169
FXUS66 KPDT 131117
AFDPDT

Area Forecast Discussion
National Weather Service Pendleton OR
417 AM PDT Tue Aug 13 2024

Updated aviation discussion

.SHORT TERM...Today through Thursday...The center of a broad trough
will envelop our forecast area for much of the day today, making for
continued breezy conditions as well as some intermittent shower
activity across the far eastern border of our CWA. Some isolated
storms may develop across the eastern mountains early this morning
and during the day today, but given the colder air pouring into the
area what with the trough overhead, current thinking is that any
storm activity today will be very isolated.

CAMs generally suggest a band of showers lifting out of the SW
through eastern Grant County and eventually up through Wallowa
County before exiting our area by the late afternoon. Guidance
suggests that Wallowa County would be the most likely candidate to
see storms, but with early morning temps reading in the mid 50s and
models depicting so-so MUCAPE, thinking that the storm threat will
overall be isolated. Elsewhere, expect winds through the gaps to
gust over 30 mph at times, with 20-30 mph gusts spilling over into
the Basin. RHs will remain elevated in light of the cooler air mass
advecting in, however.

Wednesday looks to be quiet as transitory ridging briefly
establishes itself overhead, before another low moves in on
Thursday. The convective setup for this system looks better than
today`s, however shear is very weak as the low sits between more
amplified flow to the south and north, which will eventually bring us
a more long-term, broad low over the coming weekend. Did mention a
chance for storms across an area stretching from central Oregon
through the eastern mountains during the day Thursday, but given the
paltry bulk shear, any storms that do form look to be pulse-like in
nature. Should note that confidence in Red Flag conditions for the
area are low on Thursday, however, as storm chances will be
prevalent, but the synoptic set-up along with the meager depiction
of precip across deterministic guidance doesn`t exactly inspire
confidence on critical fire weather conditions. Evans/74

.LONG TERM...Friday through Tuesday...Long term forecast will be
determined by a large scale closed upper level low pressure system
off the coast. Models have this system developing late this week and
then stalling off the coast before moving inland around late
Tuesday or Wednesday. This will place the forecast area under a
southerly flow with some instability leading to some initial
showers and thunderstorms Friday and Saturday. Sunday through
Tuesday the NBM reduces instability and limits showers mainly along
the Cascade crest. This reduction in instability could be a little
underdone under this pattern but for now will remain in line with
the NBM. Temperatures look to remain seasonable through the
extended time period.

&&

.AVIATION...12Z TAFS (Previous Discussion)...VFR conditions
expected through the TAF period under mostly clear skies. There will
continue to be some smoke concerns mainly impacting BDN/RDM/YKM at
times mainly with smoke aloft. Winds will generally be less than
10kts through the early morning then becoming 5-15kts through the
evening. DLS will be a little stronger with 15-20kts winds and gusts
around 30kts.

&&

.PRELIMINARY POINT TEMPS/POPS...
PDT  79  50  82  53 /   0   0   0   0
ALW  83  55  86  57 /  10   0   0   0
PSC  85  59  87  59 /   0   0   0   0
YKM  84  52  86  54 /   0   0   0   0
HRI  83  56  86  58 /   0   0   0   0
ELN  82  55  86  56 /   0   0   0   0
RDM  78  44  82  50 /   0   0   0  20
LGD  81  48  84  52 /  20  10   0  10
GCD  84  48  85  52 /  10   0   0  20
DLS  77  57  85  61 /   0   0   0   0

&&

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

$$

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