270
FXUS66 KPQR 302343
AFDPQR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
443 PM PDT THU JUL 30 2026
UPDATED AVIATION DISCUSSION.
SYNOPSIS
ONSHORE FLOW PERSISTS THROUGH MUCH OF THE NEXT
WEEK, WHILE HIGH PRESSURE BUILDING OFFSHORE WILL SEE
TEMPERATURES TREND WARMER THROUGH FRIDAY. A FRONTAL SYSTEM
SATURDAY WILL BRING THE NEXT CHANCES FOR LIGHT RAIN AND GUSTY
WINDS. TRAILING THIS SYSTEM, A BROAD PATTERN CHANGE FAVORING
WARMER WEATHER INTO NEXT WEEK IS EXPECTED WITH MODERATE HEATRISK
POTENTIAL AND NORTHERLY WINDS. .
SHORT TERM...NOW THROUGH FRIDAY NIGHT
LITTLE CHANGE IN THE
FORECAST AS HIGH PRESSURE CONTINUES TO BUILD OVER THE AREA.
RADAR AND SATELLITE IS SHOWING A WEAK SHORTWAVE PASSING OVER THE
REGION THIS AFTERNOON WHICH IS PRODUCING SOME RETURNS. HOWEVER,
THE LOWER LEVELS OF THE ATMOSPHERE ARE DRY ENOUGH THAT ANY RAIN
THAT HAS PRODUCED IS NOT MAKING IT TO THE SURFACE. CLEAR SKIES
WILL LINGER THROUGH FRIDAY WHICH WILL SET UP THE SCENARIO FOR
WARMER TEMPERATURES AND LOWER DAYTIME RELATIVE HUMIDITY. WHILE
HIGHS WILL BE WARMER THAN THE LAST SEVERAL DAYS, WE ARE NOT
EXPECTING ANY RECORD BREAKING PEAKS BUT RATHER JUST SLIGHTLY
ABOVE NORMAL. NO REAL CONCERNS IN THE SHORT TERM FORECAST.
-27
LONG TERM...SATURDAY THROUGH THURSDAY
A BIT MORE OF AN ACTIVE
PATTERN THIS WEEKEND AS A BROAD TROUGH ALOFT OVER THE NORTHEAST
PACIFIC WILL BE THE WEATHER DRIVER. THIS TROUGH IS PRODUCING A
COLD FRONT THAT WILL PUSH INLAND ON SATURDAY WHICH WILL CAUSE
TEMPERATURES TO LOWER AND INCREASE CHANCES FOR RAINFALL THROUGH
THE DAY. THIS TROUGH IS COUPLED WITH A RIDGE OVER THE FOUR
CORNERS REGION OF THE US WHICH IS FAIRLY AMPLIFIED. THE
COMBINATION OF COOLER NEXT TO WARMER AIR, AND THE PRESSURE
GRADIENT, WILL CAUSE WINDS TO INCREASE SIGNIFICANTLY. WINDS WILL
BLOW WEST TO EAST THROUGH THE DAY AND INCREASE THROUGH THE
AFTERNOON. THE TYPICAL AREAS WILL SEE THE GUSTIEST WINDS (UPPER
HOOD RIVER VALLEY, COLUMBIA RIVER GORGE, GAPS OF THE COAST
RANGE). THE NBM MAX WIND GUSTS SHOW A MEAN OF AROUND 30 MPH
WITHIN THE COLUMBIA RIVER GORGE WITH SLIGHTLY HIGHER VALUES
AROUND THE WINDIEST OF LOCATIONS LIKE CROWN POINT. HOWEVER, IF
WE LOOK AT THE 90TH PERCENTILE (10% CHANCE OF OCCURRING), GUSTS
COULD REACH AS HIGH AS 45 MPH IN HOOD RIVER AND THE MORE EXPOSED
TERRAIN. FOR THE WILLAMETTE VALLEY, THERE IS A 10% CHANCE OF
GUSTS UP TO 25 MPH BUT BASED ON THE WIND DIRECTION, FOR MOST
AREAS THIS MAY BE A BIT OVERDONE. IN ADDITION TO THE WIND, RAIN
IS EXPECTED WITH THE FRONTAL PASSAGE THOUGH ACCUMULATION WILL BE
MINIMAL. OVERALL LOOKING AT HIGH CONFIDENCE (>80%) FOR THE NORTH
COASTAL AREAS FOR ACCUMULATING RAIN, 60% FOR SOUTHWEST
WASHINGTON, AND LESS THAN 10% FOR MOST OF THE INTERIOR PORTIONS
OF OREGON.
