503  
FXUS66 KPQR 190444 AAA  
AFDPQR  
 
AREA FORECAST DISCUSSION...UPDATED  
NATIONAL WEATHER SERVICE PORTLAND OR  
944 PM PDT SAT APR 18 2026  
   
..UPDATED AVIATION DISCUSSION
 
 
   
SYNOPSIS
 
HIGH PRESSURE OVERHEAD IS KEEPING NORTHWEST OREGON  
AND SOUTHWEST WASHINGTON WARM AND DRY TODAY. OUT OVER THE  
PACIFIC, A STORM SYSTEM IS ORGANIZING AND IS EXPECTED TO BECOME  
A SLOW-MOVING CLOSED LOW LATE THIS WEEKEND INTO EARLY NEXT WEEK.  
THAT WILL GRADUALLY BRING MORE CLOUDS ON MONDAY, THEN A BETTER  
CHANCE FOR COOLER, WETTER WEATHER BY THE MIDDLE OF THE WEEK.  
CONFIDENCE IS INCREASING THAT SHOWERS BECOME MORE LIKELY LATE  
MONDAY INTO TUESDAY AS THE SYSTEM BEGINS TO SPREAD MOISTURE  
INLAND. WEDNESDAY STILL LOOKS LIKE THE COOLEST AND MOST SHOWERY  
DAY OVERALL.  
 

 
   
SHORT TERM...NOW THROUGH SUNDAY NIGHT
 
THIN CLOUDS HIGH IN  
THE SKY HAVE BEEN STREAMING ACROSS THE AREA AT TIMES TODAY  
(MOST NOTICEABLE NEAR THE COAST AND INTO SOUTHWEST WASHINGTON),  
BUT CONDITIONS REMAIN DRY AND TEMPERATURES ARE STILL WARMING UP  
NICELY INLAND. EXPECT INLAND HIGHS MAINLY IN THE LOWER TO MID  
70S TODAY, WHILE THE COAST STAYS COOLER, GENERALLY UPPER 50S TO  
MID 60S.  
 
LATER TODAY AND TONIGHT, A WEAKENING FRONT WILL APPROACH THE  
COASTAL WATERS. MOST OF THE MOISTURE AND LIFT LOOK LIKE THEY  
WILL REMAIN OFFSHORE, SO FOR MOST LOCATIONS THE MAIN CHANGE WILL  
BE INCREASING CLOUDS THIS EVENING AND OVERNIGHT. WHILE LIGHT  
SHOWERS WILL MOST LIKELY STAY OVER THE OCEAN, THERE IS A SMALL  
CHANCE A BRIEF SHOWER COULD BRUSH THE IMMEDIATE NORTH COAST LATE  
TONIGHT INTO SUNDAY MORNING. NO RAIN IS EXPECTED FOR INLAND  
AREAS.  
 
CLOUD COVER TONIGHT WILL KEEP TEMPERATURES MILDER THAN THIS  
MORNING. LOWS SHOULD BE MOSTLY IN THE MID TO UPPER 40S INLAND (A  
FEW COOLER VALLEYS COULD DIP A BIT LOWER), AND GENERALLY IN THE  
40S NEAR THE COAST. WITH CLOUDS AND WARMER NIGHTTIME  
TEMPERATURES, FROST IS NOT EXPECTED OVER AT LEAST THE NEXT  
COUPLE MORNINGS.  
 
SUNDAY LOOKS SIMILAR TO TODAY; WARM AND DRY FOR MOST AREAS,  
WITH MORE THIN HIGH CLOUDS AROUND. INLAND HIGHS SHOULD AGAIN  
REACH THE LOW TO MID 70S. PARTS OF THE PORTLAND/VANCOUVER METRO  
AND NEARBY COMMUNITIES COULD STILL REACH 80 DEGREES IF CLOUDS  
THIN ENOUGH DURING THE WARMEST PART OF THE DAY, BUT THAT WILL  
DEPEND ON HOW QUICKLY CLOUD COVER THICKENS (30-60% CHANCE OF  
DAYTIME TEMPERATURES EXCEEDING 80 DEGREES). THERE IS MODERATE TO  
HIGH CONFIDENCE THAT THESE HIGH CLOUDS WILL REMAIN THIN,  
ALLOWING FOR GOOD DAYTIME HEATING. COASTAL HIGHS STAY IN THE  
UPPER 50S TO MID 60S. SUNDAY NIGHT REMAINS DRYS INLAND WITH LOWS  
MAINLY IN THE 40S.  
 

