011  
FXUS66 KPDT 091740  
AFDPDT  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE PENDLETON OR  
1040 AM PDT MON JUN 9 2025  
   
UPDATED FOR AVIATION  
 
   
AVIATION  
 
18Z TAFS...VFR CONDITIONS ARE EXPECTED THROUGH THE TAF PERIOD.  
WINDS WILL GUST THIS AFTERNOON/EVENING IN THE 20 TO 25 KT RANGE  
AT DLS/BDN/RDM/YKM BEFORE DECREASING TO 10 KTS OR LESS. THE OTHER  
SITES WILL REMAIN 10 KTS OR LESS THROUGHOUT THE PERIOD.  
 
 
   
PREV DISCUSSION  
/ISSUED 1016 PM PDT SUN JUN 8 2025/  
 
EVENING UPDATE...RED FLAG WARNINGS HAVE BEEN ISSUED FOR THE LOWER  
KITTITAS VALLEY AND THE LOWER COLUMBIA BASIN FOR WINDS AND RHS  
BEGINNING 2 PM MONDAY AND LASTING THROUGH UNTIL TUESDAY AT 8 PM.  
WINDS WILL TO INCREASE THROUGH THE KITTITAS VALLEY, COLUMBIA  
RIVER GORGE,AND INTO THE COLUMBIA BASIN STARTING MONDAY  
AFTERNOON. PROBABILITIES OF THESE AREAS SEEING 25 MPH GUSTS IS  
90-100% AND 39 MPH GUSTS IS 49%, 10-40%, 20-30% RESPECTIVELY.  
THIS, COMBINED WITH VERY LOW RHS DUE TO THE ONGOING HEAT WAVE,  
WILL MAKE FOR INCREASED RISKS FOR WILDFIRE SPREAD, ESPECIALLY  
DURING THE AFTERNOON AND EARLY EVENING HOURS ON BOTH MONDAY AND  
TUESDAY. BENNESE/90  
 
UPDATED AVIATION...06Z TAFS...VFR CONDITIONS WILL PERSIST  
THROUGH THE FORECAST PERIOD WITH WARM AND DRY CONDITIONS. CIGS  
WILL BE SKC THROUGH THE PERIOD WITH DIURNALLY DRIVEN WINDS  
OVERNIGHT AND THROUGH THE DAY UNTIL 19-22Z BEGINNING WITH DLS THEN  
RDM AND FOLLOWED BY BDN. THESE TAF SITES WILL SEE WINDS INCREASE  
NEARING 15-20 KTS SUSTAINED AND GUSTS NEARING 20-30 KTS GUSTS.  
OTHERWISE, THE REMAINING SITES WILL REMAIN BELOW 10 KTS.  
BENNESE/90  
 
PREV DISCUSSION... /ISSUED 1250 PM PDT SUN JUN 8 2025/  
 
SHORT TERM...TODAY THROUGH TUESDAY...TEMPERATURES ARE QUICKLY  
WARMING UP TODAY AS A STRONG HIGH PRESSURE RIDGE MOVES INTO THE  
PACNW. MONDAY STILL LOOKS TO BE THE HOTTEST DAY OF THE PERIOD, WHEN  
THE RIDGE AXIS IS EXPECTED TO BE OVER THE FORECAST AREA. NOT MUCH  
CHANGE IN THE TEMPERATURE FORECAST, WITH MID TO UPPER 90S EXPECTED  
TODAY AND TUESDAY ACROSS MOST OF THE LOWLANDS OF THE FORECAST AREA,  
WHILE HIGHS REACH AS HIGH AS 105 IN THE COLUMBIA BASIN ON MONDAY.  
RIDGING STARTS TO MOVE OUT BY LATE MONDAY EVENING HEADING INTO  
TUESDAY, BUT SW FLOW WILL KEEP THE HEAT IN PLACE, ALLOWING THE LOWER  
BASIN TO POTENTIALLY SEE ANOTHER DAY OF TRIPLE DIGIT TEMPERATURES  
(20-30% CHANCE ACCORDING TO NBM PROBABILISTIC).  
 
HEAT ADVISORIES REMAIN IN EFFECT UNTIL TUESDAY EVENING ACROSS THE  
BASIN, YAKIMA/KITTITAS VALLEYS, FOOTHILLS OF THE BLUES, AND COLUMBIA  
RIVER GORGE. AS MENTIONED YESTERDAY, HEATRISK GUIDANCE TECHNICALLY  
CALLED FOR EXTREME HEAT WARNINGS FOR SOME AREAS (NAMELY THE GORGE  
AND YAKIMA/KITTITAS VALLEYS) ON MONDAY, BUT IN ORDER TO SIMPLIFY  
MESSAGING, AND WITH CRITERIA ONLY REALLY BEING MET ON ONE DAY, OPTED  
TO GO WITH STRAIGHT HEAT ADVISORIES INSTEAD. THIS ALSO KEEPS THE  
HEAT HEADLINES GEOGRAPHICALLY CONSISTENT.  
 
