908
FXUS66 KPQR 041000
AFDPQR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
300 AM PDT MON MAY 4 2026
SYNOPSIS
COOLER BUT STILL ABOVE-NORMAL TEMPERATURES WITH
LARGELY DRY WEATHER EXPECTED THROUGH MUCH OF THE WORKWEEK
BENEATH BROAD AND PERSISTENT UPPER-LEVEL RIDGING. CHANCES FOR
RAIN INCREASE FRIDAY INTO SATURDAY AS THE RIDGE DEAMPLIFIES, BUT
UNCERTAINTY IN TIMING AND COVERAGE OF PRECIPITATION CONTINUES.
DISCUSSION...NOW THROUGH SUNDAY
BROAD UPPER-LEVEL RIDGING
SPANNING THE NORTHEASTERN PACIFIC AND WESTERN CONUS IS FAVORED
TO REMAIN IN PLACE WITH A SLIGHT EASTWARD TENDENCY THROUGH THE
NEXT WEEK. AN UPPER CUTOFF LOW OVER CALIFORNIA WHICH SUPPORTED
OFFSHORE FLOW RESULTING IN RECORD HIGH TEMPERATURES ON SUNDAY
WILL EXIT EASTWARD MORE QUICKLY, FAVORING A RETURN TO MORE
SEASONABLE NORTHERLY TO NORTHWESTERLY FLOW ALOFT. DESPITE UPPER
HEIGHTS RISING IN THE WAKE OF THE DEPARTING LOW, TEMPERATURES
WILL ACTUALLY TREND COOLER WHILE ALSO REMAINING SEASONABLY WARM
THANKS TO THIS PATTERN CHANGE. THROUGH MIDWEEK, RENEWED ONSHORE
AND SOUTHERLY FLOW WILL MAINTAIN FAIRLY STEADY DAYTIME HIGH
TEMPERATURES IN THE 60S ALONG THE COAST AND IN HIGH TERRAIN AND
IN THE 70S TO NEAR 80 DEGREES WITHIN INLAND VALLEYS, SOME 10 OR
SO DEGREES ABOVE NORMAL. THIS SOUTHERLY SURGE WILL SEE MARINE
OVERCAST AND PERIODS OF MIST AND DRIZZLE ALONG THE COAST AND
CLOUDS REACHING INLAND THROUGH COASTAL GAPS EACH NIGHT, BEFORE
RETREATING BACK TOWARD THE COAST DURING THE DAY. AS SUCH,
LARGELY DRY AND TRANQUIL WEATHER IS EXPECTED FOR MOST.
BY THE END OF THE WORKWEEK, LONG-RANGE ENSEMBLES DEPICT A
SHORTWAVE TROUGH TRANSITING THE APEX OF THE RIDGE, BRINGING
COOLER TEMPERATURES CLOSER TO SEASONAL NORMS AS WELL AS THE MOST
WIDESPREAD CHANCES FOR RAINFALL TO THE REGION. THERE IS STILL
UNCERTAINTY IN THE TIMING AND DISTRIBUTION OF PRECIPITATION, BUT
THE ENSEMBLE CONSENSUS FAVORS RAIN OCCURRING SOME TIME BETWEEN
FRIDAY MORNING AND SATURDAY AFTERNOON, WITH THE HIGHEST CHANCES
TO THE NORTH AND IN AREAS OF HIGHER TERRAIN AND LOWER CHANCES
TO THE SOUTH AND FOR VALLEY LOCALES. AT THIS TIME, POTENTIAL
RAINFALL AMOUNTS LOOK TO BE LIGHT, GENERALLY 0.1 INCH OR LESS.
