266
FXUS66 KPQR 282148
AFDPQR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
248 PM PDT MON APR 28 2025
SYNOPSIS
A WEAK FRONTAL SYSTEM IS EXPECTED TO BRING LIGHT
RAIN TO THE REGION ON TUESDAY BEFORE DRY AND RATHER BENIGN
WEATHER RETURNS MID WEEK. TEMPERATURES EMBARK ON A ROLLER
COASTER RIDE THIS WEEK TOO KEEPING THINGS AT LEAST A LITTLE
INTERESTING; HIGHS IN THE MID 60S ON TUESDAY JUMP INTO THE UPPER
70S/LOW 80S FOR THURSDAY BEFORE CRASHING BACK TO THE UPPER
50S/60S ON SATURDAY. ALL IN ALL, FAIRLY TYPICAL LATE APRIL
CONDITIONS.
SHORT TERM...NOW THROUGH WEDNESDAY
THIS AFTERNOON FAIRLY QUIET
CONDITIONS PREVAIL ACROSS THE PACIFIC NORTHWEST AS A WEAK
POSITIVELY TILTED RIDGE OVERHEAD SHIFTS EAST OF THE CASCADES
LEADING TO MOSTLY CLEAR SKIES. HOWEVER, TONIGHT INTO EARLY
TUESDAY MORNING WE ARE ANTICIPATING A CHANGE TO SOMEWHAT WETTER
WEATHER THANKS TO A WEAK SHORTWAVE TROUGH MOVING INTO REGION
ACCOMPANIED BY A SURFACE FRONT. ENSEMBLE AND DETERMINISTIC
MODELS CONTINUES SHOW RATHER MINIMAL QPF WITH THIS SYSTEM WHICH
IS DISAPPOINTING GIVEN HOW DRY APRIL HAS BEEN COMPARED TO
NORMAL - WE COULD USE THE RAIN. EXPECT GENERALLY 0.1-0.3" OF
RAIN FOR THE COAST RANGE/CASCADES, 0.1-0.2" IN THE COWLITZ
VALLEY DOWN THROUGH THE PORTLAND METRO, AND 0.03-0.1" ACROSS THE
REST OF THE WILLAMETTE VALLEY. OVERALL, THE NBM SHOWS A ROUGHLY
30-50% CHANCE TO SEE A WETTING RAIN (>0.25") FOR THE HIGHER
ELEVATIONS OF THE NORTH OREGON COAST RANGE/WILLAPA HILLS AND THE
SOUTHWEST WASHINGTON CASCADES ON TUESDAY. FOR THE WILLAMETTE
VALLEY THESE PROBABILITIES ARE ONLY 1-5% DURING THE SAME
TIME PERIOD, SO CONFIDENCE IS HIGH RAINFALL AMOUNTS WILL STAY
ON THE LIGHTER SIDE FOR THIS EVENT. LINGERING SHOWERS BEHIND THE
MAIN FRONTAL BAND IN THE MORNING GRADUALLY TAPER OFF BY TUESDAY
EVENING. THEN ON WEDNESDAY DRY WEATHER AND A WARMING TREND
BEGINS THANKS TO ANOTHER RIDGE OF HIGH PRESSURE BUILDING
OVERHEAD. CONFIDENCE IS HIGH THIS NEXT RIDGE OF HIGH PRESSURE
WILL LEAD TO DAYTIME TEMPERATURES RISING INTO THE UPPER 60S TO
NEAR 70S FOR THE INTERIOR LOWLANDS WEDNESDAY AFTERNOON.
LONG TERM...WEDNESDAY NIGHT THROUGH MONDAY
MOVING FORWARD THE
LATEST GUIDANCE CONTINUES TO SUGGEST THURSDAY WILL BE THE
HOTTEST DAY OF THE WEEK AS THE AXIS OF THE NOW AMPLIFIED UPPER-
LEVEL RIDGE PASSES OVERHEAD. THE NBM IS STILL INDICATING AN
80-90%+ PROBABILITY TO REACH 80 DEGREES IN THE PORTLAND METRO
AND A 40-80% CHANCE ACROSS THE REST OF THE INTERIOR VALLEY
LOCATIONS. THAT SAID, COASTAL LOCATIONS LIKELY REMAIN NOTABLY
COOLER COMPARATIVELY DUE TO THE INLAND MOVEMENT OF A NEAR
SURFACE THERMAL TROUGH ALLOWING WESTERLY MARINE INFLUENCE TO
HOLD TEMPERATURES IN THE 60S. THE PERIOD OF WARM WEATHER WILL BE
RELATIVELY SHORT LIVED AS WPC ENSEMBLE CLUSTERS CONTINUE TO
SHOW GOOD AGREEMENT IN THE BROADER RIDGE FEATURE SHIFTING EAST
BY FRIDAY AND OPENING THE DOOR FOR THE NEXT UPPER LEVEL TROUGH
APPROACHING THE REGION. THIS BRINGS ANOTHER ROUND OF COOLER AND
WETTER WEATHER TO THE AREA FRIDAY THROUGH THE WEEKEND. MOST
DETERMINISTIC GUIDANCE AND A FAIR NUMBER OF THEIR RESPECTIVE
ENSEMBLE SYSTEMS DO SHOW A TRANSITORY RIDGE PASSING OVERHEAD
LATE SUNDAY INTO MONDAY WHICH WOULD LEAD TO A TREND BACK TO
DRIER CONDITIONS. -SCHULDT/CB
AVIATION
VFR CONDITIONS ACROSS THE AREA WITH A SCATTERED CLOUD
DECK AROUND 3-5 KFT. WINDS WILL REMAIN MOSTLY LIGHT AND VARIABLE.
ALONG THE COAST, WESTERLY FLOW LESS THAN 10 KT EXPECTED. A WEAK
DISTURBANCE APPROACHING THE AREA TONIGHT WILLS SUPPORT LIGHT RAIN
AND MVFR (OR LOWER) CIGS TO ALL TERMINALS LATE TONIGHT INTO
TUESDAY MORNING.
PDX AND APPROACHES...VFR CONDITIONS PERSIST INTO TONIGHT WITH MVFR
CIGS POSSIBLE LATE TONIGHT AS A DISTURBANCE APPROACHES THE
REGION. LIGHT WINDS GENERALLY NORTHWESTERLY THROUGH THE PERIOD.
CHANCE FOR LIGHT RAIN AND MVFR CONDITIONS LATE TONIGHT INTO
TUESDAY MORNING. -BATZ
MARINE
HIGH PRESSURE OVER THE NORTHEAST PACIFIC CONTINUES TO SHIFT
INLAND, SUPPORTING BENIGN CONDITIONS MUCH OF THE WORK WEEK.
EXPECT SEAS AROUND 4 TO 7 FEET AND MOSTLY NORTHWESTERLY WINDS AT
OR BELOW 10 KT WITH GUSTS 15 KT OR LESS.
A SHORT SMALL CRAFT ADVISORY FOR THE COLUMBIA RIVER BAR HAS BEEN
ISSUED FOR STEEP EBB CHOP AND WILL COME TO END BY 9 AM TUESDAY.
EBB CURRENT OF 7.36 KT AND SEAS AROUND 9 FEET IS EXPECTED AROUND
622 AM TUESDAY. -HALL/BATZ
PQR WATCHES/WARNINGS/ADVISORIES
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FROM 3 AM TO 9 AM PDT TUESDAY FOR PZZ210.
WWW.WEATHER.GOV/PORTLAND
INTERACT WITH US VIA SOCIAL MEDIA:
WWW.FACEBOOK.COM/NWSPORTLAND
X.COM/NWSPORTLAND
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