327  
FXUS66 KPQR 161752  
AFDPQR  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE PORTLAND OR  
1052 AM PDT FRI MAY 16 2025  
 
UPDATED AVIATION DISCUSSION.  
   
SYNOPSIS  
A PROGRESSIVE WEATHER PATTERN WILL BRING PERIODS OF  
LIGHT RAIN THROUGH THE WEEKEND, AND POSSIBLY INTO EARLY NEXT  
WEEK. EXPECT TEMPERATURES TO REMAIN SLIGHTLY BELOW AVERAGE  
DURING THIS PERIOD. RAIN SHOWERS INCREASE LATE FRIDAY NIGHT  
THROUGH SATURDAY, ALONG WITH A 10-20% CHANCE OF THUNDERSTORMS  
SAT AFTERNOON. LINGERING SHOWERS INTO SUNDAY, THOUGH MOST AREAS  
LIKELY DRIER. TEMPERATURES TRENDING WARMER TOWARD THE END OF  
NEXT WEEK.  
 
 
   
DISCUSSION...TONIGHT THROUGH THURSDAY  
ZONAL FLOW ACROSS THE  
PACNW WILL PERSIST THROUGH MUCH OF FRIDAY, SUPPORTING ONSHORE  
FLOW AND LIGHT RAIN SHOWERS. SHOWER ACTIVITY WILL BE MAINLY  
ACROSS SOUTHWEST WA AND THE NORTHWEST OREGON COAST RANGE WITH  
TOTALS OF A FEW HUNDREDTHS. COOL TEMPS ARE EXPECTED AGAIN WITH  
MID TO UPPER 60S INLAND AND UPPER 50S ALONG THE COAST. SLIGHTLY  
WARMER TEMPS ARE EXPECTED ACROSS THE SOUTHERN PORTION OF THE  
AREA DUE TO BREAKS IN CLOUD COVER AND LESS OF A CHANCE FOR  
PRECIPITATION.  
 
THE NEXT SYSTEM APPROACHES THE PACNW FROM THE NORTHWEST AS A  
SHORTWAVE DIGS ALONG THE BRITISH COLUMBIA COAST TONIGHT INTO  
SATURDAY. THIS WILL BRING ANOTHER ROUND OF WIDESPREAD SHOWERS  
THROUGH SATURDAY NIGHT. ANOTHER, STRONGER SYSTEM WILL MOVE OVER  
VANCOUVER ISLAND AND ACROSS WA DURING THE LATTER HALF OF SATURDAY,  
SUPPORTING NORTHWEST FLOW IN THE UPPER LEVELS. THIS WILL ALSO BRING  
A SLIGHT CHANCE (10-20%) OF THUNDERSTORMS TO THE AREA FOR SATURDAY  
AFTERNOON/EVENING. PERSISTENT SHOWERS WILL LIKELY PRODUCE A BIT MORE  
SUBSTANTIAL RAINFALL AMOUNTS, INCLUDING A 30-50% CHANCE OF EXCEEDING  
0.25 INCH THROUGH SATURDAY NIGHT ACROSS MUCH OF THE FORECAST AREA.  
SHOWERS WILL LIKELY PERSIST ALONG THE HIGHER TERRAIN, INCLUDING THE  
CASCADE FOOTHILLS, WHERE AMOUNTS CLOSER TO 0.50-1.00 INCH OF TOTAL  
(48-HR) RAINFALL THROUGH 5 PM SUNDAY.  
 
CONDITIONS TREND DRIER ON SUNDAY, THOUGH LIGHT SHOWERS WILL PERSIST  
INTO THE AFTERNOON. WEAK RIDGING WILL BUILD INTO THE REGION,  
SUPPORTING PARTLY SUNNY SKIES THOUGH TEMPS WILL REMAIN 5-8 DEGREES  
BELOW AVERAGE, TOPPING OUT IN THE LOW 60S INLAND. MODEL AGREEMENT IS  
INCREASING FOR ANOTHER WEAK SYSTEM TO CROSS THE REGION ON MONDAY  
WITH ANOTHER ROUND OF LIGHT RAIN SHOWERS EXPECTED. ZONAL FLOW WITH  
ANOTHER EMBEDDED DISTURBANCE PASSING TO THE NORTH MAY MAINTAIN LIGHT  
SHOWERS INTO TUESDAY. AGREEMENT DEGRADES MIDDLE TO END OF NEXT WEEK  
WITH CLUSTER ANALYSIS SHOWING SPLIT PRETTY EQUALLY BETWEEN RIDGING  
AND TROUGHING. -BATZ  
 
