156
FXUS66 KPQR 020429
AFDPQR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
929 PM PDT FRI MAY 1 2026
SYNOPSIS
HIGH PRESSURE OVER THE REGION WILL MAINTAIN
GENERALLY DRY CONDITIONS THROUGH THE NEXT SEVERAL DAYS. AN UPPER
LEVEL LOW THOUGH WILL INCREASE INSTABILITY AND ADD MOISTURE TO
THE ENVIRONMENT BRINGING CHANCES FOR ELEVATED THUNDERSTORMS OVER
THE CASCADES ON SATURDAY. TEMPERATURES CONTINUE TO RISE THROUGH
THE WEEKEND WITH SUNDAY BEING THE WARMEST WITH RECORD BREAKING
HIGHS IN THE FORECAST. SLIGHTLY COOLER IN THE LONG-TERM FORECAST
BUT OVERALL, FAIRLY TYPICAL SPRING TIME CONDITIONS.
SHORT TERM...NOW THROUGH SUNDAY
UPPER LEVEL RIDGING PERSISTS
TODAY WHICH HAS LEAD TO WARMING TEMPS AND EVENTUALLY CLEARING
SKIES. STABLE CONDITIONS THOUGH HAVE MAINTAINED COASTAL STRATUS
AND INSTABILITY ALONG THE CASCADES IS PROMOTING CUMULUS. THIS
SURFACE RIDGE IS COUPLED WITH A LOW ALOFT WHICH WILL BE A
WEATHER MAKER ON SATURDAY...THOUGH NOT ALL LOCATIONS WILL SEE
ACTIVE WEATHER. ON SATURDAY THE LOW ALOFT WILL DROP SOUTHWARD
GETTING HUNG UP ALONG THE OREGON/CALIFORNIA BORDER COAST IN THE
AFTERNOON.
AS IT PUSHES SOUTHWARD MOISTURE WILL BE ADDED TO THE ATMOSPHERE
AND INSTABILITY WILL BE INCREASED CONSIDERABLY. THIS INSTABILITY
CAN BE DISPLAYED LOOKING AT THE CAPE AND OMEGA VALUES. OMEGA
DROPS MEANING THERE IS SUPPORT ALOFT FOR LIFT, AND THE CAPE
BUILDS TO NEAR 1000 J/KG WHICH IS VERY HIGH FOR THIS AREA. IN
FACT, SOME AREAS WILL SEE CAPE GREATER THAN 1500 J/KG. THE
CASCADES WILL BE THE HARDEST HIT WITH THE WARMING TEMPERATURES
AND ELEVATED INSTABILITY THEREFORE HAVE INCREASED THE THREAT FOR
THUNDERSTORMS IN THE FORECAST. MODELS WERE SUGGESTING AROUND A
10% CHANCE, BUT HAVE INCREASED CLOSER TO 25% FOR THE LANE COUNTY
CASCADES WITH DECREASING PROBABILITIES AS YOU MOVE NORTHWARD.
THE MOST LIKELY SCENARIO IS ELEVATED THUNDERSTORMS WHICH WOULD
PRODUCE MINIMAL RAIN WHICH IS ALSO SUPPORTED BY THE LOWER THAN
DESIRED PRECIPITABLE WATER AMOUNTS. ELEVATED STORMS TOO MAKE
STRONG OUTFLOW GUSTS DIFFICULT. HOWEVER, CANNOT RULE OUT
LIGHTNING AND PERIODS OF HEAVY RAIN. HAIL IS A LESSER THREAT AS
THERE IS LESS MOISTURE WITHIN THE HAIL GROWTH ZONE ALOFT. A
LIMITING FACTOR WILL BE THE SHEAR AMOUNT OF DRY AIR ABOVE 1000
FT.