ONCE SW FLOW KICKS IN ON TUESDAY, FOCUS WILL SHIFT TOWARD THAT OF  
WINDS AND MOUNTAIN THUNDERSTORMS. THESE TYPE OF RIDGE BREAKDOWN  
SCENARIOS AFTER A PERIOD OF HOT AND DRY CONDITIONS ARE OFTEN  
CONDUCIVE FOR DRY THUNDERSTORMS OVER THE MOUNTAINS OF CENTRAL AND  
EASTERN OREGON. EVEN THE NBM, WHICH NOTORIOUSLY DOWNPLAYS DRY  
THUNDERSTORM RISKS, IS PICKING UP ON THE POTENTIAL TUESDAY  
AFTERNOON. THIS, COMBINED WITH THE RELATIVELY PROGRESSIVE PATTERN  
EXPECTED ONCE THIS RIDGE MOVES OUT OF THE REGION, MAY CREATE A  
PROLONGED PERIOD OF HEIGHTENED WILDFIRE RISK THROUGH THE WEEK, AS  
WINDS WILL PICK UP THROUGH THE CASCADE GAPS AND INTO THE BASIN  
THROUGH THE MIDWEEK. CONCERNS WOULD PRIMARILY BE CENTERED AROUND THE  
BASIN AND ADJACENT VALLEYS, AS NOT ONLY ARE FUELS IN THE MOUNTAINS  
GENERALLY NOT AT CRITICAL LEVELS, BUT AS SW FLOW PERSISTS THROUGH  
THE MIDWEEK, PWATS KICK UP ENOUGH TO INCREASINGLY DILUTE THE  
WILDFIRE RISK FROM DRY THUNDERSTORMS. EVANS/74  
 
LONG TERM...WEDNESDAY THROUGH SUNDAY...A PARENT LOW OFF THE GULF OF  
ALASKA WILL DRIVE A PROGRESSIVE PATTERN THROUGH NEXT WEEKEND, AS  
THIS LOW CIRCULATES PERSISTENT SW FLOW, AS WELL AS SOME SHORTWAVES,  
THROUGH THE PACNW. ENSEMBLES MORE OR LESS HAVE US LOCKED IN UNDER  
THIS SW FLOW PATTERN THROUGH THE PERIOD AS A RESULT, WITH THE ONLY  
VARIATIONS BEING IN HOW STRONG SW FLOW WILL BE, BASED ON THE ARRIVAL  
OF ATTENDANT SHORTWAVES (SEEN MORE CLEARLY THROUGH THE DETERMINISTIC  
GFS) AND OVERALL UPPER-LEVEL WIND SPEEDS.  
 
WHILE THE TUESDAY-WEDNESDAY PERIOD LOOKS TO BE DICEY FOR THE BASIN,  
AS WELL AS THE YAKIMA/KITTITAS VALLEYS AS FAR AS FIRE WEATHER DANGER  
IS CONCERNED, THE LONGER WE REMAIN LOCKED IN THIS PATTERN, THE MORE  
RHS WILL TREND UPWARD OVER THE COURSE OF THE WEEK. GUIDANCE OVERALL  
HOLDS STEADY ON BREEZY WINDS THROUGH THE CASCADE GAPS, SPILLING INTO  
THE BASIN AS WELL, BUT AS THIS AFOREMENTIONED LOW GRADUALLY EASES  
ITS WAY ON SHORE, SO DOES ITS COOLER AIR, RESULTING IN HIGH  
TEMPERATURES TRENDING MORE TOWARD THE LOW 80S FOR THE BASIN AND 70S  
ELSEWHERE. THE INCREASE IN MOISTURE WILL ALSO MAKE FOR MORE OF A  
SHOWER RATHER THAN THUNDERSTORM THREAT AS CLOUD COVER POURS IN AND  
INSTABILITY IS HINDERED, ALTHOUGH TO BE FAIR THE DRY THUNDERSTORM  
RISK FOR WILDFIRE STARTS ACROSS THE MOUNTAINS WAS ADMITTEDLY  
DOWNPLAYED GIVEN HOW EARLY IN THE WARM SEASON WE ARE FOR FUELS TO BE  
AT CRITICAL LEVELS. STILL, IT'LL BE GOOD TO SEE AT LEAST SOME  
SEMBLANCE OF RELIEF OVER TIME GIVEN THE POTENTIALLY CRITICAL  
CONDITIONS THAT LOOK TO SHAPE UP TUESDAY INTO WEDNESDAY, ASSUMING  
THAT SAID PERIOD DOESN'T END UP BEING TOO ACTIVE IN TERMS OF NEW  
FIRE STARTS. EVANS/74  
 
 
   
PRELIMINARY POINT TEMPS/POPS  
 
PDT 101 64 97 62 / 0 0 0 0  
ALW 100 69 95 66 / 0 0 0 0  
PSC 104 64 100 60 / 0 0 0 0  
YKM 103 64 99 62 / 0 0 0 0  
HRI 104 65 100 63 / 0 0 0 0  
ELN 100 65 95 62 / 0 0 0 0  
RDM 98 56 94 50 / 0 0 0 10  
LGD 95 61 92 59 / 0 0 10 10  
GCD 95 60 94 57 / 0 0 10 30  
DLS 100 65 94 62 / 0 0 0 0  
 
 
   
PDT WATCHES/WARNINGS/ADVISORIES  
 
OR...HEAT ADVISORY UNTIL 9 PM PDT TUESDAY FOR ORZ041-044-507.  
 
WA...HEAT ADVISORY UNTIL 9 PM PDT TUESDAY FOR WAZ024-026>029.  
 
RED FLAG WARNING FROM 2 PM THIS AFTERNOON TO 8 PM PDT TUESDAY  
FOR WAZ690-691.  
 
 
 
 
 
SHORT TERM...77  
LONG TERM....77  
AVIATION...77  
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