024  
FXUS66 KPQR 191110  
AFDPQR  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE PORTLAND OR  
310 AM PST SUN JAN 19 2025  
   
SYNOPSIS
 
HIGH PRESSURE WILL REMAIN IN PLACE THROUGH NEXT  
WEEK, MAINTAINING DRY CONDITIONS, MOSTLY SUNNY SKIES, AND CHILLY  
OVERNIGHT TEMPERATURES. COULD SEE SOME INCREASED CLOUD COVER  
MONDAY NIGHT INTO TUESDAY AS A DRY FRONT APPROACHES THE AREA.  
GUIDANCE SUGGESTS HIGH PRESSURE BREAKS DOWN THURSDAY TO FRIDAY,  
WITH POTENTIAL RETURN FOR PRECIPITATION. HIGH UNCERTAINTY  
REMAINS WITH THIS SYSTEM AT THE END OF THE WEEK.  
 

 
   
SHORT TERM...NOW THROUGH TUESDAY NIGHT
 
UPPER LEVEL PATTERN  
REMAINS LARGELY UNCHANGED OVER THE LAST 24 HOURS WITH DEEP  
TROUGHING OVER THE CONTINENTAL US AND A NARROW, AMPLIFIED RIDGE  
AXIS JUST OFF THE WEST COAST. CLEAR OVERNIGHT CONDITIONS  
SUPPORTING EFFICIENT RADIATIVE COOLING WITH INLAND LOWS DROPPING  
BELOW THE FREEZING MARK FOR MOST LOCATIONS. DRIER CONDITIONS  
ARE KEEPING STRATUS AND FOG FROM DEVELOPING EXCEPT FOR THE FAR  
SOUTHERN WILLAMETTE VALLEY AROUND EUGENE WHICH SEEING PATCHY  
DENSE FOG. EXPECT ANOTHER QUIET AND DRY DAY TO END THE WEEKEND  
WITH INLAND TEMPS REACHING INTO THE LOW TO MID 40S, COASTAL  
AREAS COULD SEE TEMPS CLOSER TO THE 50 MARK WHILE THE CASCADES  
WILL STAY IN THE 30S.  
 
THE OFFSHORE RIDGE AXIS WILL SHIFT INLAND LATE SUNDAY INTO MONDAY,  
LEADING TO ANOTHER CLEAR AND COLD NIGHT ACROSS THE REGION. MANY  
LOCATIONS WEST OF THE CASCADES ARE EXPECTED TO DROP INTO THE LOW TO  
MID 20S, SLIGHTLY WARMER AROUND METRO IN THE UPPER 20S AND ALONG THE  
COASTAL AREAS. A COLD WEATHER ADVISORY REMAINS IN EFFECT FOR AREAS  
WEST OF THE CASCADES AND THROUGHOUT THE COLUMBIA RIVER GORGE AND  
UPPER HOOD RIVER VALLEY.  
 
MONDAY WILL BE DRY AND MOSTLY SUNNY AS THE RIDGE SHIFTS OVERHEAD,  
BUT AN APPROACHING UPPER LEVEL SHORTWAVE TROUGH WILL RETURN HIGH  
CLOUD COVER BY MONDAY NIGHT. THE SHORTWAVE IS NOT EXPECTED TO BRING  
ANY PRECIPITATION TO THE AREA. OVERNIGHT LOWS WILL STILL BE CHILLY  
MONDAY NIGHT INTO TUESDAY MORNING BUT CONFIDENCE IS LOWER FOR  
MEETING COLD WEATHER ADVISORY CRITERIA AS CLOUD COVER COULD KEEP  
TEMPERATURES A FEW DEGREES WARMER. HIGH PRESSURE REBUILDS BEHIND  
THIS TROUGH, CLEARING SKIES BY TUESDAY AFTERNOON. -BATZ  
 
   
LONG TERM...WEDNESDAY THROUGH FRIDAY
 
THE MAJORITY OF  
ENSEMBLE MEMBERS FROM THE WPC CLUSTER ANALYSES ARE IN AGREEMENT  
ON UPPER LEVEL RIDGING CONTINUING WEDNESDAY, MAINTAINING DRY  
WEATHER WITH MOSTLY CLEAR SKIES AND CHILLY NIGHTS. ON THURSDAY,  
THE CLUSTERS ALL BEGIN TO SHOW THE RIDGE BEGINNING TO WEAKEN AS  
A SYSTEM BEGINS TO DIP SOUTHWARD FROM CANADA. THURSDAY NIGHT TO  
FRIDAY, ABOUT 75% OF ENSEMBLE MEMBERS SHOW THE RIDGE COMPLETELY  
BREAKING DOWN OR SHIFTING EASTWARD. THIS WOULD RETURN CHANCES  
FOR PRECIPITATION AT THE END OF THE WEEK, HOWEVER, THERE IS  
STILL HIGH UNCERTAINTY WITH THE EXACT TIMING, MAGNITUDE, AND  
TRACK OF THIS POTENTIAL SYSTEM. -ALVIZ  
 

