215
FXUS66 KPDT 122132
AFDPDT

Area Forecast Discussion
National Weather Service Pendleton OR
232 PM PDT Mon Aug 12 2024

.SHORT TERM...Today through Wednesday...An increase in cumulus
development noted over the Blue Mountains this afternoon. This
remains the favored location for any shower or storm development.
Mesoanalysis continues to demonstrate CIN over the area, though
this will continue to breakdown for isolated thunderstorm
development this afternoon and evening. The best storm development
is favored east of the forecast area, with a 5-10% chance for
development over the Blue Mountains today. Otherwise, gusty to
breezy winds will remain over much of the area through the evening
hours.

Tuesday will see the passage of a trough through the forecast area.
This system will bring another opportunity for showers and
thunderstorms, with instability parameters showing more potential
for development (20-30% chance), especially across Wallowa County in
Oregon. Precipitable waters across the area expected to see impact
ranges from 0.8" to 1.2". This could result in some wetting rain
potential with activity, though lightning could still impact fire
conditions. Analysis demonstrates a 10-20% chance for 0.25" of QPF
with Tuesday`s showers.

Passage of the trough will bring cooler conditions across the area,
with temperatures falling to 5-10 degrees below seasonal normals.
Wednesday will see more stable and dry conditions.
Branham/76


.LONG TERM...Wednesday night through Monday...Low pressure is
expected to advance towards the forecast area by Wednesday night.
This is favored to result in showers over central Oregon during the
overnight hours. Weak instability noted overnight. While showers are
mostly included in the forecast, an isolated nocturnal thunderstorm
cannot be ruled out and the potential will continue to be monitored
(currently the probability for nocturnal thunder is around 5-15%).
Moisture and instability increase through the day across central and
eastern Oregon, with showers and thunderstorm coverage increasing
(thunderstorm development probability increases to near 40% by
Thursday afternoon).

Instability should improve by Friday, though isolated thunderstorms
remain across much of the area for Friday as the area of low
pressure remains off the WA/OR coast. Drier conditions then return
to the area over the weekend and continue through Monday, with most
activity confined to the Cascades (5-15% chance of development).
Temperatures generally remain below normal (0-10 degrees) through
the long term.

Overall, clusters are in good agreement with the progression of the
weather through the long term, with only slight variations on timing
and intensity. Branham/76

&&

.AVIATION...18z TAFs...Mostly VFR. The exception will be KBDN
where smoke from nearby fires has been creating MVFR conditions.
Dry conditions expected at terminals today. Surface wind will be
gusty to breezy through the afternoon and into the early evening
hours with gusts of 20-30 kts forecast at terminals. Wind should
weaken between 00z and 06z tonight, with KDLS remaining gusty
through the period. Branham/76

&&

.PRELIMINARY POINT TEMPS/POPS...
PDT  53  79  50  82 /  10   0   0   0
ALW  58  83  55  86 /  10  10   0   0
PSC  61  84  58  87 /   0   0   0   0
YKM  53  83  52  85 /   0   0   0   0
HRI  58  83  56  87 /   0   0   0   0
ELN  55  80  54  86 /   0   0   0   0
RDM  45  78  44  82 /   0   0   0   0
LGD  52  81  48  84 /  40  30  10   0
GCD  52  83  48  85 /  40  10   0   0
DLS  58  77  57  85 /   0   0   0   0

&&

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

$$

SHORT TERM...76
LONG TERM....76
AVIATION...76