AS ANY ISOLATED STORMS DIE OUT, RIDGING ONCE AGAIN BUILDS IN ON
SUNDAY. THE FLOW ALOFT IS SOUTHERLY WHICH WILL USHER IN MUCH
WARMER AND DRIER AIR TO THE REGION. LOOKING AT RECORD BREAKING
HIGH TEMPERATURES ON SUNDAY WITH AREAS WITHIN THE GREATER
PORTLAND-VANCOUVER METRO AREA SEEING HIGHS EASILY NEAR 90
DEGREES. RECENT RUNS OF THE NBM 5.0 ARE SUGGESTING A MEDIAN
TEMPERATURE AT PORTLAND INTL AIRPORT OF AROUND 90 DEGREES F,
WITH A 10% CHANCE OF HIGHS GREATER THAN 95 DEGREES. IF WE DO IN
FACT HIT 90 DEGREES IN PORTLAND, THEN IT OFFICIALLY WILL BE THE
2ND EARLIEST 90 DEGREE DAY ON RECORD. OVERNIGHT TEMPERATURES
(BOTH SUNDAY MORNING AND INTO MONDAY MORNING) WILL FALL INTO THE
50S SO THERE WILL BE VERY GOOD OVERNIGHT RECOVERY. DAYTIME
HIGHS THOUGH ARE HIGH ENOUGH WITHIN THE PORTLAND-VANCOUVER METRO
AREA THAT A HEAT ADVISORY HAS BEEN ISSUED. OTHER PORTIONS OF
THE AREA TOO WILL BE QUITE WARM WITH HIGHS IN THE MID TO UPPER
80S SO THERE WILL BE VERY LITTLE ESCAPE.
WHILE THIS IS JUST A ONE DAY HEAT SPIKE, MANY WILL WANT TO HIT
THE WATER TO FIND SOME RELIEF. PLEASE REMEMBER THAT AREA LAKES
AND RIVERS ARE STILL VERY COLD WITH TEMPERATURES IN THE
MID-40S. THESE TEMPERATURES ARE COLD ENOUGH TO CAUSE COLD SHOCK
AND FATALITIES. PLEASE BE CAUTIOUS AROUND WATER AND ALWAYS USE A
LIFE JACKET. FOR THOSE SEEKING A BREAK FROM THE HEAT ALONG THE
COAST, THERE IS STILL AN ELEVATED CHANCE FOR SNEAKER WAVES ALONG
THE BEACHES THROUGH SUNDAY. SNEAKER WAVES CAN SWEEP YOU OFF OF
YOUR FEET AND DISLODGE LOGS CAUSING HAZARDOUS CONDITIONS. NEVER
TURN YOUR BACK TO THE OCEAN. -27
LONG TERM...MONDAY THROUGH FRIDAY
BY THE BEGINNING OF THE
WORKWEEK, ENSEMBLE GUIDANCE CONTINUES TO FAVOR MODERATING
TEMPERATURES AS THE UPPER RIDGE AXIS MOVES INLAND. A SOUTHERLY
WIND REVERSAL WILL INCREASE MARINE STRATUS COVERAGE ALONG THE
COAST, WITH BROADER ONSHORE FLOW COOLING INLAND AREAS AS WELL.
THERE IS GENERAL CONSENSUS IN DRY CONDITIONS ACROSS MOST OF THE
REGION, HOWEVER A MINORITY OF ENSEMBLE MEMBERS DEPICT VERY LIGHT
RAIN OR DRIZZLE WITHIN THE SHALLOW MARINE LAYER, MOST LIKELY IN
THE OVERNIGHT HOURS.
ON FRIDAY AN UPPER LEVEL LONGWAVE TROUGH WILL BEGIN TO ADVANCE
TOWARDS THE REGION WHICH WILL BEGIN TO DISRUPT THE OVERALL PATTERN.
WILL SEE THE RIDGE BEGIN TO FLATTEN AND TEMPERATURES LOWER EVEN
FURTHER TO MUCH MORE SEASONABLE HIGHS IN THE 70S. -27/36
AVIATION
NORTHERLY FLOW AT THE SURFACE CONTINUES TO SUPPORT A
MVFR/IFR MARINE LAYER ALONG THE COAST. FLIGHT CONDITIONS ALONG
THE COAST ARE EXPECTED TO BECOME MORE IFR/LIFR FROM 07Z-10Z
SATURDAY, WITH A HIGHER PROBABILITY OF LIFR CONDITIONS FOR KAST.
WHILE NORTHERLY FLOW AT THE SURFACE IS PRESENT FOR INLAND
TERMINALS, THERE IS SOUTHERLY FLOW ALOFT (WHICH CAN BE OBSERVED
VIA SATELLITE). THIS PATTERN IS MAINTAINING HIGH LEVEL CLOUDS
ACROSS THE AIRSPACE ABOVE FL200-FL250. WEST TO NORTHWEST WINDS AT
THE SURFACE 5-10 KT THROUGH THE EVENING, BECOMING LIGHT AND
VARIABLE OVERNIGHT. EXPECT SLOWLY LOWERING CIGS DOWN TOWARDS
FL050-FL100 AROUND THROUGH 10Z SAT.
