Thorp, Washington Weather Forecast Discussion

682
FXUS66 KPDT 261718
AFDPDT
Area Forecast Discussion
National Weather Service Pendleton OR
1018 AM PDT Fri Sep 26 2025
.AVIATION...
/18Z TAFs/
Aviation impacts will be minimal today as VFR conditions prevail
across the region. The only concern is the potential for FU/HZ
downwind of the Wildfires in Kittitas and Yakima Counties, though
visibility will generally remain P6SM. Otherwise, expect a few
high clouds with light winds following more typical diurnal
trends. /MJ
&&
.PREV DISCUSSION... /issued 407 AM PDT Fri Sep 26 2025/
AVIATION...12z TAFs...VFR conditions expected. Few-sct high
clouds will give way to clear skies during the day today, before
building back in later this evening. Winds will be light and
terrain-driven less than 12 kts across all sites. Evans/74
PREV DISCUSSION... /issued 334 AM PDT Fri Sep 26 2025/
DISCUSSION...
Dry and warm weather is  expected though at least the end of
Sunday. Surface high pressure will dominate the Inland Northwest
creating conditions for light winds, low relative humidity, and
warm temperatures climbing back into the lows 80s through the
Columbia Basin and lower elevations of central Oregon Saturday and
Sunday. Visibility may drop locally to 2-5 miles in the early
through late afternoon across sections of northern Yakima and
Kittitas counties where wild fires continue.
Late day Sunday or early Sunday evening might be the first
instance of showers popping up across the eastern Mountains. The
upper synoptic pattern transitions from a weak upper ridging
pattern over the greater region to a southwest flow aloft as a
trough approaches the coast. This sets up a band of higher mid
level RH / clouds and rain over the weekend along the PAC NW ,
with increasing chances for rain showers and wetting rains across
the Interior NW by late Sunday into Monday as the first lead
shortwave breaks off the larger trough and heads inland. The
synoptic trough will then pivot poleward through Wednesday toward
the BC coast. NBM suggests a couple of peak times for highest
chances of rain; late day/evening Monday and Tuesday
night/overnight (40-60%) across a 6 hour basis, and 60-80%
chances across a 24 hour basis (for measurable rain). Rain
shadowing will relegate better than 50% chances for a quarter of
one inch of rain to the eastern slopes of the Cascades. A more
conservative one tenth of one inch or more has about a 50-70
percent chance of occurring across the Eastern Mountains. Tuesday
night is the first instance of NBM producing a little snow
accumulation in the Eagle Caps of the Wallowa Mountains..but
negligible ( less than one half inch) in total with very low now
to liquid ratios (probably mixed with rain). 71/Russell
FIRE WEATHER...
Low relative humidity returns This Afternoon across the area and
the greater risk areas are east of the Oregon Cascades where the
25th percentile NBM members show relative humidity falling to 10
to 15% east of highway 97. A lack of wind however will steer the
area clear of critical fire weather thresholds, as winds remain
below 10 mph area-wide, both Friday and Saturday. A brief uptick
in surface winds is anticipated on Sunday but with an increase in
overall relative higher relative humidity. HRRR vertically
integrated smoke fields show a marked increase in concentrations
after 19z (11 am) downwind of the Wildcat and Labor Mountain Fires
(Kittitas and Yakima counties). 71/Russell
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT  73  47  80  51 /   0   0   0   0
ALW  73  52  80  56 /   0   0   0   0
PSC  75  45  79  49 /   0   0   0   0
YKM  75  49  79  50 /   0   0   0   0
HRI  75  46  80  51 /   0   0   0   0
ELN  72  44  78  46 /   0   0   0   0
RDM  73  38  83  43 /   0   0   0   0
LGD  71  42  81  47 /   0   0   0   0
GCD  72  44  84  48 /   0   0   0   0
DLS  77  52  83  54 /   0   0   0   0
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...None.
WA...None.
&&
$$
DISCUSSION...71
AVIATION...MJ

NWS PDT Office Area Forecast Discussion