650
FXUS66 KPDT 181748
AFDPDT

Area Forecast Discussion
National Weather Service Pendleton OR
1048 AM PDT Wed Sep 18 2024

.Updated for Aviation




.AVIATION...
18Z TAFS...VFR conditions with winds mainly 10 kts or less are
expected through the TAF period.

&&

.PREV DISCUSSION... /issued 230 AM PDT Wed Sep 18 2024/

SHORT TERM...Today through Friday...As an upper-level low cuts off
and dives down into the southwestern CONUS, the PacNW will be left
under a drier airmass as weak N to NW flow prevails over the
forecast area. With this drier air overhead, expect clearing skies
and temperatures around seasonable averages for the majority of the
CWA. Once the flow aloft develops a more defined NW pattern Thursday
into Friday, expect gusty conditions through the Cascade Gaps and a
slight chance for showers across primarily the WA Cascade crests.
Not expecting gusts as strong as what we saw on Tuesday, but the
Gorge and Kittitas Valley are forecast to receive gusts approaching
30 mph both Thursday and Friday. These winds may spread a bit into
the Basin, but gusty conditions are largely expected to be secluded
to the Gaps.

Otherwise, the remainder of the work week looks to be benign amidst
an otherwise active synoptic pattern. Could see some chilly
overnight lows across central and south central Oregon over the next
few nights as this dry air mass causes RHs to drop, allowing for
efficient nighttime cooling, but outside of the elevated valleys
like the Bear Valley, am currently not anticipating lows to drop
below freezing. Evans/74

LONG TERM...Saturday through Wednesday...Ensemble runs show good
agreement through the period dominated by a westerly flow. This
westerly flow will see a weak shortwave trough clipping the region
on Sunday as it passes through western Canada. It will bring a
chance of some showers to the Cascades and the eastern mountains but
otherwise it looks to remain dry across the rest of the forecast
area. This will be followed by a flat ridge pattern over the region
through the first of the week as an upper level trough forms and
deepens over the Gulf of Alaska. The trough will eventually push its
way into western Canada and the Pacific Northwest midweek bringing a
chance of showers back to the forecast area on Wednesday. Overall
temperatures look to remain near seasonable norms with some minor
fluctuations associated with the expected trough to ridge to trough
pattern.


AVIATION...12Z TAFs...VFR conditions expected over the next 24
hours with cloud cover continuing to decrease and becoming
mostly clear. Winds will generally be less than 10 knots except for
some 10-15kt winds at DLS through the afternoon and evening
period.

&&

.PRELIMINARY POINT TEMPS/POPS...
PDT  74  48  77  47 /   0   0   0   0
ALW  76  52  79  51 /   0   0   0   0
PSC  79  55  81  52 /   0   0   0   0
YKM  80  49  81  45 /   0   0   0   0
HRI  79  52  81  51 /   0   0   0   0
ELN  76  49  77  49 /   0   0   0   0
RDM  72  42  78  39 /   0   0   0   0
LGD  72  46  78  44 /   0   0   0   0
GCD  72  45  78  42 /   0   0   0   0
DLS  78  52  80  52 /   0   0   0   0

&&

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

$$

SHORT TERM...74
LONG TERM....91
AVIATION...77