BEYOND THIS LATE-WEEK SYSTEM, RIDGING ALOFT WILL MOST LIKELY
REBUILD, FAVORING A RETURN TO DRY AND WARMER-THAN-NORMAL
CONDITIONS. THERE REMAINS UNCERTAINTY, HOWEVER, IN THE
POSITION, ORIENTATION, AND AMPLITUDE OF RIDGING, WHICH COULD
AFFECT THE SENSIBLE WEATHER ON THE GROUND. -36
AVIATION
CURRENT OBSERVATIONS SHOW VFR CONDITIONS FOR INLAND
AREAS WITH IFR/LIFR MARINE STRATUS MOVING NORTHWARD ALONG THE
COAST AND INFILTRATING AROUND THE SOUTHERN COASTAL RANGE AND
THROUGH THE GAPS AND FLOWS. OVERNIGHT, A WIND REVERSAL WILL SEE
SOUTHERLY FLOW DEVELOP ALONG THE COAST WITH A SLIGHT DELAY FOR
INLAND LOCATIONS. SOUTHERLY WINDS WILL PERSIST THROUGH THE TAF
PERIOD. THIS WIND REVERSAL WILL ALSO SUPPORT THE IFR/LIFR
MARINE STRATUS MENTIONED PREVIOUSLY AND HELP TO SPREAD THE
MARINE STRATUS NORTHWARD ALONG THE COAST THROUGH 12Z SUNDAY.
CURRENT OBSERVATIONS ALREADY SHOW KONP BEING IMPACTED WITH KTMK,
LIKELY SEE IMPACTS AROUND KTMK BY 05Z SUNDAY AND THE MARINE
STRATUS REACHING KAST AROUND 10Z SUNDAY. ADDITIONALLY, THERE'S A
50-75% CHANCE MVFR CIGS REACH KEUG AROUND 11Z SUNDAY, A 30-50%
CHANCE THE MVFR CIGS REACH KSLE AND A 15-20% CHANCE THEY REACH.
KUAO, KPDX AND SURROUNDING TERMINALS. IF LOWERED FLIGHT
CONDITIONS DEVELOP, INLAND LOCATIONS EXPECTED TO IMPROVE TO VFR
AROUND 18Z-21Z MONDAY. COASTAL LOCATIONS WILL LIKELY STAY
IFR/LIFR THROUGH THE TAF PERIOD.
KPDX AND APPROACHES...VFR CONDITIONS EXPECTED THROUGHOUT THE
PERIOD. SOUTHERLY WILL DEVELOP THOUGH 12Z MONDAY. THERE'S A
15-20% CHANCE OF MARINE STRATUS WITH MVFR CONDITIONS IMPACTING
KPDX AND SURROUNDING TERMINALS AFTER 12Z MONDAY. IF LOWERED
FLIGHT CONDITIONS DEVELOP, EXPECTED IMPROVEMENT TO VFR AROUND
18Z-21Z MONDAY. /42
MARINE
A SOUTHERLY SURGE IS UNDERWAY THIS MORNING, BRINGING
GUSTY SOUTH WINDS UP TO 20 KT, MARINE OVERCAST, AND PATCHY MIST
AND DRIZZLE TO THE COASTAL WATERS, ESPECIALLY WITHIN 20-30 NM
OF SHORE. A DIURNAL TENDENCY WILL PERSIST THROUGH WEDNESDAY,
WITH INCREASING CLOUDS, WIND, AND CHANCES FOR DRIZZLE OR LIGHT
RAIN AT NIGHT BEFORE CLOUDS RECEDE AND WINDS EASE DURING THE
DAY. A LESSENING NORTHWEST SWELL WILL SEE SEAS FALL FROM 6-8 FT
TODAY TO 4-5 FT BY WEDNESDAY.
WINDS LOOK TO TURN NORTHERLY WEDNESDAY THROUGH THURSDAY NIGHT
WITH PERSISTENT SEAS OF 5-7 FT. A SYSTEM MOVING ONSHORE FRIDAY
INTO SATURDAY WILL FAVOR A RETURN OF SOUTHERLY FLOW AND
INCREASED CHANCES FOR RAIN SHOWERS, BEFORE HIGH PRESSURE
REBUILDS LATER THIS WEEKEND AND NORTHERLY FLOW STRENGTHENS.
CHANCES INCREASE LATE SATURDAY INTO SUNDAY FOR NORTHERLY GUSTS
OF 20 KT, CONDITIONS WHICH MAY BE HAZARDOUS TO SMALL CRAFT. -36
PQR WATCHES/WARNINGS/ADVISORIES
OR...NONE.
WA...NONE.
PZ...NONE.
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