821
FXUS66 KPQR 231735 AAA
AFDPQR
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PORTLAND OR
1034 AM PDT WED APR 23 2025
UPDATED AVIATION DISCUSSION.
SYNOPSIS
A STRETCH OF DRY, SUNNY WEATHER CONTINUES TODAY AND
THURSDAY AS HIGH PRESSURE REMAINS OVER THE REGION. HOWEVER, A SHIFT
IN THE WEATHER PATTERN IS EXPECTED LATE THURSDAY INTO FRIDAY,
BRINGING INCREASING CLOUDS, COOLER TEMPERATURES, AND A CHANCE OF RAIN
AS A NEW SYSTEM APPROACHES FROM THE PACIFIC.
SHORT TERM...NOW THROUGH THURSDAY NIGHT
EXPECT DRY AND MOSTLY
CLEAR WEATHER THROUGH THURSDAY AS HIGH PRESSURE MAINTAINS SUNNY
SKIES AND LIGHT WINDS. A RIDGE ALOFT IS GRADUALLY BUILDING
INLAND, WITH UPPER-LEVEL WINDS BEGINNING TO SHIFT MORE NORTHERLY
LATER TODAY. TEMPERATURES WILL CONTINUE A WARMING TREND, WITH
INTERIOR VALLEYS REACHING THE UPPER 60S TO LOW 70S TODAY, THEN
RISING INTO THE LOW TO UPPER 70S ON THURSDAY. A FEW SPOTS,
ESPECIALLY AROUND THE PORTLAND AND VANCOUVER METRO, COULD
BRIEFLY HIT 80 DEGREES, WITH PROBABILITIES IN THE 30-60% RANGE.
OVERNIGHT LOWS REMAIN SEASONABLY COOL, GENERALLY IN THE 40S
ACROSS THE LOWLANDS. ALONG THE COAST, EXPECT SOME GUSTY
NORTHWESTERLY WINDS THIS AFTERNOON, TOPPING OUT AROUND 20-25
MPH.
THURSDAY NIGHT, A BROAD UPPER-LEVEL TROUGH BEGINS TO APPROACH
FROM THE PACIFIC, SHIFTING THE FLOW ALOFT MORE SOUTHERLY. THIS
PATTERN FAVORS INCREASING MOISTURE AND ELEVATED INSTABILITY,
PARTICULARLY OVER THE CASCADES. WHILE THUNDERSTORMS POTENTIAL
REMAINS LIMITED, SOME MODELS SUGGEST A SMALL WINDOW FOR ELEVATED
CONVECTION OVER THE LINN AND LANE COUNTY CASCADES THURSDAY
EVENING. THE NAM INDICATES MODEST INSTABILITY (MUCAPE ~300-400
J/KG), THOUGH OTHER GUIDANCE IS LESS SUPPORTIVE. AS A RESULT,
THUNDERSTORM CHANCES HAVE BEEN NUDGED SLIGHTLY HIGHER TO AROUND
10-15% IN THAT AREA. WILL NEED TO KEEP AN EYE ON HOW MODELS
TREND TODAY. OTHERWISE, CONDITIONS BEGIN TO TREND COOLER AND
CLOUDIER LATE THURSDAY NIGHT INTO FRIDAY AS THE SYSTEM MOVES
INLAND. ~HALL
LONG TERM...FRIDAY THROUGH MONDAY
A MORE ACTIVE PATTERN SETS IN
FRIDAY AS A LARGE UPPER LEVEL TROUGH DROPS INTO NORTHERN
CALIFORNIA. THIS WILL PULL MOISTURE NORTHWARD INTO NORTHWEST
OREGON AND SOUTHWEST WASHINGTON, INCREASING THE CHANCE FOR RAIN
BY FRIDAY AFTERNOON. RAINFALL TOTALS BETWEEN FRIDAY MORNING
AND EARLY SATURDAY WILL VARY BY LOCATION. CURRENT MODEL
GUIDANCE SHOWS A 10-30% CHANCE OF OVER 0.25 INCHES ALONG THE
COAST AND WILLAMETTE VALLEY, WITH 30-60% PROBABILITIES IN THE
COAST RANGE AND CASCADES. BEHIND THE FRONT, COOLER AIR SETTLES
IN, BRINGING DAYTIME HIGHS DOWN TO THE UPPER 50S TO LOW 60S
ACROSS MUCH OF THE AREA WEST OF THE CASCADES. SATURDAY LOOKS TO
REMAIN UNSETTLED, WITH INTERMITTENT SHOWERS PERSISTING AS THE
SYSTEM EXITS EAST INTO THE INTERMOUNTAIN WEST.