 
   
LONG TERM...MONDAY THROUGH FRIDAY
 
ON MONDAY, THE OFFSHORE  
LOW PRESSURE SYSTEM WILL START TO HAVE MORE INFLUENCE ON OUR  
WEATHER. EXPECT MORE CLOUD COVER AND SLIGHTLY COOLER  
TEMPERATURES COMPARED TO THE WEEKEND. HIGHS SHOULD GENERALLY BE  
IN THE UPPER 60S TO NEAR 70 INLAND, AND UPPER 50S TO LOW 60S  
ALONG THE COAST. RAIN SHOWER CHANCES INCREASE LATE MONDAY INTO  
TUESDAY AS THE SYSTEM BEGINS TO MOVE CLOSER AND SPREAD MOISTURE  
INLAND, WITH THE FIRST STEADIER SHOWERS MOST LIKELY OVER THE  
HIGHER TERRAIN AND THE SOUTHERN WILLAMETTE VALLEY. EVEN SO,  
PRECIPITATION THROUGH MONDAY LOOKS LIGHT OVERALL, GENERALLY  
AROUND 0.05 TO 0.15 INCH WHERE SHOWERS OCCUR.  
 
TUESDAY IS STILL THE TRICKIEST DAY. WHILE EXACT TIMING STILL  
NEEDS REFINEMENT, CONFIDENCE IS HIGHER THAT AT LEAST SCATTERED  
SHOWERS WILL REACH MORE OF THE AREA SOMETIME LATE MONDAY INTO  
TUESDAY, RATHER THAN STAYING LARGELY OFFSHORE. IF SHOWERS DO  
BEGIN TUESDAY, THEY WOULD MOST LIKELY SHOW UP FIRST ALONG THE  
COAST AND IN AREAS FARTHER SOUTH AND WEST, THEN SPREAD INLAND  
LATER.  
 
CONFIDENCE IS HIGHER FOR TUESDAY NIGHT INTO WEDNESDAY: THIS IS  
THE MOST LIKELY PERIOD FOR A MORE WIDESPREAD COOLER, AND SHOWERY  
PATTERN ACROSS THE AREA. THE COAST RANGE AND CASCADES WILL BE  
FAVORED FOR MORE PERSISTENT SHOWERS DUE TO TERRAIN ENHANCEMENT.  
WHILE RAIN AMOUNTS REMAIN UNCERTAIN, EXPECT AROUND 0.25 TO 0.75  
INCHES IN THE LOWLANDS AND AROUND 1 TO 1.75 INCHES IN THE COAST  
RANGE AND CASCADES FROM 5 PM TUESDAY TO 5 PM WEDNESDAY.  
 
BY THURSDAY AND FRIDAY, THE PATTERN LOOKS LIKE IT WILL TREND  
DRIER AGAIN WITH TEMPERATURES SLOWLY WARMING BACK UP INTO THE  
MID 60S AND MAYBE 70S BY FRIDAY. A FEW LEFTOVER SHOWERS NEAR THE  
MOUNTAINS ARE POSSIBLE EARLY IN THAT PERIOD, BUT OVERALL  
CONDITIONS SHOULD IMPROVE LATE WEEK. ~12  
 

 
   
