780  
FXUS66 KPQR 071755 AAA  
AFDPQR  
 
AREA FORECAST DISCUSSION...UPDATED  
NATIONAL WEATHER SERVICE PORTLAND OR  
1055 AM PDT SUN AUG 7 2022  
 
UPDATED AVIATION AND FIRE DISCUSSIONS  
   
SYNOPSIS
 
HOT TEMPERATURES ARE EXPECTED TO CONTINUE INTO MONDAY AS  
AN UPPER RIDGE LAYS OVER THE PACIFIC NW. TEMPERATURES WILL THEN COOL  
AS A PACIFIC CUTOFF BEGINS TO NEAR THE COAST THROUGH THE WEEK. THE  
LOW WILL BEGIN ADVECTING MOISTURE NORTH INTO THE AREA, INCREASING THE  
CHANCE OF SHOWERS AND THUNDERSTORMS FOR SELECT AREAS THROUGH EARLY  
WEDNESDAY. A DRIER TREND WILL TAKE HOLD FOR THE LATTER HALF OF THE  
WEEK.  
 

 
   
DISCUSSION...TODAY THROUGH SATURDAY
 
AS AN UPPER RIDGE LAYS ACROSS  
THE PACIFIC NORTHWEST, CAUGHT BETWEEN A LARGE CUTOFF LOW OFFSHORE OF  
NORTHERN CALIFORNIA AND A SHORTWAVE TROUGH OVER MONTANA, CLEAR SKIES  
CAN BE FOUND ACROSS OR AND WA. THE ONE EXCEPTION IS A SURGE OF MARINE  
FOG AND STRATUS MOVING NORTH ALONG THE CENTRAL OR COAST. THE  
SUBSIDENT RIDGE HAS RESULTED IN LOW HUMIDITY SETTLING ACROSS THE  
HIGHER TERRAIN, AND A SURFACE THERMAL TROUGH STRETCHING OVER THE  
CENTRAL WILLAMETTE VALLEY UP OVER LONG BEACH, WA HAS HELPING DRAW IN  
THE DRIER WARMER AIR FROM CENTRAL OR. WARM OVERNIGHT LOWS RIGHT NOW  
AND THE EXPECTED CLEAR SKIES WILL COMBINE TO BRING THE WARMEST  
TEMPERATURES OF THE WEEKEND TODAY, WITH UPPER 90S IN MOST OF THE  
INLAND VALLEYS, WITH A FEW PLACES SEEING TRIPLE DIGITS AS  
HIGH AS 102. THE HIGHER TERRAIN WILL SEE MID 80S TO LOW 90S, WHILE  
THE COASTS REMAIN IN THE MID 60S TO MID 70S, THOUGH FURTHER NORTH  
WHERE THE SURFACE TROUGH WILL LINGER SUCH AS NEAR ASTORIA, THEY WILL  
LIKELY SEE SOME READINGS IN THE MID 80S. SOME HAZY SKIES WILL EXIST  
THIS MORNING FROM NEARBY FIRES, BUT NOTHING MUCH AT THE SURFACE  
BESIDES RIGHT NEAR THE FIRES, SUCH AS EASTERN LANE COUNTY BY THE  
CEDAR CREEK FIRE. WATCHING THE SMOKE PRODUCED YESTERDAY AND ITS  
EVENTUAL DRIFT OVERNIGHT, THERE DOESN'T SEEM TO BE ENOUGH TO AFFECT  
THE FORECASTED TEMPERATURES, SO DID NOT LOWER ANYTHING. THE SURFACE  
THERMAL TROUGH WILL BE PUSHING EAST LATE THIS MORNING BACK OVER THE  
CASCADE CREST, MEANING GUSTY EAST WINDS OVER THE CASCADES SHOULD BE  
TRENDING SLOWER BY NOON AND INTO THE AFTERNOON. HREF MEMBERS CONTINUE  
TO SHOW THE POTENTIAL FOR A FEW SHOWERS OR THUNDER NEAR OR EAST OF  
THE CASCADE CREST IN LANE COUNTY, KEPT A SLIGHT CHANCE MENTION JUST  
IN THE FARTHEST SOUTHEAST CORNER. THIS WILL LIKELY OCCUR IN THE LATE  
AFTERNOON INTO THE EARLY EVENING. OVERNIGHT, AS THE OFFSHORE CUTOFF  
LOW STARTS SLOWLY MOVING TOWARD THE COAST, A FLOW REVERSAL ALONG THE  
SHORE IN RESPONSE TO THE SURFACE TROUGH MOVING NORTH WILL ALLOW  
COOLER MARINE AIR TO SURGE NORTH AND INLAND OVER CENTRAL OR. A FEW  
FINGERS OF THE JET AHEAD OF THE UPPER LOW WILL PUSH NORTH INTO OR  
OVERNIGHT, ALLOWING FOR SOME LIFT POTENTIAL. SEVERAL HREF MEMBERS  
SHOWING SOME SPOTTY SHOWERS POSSIBLE TO SURGE NORTH EARLY MONDAY  
MORNING ACROSS THE FORECAST AREA. HAVE ADDED A 10-20% CHANCE FOR  
THESE. MOISTURE UP IN THE -10 TO -20C LAYER MAY BE JUST ENOUGH FOR A  
ROLL OF THUNDER, MAINLY ALONG THE CASCADE CREST.  
 
