091  
FXUS66 KPDT 051701  
AFDPDT  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE PENDLETON OR  
1001 AM PDT SAT JUL 5 2025  
   
AVIATION DISCUSSION...18Z
 
VFR CONDITIONS WILL PERSIST THROUGH  
THE FORECAST PERIOD WITH MOSTLY CLEAR SKIES. WINDS WILL BE  
ELEVATED AT DLS WITH 32015G25KT THROUGH 04Z THEN DECREASING TO  
12KTS AND UNDER. ALL OTHER SITES WILL BE 10KTS OR LESS. BENNESE/90  
 

 
 
PREV DISCUSSION... /ISSUED 201 PM PDT FRI JUL 4 2025/  
 
SHORT TERM...THIS AFTERNOON THROUGH SUNDAY...AN UPPER-LEVEL LOW-  
PRESSURE SYSTEM IS MOVING ONSHORE INTO WESTERN OREGON THIS  
AFTERNOON, INDUCING WIDESPREAD CLOUDINESS AND PRECIPITATION OVER  
THE FORECAST AREA.  
 
THE FIRST OF TWO SHORTWAVES EMBEDDED WITHIN THE BROADER LOW IS  
CONTINUING TO MOVE INLAND ACROSS EASTERN OREGON, WESTERN IDAHO,  
AND SOUTHEAST WASHINGTON. ACTIVITY WITH THIS WAVE HAS DEVELOPED  
INTO A WEAK DEFORMATION BAND AND IS SUPPRESSING AFTERNOON  
TEMPERATURES.  
 
MEANWHILE, CLEARING ACROSS CENTRAL OREGON AND THE OCHOCO-JOHN DAY  
HIGHLANDS EARLY AFTERNOON HAS FACILITATED MODEST (250-500 J/KG)  
SURFACE-BASED CAPE. THE SECOND SHORTWAVE IS MOVING INTO SOUTHWEST  
OREGON AND IS PROGGED TO PROPAGATE IN INLAND OVER SOUTH-CENTRAL  
AND EASTERN OREGON THROUGH THE REMAINDER OF THE AFTERNOON AND  
EVENING. COUPLED WITH FALLING HEIGHTS ALOFT AS THE MAIN UPPER LOW  
MOVES OVERHEAD, THIS SHOULD AID ADDITIONAL THUNDERSTORM  
DEVELOPMENT PRIMARILY FOR DESCHUTES, CROOK, WHEELER, AND GRANT  
COUNTIES.  
 
OF NOTE, 12Z HREF NEIGHBORHOOD PROBABILITIES ARE HIGHLIGHTING UP  
TO A 70% CHANCE OF 3-HR PRECIPITATION EXCEEDING 1 INCH OVER LAST  
YEAR'S BURN SCARS IN THE OCHOCO-JOHN DAY HIGHLANDS. THE MAIN BURN  
SCARS OF CONCERN INCLUDE THOSE ASSOCIATED WITH THE WILEY FLAT,  
RAIL RIDGE, CRAZY CREEK, AND FALLS FIRES. AFTER COLLABORATION  
WITH BOI, HAVE ISSUED A FLASH FLOOD WATCH FOR THE AFOREMENTIONED  
BURN SCARS, VALID THROUGH 8PM PDT.  
 
QUIETER WEATHER WILL RETURN SATURDAY AND SUNDAY AS THE LOW EXITS  
TO THE EAST AND DRIER ZONAL FLOW ALOFT MOVES OVERHEAD.  
PLUNKETT/86  
 
