914  
FXUS66 KPQR 262210  
AFDPQR  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE PORTLAND OR  
310 PM PDT SAT APR 26 2025  
   
SYNOPSIS  
SHOWERS CONTINUE TO DISSIPATE WITH NORTHEASTERLY  
FLOW ALOFT. UPPER LEVEL LOW REMAINS NEARLY STATIONARY THROUGH  
SUNDAY MORNING WITH THE ONLY CHANCES FOR RAIN BEING OVER THE  
LANE COUNTY CASCADES AND NORTH COAST. ACCUMULATION WILL BE  
MINIMAL. RIDGING ON MONDAY WILL LEAD TO DRY AND BREEZY ONSHORE  
FLOW, THEN ANOTHER FRONT ARRIVES TUESDAY INTO WEDNESDAY. HIGH  
CONFIDENCE IN ABOVE NORMAL TEMPERATURES FOR THURSDAY.  
 
 
   
SHORT TERM...NOW THROUGH MONDAY NIGHT  
AN UPPER LEVEL LOW SITS  
OVER NORTHERN CALIFORNIA TODAY AND WILL SHIFT EASTWARD SLOWLY  
OVERNIGHT INTO SUNDAY. SOUTHEASTERLY FLOW ALOFT WILL PERSIST  
BRINGING LIGHT SHOWERS OVER THE REGION. THESE SHOWERS HAVE  
PRODUCED VERY LITTLE ACCUMULATION AND IS GENERALLY ISOLATED OVER  
LANE COUNTY AND THE CASCADES. BASED ON SATELLITE IMAGERY, THERE  
ARE SOME INDICATIONS OF THUNDERSTORMS BUT SO FAR HAVE REMAINED  
EAST AND SOUTH OF THE AREA. WILL CONTINUE TO WATCH AS SKIES  
CLEAR AND PEAK DAYTIME HEATING ALLOWS FOR MORE VERTICAL  
CONVECTION. SATELLITE ALSO SHOW CUMULUS FORMING ALONG THE  
OREGON/WASHINGTON BORDER AND OVER THE WATERS AGAIN SHOWING THE  
CONVECTIVE NATURE OF THE ATMOSPHERE. WINDS HAVE BEGUN TO  
INCREASE ALONG THE COAST WITH GUSTS UP TO 25 MPH REPORTED AROUND  
TILLAMOOK AND NEWPORT. THESE WINDS ARE DUE TO A NORTHERLY WIND  
REVERSAL WHICH IS COMMONLY ASSOCIATED WITH A SUMMER PATTERN.  
 
AS THE UPPER LOW EXITS TO THE EAST, A WEAK RIDGE BEGINS TO BUILD  
SUNDAY NIGHT INTO MONDAY MORNING. DURING THE BRIDGE BETWEEN  
THESE TWO SYSTEMS, CONDITIONS WILL NOT NECESSARILY BE EXCITING.  
THERE IS AROUND A 10-15% CHANCE OF SHOWERS ALONG THE NORTH  
OREGON AND SOUTH WASHINGTON COASTS THROUGH THE AFTERNOON.  
ONSHORE FLOW WILL INTENSIFY AS THE PRESSURE AND TEMPERATURE  
GRADIENT INCREASES. BASED ON THE NBM, THE UPPER HOOD RIVER  
VALLEY HAS AROUND A 50-65% CHANCE OF SEEING 24 HOUR WIND GUSTS  
GREATER THAN 35 MPH. HIGH RESOLUTION MODELS SHOW A LOWER  
PROBABILITY (AROUND 10-15% CHANCE). OVERALL, WINDS WILL BE  
DECIDED UPON BY WHERE THE LOW ENDS UP TRACKING. MOST OF THE  
HIGHER WINDS WILL BE EAST OF THE CASCADES OR ALONG THE HIGHER  
TERRAIN.  
 
ON MONDAY THE RIDGE WILL BUILD WITH DRY CONDITIONS BOTH AT THE  
SURFACE AND ALOFT. -MUESSLE  
   
LONG TERM...TUESDAY NIGHT THROUGH FRIDAY  
WPC ENSEMBLE  
CLUSTERS CONTINUE TO ADVERTISE A RETURN OF UPPER LEVEL RIDGING  
MID TO LATE NEXT WEEK, BRINGING ANOTHER WARMING TREND WITH HIGHS  
BACK IN THE 70S IN THE INTERIOR LOWLANDS NEXT WEDNESDAY AND  
THURSDAY. RECENT RUNS OF THE NBM ARE SHOWING EVEN HIGHER  
PROBABILITY FOR TEMPERATURES GREATER THAN 80 DEGREES F ON  
THURSDAY. THROUGH THE WILLAMETTE VALLEY, PROBABILITIES RANGE  
FROM NEAR 90% CHANCE NEAR PORTLAND TO 50% CHANCE IN EUGENE. THIS  
GRADIENT IS DRIVEN BY THE EAST TO NORTHEASTERLY FLOW ALOFT.  
WARMER AIR FROM THE COLUMBIA BASIN WILL MOVE INTO THE REGION  
IMPACTING THE AREAS WITHIN THE EAST-WEST ALIGNED TERRAIN OR  
EXPOSURE THE MOST. SOME CLOUD COVER MAY ALSO BE PRESENT TO THE  
SOUTH WHICH WOULD DAMPEN THOSE TEMPERATURES. BASED ON THE GFS,  
850 MB TEMPERATURES WILL BE AROUND 8 DEG C WHICH IS WARM FOR  
THIS TIME OF YEAR. INTERESTINGLY, GIVEN THE DISTANCE IN TIME,  
MODELS ARE IN FAIRLY GOOD AGREEMENT IN REGARDS TO THE HIGH  
TEMPERATURE FORECAST. THE AREAS WITH THE LEAST AGREEMENT, 4-6  
DEGREE F SPREAD BETWEEN THE 25TH-75TH PERCENTILE, IS ALONG THE  
COAST RANGE. OTHERWISE, IT'S ONLY AROUND A 2-3 DEGREE SPREAD.  
 
