975
FXUS66 KPDT 092204
AFDPDT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
304 PM PDT THU JUL 9 2026
KEY MESSAGES
- WARM AND DRY CONDITIONS WILL PERSIST THROUGH THE WEEK
- BREEZY TO LOCALLY BREEZY CONDITIONS THROUGH MOST OF THE WEEK
IN THE CASCADE GAPS AND OR COLUMBIA BASIN
- ELEVATED FIRE WEATHER CONCERNS FOR WIND AND RELATIVE HUMIDITY
IN THE CASCADE GAPS THROUGH SATURDAY, THEN ELEVATED FIRE
WEATHER CONCERNS FOR UNSTABLE CONDITIONS AND THUNDERSTORMS
MONDAY AND TUESDAY
DISCUSSION
TODAY THROUGH SUNDAY: SATELLITE IMAGERY THIS
AFTERNOON SHOWS A DECK OF CUMULUS PUSHING INTO FAR NORTHEAST OR,
WHILE THE REMAINDER OF THE FORECAST AREA IS UNDER MOSTLY CLEAR
SKIES. AT THE SURFACE, BREEZY WINDS HAVE DEVELOPED THROUGH THE
CASCADE GAPS, BUT ARE HAVING A TOUGH TIME PUSHING FURTHER EAST
INTO THE COLUMBIA BASIN AND CENTRAL OR.
THROUGH SATURDAY, AN UPPER LEVEL LOW IN THE GULF OF ALASKA IS
EXPECTED TO DROP DOWN TO VANCOUVER ISLAND THEN SLIDE INTO
SOUTHERN BC. AHEAD OF THE UPPER LOW, FLOW ALOFT WILL TURN MORE
SOUTHWEST, ALLOWING FOR SLIGHT WARMING INTO THE LOWER TO MID 90S
IN THE LOWER ELEVATIONS FRIDAY AFTERNOON. SATURDAY AND SUNDAY,
LOWER ELEVATION TEMPERATURES ARE EXPECTED TO LOWER BACK INTO THE
MID 80S TO LOWER 90S BEHIND THE UPPER LOW EXIT. THE EXCEPTION
IS GOING TO BE THE SNAKE RIVER AREA ALONG THE ID/OR BORDER.
TEMPERATURES IN THE RIVER VALLEY ARE EXPECTED TO INCREASE UP TO
105 DEGREES FRIDAY AND SATURDAY, BRINGING HEATRISK INTO THE
UPPER MODERATE TO LOWER MAJOR CATEGORY.
OTHERWISE, THE UPPER LOW APPROACH WILL RESULT IN INCREASING
WINDS THROUGH THE CASCADE GAPS FRIDAY AND SATURDAY, WITH WEST TO
NORTHWEST WINDS 20-30 MPH AND GUSTS UP TO 40 MPH DEVELOPING IN
THE KITTITAS VALLEY AND THE EASTERN GORGE. THIS WILL BRING
ELEVATED FIRE WEATHER CONDITIONS INTO THESE AREAS, BUT A WEAK
PUSH OF MOISTURE WITH THE INCOMING TROUGH MAY KEEP RELATIVE
HUMIDITY VALUES JUST ABOVE CRITICAL THRESHOLDS. OF THE TWO DAYS,
FRIDAY WILL SEE THE BIGGEST THREAT, THOUGH PROBABILITIES OF
CRITICAL FIRE WEATHER CONDITIONS BEING MET IS WIDELY 25-45%
ACROSS THE BASIN AND CENTRAL OR, HOWEVER THERE IS SOME LOCALIZED
AREAS OF 50-75% CHANCES IN THE OR COLUMBIA BASIN. AT THIS TIME,
HAVE OPTED NOT TO ISSUE RED FLAG WARNINGS.
BY SUNDAY, WEAK TROUGHING WILL BE LEFT OVER FROM THE MAIN LOW
EXITING THE REGION. WHILE TEMPERATURES WILL MODERATE BETWEEN
SATURDAY AND SUNDAY, WINDS WILL BECOME LOCALLY BREEZY IN THE
AFTERNOON (CONFIDENCE 65-80%).
