320
FXUS66 KPQR 081714 AAB
AFDPQR
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PORTLAND OR
1014 AM PDT WED APR 8 2026
SYNOPSIS
TRENDING EVEN WARMER THURSDAY AND FRIDAY WITH
MAINLY DRY CONDITIONS WEST OF THE CASCADE FOOTHILLS. THERE IS A
40-70% CHANCE OF SHOWERS AND A 10-25% CHANCE OF THUNDERSTORMS
OVER THE CENTRAL OREGON CASCADES ON THURSDAY. ON FRIDAY, THERE
IS A 70-90% CHANCE OF SHOWERS AND A 15-25% CHANCE OF
THUNDERSTORMS OVER THE CENTRAL AND NORTHERN OREGON CASCADES. A
FEW STRAY SHOWERS OR STORMS MAY DRIFT INTO THE WILLAMETTE VALLEY
AND COAST RANGE, ESPECIALLY LATE FRIDAY. BECOMING COOLER AGAIN
OVER THE UPCOMING WEEKEND WITH INCREASING CHANCES FOR WIDESPREAD
SHOWERS.
SHORT TERM...WEDNESDAY THROUGH FRIDAY NIGHT
THE SHORT TERM
FORECAST IS HIGHLIGHTED BY A WARMING TREND WITH MAINLY DRY
CONDITIONS WEST OF THE CASCADE FOOTHILLS. TEMPERATURES WILL
START OFF CHILLY WEDNESDAY MORNING BEFORE THE WARMING TREND SETS
IN. MORNING LOWS ARE COLD ENOUGH TO SUPPORT AREAS OF FROST OVER
PORTIONS OF SOUTHWEST WA AND NORTHWEST OR, MAINLY IN RURAL
AREAS AWAY FROM URBAN CORES. WILL NOTE TEMPERATURES HAVE NOT
COOLED AS MUCH AS EXPECTED OVER THE WILLAMETTE VALLEY AS OF 3 AM
PDT WEDNESDAY AS OBSERVATIONS SHOW MANY LOCATIONS HOVERING IN
THE UPPER 30S TO LOWER 40S, HOWEVER THERE IS STILL SOME TIME
BEFORE SUNRISE FOR TEMPERATURES TO DIP A FEW MORE DEGREES GIVEN
THE CALM WINDS AND MOSTLY CLEAR SKIES IN PLACE. AS SUCH, VARIOUS
FROST ADVISORIES REMAIN IN EFFECT THROUGH 9 AM PDT WEDNESDAY
FOR POTENTIAL IMPACTS TO SENSITIVE OUTDOOR VEGETATION. DESPITE
THE CHILLY START TO THE DAY, ABUNDANT SUNSHINE WILL ALLOW
TEMPERATURES TO REBOUND INTO AT LEAST THE MID TO UPPER 60S FOR
INLAND VALLEYS. IN FACT, HIGHS IN THE LOWER 70S CANNOT BE RULED
OUT. THE NBM IS SUGGESTING THERE IS A 15-35% CHANCE FOR HIGHS OF
70 DEGREES OF WARMER ACROSS THE WILLAMETTE VALLEY AND PORTLAND
METRO, EXCEPT 60-80% IN THE SOUTHERN WILLAMETTE VALLEY.
TEMPERATURES ARE STILL ON TRACK TO TREND EVEN WARMER ON THURSDAY AND
FRIDAY IN RESPONSE TO AN UPPER LEVEL SHORTWAVE RIDGE ON THE NORTHEAST
PERIPHERY OF A LOW PRESSURE SYSTEM CENTERED OFF THE NORTHERN
CALIFORNIA COAST. OVERALL TEMPERATURE SPREAD ON THE NBM 1D VIEWER IS
VERY NARROW, SUGGESTING CONFIDENCE IS HIGH WARMER TEMPERATURES WILL
MATERIALIZE WITH HIGHS GENERALLY IN THE LOW TO MID 70S ACROSS THE
LOWLANDS, EXCEPT 60S AT THE COAST. THURSDAY WILL LIKELY REMAIN DRY
FOR MOST LOCATIONS, EXCEPT FOR PORTIONS OF THE CENTRAL OREGON
CASCADES AND FOOTHILLS. THIS AREA WILL SEE INCREASING MOISTURE AND
INSTABILITY ASSOCIATED WITH SOUTHERLY TO SOUTHEASTERLY FLOW ALOFT,
WARRANTING A 40-70% CHANCE OF SHOWERS AND A 10-25% CHANCE OF
THUNDERSTORMS MAINLY DURING THE AFTERNOON AND EVENING HOURS. A FEW
STRAY SHOWERS AND STORMS MAY EVEN DRIFT INTO THE CENTRAL OREGON
CASCADE FOOTHILLS (30-50% CHANCE) AND SOUTHERN WILLAMETTE VALLEY
(15-30% CHANCE) LATE IN THE DAY.