WITH THE UPPER RIDGING BREAKING DOWN SLIGHTLY WITH THE NEARING OF THE  
UPPER LOW, ALONG WITH THE INCREASE IN MOISTURE FROM THE SOUTH, LOOK  
FOR TEMPERATURES ON MONDAY TO BE SEVERAL DEGREES COOLER. THE AREAS  
IN THE CURRENT HEAT ADVISORY WILL STILL SEE TEMPERATURES IN THE LOW  
TO MID 90S, HENCE THE HEAT ADVISORY EXPIRATION TIME STAYING AT 8PM  
MONDAY. ADDITIONAL MOISTURE MOVING UP WILL CONTINUE TO KEEP A SLIGHT  
CHANCE OF SHOWERS OVER THE CASCADES MONDAY AFTERNOON. MONDAY NIGHT,  
THE JET ON THE FORWARD SIDE OF THE UPPER LOW WILL STRENGTHEN OVER  
SOUTHERN OR TO CREATE ADDITIONAL LIFT OVER THE FORECAST AREA.  
MONSOONAL MOISTURE SURGING NORTH FROM THE DESERT SOUTHWEST WILL AID  
IN A 20% CHANCE OF SHOWERS ACROSS MUCH OF THE AREA MONDAY NIGHT INTO  
TUESDAY MORNING. THE WHOLE ATMOSPHERIC COLUMN WILL BEGIN COOLING AS  
THE LOW NEARS, RESULTING IN COOLER TEMPERATURES, ESPECIALLY WITH  
ADDITIONAL CLOUDS.  
 
TUESDAY NIGHT INTO WEDNESDAY, ALMOST ALL DETERMINISTIC AND ENSEMBLE  
MODELS SHOW THE UPPER LOW NORTH JUST OFFSHORE OF THE OR COAST, TO  
SPREAD IN COOLER AIR AND AND BRING BREEZY WINDS. ECMWF EFI SHOWING  
SOME HIGHER VALUES ALONG THE CASCADES FOR WEDNESDAY, INDICATING AN  
ANOMALY. TEMPERATURES WILL BE BACK TOWARD NORMAL FOR MID-AUGUST.  
 
THE CUTOFF LOW IS THEN SHOWN TO STALL A BIT OFF OF VANCOUVER  
ISLAND THURSDAY AND FRIDAY, MAINTAINING ONSHORE FLOW AND SEASONABLE  
CONDITIONS. WPC CLUSTER MEAN KEEP THE WEAK TROUGHING JUST OFFSHORE  
FOR SATURDAY AS WELL, SUPPORTING THE DRY AND JUST ABOVE NORMAL  
TEMPERATURE FORECAST. /KRIEDERMAN  
 

 
   
