668  
FXUS66 KPDT 172321  
AFDPDT  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE PENDLETON OR  
421 PM PDT SUN MAY 17 2026  
   
KEY MESSAGES  
 
- SCATTERED RAIN AND SNOW SHOWERS AND SLIGHT CHANCE (10-15  
PERCENT) OF THUNDER OVER WALLOWA COUNTY TODAY. VERY LOW (5-10  
PERCENT) CHANCE OF SHOWERS AND THUNDER ELSEWHERE.  
 
- MOSTLY DRY AND WARMING CONDITIONS REGION-WIDE MONDAY THROUGH  
SATURDAY.  
 
 
   
DISCUSSION  
 
SCATTERED RAIN AND SNOW SHOWERS ARE ONGOING ACROSS WALLOWA  
COUNTY THIS AFTERNOON AS AN UPPER-LEVEL TROUGH DIGS SOUTHEAST  
OVER THE GREAT BASIN, PLACING THE PACIFIC NORTHWEST UNDER A  
COOL NORTHERLY FLOW ALOFT. THROUGH AFTERNOON, THERE ARE LOW  
(10-15 PERCENT) CHANCES OF THUNDER FOR WALLOWA COUNTY, BUT HAVE  
YET TO OBSERVE ANY CONVECTION DEEP ENOUGH TO PRODUCE LIGHTNING.  
ELSEWHERE, THERE ARE LOW (5-10 PERCENT) CHANCES OF RAIN SHOWERS  
AND THUNDER ACROSS THE WASHINGTON CASCADES AND PORTIONS OF  
SOUTH-CENTRAL WASHINGTON AND FAR NORTHERN OREGON.  
 
MONDAY THROUGH SATURDAY, WARMING TEMPERATURES AND MOSTLY DRY  
CONDITIONS ARE FORECAST REGION-WIDE AS AN UPPER-LEVEL RIDGE OF  
HIGH PRESSURE WILL LIKELY (90-95 PERCENT CHANCE) BUILD INTO THE  
REGION FROM THE PACIFIC AND DOMINATE THE WEATHER. A COUPLE WEAK  
SHORTWAVES PASSING THROUGH NORTHWESTERLY FLOW ALOFT MAY  
FACILITATE SOME ISOLATED SHOWERS FOR THE MOUNTAINS, BUT POPS ARE  
LOW (GENERALLY 5-10 PERCENT, EXCEPT 15-35 PERCENT FOR THE  
NORTHERN BLUES AND WALLOWA COUNTY ON MONDAY).  
 
BREEZY WESTERLY WINDS ARE FORECAST THROUGH THE CASCADE GAPS EACH  
DAY OF THE WEEK, BUT NOT ANTICIPATING A NEED FOR ANY WIND  
HEADLINES. THURSDAY AND SATURDAY HAVE THE HIGHEST CHANCES  
(10-40 PERCENT, AND 20-60 PERCENT, RESPECTIVELY) OF REACHING  
ADVISORY-LEVEL WINDS THROUGH WIND-PRONE AREAS OF THE LOWER  
ELEVATIONS, PRIMARILY THE EASTERN COLUMBIA RIVER GORGE, NORTH-  
CENTRAL OREGON, THE FOOTHILLS OF THE BLUE MOUNTAINS, AND THE  
KITTITAS VALLEY.  
 
THE ALTERNATE, LESS-LIKELY SCENARIO (A CLOSED LOW FROM CANADA,  
WITH COOL, SHOWERY WEATHER BETWEEN WEDNESDAY AND THURSDAY) FROM  
YESTERDAY'S DISCUSSION APPEARS TO HAVE ALMOST ENTIRELY DROPPED  
OUT OF THE ENSEMBLE ENVELOPE OF SOLUTIONS AND DOES NOT APPEAR IN  
ANY CLUSTER OF ENSEMBLE SOLUTIONS.  
 
 
   
AVIATION /00Z TAFS THROUGH 00Z TUESDAY/  
 
VFR CONDITIONS PREVAIL GOING THROUGH THE NEXT 24-HOURS. NOT  
EXPECTING ANY CIG OR VIS ISSUES AT ANY SITES. WINDS WILL BE  
SLIGHTLY BREEZY IN THE DLS TOMORROW AFTERNOON WITH 15-25 KNOT  
GUSTS DEVELOPING.  
 
 
   
PRELIMINARY POINT TEMPS/POPS  
 
PDT 39 69 42 72 / 0 0 0 0  
ALW 43 69 46 72 / 0 0 0 0  
PSC 42 75 45 77 / 0 0 0 0  
YKM 42 74 44 77 / 0 0 0 0  
HRI 41 73 44 76 / 0 0 0 0  
ELN 39 68 40 70 / 10 10 10 0  
RDM 29 68 31 73 / 0 0 0 0  
LGD 33 64 36 69 / 0 0 0 0  
GCD 30 65 34 71 / 0 0 0 0  
DLS 44 73 45 75 / 0 0 10 0  
 
 
   
PDT WATCHES/WARNINGS/ADVISORIES  
 
WA...NONE.  
OR...NONE.  
 
 
 
 
 
DISCUSSION...86  
AVIATION...95  
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