888
FXUS66 KPQR 131120
AFDPQR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
420 AM PDT MON JUL 13 2026
SYNOPSIS
NEAR NORMAL TEMPERATURES EXPECTED TODAY, THEN
INCREASING MONDAY AND TUESDAY AS A RIDGE AMPLIFIES OVER THE
NORTHERN PLAINS. THE TEMPERATURE AND PRECIPITATION FORECAST
BECOMES MORE UNCERTAIN LATE WEDNESDAY INTO THURSDAY, HOWEVER
CHANCES FOR RAIN SHOWERS DURING THAT TIME HAVE INCREASED WITH
THE LATEST FORECAST UPDATE. TRENDING WARM AND DRY FRIDAY AND
SATURDAY.
SHORT TERM...NOW THROUGH TUESDAY NIGHT
CLEAR SKIES AND LIGHT TO
CALM WINDS ACROSS THE AREA HAVE ALLOWED TEMPERATURES TO COOL
OFF NICELY INTO THE 50S FOR MOST LOCATIONS. CONFIDENCE IN THE
TEMPERATURES TODAY AND TUESDAY REMAIN HIGH AS UPPER LEVEL
HEIGHTS CONTINUE TO INCREASE. THE 500 MB PATTERN WILL AMPLIFY
WITH A LARGE RIDGE OF HIGH PRESSURE CENTERED OVER THE NORTHERN
PLAINS WHILE A SHORT WAVE DROPS SOUTHWARD ALONG THE WESTERN
PREPHERY OF THE RIDGE, OFF THE WESTERN CANADA COAST AND TOWARD
HE PACNW. AN UPPER LEVEL CLOSED LOW IS EXPECTED TO DEVELOP AS
THE SHORT WAVE PINCHES OFF FROM THE MAIN FLOW OVER THE FAR
NORTHEASTERN PACIFIC. SPREAD IN HIGH TEMPERATURES FOR TODAY AND
TOMORROW SMALL WITH INTERIOR LOWLAND HIGHS IN THE MID TO UPPER
80S TODAY AND UPPER 80S TO LOW 90S ON TUESDAY. COASTAL AREAS ARE
EXPECTED TO REMAIN COOLER IN THE MID 60S TO LOW 70S AS ON SHORE
FLOW PERSISTS.
CONDITIONS ARE EXPECTED TO REMAIN PREDOMINANTLY DRY ACROSS THE
AREA. THE ONE EXCEPTION WILL BE THE LANE AND LINN COUNTY
CASCADES TUESDAY EVENING AND INTO THE OVERNIGHT HOURS. A SUBTLE
DISTURBANCE IN THE UPPER LEVEL FLOW WILL PASS OVER CENTRAL
OREGON, SUPPORTING A 20-30% CHANCE FOR A SCATTERED SHOWER AND A
~10% CHANCE FOR AN ISOLATED THUNDERSTORM. MODELS CONTINUE TO
SHOW MOST OF THE CONVECTION EAST OF THE CASCADE CREST BUT A
STRAY SHOWER OR STORM CANT BE RULED OUT AT THIS TIME.