ON FRIDAY, CHANCES FOR SHOWERS INCREASE AND EXPAND IN COVERAGE AS
SOUTHERLY TO SOUTHEASTERLY FLOW ALOFT PERSISTS WITH AN EMBEDDED UPPER
LEVEL IMPULSE MOVING NORTHWARD OVER THE CASCADES. CHANCES FOR
THUNDERSTORMS REMAIN SIMILAR TO THURSDAY, BUT ALSO EXPAND IN
COVERAGE. THE LATEST FORECAST NOW SUGGESTS THERE IS A 70-90% CHANCE
OF SHOWERS AND A 15-25% CHANCE OF THUNDERSTORMS OVER THE CENTRAL AND
NORTHERN OREGON CASCADES AND FOOTHILLS FRIDAY AFTERNOON AND EVENING.
IF STEERING FLOW REMAINS MORE SOUTHEASTERLY RATHER THAN GOING DUE
SOUTH, SOME SHOWERS AND STORMS WOULD LIKELY DRIFT WEST OF THE CASCADE
FOOTHILLS INTO THE WILLAMETTE VALLEY, COAST RANGE, AND/OR
PORTLAND/VANCOUVER METRO. CHANCES FOR SHOWERS AND STORMS TO DRIFT
WEST OF THE CASCADE FOOTHILLS ARE HIGHEST AFTER 5 PM FRIDAY WHEN
PROBABILITIES FOR PRECIPITATION PEAK BETWEEN 25-45%, EXCEPT 15-30%
OVER THE COAST RANGE. GIVEN PWATS WILL BE APPROACHING 0.8-1.0 INCHES
PER ENSEMBLE GUIDANCE, ANY THUNDERSTORM THAT DOES DEVELOP WILL LIKELY
BRING BRIEF HEAVY RAIN. OTHER POTENTIAL HAZARDS WILL INCLUDE
CLOUD-TO-GROUND LIGHTNING, SMALL HAIL, AND LOCALIZED OUTFLOW WIND
GUSTS UP TO 40 MPH. SINCE FORECAST SOUNDINGS SUGGEST THERE WILL BE
RELATIVELY WEAK WIND SHEAR WITHIN THE CLOUD LAYER WITH A LONG/SKINNY
CAPE PROFILE, SEVERE STORMS CAPABLE OF PRODUCING DAMAGING WIND GUSTS
OVER 58 MPH AND/OR LARGE HAILSTONES AROUND THE SIZE OF QUARTERS OR
LARGER ARE NOT EXPECTED. -23
LONG TERM...SATURDAY THROUGH TUESDAY NIGHT
THE LONG TERM FORECAST
IS HIGHLIGHTED BY A COOL AND SHOWERY WEATHER PATTERN THAT IS MORE
TYPICAL FOR MID APRIL. THE GEFS/ENS/GEPS ENSEMBLE MEAN FOR 500 MB
HEIGHTS ALL SHOW A TROUGH MOVING INTO THE WESTERN CONUS SATURDAY
INTO SUNDAY, THROUGH WPC'S CLUSTER ANALYSIS REVEALS THERE IS STILL
SOME UNCERTAINTY REGARDING THE EXACT TIMING AND AMPLITUDE OF THIS
TROUGH. THAT SAID, OVERALL UNCERTAINTY IN THESE DETAILS IS LESS
COMPARED TO YESTERDAY. AS SUCH, PROBABILITIES FOR PRECIPITATION HAVE
INCREASED THIS WEEKEND. IN FACT, 6 HOURLY POPS NOW PEAK BETWEEN
60-90% ON BOTH SATURDAY AND SUNDAY, WITH THE HIGHEST PROBABILITIES
OVER THE CASCADES AND FOOTHILLS. NOTE 24-HOUR POPS ARE EVEN HIGHER,
PEAKING BETWEEN 80-100% ON SATURDAY. IN OTHER WORDS, AT LEAST SOME
RAIN IS VERY LIKELY TO OCCUR THIS UPCOMING WEEKEND. ALTHOUGH
CONFIDENCE IS HIGH RAIN WILL OCCUR, CONFIDENCE IS NOT AS HIGH
REGARDING EXACT RAIN AMOUNTS, ESPECIALLY GIVEN THE SHOWERY NATURE OF
PRECIPITATION. NEVERTHELESS, THE NBM V5.0 SUGGESTS THERE IS A 50-80%
CHANCE FOR AT LEAST 0.25 INCHES OF RAIN BETWEEN 5AM SATURDAY AND 5AM
SUNDAY, EXCEPT A 30-50% CHANCE ALONG THE SOUTH WA/NORTH OR COAST.