SUNDAY WILL BE A TRANSITIONAL DAY WITH DRY AND SLIGHTLY WARMER
CONDITIONS. VERY LITTLE IMPACT EXPECTED. HOWEVER, MONDAY AND
TUESDAY WILL SEE MORE CHANGE. ON MONDAY WE WILL SEE THE PROGRESSIVE
UPPER TROUGH EXIT EASTWARD WHICH LEADS TO HIGHER UNCERTAINTY IN
THE EVOLUTION OF THE PATTERN BY EARLY NEXT WEEK. LONG-RANGE
ENSEMBLES DEPICT A HIGH PROBABILITY OF STRONG UPPER RIDGING
DEVELOPING OVER THE FOUR CORNERS, BUT WHETHER THAT WILL
TRANSLATE TO HOT WEATHER LOCALLY IS LOWER CONFIDENCE. WHILE
TEMPERATURES ARE VERY LIKELY TO BE WARMER COMPARED TO THE
WEEKEND, THE SPREAD OF POTENTIAL SOLUTIONS REMAINS SOMEWHAT
WIDE. AT THIS POINT, THERE IS AN 80% CHANCE OF HIGHS IN THE 80S
WITHIN INLAND VALLEYS ON MONDAY AND A 75% CHANCE OF REACHING THE
90S ON TUESDAY, BEFORE THE POTENTIAL ENVELOPE OF OUTCOMES
WIDENS SUBSTANTIALLY ON WEDNESDAY, WHEN HIGHS ANYWHERE IN THE
80S OR 90S REMAIN POSSIBLE. IN THE WARMER SOLUTIONS, INLAND
RIDGING AND RESULTANT COASTAL THERMAL TROUGHING MAY BE
SUFFICIENT TO DRIVE PERIODS OF OFFSHORE FLOW, RESULTING IN
POTENTIAL GUSTY NORTH WINDS ALONG THE COAST AND WITHIN THE
WILLAMETTE VALLEY. -27/36
AVIATION...THROUGH 00Z SATURDAY
VFR CONDITIONS WITH SCATTERED
LOW CLOUDS OVER THE AIRSPACE CONTINUE INTO THURSDAY EVENING.
EXPECT VFR CONDITIONS TO CONTINUE THROUGH THE TAF PERIOD FOR MOST
TERMINALS. THE ONLY EXCEPTION WILL BE ALONG THE COAST, WHERE
THERE IS A 25-35% CHANCE OF MVFR CIGS FOR ANY GIVEN HOUR BETWEEN
12-16Z FRI. NORTHWESTERLY WINDS AROUND 5-11 KT WILL THEN BECOME
LIGHT AND VARIABLE AFTER 04-09Z FRI (EARLIEST ALONG THE COAST,
LATEST INLAND).
KPDX AND APPROACHES...VFR CONDITIONS WITH MOSTLY CLEAR SKIES
CONTINUE THROUGH THE PERIOD. DIURNAL NORTHWEST WINDS AROUND 6-9
KT WILL EASE AFTER 05-08Z FRI. -12/03
MARINE
BUOY OBSERVATIONS AS OF 3 PM THURSDAY CONTINUE TO
SHOW SEAS OF 3-4 FT, WHICH ARE EXPECTED TO PERSIST THROUGH MUCH
OF THE WEEK WITH A WEST TO NORTHWEST SWELL AT 7-9 SECONDS AND A
SECONDARY LONG-PERIOD SOUTH-SOUTHWESTERLY SWELL. A FRONTAL
SYSTEM APPROACHING THE WATERS FRIDAY INTO SATURDAY WILL BRING
INCREASED WINDS, MAINLY FOR THE INNER WATERS NORTH OF CAPE
FALCON AND ALL OF THE OUTER WATERS. CHANCES FOR RAIN PEAK
SATURDAY MORNING DURING THE FRONTAL PASSAGE, LIKELY CLEARING OUT
THROUGH THE AFTERNOON.
BEHIND THE BOUNDARY, INITIAL WESTERLY FLOW WILL VEER OUT OF THE
NORTH THROUGH THE WEEKEND AS SURFACE HIGH PRESSURE BUILDS
OFFSHORE. CHANCES FOR MAXIMUM WIND GUSTS OF AT LEAST 20-25 KT
ARE GREATER THAN 90% ACROSS THE WATERS FROM SUNDAY THROUGH AT
LEAST TUESDAY. CHANCES THAT PEAK AFTERNOON GUSTS REACH GALE-FORCE
ARE THE HIGHEST ON MONDAY AFTERNOON AND INCREASE TO THE SOUTH,
FROM LESS THAN 5% NORTH OF CAPE FALCON TO 35-50% SOUTH OF CAPE
FOULWEATHER. -12/36
PQR WATCHES/WARNINGS/ADVISORIES
OR...NONE.
WA...NONE.
PZ...NONE.
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