HAZY SKIES WILL BE POSSIBLE IN EASTERN LANE COUNTY DURING THE LATE
AFTERNOON/EVENING HOURS TODAY DUE TO SMOKE COMING FROM A WILDFIRE
BURNING IN NORTHWEST JACKSON COUNTY BETWEEN WIMER, OR AND SHADY
GROVE, OR. THE RRFS SMOKE MODEL BACKS UP THIS EXPECTATION, WITH
VERTICALLY INTEGRATED SMOKE VALUES INCREASING TO NEAR 25 MG/M^2 NEAR
THE CASCADE CREST. FORTUNATELY, SMOKE ALOFT IS NOT EXPECTED TO MIX
DOWN TO THE SURFACE IN EASTERN LANE COUNTY. -19/23
LONG TERM...WEDNESDAY THROUGH SUNDAY NIGHT
CONFIDENCE HAS
INCREASED FOR TEMPERATURES ON WEDNESDAY WITH THE CLOSED LOW
EXPECTED TO REMAIN OFFSHORE. THIS MEANS THE WARMER SOLUTION IS
FAVORED AT THIS TIME WITH A MUCH SMALLER RANGE IN 10TH- 90TH
TEMPERATURES, NOW RANGING FROM THE LOW 80S TO LOW 90S FOR THE
INTERIOR LOWLANDS. THIS IS STILL A DECENT SPREAD BUT MUCH
BETTER THAN A FEW DAYS AGO. CLUSTER ANALYSIS FAVORS THIS
SOLUTION WITH 50% OF MEMBERS KEEPING THE LOW OFFSHORE, AROUND
20% SLIGHTLY CLOSER TO THE WA/OR COAST BUT NOT QUITE OVERHEAD,
AND THE REMAINING 30% WITH THE DISTURBANCE DIRECTLY OVERHEAD
BUT WEAKER. IF THE LOW TAKES THE OVERHEAD ROUTE, EXPECT
TEMPERATURES TO BE ON THE COOLER END OF THE SPREAD. THE BIGGER
QUESTION HAS NOW SHIFTED TO THURSDAY REGARDING THE PROGRESSION
OF THE UPPER LOW. CLUSTER ANALYSIS SHOWS A MAJORITY, AROUND 50%
OF MEMBERS, DEPICTING THE LOW DIRECTLY OVERHEAD. AROUND 30% OF
MEMBERS SHOW THE WAVE MOVING TOWARD THE WA/OR COAST AND THE
REMAINING MEMBERS ACTUALLY HAVE THE UPPER LOW DEEPENING BUT
SHIFTING FARTHER SOUTHWEST OFF THE CALIFORNIA COAST. AT THIS
TIME, THE FAVORED SOLUTION IS FOR WEDNESDAY TO BE ON THE WARMER
SIDE WITH INTERIOR HIGHS IN THE MID TO UPPER 80S AND THURSDAY
TO BE THE COOLEST DAY OF THE WEEK WITH HIGHS IN THE LOW 80S.
HOWEVER, TOTAL MODEL SPREAD FOR HIGH TEMPERATURES ON THURSDAY
REMAINS LARGE DUE TO THIS UNCERTAINTY, WITH INLAND HIGHS RANGING
ANYWHERE FROM THE LOW 70S TO UPPER 90S PER THE NBM 10TH-90TH
PERCENTILE. GIVEN HOW THE ENSEMBLES HAVE STRUGGLED, THIS
SOLUTION IS FAR FROM SET IN STONE.
WEDNESDAY EVENING INTO THURSDAY COULD BE SHOWERY AS THE UPPER
LEVEL LOW MOVES OVER THE REGION. THE LATEST NBM GUIDANCE
REFLECTS THIS WELL AND HAS INCREASED POPS TO 20-40% WEDNESDAY
NIGHT INTO THURSDAY. CHANCES FOR AT LEAST 0.25 INCHES OF RAIN OR
MORE RANGE BETWEEN 10- 20% ACROSS ALL OF NORTHWEST OR AND
SOUTHWEST WA FROM THE COAST TO THE CASCADE CREST, WITH THE
HIGHEST PROBABILITIES OVER SOUTHWEST WA, THE NORTH OR
COAST/COAST RANGE, LOWER COLUMBIA, AND PORTLAND METRO. THERE IS
A 1-10% CHANCE FOR 0.50 INCHES OF RAIN OR MORE OVER THE
SOUTHWEST WA CASCADES AND COAST RANGE, WHICH REPRESENTS THE
WETTEST MODEL SOLUTIONS.