AVIATION
 
HIGH PRESSURE WILL MAINTAIN WIDESPREAD VFR CONDITIONS  
THROUGH THE TAF PERIOD WITH SCATTERED TO BROKEN HIGH CLOUDS  
AROUND 20-25 KFT. WINDS WILL REMAIN LIGHT AND VARIABLE LESS THAN 5  
KT, EXCEPT FOR EASTERLY WINDS 5-10 KT AT KTTD. BETWEEN 12-20Z  
SUN, KTTD-KDLS PRESSURE GRADIENTS WILL TIGHTEN, STRENGTHENING  
EASTERLY WINDS THROUGH THE COLUMBIA RIVER GORGE WITH OCCASIONAL  
GUSTS UP TO 20 KT AT KTTD. NORTHERLY WINDS FOR THE REST OF THE  
WILLAMETTE VALLEY AND SOUTHWESTERLY WINDS ALONG THE COAST, ALL  
UNDER 10 KT.  
 
KPDX AND APPROACHES...VFR CONDITIONS WITH CIGS ABOVE 20-25 KFT  
THROUGH THE TAF PERIOD. VARIABLE WINDS AROUND 5 KT THROUGH EARLY  
SUNDAY MORNING, TURNING MORE EASTERLY AFTER 15Z SUN AND REMAINING  
LIGHT. -10/23  
 

 
   
MARINE
 
BENIGN CONDITIONS CONTINUE THROUGH THE WEEKEND. SOUTHERLY  
TO SOUTHWESTERLY WINDS BETWEEN 5-15 KT CONTINUE TODAY WITH SEAS  
UNDER 5 FT. WINDS WILL WEAKEN AND BECOME EAST TO SOUTHEAST BY  
EARLY SUNDAY MORNING. WINDS THEN REMAIN LIGHT THROUGH EARLY NEXT  
WEEK WITH SEAS INCREASING BY A FEW FEET, BUT STAYING UNDER 10 FT.  
 
AN AREA OF LOW PRESSURE SITTING OFF THE COAST WILL MOVE INLAND  
DURING THE MIDDLE OF NEXT WEEK. THIS WILL BRING ONSHORE FLOW,  
SHOWERS, AND INCREASING WINDS AND SEAS. HOWEVER, UNCERTAINTY  
REMAINS REGARDING EXACT WIND SPEEDS AND WAVE HEIGHTS. THE  
PLACEMENT OF THE LOW WILL DETERMINE WHAT CONDITIONS MATERIALIZE  
ACROSS THE WATERS. THE CURRENT FORECAST FAVORS A PERIOD OF  
INCREASING WEST TO NORTHWEST WINDS LATE TUESDAY INTO WEDNESDAY  
WITH WIND GUSTS REACHING 20-25 KT OR STRONGER BY WEDNESDAY  
AFTERNOON. IN FACT, THERE IS A 50-75% CHANCE FOR MAX WIND GUSTS  
OVER 25 KT. THE HIGHEST PROBABILITIES ARE BEYOND 30 NM OFFSHORE.  
SEAS ARE EXPECTED TO REACH AT LEAST 10-12 FT BY LATE WEDNESDAY,  
HOWEVER THERE IS A 40-70% CHANCE SEAS WILL PEAK OVER 12 FT OVER  
THE NORTHERN AND CENTRAL OUTER WATERS. THERE IS A 1-5% CHANCE SEAS  
WILL PEAK AS HIGH AS 15 FT, WHICH REPRESENTS THE WORST CASE  
SCENARIO.  
 
VERY STRONG EBB CURRENTS WILL CONTINUE ACROSS THE COLUMBIA RIVER BAR  
EACH MORNING THROUGH TUESDAY. WITH SEAS EXPECTED TO BUILD  
SLIGHTLY BY EARLY NEXT WEEK, A STEEP EBB CHOP MAY NECESSITATE  
SMALL CRAFT ADVISORIES IN THE HOURS AROUND PEAK FLOW EACH DAY. -23  
 

 
   
PQR WATCHES/WARNINGS/ADVISORIES
 
 
OR...NONE.  
WA...NONE.  
PZ...NONE.  
 

 
 

 
 
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