LONG TERM...MONDAY THROUGH THURSDAY...CONFIDENCE IS INCREASING  
IN WARM TO HOT WEATHER MONDAY THROUGH THURSDAY AS AN UPPER-LEVEL  
RIDGE OF HIGH PRESSURE BUILDS OVER THE PACIFIC NORTHWEST. THAT  
SAID, ENSEMBLE CLUSTERS DO DEPICT SOME DIFFERENCES IN THE 500-HPA  
HEIGHT FIELD OVER THE REGION, MOST NOTABLY THE EVOLUTION OF A  
CLOSED LOW THAT ALL CLUSTERS SHOW OFF THE NW CALIFORNIA COAST  
MONDAY. ENSEMBLE MEAN 500-HPA HEIGHTS AND VORTICITY SHOW THE  
AFOREMENTIONED LOW TRACKING INLAND ACROSS SOUTHERN OREGON AND THE  
NORTHERN GREAT BASIN LATE TUESDAY THROUGH WEDNESDAY. FARTHER NORTH  
ACROSS SOUTHERN BC, ROUGHLY HALF OF ENSEMBLE MEMBERS SHOW A  
SHORTWAVE TROUGH PROPAGATING INLAND, SIGNIFICANTLY REDUCING THE  
AMPLITUDE OF THE RIDGE OVER THE PACIFIC NORTHWEST. THE TRACK AND  
TIMING OF THE CLOSED LOW AND SHORTWAVE WILL MODULATE TEMPERATURES  
AS WELL AS SHOWER AND THUNDERSTORMS CHANCES. PROBABILITIES OF  
SHOWERS AND THUNDERSTORMS ARE CURRENTLY TOO LOW (<10%) TO HAVE IN  
THE FORECAST.  
 
FORECAST HEATRISK RANGES FROM MODERATE (LEVEL 2 OF 4) ON MONDAY  
AND WEDNESDAY TO MAJOR (LEVEL 3 OF 4) ON TUESDAY. THIS LEVEL OF  
HEAT WOULD SUPPORT HEAT ADVISORIES FOR THE YAKIMA/KITTITAS  
VALLEYS, LOWER COLUMBIA BASIN, AND FOOTHILLS OF THE NORTHERN BLUE  
MOUNTAINS ON TUESDAY. PLUNKETT/86  
 
FIRE WEATHER...THROUGH THIS EVENING, A LOW-PRESSURE SYSTEM  
MOVING OVER THE PACIFIC NORTHWEST WILL FACILITATE WIDESPREAD  
PRECIPITATION CHANCES, HIGHEST FOR OREGON. ADDITIONALLY, A CHANCE  
OF THUNDERSTORMS IS FORECAST FOR CENTRAL OREGON AND THE BLUE  
MOUNTAINS. CHANCES OF WETTING RAIN THROUGH THE EVENING ARE MEDIUM-  
HIGH (50-80 PERCENT FOR THE BLUE MOUNTAINS) WITH LOW-MEDIUM  
CHANCES (30-60 PERCENT) FOR THE REST OF CENTRAL AND EASTERN  
OREGON. NO RED FLAG WARNINGS HAVE BEEN ISSUED DUE TO THE  
ANTICIPATED WETTING RAIN, BUT FREQUENT CLOUD-TO-GROUND LIGHTNING  
IS EXPECTED. THUNDERSTORMS WILL BE CAPABLE OF PRODUCING LOCALLY  
HEAVY RAINFALL, SMALL HAIL, AND STRONG, GUSTY OUTFLOW WINDS IN  
EXCESS OF 60 MPH ACROSS SOUTHEAST DESCHUTES, CROOK, AND GRANT  
COUNTIES THIS AFTERNOON AND EVENING. PLUNKETT/86  
 

 
   
PRELIMINARY POINT TEMPS/POPS
 
 
PDT 85 55 90 58 / 0 0 0 0  
ALW 85 60 90 63 / 0 0 0 0  
PSC 88 56 92 58 / 0 0 0 0  
YKM 87 56 90 61 / 0 0 0 0  
HRI 88 56 93 58 / 0 0 0 0  
ELN 85 56 88 59 / 0 0 0 0  
RDM 81 45 88 49 / 0 0 0 0  
LGD 80 52 87 55 / 0 0 0 0  
GCD 81 50 89 55 / 0 0 0 0  
DLS 85 56 90 61 / 0 0 0 0  
 

 
   
PDT WATCHES/WARNINGS/ADVISORIES
 
 
OR...NONE.  
WA...NONE.  

 
 

 
 
SHORT TERM...86  
LONG TERM....86  
AVIATION...90  
 
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