FIRE
 
WITH AN UPPER LEVEL SUBSIDENT RIDGE OVER THE PACNW AND A  
SURFACE THERMAL TROUGH OVER THE WILLAMETTE VALLEY EARLY THIS  
MORNING, EASTERLY WINDS OVER THE CASCADES HAVE BROUGHT IN DRIER  
AIR. SOME GUSTS IN THE 10-25 MPH RANGE WITH DROPS IN HUMIDITY INTO  
THE 20-35% RANGE EARLY THIS MORNING SHOW SPOTTY RED FLAG  
CONDITIONS OVER THE MOUNTAINS. WITH THE SURFACE THERMAL TROUGH  
FORECASTED TO START MOVING BACK EAST TO BE OVER THE CASCADES AGAIN  
BY EARLY AFTERNOON, EXPECTING THE EAST WINDS TO PEAK LATE THIS  
MORNING INTO EARLY AFTERNOON. THIS TREND IS WELL CAPTURED BY THE  
LATEST HI-RES MODEL GUIDANCE. RH WILL REMAIN LOW TODAY WITH HOT  
TEMPERATURES, BUT THE THREAT OF RFW CONDITIONS WILL LIKELY DROP  
OFF QUICKLY BY MID AFTERNOON WITH THE DECREASE IN WINDS. HAVE  
THEREFORE TRIMMED BACK THE END TIME OF THE RED FLAG WARNING TO 3  
PM THIS AFTERNOON. THERE IS STILL SOME MID-LEVEL INSTABILITY TO  
CAUSE CONCERN, HOWEVER WITH THE MORE STABLE UPPER AIRMASS, THE  
CONCERN IS LESSENING.  
 
AN UPPER LOW OFF THE NORTHERN CALIFORNIA COAST WILL SLOWLY LIFT  
NORTHEASTWARD MONDAY THROUGH WEDNESDAY, RESULTING IN A PROLONGED  
PERIOD OF SOUTHERLY FLOW ALOFT OVER THE DISTRICT, COOLING  
TEMPERATURES AND ADVECTING IN ADDITIONAL MOISTURE. THIS WILL  
INCREASE THE CHANCES FOR SHOWERS AND THUNDERSTORMS MONDAY THROUGH  
WEDNESDAY MORNING, MAINLY OVER THE CASCADES DURING THE AFTERNOON  
AND EVENING HOURS, HOWEVER SOME SPOTTY ACTIVITY MAY BE OBSERVED  
ACROSS THE DISTRICT. TUESDAY APPEARS TO BE THE HIGHEST CHANCE FOR  
THUNDERSTORMS AS MOISTURE AND INSTABILITY WILL BE ON THE INCREASE.  
 

 
   
AVIATION
 
18Z TAFS: VFR CONDITIONS ARE EXPECTED TO PREVAIL  
THROUGH 18Z MONDAY FOR THE INLAND TAF SITES WITH INCREASINGLY  
HAZY SKIES DUE TO ELEVATED SMOKE COMING FROM REGIONAL WILDFIRES.  
MAY SEE SOME REDUCTION IN SLANT-WISE VISIBILITY AT TIMES,  
ESPECIALLY FROM KSLE TO KEUG. SURFACE VISIBILITY REDUCTIONS DUE TO  
SMOKE ARE NOT EXPECTED AT THIS TIME.  
 
ALTHOUGH SATELLITE AND SURFACE WEATHER OBSERVATIONS FROM 1730Z  
SUNDAY SHOWED CLEAR SKIES AT KAST AND KONP, MARINE STRATUS WAS  
HUGGING THE CENTRAL OR COAST FROM FLORENCE TO NEWPORT DUE TO A  
SOUTHERLY WIND REVERSAL. THE SOUTHERLY WIND REVERSAL IS EXPECTED  
TO BEGIN PUSHING NORTHWARD UP THE COAST THIS EVENING INTO TONIGHT,  
LIKELY MAKING IT TO KAST BY 09-12Z. EXPECT LOW STRATUS AND FOG TO  
ACCOMPANY THE SOUTHERLY WIND REVERSAL, WITH CIGS AS LOW AS 100-200  
FEET AND DENSE FOG LIKELY AT KONP AFTER 02-03Z AND CIGS AS LOW AS  
200-300 FEET AT KAST WITH SURFACE VISIBILITY REDUCTIONS ALSO  
LIKELY AFTER 10Z. THE MAIN FORECAST CHALLENGE IS DETERMINING HOW  
FAR INLAND THE MARINE STRATUS DECK WILL PUSH INTO THE SOUTHERN  
WILLAMETTE VALLEY, IF AT ALL. IT APPEARS THE STRATUS LAYER WILL BE  
TOO SHALLOW TO MAKE IT ALL THE WAY TO KEUG, HOWEVER THE STRATUS  
LAYER IS EXPECTED TO DEEPEN A BIT BETWEEN 12-16Z. THIS IS WHEN THE  
HREF IS SHOWING AROUND A 30 TO 40 PERCENT CHANCE FOR CIGS AROUND  
1000 FEET OR LESS AT KEUG. FOR NOW, HAVE DECIDED TO ONLY BRING  
SCATTERED CIGS INTO KEUG MONDAY MORNING, BUT A BROKEN STRATUS DECK  
CANNOT BE COMPLETELY RULED OUT.  
 
