760
FXUS66 KPQR 110553 AAA
AFDPQR
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PORTLAND OR
1053 PM PDT FRI JUL 10 2026
UPDATED AVIATION DISCUSSION...
SYNOPSIS
GENERALLY ONSHORE FLOW WITH WEAK RIDGING AT THE MID
LEVELS. WILL CONTINUE TO SEE NEAR TO SLIGHTLY ABOVE NORMAL
TEMPERATURES OVER THE WEEKEND, WITH THE POTENTIAL TO WARM
FURTHER EARLY NEXT WEEK. OVERALL, WILL SEE MINIMAL CHANGE IN
THE FORECAST FROM DAY TO DAY THOUGH.
SHORT TERM...NOW THROUGH SUNDAY NIGHT
OVERALL VERY LITTLE
CHANGE IN THE FORECAST AS THE ENVIRONMENT REMAINS PERSISTENT
WITH MINIMAL FORCING FOR CHANGE. THE SYNOPTIC PATTERN CAN BE
DESCRIBED BY A RIDGE AT THE SURFACE WITH A DIGGING TROUGH ALOFT
AS A LOW FORMS OFF OF THE SOUTHERN PORTION OF THE ALASKA
PANHANDLE. THIS LOW REMAINS NEARLY STATIONARY THROUGH SUNDAY
MORNING BEFORE IT SLOWLY SHIFTS INLAND OVER BRITISH COLUMBIA.
SENSIBLE WEATHER WISE, THIS WILL KEEP ONSHORE FLOW IN PLACE WITH
MARINE STRATUS IN THE MORNING CLEARING IN THE AFTERNOONS.
TEMPERATURES WILL REMAIN ELEVATED IN THE 60S ALONG THE COAST AND
NEAR 80 DEG F IN THE INTERIOR LOWLANDS. HIGH RESOLUTION
ENSEMBLES THOUGH DO SUGGEST A SLIGHTLY LOWER TEMPERATURE ON
SATURDAY, LIKELY DUE TO THEM MAINTAINING MORE WIDESPREAD CLOUD
COVER THROUGH THE DAY, WHEREAS THE NBM IS SHOWING MUCH LESS
CLOUD COVER. IN THE CASE OF MORE DENSE CLOUDS THE HIGH
TEMPERATURE COULD RANGE FROM AROUND 65-75 DEGREES F IN PORTLAND
(THE 10TH TO 90TH PERCENTILE).
SIMILAR CONDITIONS ARE EXPECTED ON SUNDAY, THOUGH AS THE LOW
ALOFT SHIFTS INLAND, MORE WARM AIR WILL MOVE IN AT THE SURFACE.
IN THE AFTERNOON, 850 MB TEMPERATURES WILL RANGE FROM 11-14 DEG
C, AND CONTINUE TO RISE THROUGH MONDAY. WITH THE WARMER AIR
ALOFT MOVING IN CAN REASONABLY SAY THAT TEMPERATURES WILL
INCREASE A FEW DEGREES SUNDAY AFTERNOON. THE REFS SHOWS THE
10TH-90TH PERCENTILE HIGH TEMPERATURE AT PORTLAND AROUND 74-81
DEG F. IN COMPARISON, THE NBM HAS A SKEWED HIGHER SPREAD RANGING
FROM 77-83 DEG F. EITHER WAY, THERE IS FAIRLY HIGH CONFIDENCE IN
HIGHS BEING AROUND 80 DEGREES INLAND, AND AROUND 60-65 DEG F
ALONG THE COAST. THE CASCADES TOO WILL REMAIN WARM CONSIDERING
THE ELEVATION WITH A 10% CHANCE OF A HIGH OF 77 DEG F ALONG THE
WESTERN SLOPES.
WINDS WILL CONTINUE TO BE ONSHORE AT THE SURFACE AND ALOFT WITH
SLIGHTLY BREEZIER NORTHERLY WINDS ALONG THE COAST AND THE
WILLAMETTE VALLEY SUNDAY AFTERNOON WITH THE INFLUENCE OF DIURNAL
HEATING. -27
LONG TERM...MONDAY THROUGH FRIDAY
HIGH PRESSURE AT THE
SURFACE REALLY BEGINS TO TAKE HOLD OVER THE NORTHEAST PACIFIC ON
MONDAY WHICH WILL TREND CONDITIONS TOWARDS WARMER AND DRIER
CONDITIONS. 850 MB TEMPERATURES CONTINUE TO RISE THROUGH AT
LEAST WEDNESDAY WITH THE PEAK BEING TUESDAY AND WEDNESDAY.
AROUND 15-17 DEG C. THERE IS AN EXTENSIVE RIDGE ALOFT BUILDING
INLAND, WITH AROUND HALF OF THE ENSEMBLES SUGGESTING WEAK
TROUGH FORMING NEAR THE COAST LINE. THIS PATTERN ORIENTATION
WILL HAVE A SIGNIFICANT IMPACT ON JUST HOW HOT CONDITIONS WILL
BE. THE SPREAD OF POSSIBILITIES IS QUITE WIDE WITH AROUND A 8-10
DEG F SPREAD BETWEEN THE 10TH-90TH PERCENTILE ALONG THE COAST
AND AROUND A 12 DEG F SPREAD IN THE INTERIOR VALLEYS. LETS DIVE
INTO A FEW OF THE LOCATIONS FOR AN EXAMPLE OF THE LEVEL OF
UNCERTAINTY WE ARE DEALING WITH. I WILL NOTE THAT MODELS HAVE
FLUCTUATED QUITE A BIT OVER THE LAST 24-HOURS.
