186  
FXUS66 KPDT 130541  
AFDPDT  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE PENDLETON OR  
1040 PM PDT SUN APR 12 2026  
 
.UPDATED AVIATION DISCUSSION.  
 
   
KEY MESSAGES  
 
- SHOWERS TODAY, WITH LOW THUNDERSTORM CHANCES, MAINLY OVER  
EASTERN AREAS.  
 
- THE NEXT SYSTEM WILL BRING RAIN TO THE LOWER ELEVATIONS AND  
SNOW TO THE MOUNTAINS WEDNESDAY INTO THURSDAY.  
 
- TEMPERATURES WILL BE ABOUT 5 TO 10 DEGREES BELOW NORMAL  
WEDNESDAY AND THURSDAY BEFORE RISING TO NEAR AND POSSIBLY  
ABOVE NORMAL LATER IN THE WEEK.  
 
 
   
DISCUSSION  
 
AN UPPER LEVEL LOW CURRENTLY OVER NORTHERN CALIFORNIA WILL  
WEAKEN AND GRADUALLY MOVE INLAND THROUGH TONIGHT. THE BROADER  
UPPER TROUGH WILL ALSO MOVE EASTWARD THROUGH MONDAY, WITH THE  
AXIS OF THE TROUGH OVER THE GREAT BASIN BY MONDAY NIGHT. UNTIL  
THE TROUGH IS EAST OF THE PACIFIC NORTHWEST, UNSETTLED  
CONDITIONS WILL CONTINUE.  
 
LATEST RADAR IMAGERY SHOWED A LARGE AREA OF SHOWERS, WITH SOME  
EMBEDDED THUNDERSTORMS OVER EXTREME SOUTHEASTERN OREGON AND  
SOUTHWESTERN IDAHO. GUIDANCE HAS THIS AREA SLOWLY PIVOTING  
NORTHWARD AND MORE DEVELOPING NORTHWESTWARD AROUND THE LARGER  
CIRCULATION AND THROUGH THE REMAINDER OF TODAY AND INTO TONIGHT.  
AS THIS AREA MOVES NORTHWARD, DECENT QPF IS FORECAST ACROSS THE  
BLUE MOUNTAINS AND POINTS EASTWARD THROUGH MONDAY MORNING.  
 
LINGERING QPF IS STILL EXPECTED OVER EASTERN AREAS ON MONDAY,  
BUT WITH THE TROUGH MOVING OUT OF THE REGION, CONDITIONS SHOULD  
BEGIN TO IMPROVE BY LATER MONDAY AND DRYING IS EXPECTED ACROSS  
MOST OF THE REGION, WHICH WILL CONTINUE INTO TUESDAY.  
 
HOWEVER, BY LATER TUESDAY INTO WEDNESDAY PRECIPITATION CHANCES  
INCREASE AS A LOW DROPS INTO THE PACIFIC NORTHWEST FROM CANADA.  
THIS LOW WILL BRING COLDER AIR AND TEMPERATURES WILL BE ABOUT 5  
TO 10 DEGREES COLDER THAN NORMAL WEDNESDAY AND THURSDAY.  
 
OVERNIGHT LOWS WEDNESDAY NIGHT AND THURSDAY NIGHT LOOK TO BE  
QUITE CHILLY WITH TEMPERATURES BELOW FREEZING IN THE YAKIMA AND  
KITTITAS VALLEYS AND CLOSE TO FREEZING ALONG PORTIONS OF THE  
FOOTHILLS OF THE NORTHERN BLUE MOUNTAINS. NBM PROBABILITIES OF  
LOW TEMPERATURES <=32 DEGREES ARE 80 TO 90 PERCENT ON BOTH THESE  
MORNINGS.  
 
FURTHERMORE, THERE WILL BE BREEZY DIURNAL WINDS EACH DAY THROUGH  
WEDNESDAY, IN THE CASCADE GAPS AND PORTIONS OF THE COLUMBIA  
BASIN AND FOOTHILLS OF THE SOUTHERN BLUE MOUNTAINS. WINDS COULD  
GUST IN THE 30 TO 35 MPH RANGE AND POSSIBLY AS HIGH AS 40 MPH.  
 
ADDITIONALLY, THE LOW WILL BRING AT LEAST SOME PRECIPITATION TO  
ALL AREAS, WITH RAIN IN THE LOWER ELEVATIONS (GENERALLY 0.15  
INCHES OR LESS) AND SNOW IN THE MOUNTAINS. SNOW LEVELS WILL DROP  
FROM ABOVE 4000 FEET ON WEDNESDAY TO BELOW PASS LEVEL BY  
THURSDAY MORNING. THERE IS THE POTENTIAL FOR APPRECIABLE SNOW,  
ESPECIALLY ABOVE 5000 FEET, BUT THERE ARE MANY CAVEATS AS WELL,  
INCLUDING THE TIME OF YEAR AND THE FACT THAT ANY SNOW THAT FALLS  
DURING THE DAY HAS A MUCH MORE DIFFICULT TIME ACCUMULATING OR IS  
VERY WET IN MID-APRIL AND THE GROUND IS WARM.  
 
THIS SYSTEM WILL MOVE OUT OF THE REGION BY LATER THURSDAY AND  
AND RIDGING BUILDS BACK IN BRINGING DRY CONDITIONS FOR THE END  
OF THE WEEK INTO THE WEEKEND. ANOTHER LOW MAY APPROACH THE  
PACIFIC NORTHWEST FOR SUNDAY.  
 
 
   
AVIATION /06Z TAFS THROUGH 06Z TUESDAY/  
 
VFR CONDITIONS CURRENTLY AT MOST SITES, WITH KALW BEING THE ONLY  
TERMINAL EXPERIENCING MVFR CONDITIONS DUE TO REDUCED CEILINGS OF  
1800 FEET. THIS IS EXPECTED TO PERSIST OVERNIGHT AND THROUGH MID-  
MORNING MONDAY AS LIGHT RAIN CONTINUES. LIGHT RAIN IS ALSO OCCURRING  
AT KPDT, BUT SHOULD TAPER OFF INTO THE EARLY MORNING HOURS. HOWEVER,  
DECREASING CEILINGS SHOULD LEAD TO MVFR CONDITIONS AROUND SUNRISE  
BEFORE IMPROVING AROUND NOON.  
 
WIDESPREAD BREEZY WINDS ARE ANTICIPATED OVERNIGHT ANT THROUGH THE  
MORNING FOR ALL SITES, WITH GUSTS OF 20-30KTS EXPECTED.  
KPSC/KYKM/KRDM/KBDN WILL SEE INCREASED WINDS BY MID-TO LATE MORNING  
AND EXTEND THROUGH THE PERIOD. 75  
 
 
   
PRELIMINARY POINT TEMPS/POPS  
 
PDT 44 59 37 58 / 80 40 0 10  
ALW 46 59 41 58 / 80 50 10 10  
PSC 48 67 41 61 / 50 10 0 10  
YKM 43 64 36 58 / 30 0 0 10  
HRI 46 63 39 61 / 60 10 0 0  
ELN 42 56 36 52 / 20 0 0 20  
RDM 34 54 28 56 / 50 10 0 0  
LGD 40 53 34 57 / 100 80 20 10  
GCD 37 51 31 56 / 100 80 10 10  
DLS 46 60 41 58 / 30 10 0 20  
 
 
   
PDT WATCHES/WARNINGS/ADVISORIES  
 
WA...NONE.  
OR...NONE.  
 
 
 
 
 
DISCUSSION...77  
AVIATION...75  
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