032  
FXUS66 KPQR 160434 AAA  
AFDPQR  
 
AREA FORECAST DISCUSSION...UPDATED  
NATIONAL WEATHER SERVICE PORTLAND OR  
933 PM PDT THU MAY 15 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. LIGHT, STEADY RAIN EXPECTED AS A WEAK FRONT  
MOVES ACROSS THE AREA TODAY. 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
 
RADAR IMAGERY SHOWS LIGHT  
RAIN SPREADING ACROSS THE AREA THIS AFTERNOON AS A WEAK FRONT PUSHES  
ONSHORE. EXPECT THE COOL, CLOUDY AND DAMP CONDITIONS TO PERSIST  
THROUGH THIS EVENING. ONSHORE FLOW WILL MAINTAIN LIGHT SCATTERED  
RAIN SHOWERS OVERNIGHT INTO FRIDAY, WITH THE HIGHEST CHANCES OF RAIN  
PERSISTING ALONG THE NORTHERN COAST AND COAST RANGE THROUGH FRIDAY.  
TOTAL RAINFALL AMOUNTS ARE GENERALLY EXPECTED AROUND A TENTH OF AN  
INCH OR LESS, EXCEPT 0.20-0.40 INCH NORTH OF ASTORIA, INCLUDING THE  
WILLAPA HILLS. HIGH TEMPERATURES WARM INTO THE MID-60S INLAND, UPPER  
50S ALONG THE COAST, ON FRIDAY, POTENTIALLY WARMER ACROSS SOUTHERN  
PORTIONS OF THE AREA (E.G. LANE COUNTY) WHERE MORE SUNSHINE IS  
POSSIBLE AS CLOUDS SCATTER OUT.  
 
THE ACTIVE PATTERN CONTINUES LATE FRIDAY INTO SATURDAY AS AN UPPER  
LEVEL JET OVER THE NORTH PACIFIC MOVES TOWARDS THE OREGON COAST. AN  
INITIAL SHORTWAVE TROUGH SLIDES ACROSS WESTERN OREGON EARLY SATURDAY  
MORNING, INITIATING WIDESPREAD RAIN SHOWERS. NORTHWEST FLOW ALOFT IS  
MAINTAINED AS THE STRONGER SYSTEM DROPS SOUTHWARD ALONG THE BRITISH  
COLUMBIA COAST, DIGGING INTO THE PACIFIC NORTHWEST. 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 ARE POSSIBLE.  
 
MOST AREAS SHOULD EXPECT CONDITIONS TRENDING DRIER ON SUNDAY, WITH  
MORE SUN BREAKS THROUGH THE CLOUDS BY THE AFTERNOON. TEMPERATURES  
STILL REMAIN ON THE COOLER SIDE WITH HIGHS REACHING THE LOWER TO MID-  
60S INLAND. MODELS AND THEIR ENSEMBLES ARE COMING INTO BETTER  
AGREEMENT THAT A WEAK FRONT BRINGS ANOTHER ROUND OF LIGHT RAIN  
ACROSS THE REGION ON MONDAY. CLUSTER ANALYSIS ALSO SHOWING MORE ZONAL  
FLOW LIKELY ON TUESDAY, KEEPING THE DOOR OPEN FOR SOME LIGHT  
SHOWERS. BUT STILL, UNCERTAINTY REMAINS INTO THE MIDDLE OF NEXT WEEK  
AS ABOUT 60% OF THE CLUSTERS SHOW SOME TYPE OF WEAK RIDGING. STILL,  
THE NBM SUGGEST TEMPERATURES ARE LIKELY TO TREND CLOSER TO NORMAL.  
/DH  
 

 
   
AVIATION
 
RADAR AND SATELLITE IMAGERY AS OF 04Z FRI DEPICTS THE  
LATEST FRONTAL SYSTEM MOVING EAST OF THE CASCADES WITH WIDESPREAD  
RAIN NOW TRANSITIONING INTO POST-FRONTAL SHOWERS. SHOWER ACTIVITY  
WILL GRADUALLY DECREASE TONIGHT, WITH MOST TERMINALS BECOMING DRY ON  
FRIDAY. AN EXCEPTION WOULD BE THE NORTH OREGON COAST (KAST), WHERE  
LIGHT SHOWERS ARE FORECAST TO PERSIST THROUGHOUT THE DAY WITH  
PREDOMINATELY MVFR CIGS. ALONG THE CENTRAL OREGON COAST AND  
WILLAMETTE VALLEY, EXPECT MAINLY LOW-END VFR CIGS WITH INTERMITTENT  
MVFR CIGS (25-45% CHANCE). FRIDAY EVENING, ANOTHER FRONT WILL RETURN  
RAIN AND MORE WIDESPREAD MVFR CIGS ALONG THE COAST. EXPECT SOUTHERLY  
TO SOUTHWESTERLY WINDS UNDER 10 KT ACROSS ALL TERMINALS THROUGH THE  
TAF PERIOD.  
 
PDX AND APPROACHES...LOW-END VFR CIGS WITH INTERMITTENT MVFR CIGS  
THROUGH FRIDAY MORNING (25-45% CHANCE). AFTER 21Z FRI, EXPECT  
PREDOMINATELY VFR CIGS. SOUTHERLY WINDS AROUND 5 KT OR LESS.  
-ALVIZ  
 

 
   
MARINE
 
SEAS OF 5-7 FT AT 10 SECONDS WILL CONTINUE TO SLOWLY  
SUBSIDE TO 4-6 FT BY EARLY FRIDAY MORNING. NORTHWEST WINDS OF LESS  
THAN 10 KT WILL BACK OUT OF THE SOUTHWEST TO SOUTH THROUGH TONIGHT,  
INCREASING TO 10-15 KT ON FRIDAY AS A REINVIGORATED NORTHWEST SWELL  
ARRIVES AHEAD OF A FRONTAL SYSTEM. SOUTH TO SOUTHWEST FLOW AHEAD OF  
THE FRONT WILL VEER BACK OUT OF THE NORTHWEST IN ITS WAKE, WITH A 25-  
45% CHANCE OF GALE-FORCE GUSTS BEYOND 30 NM ON SATURDAY, DECREASING  
TO 5-20% ON SUNDAY. 70-90% AGREEMENT IN AT LEAST SMALL CRAFT CRAFT  
WINDS DURING THAT TIME. AFTERWARDS THE NEXT DISTURBANCE ARRIVES  
MONDAY, MARKING A RETURN TO SOUTHERLY WINDS AROUND 10-15 KTS.  
-PICARD/JLIU  
 

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

 
 

 
 
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