RADAR IS ALSO SHOWING SOME SHOWERS ALONG THE CASCADES AND THEY
ARE HIGH BASED. THERE ARE SOME EMBEDDED THUNDERSTORMS WITHIN
THESE SHOWERS AND AS THE UPPER LEVEL FLOW SLOWLY BECOMES MORE
SOUTHEASTERLY THROUGH THE TAF PERIOD, THESE SHOWER COULD PUSH
FURTHER INLAND, RESULTING IN BRIEF PERIODS OF MVFR CONDITIONS.
GENERAL INSTABILITY WILL CONTINUE TO DECREASE AS SURFACE CONDITIONS
COOL. STILL, THE LOCATION AND TIMING OF ANY SHOWERS IS UNCERTAIN,
WITH CONFIDENCE IN ANY IMPACTS TO TERMINALS REMAINING VERY LOW.
KPDX AND APPROACHES...VFR CONDITIONS BENEATH INCREASING HIGH
CLOUDS EXPECTED THROUGH THE PERIOD, WITH CIGS FALLING FROM
FL200-FL250 TOWARDS FL100 THROUGH 08Z SATURDAY. NORTHWEST WINDS
TO 5-10 KT EASING BELOW 5 KT AROUND 06Z SATURDAY. /42
MARINE
HIGH PRESSURE WILL SUPPORT NORTHERLY WINDS THROUGH THE
WEEKEND, PEAKING THIS EVENING. WIND GUSTS OF 20-25 KT ARE MOST
LIKELY FOR ALL WATERS SOUTH OF CAPE FALCON AND NORTH OF CAPE
FALCON BEYOND 25-30 NM A SMALL CRAFT ADVISORY IS IN EFFECT FOR
THESE ZONES THROUGH 2 AM SATURDAY WITH WIND GUSTS EASING BELOW 20
KT AFTER THAT TIME. A WIND GUSTS AROUND 20 KT IS STILL POSSIBLE
OVER THE WATERS WITHIN 25-30 NM NORTH OF CAPE FALCON BUT THE
FREQUENCY IS EXPECTED TO BE MUCH LESS COMPARED TO THE REST OF THE
WATERS. SEAS REMAIN AROUND 6-8 FEET THROUGH THE WEEKEND THOUGH THE
PERIOD WILL INCREASE FROM AROUND 11-12 SECONDS TO AROUND 16-17
SECONDS SATURDAY AS A LONG PERIOD NORTHWEST SWELL MOVES IN. A
WIND REVERSAL ON MONDAY WILL SEE SOUTHERLY TO SOUTHWESTERLY FLOW
DEVELOP EARLY NEXT WEEK WITH INCREASED LOW MARINE STRATUS AND
OVERNIGHT DRIZZLE OR LIGHT RAIN. MORE SEASONABLE NORTHERLY FLOW
REDEVELOPS IN THE LATTER HALF OF THE WEEK WITH PERSISTENT SEAS OF
4-7 FT. -19/36
CLIMATE
DAILY RECORD HIGH TEMPERATURES FOR SUNDAY, MAY 3
LOCATIONFORECAST RECORD (YEAR)
ASTORIA 7581 (1992, 1944)
VANCOUVER 8984 (1944)
PORTLAND INT'L 9289 (1992)
HILLSBORO 9082 (2017)
MCMINNVILLE 8787 (1992)
SALEM 8986 (1992)
EUGENE 8583 (1944)
PQR WATCHES/WARNINGS/ADVISORIES
OR...HEAT ADVISORY FROM 8 AM TO 11 PM PDT SUNDAY FOR ORZ108-109-111-
112.
WA...HEAT ADVISORY FROM 8 AM TO 11 PM PDT SUNDAY FOR WAZ204>207.
PZ...SMALL CRAFT ADVISORY UNTIL 2 AM PDT SATURDAY FOR PZZ252-253-271.
SMALL CRAFT ADVISORY UNTIL 8 AM PDT SATURDAY FOR PZZ272-273.
WWW.WEATHER.GOV/PORTLAND
INTERACT WITH US VIA SOCIAL MEDIA:
WWW.FACEBOOK.COM/NWSPORTLAND
X.COM/NWSPORTLAND
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