FOR TUESDAY, PORTLAND IS SHOWING A 10% CHANCE OF HIGH
TEMPERATURES OF 85 DEG F, AND EQUAL CHANCES OF THEM BEING 98
DEG F. ELSEWHERE IN THE WILLAMETTE VALLEY SHOWS SIMILAR RANGES.
THE UPPER HOOD RIVER VALLEY RANGES FROM AROUND 85-95 DEG F, AND
LONGVIEW 82-95 DEG F. MOVING INTO WEDNESDAY THOUGH THE
UNCERTAINTY GROWS SIGNIFICANTLY. IN FACT, THE RANGE FROM THE
COOLEST HIGH TEMPERATURE TO THE WARMEST (10TH TO 90TH
PERCENTILE) IS AROUND 20 DEG FOR THE WILLAMETTE VALLEY AND 10
DEG FOR THE COAST. IN FACT THERE IS AROUND A 10% CHANCE OF HIGHS
OF 70-75 DEG F FOR THE COAST, AND 100-105 DEG F FOR THE INLAND
VALLEYS INCLUDING SOME AREAS LIKE ESTACADA AND STAYTON. WITH
THIS BEING SAID THOUGH, THERE ARE EQUAL CHANCES OF TEMPERATURES
IN THE LOWER 80S. THEREFORE, NOT BITING ON ANY SPECIFIC OUTCOME
IN PARTICULAR AND HAVE MORESO STUCK WITH THE MEDIAN WITHIN THE
FORECAST TO ACCOUNT FOR SOME OF THE OUTLIERS. A SIMILAR TREND
OCCURS THUS FAR ON THURSDAY.
IF THESE TEMPERATURE FORECASTS REMAIN, WE ARE LOOKING AT THE
POTENTIAL FOR MODERATE HEATRISK WITH A 20% CHANCE OF MAJOR
HEATRISK FOR URBAN AREAS ON WEDNESDAY. -27
AVIATION
A WEAK UPPER LEVEL TROUGH CONTINUES TO MOVE SOUTH
TOWARDS AIRSPACE, TURNING THE FLOW ALOFT MORE SOUTHWESTERLY. THIS
TROUGH WILL THEN SHIFT NORTHEASTWARD AROUND 00Z SUN, KEEPING
PRECIPITATION OUT OF THE AIRSPACE. AS OF 06Z SAT, MARINE STRATUS
REMAINS PUSHED INTO THE COAST, MAINTAINING A MIX CONDITIONS FROM
VFR TO LIFR AT COASTAL TERMINALS. WHILE GUIDANCE SUGGESTS THAT
KAST WILL STAY MVFR THROUGH THE TAF PERIOD WITH ONLY A 10-30%
CHANCE OF IFR CIGS BETWEEN 07-10Z SAT, KONP WILL LIKELY STAY
UNDER LIFR/IFR CONDITIONS THROUGH MOST OF THE TAF PERIOD.
PROBABILISTIC GUIDANCE SUGGESTS A 70-90% CHANCE OF LIFR
CONDITIONS AT KONP UNTIL 12Z SAT, THEN A 40-60% CHANCE UNTIL 18Z
SUN. BEYOND 18Z SAT, KONP MAY STAY IFR OR IMPROVE TO MVFR, WITH A
10-30% CHANCE OF LIFR. DISAGREEMENT BETWEEN MODELS LEAVE MUCH
UNCERTAINTY BEYOND 18Z SAT FOR KONP.
AS FOR INLAND TERMINALS, EXPECT VFR CONDITIONS TO PERSIST UNTIL
07-09Z SAT, POSSIBLY DETERIORATE TO MVFR CIGS UNTIL 18-20Z SAT
(50-70% CHANCE), THEN RETURN TO VFR FOR THE REMAINING OF THE TAF
PERIOD. BACK BUILDING OFF OF THE CASCADES WILL BE THE MAIN DRIVER ON
WHETHER WE SEE THE DEEP STRATUS DEVELOP INLAND.
CURRENT WEST TO NORTHWESTERLY WINDS AROUND 5-10 KT WILL GRADUALLY
SHIFT MORE WEST TO SOUTHWESTERLY AND BECOME LIGHT TOWARDS 09Z
SAT. WINDS WILL THEN PICK BACK UP TO 5-10 KT AND GRADUALLY SHIFT
MORE WESTERLY TOWARDS TOMORROW AFTERNOON.
KPDX AND APPROACHES...VFR CONDITIONS WITH A 50-70% CHANCE OF MVFR
CIGS BETWEEN 09-18Z SAT. NORTHWESTERLY WINDS AROUND 5-10 KT WILL
BECOME LIGHT AND VARIABLE BY 12Z SAT, THEN INCREASE BACK TO 5-10
KT AND SHIFT SOUTHWESTERLY BY 18Z SAT.~12
MARINE
HIGH PRESSURE REBUILDS OVER THE COASTAL WATERS
THROUGH THE WEEKEND, RETURNING NORTHERLY WINDS LATER SATURDAY
AND INCREASING PRESSURE GRADIENTS ON SUNDAY. CHANCES FOR GUSTS
UP TO 25 KT RETURN SUNDAY AFTERNOON, MAINLY ACROSS THE CENTRAL
AND SOUTHERN WATERS OUT TO 30-40 NM. SEAS ARE EXPECTED TO
REMAIN AROUND 4 TO 6 FT AS RELATIVELY BENIGN CONDITIONS PERSIST
THROUGH THE WEEKEND AND INTO THE START OF NEXT WEEK. -19/DH
PQR WATCHES/WARNINGS/ADVISORIES
OR...NONE.
WA...NONE.
PZ...NONE.
WWW.WEATHER.GOV/PORTLAND
INTERACT WITH US VIA SOCIAL MEDIA:
WWW.FACEBOOK.COM/NWSPORTLAND
X.COM/NWSPORTLAND
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