWESTERLY
WINDS BELOW 8 KT THROUGH THE PERIOD. ~12
MARINE
A TYPICAL SUMMERTIME PATTERN WILL CONTINUE THROUGH
THE MIDDLE OF THIS WEEK WITH PERSISTENT NORTH TO NORTHWEST
WINDS OVER THE COASTAL WATERS. GUSTY WINDS AND STEEP SEAS WILL
GRADUALLY DECREASE THIS MORNING, BRINGING AN END TO HAZARDOUS
CONDITIONS FOR SMALL CRAFT ACROSS ALL WATERS. AS SUCH, SMALL
CRAFT ADVISORIES FOR ALL THE WATERS WILL REMAIN IN EFFECT UNTIL
11 AM THIS MORNING. BENIGN CONDITIONS EXPECTED LATE TODAY INTO
LATE THIS WEEK. ~12
PQR WATCHES/WARNINGS/ADVISORIES
OR...HEAT ADVISORY FROM 10 AM TUESDAY TO 11 PM PDT WEDNESDAY FOR
ORZ108-109-111-112-115-120>122.
WA...HEAT ADVISORY FROM 10 AM TUESDAY TO 11 PM PDT WEDNESDAY FOR
WAZ204>207-209-210.
PZ...SMALL CRAFT ADVISORY UNTIL 11 AM PDT THIS MORNING FOR PZZ251>253-
271>273.
WWW.WEATHER.GOV/PORTLAND
INTERACT WITH US VIA SOCIAL MEDIA:
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