CONFIDENCE IN THE FORECAST ACTUALLY INCREASES A BIT FRIDAY AND INTO
THE WEEKEND. ENSEMBLE GUIDANCE IS IN GOOD AGREEMENT FOR DRY AND WARM
CONDITIONS, WITH HIGH TEMPERATURES SOMEWHERE IN THE 80S OR 90S FOR
INLAND VALLEYS. CHANCES FOR HIGHS OF 90 DEGREES OR WARMER PEAK ON
SUNDAY AT 50-60% ACROSS THE WILLAMETTE VALLEY, PORTLAND METRO,
COLUMBIA RIVER GORGE, AND UPPER HOOD RIVER VALLEY. CHANCES FOR
HIGHS ABOVE 100 DEGREES ARE AROUND 5-15%, SUGGESTING EXTREME
HEAT AND SIGNIFICANT HEAT-RELATED IMPACTS ARE UNLIKELY TO OCCUR
NEXT WEEKEND. BEYOND THE 7 DAY FORECAST, IT IS POSSIBLE THE WARM
AND DRY CONDITIONS PERSIST INTO NEXT WEEK. -19/23
AVIATION
HIGH PRESSURE OVER THE REGION CONTINUES TO MAINTAIN
WIDESPREAD VFR CONDITIONS. A WEAK LOW PRESSURE SYSTEM DIGS
SOUTHWARD OVER THE OCEAN THROUGH THE TAF PERIOD, BREAKING DOWN THE
HIGH PRESSURE AND GRADUALLY SHIFTING THE FLOW ALOFT TO SOUTHERLY.
THROUGH THE TAF PERIOD, EXPECT VFR CONDITIONS TO CONTINUE INLAND
AND MOSTLY VFR CONDITIONS ALONG THE COAST (THE EXCEPTION BEING A
20-30% CHANCE OF IFR CIGS BETWEEN 11-17Z MON DUE TO THE POTENTIAL
OF PATCHY LOW STRATUS). OTHERWISE, EXPECT LIGHT NORTH TO
NORTHWESTERLY WINDS OVERNIGHT, THEN 5-10 KT INLAND AND 10-15 KT
AT THE COAST BETWEEN 18Z MON AND 05Z TUE. COASTAL TERMINALS MAY
SEE GUSTS UP TO 20-25 KT.
KPDX AND APPROACHES...VFR WITH NORTHWESTERLY WINDS AROUND 5-10 KT.
~12
MARINE
HIGH PRESSURE OVER THE WATERS WITH A TYPICAL SUMMER
TIME PATTERN. FLOW REMAINS NORTH TO NORTHWEST WITH A THERMAL
TROUGH FORMING ALONG THE COAST. WINDS ARE GENERALLY 8-10 KT BUT
WILL CONTINUE TO RISE THROUGH THE AFTERNOON WITH GUSTS UP TO 25
KT. ALONG THE COASTLINE AND MOORAGES, GUSTS UP TO 25 KT HAVE
BEEN REPORTED. SMALL CRAFT ADVISORY (SCA) WINDS ARE EXPECTED
WITH SUSTAINED WINDS OF 15-20 KT AND GUSTS TO 25 KT OVER MUCH OF
THE WATERS, BUT LATEST MODELS HAVE REDUCED COVERAGE IN THE
NORTHERN WATERS. OVERALL, THE SCA IS MARGINAL AND WILL LIKELY
FLUCTUATE BELOW AND ABOVE CRITERIA. WINDS WILL EASE OVERNIGHT
INTO MONDAY MORNING AND THEREFORE HAVE SHORTENED THE LENGTH OF
TIME FOR THE HAZARD. SEAS WILL BE AROUND 5-7 FT AT 6-8 SECONDS.
COULD SEE PERIODS OF CHOPPIER SEAS, BUT NOT NECESSARILY
WIDESPREAD ENOUGH FOR HAZARDOUS SEAS. CONDITIONS THE REST OF THE
WORK WEEK ARE EXPECTED TO BE BENIGN WITH WIND WAVES RAMPING UP
ON SATURDAY.
A SCA HAS BEEN ISSUED AS WELL FOR ROUGH SEAS IN THE COLUMBIA RIVER
BAR DUE TO A STRONG EBB AND SEAS OF 7 FT.
-27
PQR WATCHES/WARNINGS/ADVISORIES
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY UNTIL 7 AM PDT THIS MORNING FOR PZZ210.
SMALL CRAFT ADVISORY FROM 2 AM TO 9 AM PDT TUESDAY FOR PZZ210.
WWW.WEATHER.GOV/PORTLAND
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