MONDAY THROUGH WEDNESDAY: MONDAY INTO TUESDAY, THERE IS MODERATE
CONFIDENCE (55-65%) THAT THE PACNW WILL REMAIN UNDER A
SOUTHWEST FLOW ALOFT WHILE A SECONDARY UPPER LOW DIVES DOWN AND
SETS UP OFF VANCOUVER ISLAND. THE PERSISTENT SOUTHWEST FLOW
ALOFT WILL LEAD TO INCREASING UNSTABLE CONDITIONS FOR MONDAY,
WHICH WILL BRING ELEVATED FIRE WEATHER CONCERNS TO OUR EXISTING
FIRES OVER THE SOUTHERN BLUE MOUNTAINS. A MONSOONAL MOISTURE
PUSH ROUNDING THE UPPER HIGH OVER THE SOUTHWEST CONUS WILL ALSO
BRING A LOW CHANCE (10-15%) OF AN ISOLATED THUNDERSTORM THREAT
FROM THE CENTRAL OR CASCADES TO THE ELKHORN CREST MONDAY
AFTERNOON. BY TUESDAY, CHANCES (15-25%) FOR ISOLATED TO
SCATTERED THUNDERSTORMS WILL SPREAD ACROSS THE HIGH TERRAIN
BETWEEN THE CENTRAL OR CASCADES AND WALLOWA COUNTY, BRINGING A
ELEVATED FIRE WEATHER THREAT DUE TO LIGHTNING. AS OF THIS
DISCUSSION, CONFIDENCE IS MODERATE (55-65%) THAT RED FLAG
WARNINGS MAY BE NEEDED FOR MONDAY AND TUESDAY.
HEAT WILL BE THE SECONDARY CONCERN THROUGH THIS PERIOD, AS
TEMPERATURES ARE EXPECTED TO WARM BACK INTO THE 90S ACROSS THE
LOWER ELEVATIONS (CONFIDENCE 65-85%). HOWEVER, THE LACK OF UPPER
LEVEL RIDGING OVER THE REGION WILL LIMIT HOW HOT IT WILL GET
ACROSS THE REGION, WITH CHANCES OF HITTING THE 100 DEGREE MARK
ONLY 15-35% ACROSS PORTIONS OF THE COLUMBIA BASIN.
TUESDAY NIGHT INTO WEDNESDAY, UNCERTAINTY GROWS AMONGST ENSEMBLE
CLUSTER SOLUTIONS IN REGARDS TO WHAT HAPPENS WITH THE UPPER
LEVEL TROUGHING. SOLUTIONS RANGE FROM THE TROUGH WEAKENING AS IT
COMES ONSHORE, SLOWLY COMING ONSHORE, OR REMAINING OFFSHORE THE
PACNW. LOOKING FOR THE MOST IMPACTFUL SOLUTION, THE SLOW MOVING
ONSHORE TROUGH SOLUTION DURING THIS PERIOD (ABOUT 28% OF
MEMBERS) WOULD RESULT IN ANOTHER ROUND OF THUNDERSTORM ACTIVITY
ACROSS THE MOUNTAINS OF THE FORECAST AREA. LAWHORN/82
AVIATION /00Z TAFS THROUGH 00Z FRIDAY/
VFR CONDITIONS ARE
EXPECTED THROUGH THE TAF PERIOD. WINDS WILL MAINLY BE 10 KTS OR
LESS. HOWEVER, BOTH DLS AND PDT HAVE HAD WIND GUSTS TO AROUND 25
KTS AND 20 KTS, RESPECTIVELY TODAY. THESE WINDS WILL DECREASE
THIS EVENING TO 10 TO 15 KTS AT DLS AND AROUND 10 KTS AT PDT.
WINDS ARE EXPECTED TO GUST AGAIN ON FRIDAY TO AROUND 25 KTS AT
DLS AND 20 KTS AT PDT.
FIRE WEATHER
BREEZY CASCADE GAP WINDS WILL CONTINUE INTO THE
WEEKEND, PRODUCING AN ELEVATED THREAT OF FIRE WEATHER CONDITIONS.
AFTERNOON RHS WILL GENERALLY BE IN THE TEENS TO MID 20S ACROSS
THE REGION THROUGH THE PERIOD. EARLY NEXT WEEK, TEMPERATURES WILL
BE ON THE RISE, AS WELL AS UNSTABLE CONDITIONS OVER THE EASTERN
OREGON MOUNTAINS. IN THIS AREA, A LOW CHANCE (10-15%) OF ISOLATED
THUNDERSTORMS WILL BE POSSIBLE MONDAY, WITH SLIGHT CHANCE (15-20%)
FOR ISOLATED TO SCATTERED THUNDERSTORMS TUESDAY.
PRELIMINARY POINT TEMPS/POPS
PDT 56 90 55 86 / 0 0 0 0
ALW 61 92 61 89 / 0 0 0 0
PSC 59 95 60 91 / 0 0 0 0
YKM 59 93 57 89 / 0 0 0 0
HRI 60 93 59 89 / 0 0 0 0
ELN 56 86 53 82 / 0 0 0 0
RDM 50 88 48 88 / 0 0 0 0
LGD 54 93 55 93 / 0 0 0 0
GCD 53 95 53 96 / 0 0 0 0
DLS 59 87 59 84 / 0 0 0 0
PDT WATCHES/WARNINGS/ADVISORIES
WA...NONE.
OR...HEAT ADVISORY FROM NOON FRIDAY TO 7 PM PDT SUNDAY FOR ORZ050.
DISCUSSION...82
AVIATION...82
FIRE WEATHER...82
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