CONDITIONS BEGIN DRYING OUT BY LATE SUNDAY INTO MONDAY, AS
ENSEMBLE GUIDANCE SUPPORTS HIGH PRESSURE REBUILDING ACROSS THE
REGION, FAVORING A RETURN TO QUIETER AND DRIER WEATHER INTO
EARLY NEXT WEEK. ~HALL
AVIATION
THE FORECAST REMAINS ON TRACK FOR THE 18Z TAF PACKAGE.
CLEAR SKIES/VFR FLIGHT CONDITIONS SHOULD CONTINUE ACROSS THE
AIRSPACE THROUGH 18Z THURSDAY. A FEW THIN HIGH CLOUDS AROUND 25
KFT WILL MOVE IN FROM THE SOUTH AFTER 12Z THURSDAY. HOWEVER,
THERE IS A 10-30% CHANCE OF BROKEN COASTAL STRATUS FORMING AROUND
13-16Z WEDNESDAY IF NORTHERLY WINDS ALONG THE COAST TAKE ON MORE
OF A NORTHWESTERLY COMPONENT, WHICH COULD PRODUCE MVFR OR HIGH END
IFR CEILINGS. THAT SAID, MOST GUIDANCE CONTINUES TO INDICATE
COASTAL WINDS WILL INSTEAD TURN TO THE NORTHEAST, WHICH IS WHY
SKIES WILL MOST LIKELY STAY CLEAR AT THE COAST. WINDS REMAIN
NORTHERLY AND GENERALLY LESS THAN 10 KTS FOR INLAND AREAS. ALONG
THE COAST, NORTH WINDS INCREASE AFTER 18-20Z WEDNESDAY WITH GUSTS
20-25 KTS POSSIBLE ALONG THE CENTRAL OREGON COAST, INCLUDING KONP.
COASTAL WINDS WILL DECREASE AFTER 02-04Z THURSDAY. -TK/HEC
PDX AND APPROACHES...VFR CONDITIONS AND CLEAR SKIES CONTINUE
THROUGH THE TAF PERIOD. NORTHWESTERLY WINDS BECOME NORTH-NORTHEAST
AFTER 19-21Z WEDNESDAY, GENERALLY AROUND 5-10 KTS THROUGH THE
PERIOD. -TK/HEC
MARINE
STRONG HIGH PRESSURE OFFSHORE ALONG WILL MAINTAIN
NORTHERLY WINDS ACROSS ALL WATERS THROUGH THE END OF THE WEEK. A
SURFACE LEVEL THERMAL TROUGH REMAINS OVER THE SOUTHERN AND
CENTRAL OREGON COAST THROUGH TODAY, WHICH COMBINED WITH THE HIGH
PRESSURE OFFSHORE WILL CONTINUE INCREASED WINDS ACROSS THE WATERS
WITH GUSTS UP TO 25-30 KTS AT TIMES. A SMALL CRAFT ADVISORY
REMAINS IN EFFECT FOR ALL ZONES (EXCEPT THE COLUMBIA RIVER BAR)
UNTIL 11 PM TONIGHT. STRONGEST WINDS ARE EXPECTED IN THE LATE
AFTERNOON TO OVERNIGHT HOURS, AS WELL AS FOR THE CENTRAL OREGON
COASTAL WATERS. THE THERMAL TROUGH WILL BREAK DOWN TONIGHT,
ALLOWING WINDS TO EASE THURSDAY INTO FRIDAY. SEAS ARE EXPECTED TO
PERSIST AROUND 5 TO 8 FT AROUND 10 SECONDS THROUGH THE MIDDLE OF
THE WEEK. -HEC
PQR WATCHES/WARNINGS/ADVISORIES
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY UNTIL 11 PM PDT THIS EVENING FOR
PZZ251>253-271>273.
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