587
FXUS66 KPDT 181140
AFDPDT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
440 AM PDT FRI SEP 18 2026
KEY MESSAGES
- SLIGHT CHANCE (15 TO 20%) OF THUNDERSTORMS THROUGH THE
WALLOWAS THROUGH FRIDAY AFTERNOON.
- DRIER WEATHER PATTERN THROUGH AT LEAST THE BEGINNING OF THE
WEEK, WITH HIGH TEMPERATURES CLIMBING INTO THE LOW TO MID 80S
BY THE WEEKEND.
- UNCERTAIN WEATHER PATTERN BY LATE NEXT WEEK, AS CLUSTERS
ADVERTISE A THIRD/THIRD/THIRD SOLUTION ON A DRY, WET, OR ZONAL
PATTERN BY FRIDAY.
DISCUSSION
THE UPPER LEVEL LOW PRESSURE SYSTEM THAT BROUGHT SHOWERS AND
THUNDERSTORMS IN THE AREA EARLIER ON THURSDAY WILL CONTINUE TO PUSH
TOWARDS THE EAST. WE'LL SEE SOME LINGERING MOISTURE DEVELOP
THUNDERSTORMS (15 TO 20% CHANCES) ACROSS THE EASTERN BLUE
MOUNTAINS AND WALLOWAS THROUGH FRIDAY AFTERNOON. BY SATURDAY,
THE LOW WILL MOVE OUT OF THE AREA WITH AN UPPER LEVEL RIDGE
MOVING IN IT'S PLACE. WE'LL SEE MOSTLY DRY CONDITIONS WITH A
WARMING TREND TAKE PLACE THROUGH THE WEEKEND WITH HIGH
TEMPERATURES CLIMBING INTO THE LOW TO MID 80S IN THE LOWER
ELEVATED AREAS.
BY TUESDAY, GUIDANCE IS IN GOOD AGREEMENT (80-90% CHANCE) THAT
THE RIDGE WILL THEN BREAK DOWN WITH ZONAL FLOW TAKING PLACE AND
TEMPERATURES WILL BE COOLER BY 5 TO 15 DEGREES AS A RESULT. OUR
NEXT CHANCE OF ANOTHER WEATHER SYSTEM WILL BE SOMETIME MID TO
LATE NEXT WEEK WITH SOME GUIDANCE MEMBERS HINTING AT A TROUGH
DIGGING DOWN IN THE PACIFIC AND PUSHING ONSHORE BY LATE NEXT
WEEK. GUIDANCE IS A BIT ALL OVER THE PLACE BY THIS POINT, WITH
ONLY 32% ADVERTISING A WETTER PATTERN WITH THE TROUGH AXIS
MOVING ONSHORE BY FRIDAY AFTERNOON. ANOTHER 38% ADVERTISE A
RIDGE OVERHEAD, WHILE THE REMAINING 30% WANTS TO KEEP ZONAL FLOW
IN PLACE. NOTHING IS FOR SURE WITH LATE NEXT WEEK, BUT THERE IS
PLENTY OF TIME TO SEE HOW THIS FORECAST EVOLVES AND WHAT
IMPACTS IT COULD BRING.
AVIATION /12Z TAFS THROUGH 12Z SATURDAY/
VFR CONDITIONS PREVAIL WITH GENERAL LIGHT WINDS AND HIGH
CEILINGS. WILL SEE SOME BREEZY WINDS DEVELOP IN THE DLS BY THE
LATE MORNING HOURS THROUGH THE LATE AFTERNOON. OTHERWISE, NO CIG
OR VIS ISSUES EXPECTED.
PRELIMINARY POINT TEMPS/POPS
PDT 77 47 79 50 / 10 0 0 0
ALW 77 54 79 54 / 10 0 0 0
PSC 81 50 82 51 / 0 0 0 0
YKM 81 50 81 52 / 0 0 0 0
HRI 81 50 82 50 / 0 0 0 0
ELN 77 49 77 50 / 0 0 0 0
RDM 75 39 78 40 / 0 0 0 0
LGD 74 46 78 48 / 10 10 0 0
GCD 74 46 78 48 / 10 0 0 0
DLS 82 54 84 56 / 0 0 0 0
PDT WATCHES/WARNINGS/ADVISORIES
WA...NONE.
OR...NONE.
DISCUSSION...95
AVIATION...95
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