PROBABILITIES FOR AT LEAST 0.25 INCHES BETWEEN 5AM SUNDAY AND 5AM
MONDAY DECREASE TO 25-40%, EXCEPT 50-65% IN THE CASCADES. BEYOND 5AM
MONDAY, CHANCES DECREASE TO UNDER 10% AS MOST MODEL GUIDANCE SUGGESTS
SHOWERS WILL BE DISSIPATING BY EARLY NEXT WEEK.
CONFIDENCE IS HIGH TEMPERATURES WILL PEAK SOMEWHERE BETWEEN THE MID
50S TO MID 60S ON SATURDAY, BETWEEN 50 AND 60 DEGREES ON SUNDAY, AND
BETWEEN 55 AND 65 DEGREES EARLY NEXT WEEK. REGARDLESS OF THE EXACT
OUTCOME, IT WILL FEEL NOTICEABLY COOLER COMPARED TO WHAT HAS BEEN
OBSERVED OVER THE PAST FEW DAYS. -23
AVIATION
WESTERLY FLOW ALOFT CONTINUES AND IS RESULTING IN
WIDESPREAD VFR CONDITIONS UNDER MOSTLY CLEAR SKIES. THROUGH THE
TAF PERIOD WITH FEW/SCT HIGH CLOUDS WILL INFILTRATE INTO THE
AIRSPACE, BUT NO IMPACTS ARE EXPECTED. OVERALL, EXPECT VFR
CONDITIONS THROUGH THE MAJORITY OF THE TAF PERIOD. THE ONLY
EXCEPTION TO THIS, IS THAT SOME "BOG FOG" COULD DEVELOP ALONG THE
COAST RESULTING IN IFR/LIFR CONDITIONS AT KAST AND KONP. HOWEVER,
THE PROBABILITY OF THAT OCCURRING IS 5-10% AND WOULD START AROUND
14Z THURSDAY IF IT WERE TO OCCUR. ANY LOWERED FLIGHT CONDITIONS
THAT DO DEVELOP SHOULD IMPROVE TO VFR BY 19Z THURSDAY. WINDS
GENERALLY OUT OF THE NORTH/NORTHWEST AROUND 3-6 KT.
KPDX AND APPROACHES...VFR FLIGHT CONDITIONS THROUGH THE TAF
PERIOD WITH FEW/SCT HIGH CLOUDS. NORTH/NORTHWESTERLY WINDS 3-6
KT. /42
MARINE
SEAS OF 5-7 FT AT 10 TO 12 SECONDS, WITH LITTLE IN THE
WAY OF ACTIVE WEATHER IS EXPECTED THROUGH THE REMAINDER OF THE
WORKWEEK OTHER THAN PASSING RAIN SHOWERS ON THE NORTHERN FLANK OF
AN AREA OF LOW PRESSURE OFF THE NORTHERN CALIFORNIA COAST BY
FRIDAY. EVEN THEN, THESE SHOWERS WILL BE FOCUSED OVER THE SOUTHERN
WATERS AND ONLY HAVE A 15-25% CHANCE OF OCCURRING. THIS FEATURE
TO THE SOUTH MAY SUPPORT FURTHER SMALL CRAFT ADVISORY CONDITIONS
AS THERE IS A 30-60% CHANCE NORTHERLY TO NORTHWESTERLY WIND GUSTS
EXCEED 25 KT ON THURSDAY, WITH THE HIGHEST PROBABILITIES OVER THE
CENTRAL WATERS. -23/36
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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