634
FXUS66 KPDT 140517
AFDPDT

Area Forecast Discussion
National Weather Service Pendleton OR
1017 PM PDT Fri Sep 13 2024

.Updated for Aviation...


.AVIATION...
06Z TAFS...VFR conditions are expected through the TAF period. A
weak disturbance will move across the region, through Saturday. A
passing shower at YKM can not be ruled out, but precip chances
are low enough (<20%) to not include in the TAF.

Otherwise, winds will increase and become gusty to around 25 kts
at DLS and 20 kts at all other sites Saturday afternoon except YKm
and PSC, where winds should remain 10 kts or less. Winds should
decrease everywhere to 10 kts or less Saturday evening.


&&

.PREV DISCUSSION... /issued Issued by National Weather Service Boise ID/

SHORT TERM...Tonight through Sunday night...A trough over the
Gulf of Alaska will move south along the British Columbia coast
and across the WA/OR coast through Sunday. As the trough
approaches, the flow aloft shifts to the west and then southwest.
Breezy westerly winds expected tonight along the Cascade gaps this
evening into Saturday afternoon. Isolated showers form across the
WA zones on Saturday morning as clouds increase from the
northwest. Much of the energy from the upper level trough moves
south along the Pacific NW coast, moving into northern CA by
Sunday night. Little sensible weather impacts expected on Sunday
for the Columbia Basin, but as the trough moves south along the
coast, a deformation zone sets up over the Blue Mountains on
Sunday morning, bringing light rain showers, with precipitation
amounts generally under 0.10 inch. The NBM 12-hr probability of
precipitation greater than 0.1 inches ending Sunday night will be
30-50% across the Blues, Ochoco-John Day highlands, and Wallowa
County. Surface winds shift to the north Sunday afternoon, with
temperatures cooling around 5 degrees from Saturday.

LONG TERM...Monday through Friday...Showers will continue over the
eastern mountains on Monday as a closed low tracks through northern
CA before lifting northeastward through Idaho. There was little
change in the forecast low track with the 12Z operational models,
which would place the best chance for precipitation over NE Oregon
and SE WA Monday night into Tuesday. With the current low track, the
heavier precipitation is still forecast to remain further east over
Idaho. A secondary low will drop south along the coast Tuesday,
taking a similar coastal track to the first system. This will focus
precipitation along the Cascade crest Tuesday into Wednesday.
Increased northerly flow aloft and a surface low to the east will
act to ramp up west-northwest winds over the region Tuesday night
into early Wednesday. Forecast models dig this second low further
south into the Great Basin before turning it eastward on Thursday.
This track favors drier conditions over all zones after Wednesday.
While there is some uncertainty on low tracks and accompanying
precipitation, there is high confidence that temperatures will be
cooler through the work week with Tuesday and Wednesday the coolest
days.

AVIATION...Generally VFR. Increasing mid and high clouds.
Isolated showers near KYKM KPSC early Sat morning. Surface winds
SW-NW 5-15kt, strongest near KDLS KPSC, increasing to W-NW
10-20kt Sat afternoon.

&&

.PRELIMINARY POINT TEMPS/POPS...
PDT  51  74  47  65 /   0  10  10  20
ALW  54  77  50  69 /  10  10  10  20
PSC  59  79  52  72 /  10  10  10  10
YKM  53  76  42  73 /  10  10   0   0
HRI  56  78  50  71 /  10  10   0  10
ELN  51  73  45  73 /  20  20  10   0
RDM  47  73  42  64 /   0   0  10  30
LGD  49  75  46  65 /   0  10  20  40
GCD  47  77  45  66 /   0   0  10  40
DLS  56  76  52  73 /   0  10  10  10

&&

.PDT WATCHES/WARNINGS/ADVISORIES...
OR...None.
WA...None.
&&

$$

SHORT TERM...99
LONG TERM....99
AVIATION...77