 
   
AVIATION  
AT 18Z FRIDAY, MIXED VFR/MVFR CIGS CONTINUE ACROSS  
THE REGION WITH RAIN SHOWERS GENERALLY ALONG AND NORTH OF A LINE  
FROM KTMK TO KPDX. INLAND, CIGS EXPECTED TO IMPROVE TO VFR BY 18-  
20Z. ALONG THE COAST, MVFR WITH OCCASIONAL IFR CONDITIONS EXPECTED  
TO CONTINUE THROUGH THE TAF PERIOD, THOUGH A FEW HOURS OF IMPROVED  
CONDITIONS POSSIBLE 20Z FRIDAY THROUGH 03Z SATURDAY. ANOTHER FRONTAL  
SYSTEM IS EXPECTED TO BRING A ROUND OF WIDESPREAD SHOWERS AND THE  
RETURN OF MVFR/IFR CIGS ALONG THE COAST BY 03-06Z SATURDAY AND MFR  
CIGS INLAND BY 06-09Z SATURDAY. SOUTHERLY TO SOUTHWESTERLY WINDS AT  
LESS THAN 10 KT WILL CONTINUE AT ALL TERMINALS THROUGH MUCH OF THE  
PERIOD, TURNING OUT OF THE NORTH TO NORTHWEST BEHIND THE FRONTAL  
BOUNDARY.  
 
PDX AND APPROACHES...VFR CIGS AROUND FL4500-6500 WITH BRIEF ISOLATED  
LIGHT RAIN SHOWERS. ANOTHER FRONTAL SYSTEM WILL BRING ADDITIONAL  
RAIN SHOWERS AND LIKELY MVFR CIGS AFTER 06-09Z FRI. SOUTHERLY WINDS  
LESS THAN 10 KT CONTINUE INTO THE EARLY AFTERNOON, BEFORE TURNING  
OUT OF THE NORTH TO NORTHWEST AFTER 21-24Z FRI. -HEC  
 
 
   
MARINE  
SEAS OF 4-6 FT AT 10-12 SECONDS WILL BUILD THROUGH  
SATURDAY AS NORTHWESTERLY SWELL RISES TO 6-8 FT AHEAD OF A  
FRONTAL SYSTEM APPROACHING THE COAST. WINDS OF 10-15 KT WITH  
GUSTS UP TO 20 KT OUT OF THE SOUTH TO SOUTHWEST THROUGH TODAY WILL  
VEER OUT OF THE NORTHWEST TONIGHT BEHIND THE BOUNDARY AS RAIN  
SHOWERS SPREAD ACROSS THE WATERS. STEADILY BUILDING NORTHWESTERLY  
SWELL WILL SEE SEAS REACH 8-10 FT LATE SATURDAY INTO SUNDAY  
MORNING, WHILE NORTHWEST WINDS OF 15-20 KT GUST AS HIGH AS 25 KT.  
CHANCES FOR GUSTS REACHING GALE-FORCE SATURDAY INTO SUNDAY HAVE  
DECREASED TO 10-20% BEYOND 30 NM AND 0-10% ELSEWHERE, HOWEVER  
THERE REMAINS HIGH CONFIDENCE IN CONDITIONS MERITING AT LEAST  
SMALL CRAFT ADVISORIES ACROSS THE WATERS THROUGH PARTS OF THE  
WEEKEND. WINDS WILL TURN SOUTHERLY AGAIN AT 10-20 KT ON MONDAY  
AHEAD OF THE NEXT APPROACHING SYSTEM, BEFORE VEERING OUT OF THE  
WEST TO NORTHWEST MONDAY NIGHT THROUGH AT LEAST MIDWEEK. -PICARD  
 
 
   
PQR WATCHES/WARNINGS/ADVISORIES  
 
OR...NONE.  
WA...NONE.  
PZ...NONE.  
 
 
 
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