495
FXUS66 KPDT 040537
AFDPDT

Area Forecast Discussion
National Weather Service Pendleton OR
1037 PM PDT Fri Oct 3 2025

.AVIATION...

Westerly surface winds will create upslope stratus along the
crests of the Cascades overnight, as light west to northwest winds
prevail across the area to the east of the range. GOES Nighttime
microphysics RGB is showing patchy stratus east and south of BDN
and RDM into central Oregon. HRRR dewpoint surface depression
trends stay dry with double digit spreads through the early
morning hours, whereas BDN and RDM might have a better shot at
some stratus development with smaller spreads (2-3 degrees) by
10-14z. Considerable HREF probability of ceilings less than 2,000
and 1,000 feet are faily well removed from the terminal
vicinities, mostly over the higher terrain Saturday morning, so
any stratus near the BDN and RDM terminals will lean VFR. Expect winds
light and variable even into the afternoon, but for DLS where
20-24 knot gusts will be common in the afternoon. Russell/71

&&

.PREV DISCUSSION... /issued 459 PM PDT Fri Oct 3 2025/

AVIATION...00Z TAFs...VFR conditions to prevail through the
period. There is a 20-30% chance that CIGs may drop to MVFR or
lower at or within vicinity of sites RDM/BDN between 8Z-16Z, but
have left only mentions of sct CIGS AOA 2.5kft to 3kft AGL at both
sites. Otherwise, CIGs will mainly be sct-bkn AOA 6kft AGL or
higher at all sites. Winds will mainly be light, 12kts or less,
at most sites...except at site DLS where winds 12-17kts with gusts
to around 25kts will persist through 6Z tonight and redevelop
around 19Z tomorrow. Lawhorn/82

PREV DISCUSSION... /issued 121 PM PDT Fri Oct 3 2025/

DISCUSSION...Skies are clearing across the Basin this afternoon
as a front moves out of the PacNW, while clouds build across the
central and eastern mountains of Oregon as NW flow aloft starts to
prevail. As a result, expect low-end chances (20-40%) for rain
across our mountain zones, followed by a gradual cooldown that may
result in the first hard freeze of the season across our elevated
valley zones by Monday morning.

NBM probabilistic guidance suggests strong odds (>70%) of below
freezing temps across central Oregon and the Wallowa Valley early
Monday morning - two areas that have flirted with a freeze these
last few weeks but have been saved partially by downsloping winds
overnight. With the flow perhaps shifting due north by Monday, this
may allow enough clearing overnight, combined with cold air
advection, to counter the warming effect of any downslope wind. A
little more uncertainty exists for the Grande Ronde Valley, which
typically sees a more pronounced downslope effect overnight and is
thus a bit more sheltered from radiational cooling on nights like
this, but the NBM does mark them for high freezing odds
nevertheless. It`s too early as of now to issue a Freeze Watch, but
could very likely see some issued tomorrow if the forecast outlook
remains the same (which it`s expected to do).

Ensembles then bring in high pressure to kick off next work week,
before bringing in the next round of widespread precip around the
midweek in the form of an offshore low. It`s too early to make
confident predictions on precip amounts, but given the ongoing haze
across the Basin and Yakima Valley, the fires across the WA Cascades
are still in need of wetting rains before we can finally put a wrap
on this wildfire season. Evans/74

&&

.PRELIMINARY POINT TEMPS/POPS...
PDT  67  47  66  42 /  10   0  20  10
ALW  69  50  66  44 /  10  10  20  20
PSC  73  47  71  43 /   0   0  10   0
YKM  72  47  70  43 /   0  20  10   0
HRI  72  48  69  43 /  10   0  10   0
ELN  67  43  66  38 /   0  30   0   0
RDM  62  36  62  32 /  10  10  10   0
LGD  62  40  60  37 /  30   0  30  20
GCD  63  40  59  37 /  20   0  20  10
DLS  72  53  71  48 /  10  20  30  10

&&

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

$$

SHORT TERM...99
LONG TERM....99
AVIATION...71