AFTER THE WARM DAY, THE RIDGE WILL BREAK DOWN AND A FRONTAL  
SYSTEM WILL ARRIVE ON FRIDAY MORNING. THIS FRONT AT THIS TIME IS  
MORE ORGANIZED THAN PREVIOUS SYSTEMS. IT WILL ALSO HAVE THE  
ADDED BENEFIT OF THESE LAST FEW DAYS OF ONSHORE FLOW TO MOISTEN  
UP THE ATMOSPHERE AND MAKE IT MORE AVAILABLE TO HAVE  
ACCUMULATING PRECIPITATION. THE CAVEAT TO THAT FORECAST WILL  
RESIDE WITH THE EXTEND OF HOW ELONGATED THE LOW BECOMES AND HOW  
FAR SOUTH IT ADVECTS. THE GFS HAS THE MOST NORTHERLY SOLUTION  
WITH THE FORECAST AREA SITTING IN THE LEFT EXIT REGION OF THE  
JET. IN CONTRAST, THE ECMWF AND CANADIAN ARE MUCH FURTHER SOUTH  
AND EVENTUALLY MOVING INTO THE LESS ACTIVE PORTION OF THE JET  
OVER THE WEEKEND. OVERALL, CONFIDENCE IN GENERAL WITH THIS  
PORTION OF THE FORECAST IS LOW. -MUESSLE  
 
 
   
AVIATION  
VFR INLAND WITH MVFR CIGS PERSISTING ALONG THE COAST.  
THERE CHANCE (20-30%) THAT THE COAST REMAINS MVFR INTO THE  
OVERNIGHT WHEN THE NEXT MARINE PUSH BEGINS TO MOVE EASTWARD. THE  
MARINE LAYER IS EXPECTED TO MOVE UP THE COLUMBIA RIVER, INTO THE  
PORTLAND METRO BETWEEN 6-9Z AND FILLING IN THE REST OF THE  
WILLAMETTE VALLEY BETWEEN 12-15Z. PROBABILITIES FOR MVFR CIGS ARE  
40-60% WITHIN THE VALLEY AND HIGHER AT 60-90% AROUND THE METRO.  
EXPECT SIMILAR TIMING FOR THE STRATUS BREAK-OUT SUNDAY MORNING.  
 
NORTHWEST WINDS AT 8-12 KT THROUGH THE EVENING, BECOMING LIGHT AND  
VARIABLE INLAND AFTER 6Z. WINDS REMAIN ELEVATED AROUND 10 KT  
ALONG THE COAST.  
 
PDX AND APPROACHES...VFR WITH NORTHWEST WINDS AROUND 10 KT THROUGH  
THE EVENING, BECOMING LIGHT AND VARIABLE AFTER 6Z. A MARINE PUSH  
IS EXPECTED TO MOVE INTO THE METRO AREA BETWEEN 6-9Z, BRINGING  
MVFR CIGS. -BATZ  
 
 
   
MARINE  
HIGH PRESSURE OVER THE NORTHEAST PACIFIC ALONG WITH A  
LOW IMPACTING CALIFORNIA HAS TIGHTENED THE PRESSURE GRADIENT  
ACROSS OUR WATERS. THIS HAS RESULTED IN NORTHWEST WINDS GUSTING UP  
TO 25-30 KT IN THE OUTER COASTAL WATERS AND UP TO 25 KT FOR THE  
INNER COASTAL WATERS. WITH THESE BREEZY CONDITIONS AND A BUILDING  
NORTHWESTERLY SWELL, EXPECT COMBINES SEAS TO REACH 10 TO 11 FEET  
THIS MORNING. AS A RESULT, THE SMALL CRAFT ADVISORY CONTINUES  
ACROSS ALL WATERS INTO TONIGHT. THE OUTER COASTAL WATERS SEE SMALL  
CRAFT CONDITIONS PERSIST INTO SUNDAY MORNING.  
 
THE COLUMBIA RIVER BAR IS ALSO EXPERIENCING SMALL CRAFT ADVISORY  
CONDITIONS BUT WILL DROP OFF AROUND 8 PM THIS EVENING. ANOTHER  
SHORT SMALL CRAFT HAS BEEN ISSUED FOR A VERY STRONG EBB OF 6.99 KT  
AT 449 AM  
 
BY EARLY SUNDAY, BOTH WINDS AND SEASONS WILL BEGIN TO EASE AS  
HIGH PRESSURE WEAKENS SLIGHTLY AND MOVES INLAND. THE START OF NEXT  
WEEK LOOKS TO BE RATHER QUIET, WITH SEAS AROUND 5 TO 7 FEET AND  
WIND GUSTS UNDER 20 KT. -BATZ/HALL  
 
 
   
PQR WATCHES/WARNINGS/ADVISORIES  
 
OR...NONE.  
WA...NONE.  
PZ...SMALL CRAFT ADVISORY UNTIL 8 PM PDT THIS EVENING FOR PZZ210.  
SMALL CRAFT ADVISORY UNTIL 2 AM PDT SUNDAY FOR PZZ251>253.  
SMALL CRAFT ADVISORY UNTIL 2 PM PDT SUNDAY FOR PZZ271>273.  
 
 
 
 
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