 
   
AVIATION
 
GENERALLY CLEAR SKIES AND VFR ACROSS THE AREA, WITH  
THE EXCEPTION OF FOG IN THE SOUTHERN WILLAMETTE VALLEY (KEUG).  
WEAK NORTHEASTERLY FLOW THROUGHOUT THE REGION, CONTINUING THROUGH  
SUNDAY, BRINGING DRY COLD AIR THAT SHOULD GENERALLY INHIBIT FOG  
FORMATION. FOG AT KEUG SHOULD BEGIN LIFTING AROUND 18-20Z SUNDAY,  
AFTER WHICH VFR CONDITIONS WILL RETURN FOR THE MAJORITY OF DAYTIME  
HOURS. KTTD ALSO WILL BE AN EXCEPTION, WITH EASTERLY FLOW THROUGH  
THE COLUMBIA RIVER GORGE INCREASING THROUGHOUT THE PERIOD.  
EASTERLY WINDS WITH GUSTS UP TO 25 KT POSSIBLE AFTER AROUND 03-05Z  
MON. OTHERWISE, MOST TERMINALS SEE CLEAR SKIES AND WEAK  
NORTHEASTERLY FLOW UNDER 8 KTS THROUGHOUT THE PERIOD.  
 
PDX AND APPROACHES...VFR THROUGHOUT THE PERIOD, WITH GENERALLY  
WEAK NORTHEASTERLY FLOW TURNING EASTERLY DURING DAYTIME HOURS ON  
SUNDAY. WINDS REMAIN UNDER 10 KT THROUGHOUT THE PERIOD, HOWEVER.  
CLEAR SKIES FOR THE DURATION OF THE TAF PERIOD. /JLIU  
 

 
   
MARINE
 
LIGHT TO MODERATE NORTH-NORTHEAST BREEZES PERSIST ACROSS  
THE COASTAL WATERS THIS AFTERNOON AS HIGH PRESSURE REMAINS  
ANCHORED OFFSHORE, WITH WINDS REMAINING UNDER 15-20 KT FOR THE  
FORESEEABLE FUTURE. LITTLE CHANGE EXPECTED THROUGH THE WEEKEND AS  
HIGH PRESSURE PERSISTS. LONG PERIOD SWELL ENTERING THE WATERS AT  
AROUND 7 FT AT 20 SECONDS; THIS RISES TO 8-9 FT AT 18 SECONDS  
THROUGH SUNDAY EVENING. AFTERWARDS WAVES COME BACK DOWN SLOWLY  
OVER THE NEXT FEW DAYS. WINDS SHIFT MORE OFFSHORE EARLY NEXT WEEK,  
WITH A FEW STRONGER GUSTS POSSIBLE IN THE NEARSHORE WATERS OUT OF  
GAPS IN THE COASTAL TERRAIN. GENERALLY BENIGN CONDITIONS EXPECTED  
TO PERSIST WELL INTO NEXT WEEK AS SEAS RESIDE IN THE 5-7 FT RANGE  
DOMINATED BY MID PERIOD WESTERLY SWELL AT 13-15 SECONDS. /CB/JLIU  
 

 
   
BEACH HAZARDS
 
A LONG PERIOD WESTERLY SWELL CONTINUES TO IMPACT  
THE REGION, WITH SEAS AT 7 FT AROUND 20 SECONDS AS OF 3AM SUNDAY.  
ENHANCED SNEAKER WAVE THREAT AT BEACHES UNTIL SUNDAY NIGHT AS  
THE SWELL PERSISTS AT 7-9 FT AT 18-20 SECONDS. BEACHGOERS SHOULD  
REMAIN VIGILANT FOR WAVES OCCASIONALLY RUNNING UP MUCH FARTHER  
ONTO THE BEACH THAN BACKGROUND WAVE CONDITIONS. STAY OFF OF  
ROCKS AND JETTIES AND NEVER TURN YOUR BACK TO THE OCEAN. /CB  
 

 
   
PQR WATCHES/WARNINGS/ADVISORIES
 
 
OR...COLD WEATHER ADVISORY FROM 10 PM THIS EVENING TO 10 AM PST  
MONDAY FOR ORZ101>125.  
 
WA...COLD WEATHER ADVISORY FROM 10 PM THIS EVENING TO 10 AM PST  
MONDAY FOR WAZ201>210.  
 
PZ...NONE.  
 

 
 

 
 
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