253 
FXUS66 KPDT 250001
AFDPDT

Area Forecast Discussion
National Weather Service Pendleton OR
501 PM PDT Wed Sep 24 2025

.AVIATION...00Z TAFs...VFR conditions are forecast for all sites
through the period; however, confidence in VSBYs at KYKM/KPSC is 
lower than average given the presence of active wildfires along 
the east slopes of the Washington Cascades. Sub-VFR VSBYs
overnight and Thursday morning may occur, but confidence was too
low (<30%) to include anything below 6SM HZ.

A dry cold front will then sweep across the region from west to 
east Thursday, with increasingly strong westerly winds during the 
day. Winds of 10-20 kts with gusts of 20-30 kts are forecast,
strongest at KDLS. Plunkett/86

&&

.PREV DISCUSSION... /issued 302 PM PDT Wed Sep 24 2025/ 

DISCUSSION...Today through Saturday: Warm, dry conditions continue 
today with the high pressure system over the PacNW. For tomorrow, 
model guidance show a shortwave trough strengthening while 
approaching across our forecast area. This will give an extra push
on the dry cold front, making the Columbia Basin and Cascade Gaps
drier. This front will also enhance surface pressure gradients, 
bringing strong westerly sustained winds up to 20-25 mph with 
gusts at 30-35 mph across the aforementioned areas. HREF 00Z and 
12Z showed a slight increase in the gusty west winds to account 
for the dry front. Daytime RHs remain in the teens and low 20s, 
though had to lower them into the low-mid teens for Columbia Basin
and Cascade Gaps for tomorrow. The NBM even favored a 50-90% 
probability for overlapped high winds and low RHs. Given the 
weather pattern and these conditions potentially affecting nearby 
wildfires, this boosted our confidence level (60-90%) to upgrade 
our Fire Weather Watches for WAZ690 and ORZ691/703 into Red Flag 
Warnings with WAZ691/695 and ORZ701 included for tomorrow. These 
warnings will end tomorrow late evening as the front passes. The 
upper ridge arrive to the PacNW Friday before flattening Saturday.
Both days will remain dry with relatively light diurnally-driven 
winds.

Sunday through Tuesday: Another upper-level wave will arrive Sunday, 
bringing slight chances (<30%) of showers along the WA/OR Cascades 
before becoming widespread Monday onwards. Based on the raw 
ensembles, it seems like there is a 30-50% prob for mountain areas 
receiving up to 0.15" or more with lower elevations having below 
0.10". Regardless on the slight timing differences from the models, 
they seem to look more aligned with this wetter pattern. Feaster/97

&&

.PRELIMINARY POINT TEMPS/POPS...
PDT  48  82  46  74 /   0   0   0   0 
ALW  53  83  51  73 /   0   0   0   0 
PSC  51  84  46  74 /   0   0   0   0 
YKM  49  83  45  76 /   0   0   0   0 
HRI  50  84  47  75 /   0   0   0   0 
ELN  45  73  44  72 /   0   0   0   0 
RDM  46  82  36  74 /   0   0   0   0 
LGD  44  85  42  72 /   0   0   0   0 
GCD  44  85  42  75 /   0   0   0   0 
DLS  53  78  50  78 /   0   0   0   0 

&&

.PDT WATCHES/WARNINGS/ADVISORIES...
OR...Red Flag Warning from 1 PM to 11 PM PDT Thursday for ORZ691-701-
     703.

WA...Red Flag Warning from 1 PM to 11 PM PDT Thursday for WAZ691.

     Red Flag Warning from 11 AM to 11 PM PDT Thursday for WAZ690-695.

&&

$$

SHORT TERM...97
LONG TERM....97
AVIATION...86