FOR DETAILED PAC NW AVIATION WEATHER INFORMATION, GO ONLINE TO:  
HTTPS://WEATHER.GOV/ZSE  
 
KPDX AND APPROACHES...EXPECT VFR CONDITIONS TO CONTINUE THROUGH  
18Z MONDAY. SKIES MAY BECOME A BIT HAZY SUNDAY AFTERNOON AS UPPER  
LEVEL SMOKE COMING FROM THE CEDAR CREEK WILDFIRE TO THE SOUTH  
DRIFTS NORTHWARD TOWARDS SOUTHWEST WA. SURFACE VISIBILITY  
REDUCTIONS ARE NOT EXPECTED, HOWEVER SLANT-WIDE VISIBILITY MAY BE  
IMPACTED AT TIMES SUNDAY AFTERNOON INTO SUNDAY NIGHT. -TK  
 

 
   
MARINE
 
HIGH PRESSURE OFFSHORE CONTINUE NORTHERLY WINDS ACROSS  
THE WATERS WITH GUSTS NEAR 20 KT THIS MORNING OVER THE OUTER  
WATERS. NEARSHORE, A RIDGE OF HIGH PRESSURE CONTINUES TO DEVELOP  
OVER THE SOUTH OREGON COAST WHICH WILL SPREAD SOUTHERLY WINDS  
NORTHWARD ACROSS THE WATERS, REACHING THE SOUTHERN ZONES THIS  
MORNING, BUT NOT REACH THE SOUTH WASHINGTON WATERS UNTIL LATE  
SUNDAY NIGHT. THE SOUTHERLY WIND REVERSAL IS USUALLY ACCOMPANIED  
BY A SHALLOW STRATUS LAYER OR FOG WHICH CAN RESULT IN RAPIDLY  
DETERIORATING VISIBILITY. WILL NEED TO CLOSELY MONITOR FOR THE  
DENSE FOG POTENTIAL. SO FAR THE SPARSE OBSERVATIONS AVAILABLE  
SHOW VISIBILITIES ABOVE 6 MILES, BUT LOCALLY FLUCTUATING BELOW 1  
MILE.  
 
SEAS WILL REMAIN AROUND 4 TO 7 FT AT 7 TO 9 SECONDS WITH A  
DOMINANT NORTHWESTERLY SWELL. /MH  
 
FOR INFORMATION ABOUT UPCOMING MARINE ZONE CHANGES, GO ONLINE TO:  
HTTPS://WWW.WEATHER.GOV/PQR/MARINEZONE  
 

 
   
PQR WATCHES/WARNINGS/ADVISORIES
 
 
OR...RED FLAG WARNING UNTIL 3 PM PDT THIS AFTERNOON FOR MT. HOOD  
NATIONAL FOREST WEST OF CASCADE CREST-NORTH OREGON CASCADE  
FOOTHILLS.  
 
HEAT ADVISORY UNTIL 8 PM PDT MONDAY FOR CENTRAL COLUMBIA RIVER  
GORGE-GREATER PORTLAND METRO AREA-UPPER HOOD RIVER VALLEY-  
WESTERN COLUMBIA RIVER GORGE.  
 
WA...RED FLAG WARNING UNTIL 3 PM PDT THIS AFTERNOON FOR EXTREME SOUTH  
 
WASHINGTON CASCADES AND FOOTHILLS.  
 
HEAT ADVISORY UNTIL 8 PM PDT MONDAY FOR CENTRAL COLUMBIA RIVER  
GORGE-GREATER VANCOUVER AREA-WESTERN COLUMBIA RIVER GORGE.  
 
PZ...DENSE FOG ADVISORY UNTIL 2 PM PDT THIS AFTERNOON FOR COASTAL  
WATERS FROM CASCADE HEAD TO FLORENCE OR OUT 10 NM.  
 

 
 

 
 
WWW.WEATHER.GOV/PORTLAND  
 
INTERACT WITH US VIA SOCIAL MEDIA:  
WWW.FACEBOOK.COM/NWSPORTLAND  
WWW.TWITTER.COM/NWSPORTLAND  
 
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