Union, Oregon Weather Forecast Discussion

233
FXUS66 KPDT 070540
AFDPDT
Area Forecast Discussion
National Weather Service Pendleton OR
1040 PM PDT Sat Sep 6 2025
.UPDATED AVIATION...06Z TAFs...T-storms have fizzled out over
central OR and the Gorge. VFR conditions will persist across most
of the TAF sites with PSC seeing sub-VFR at 6SM due to HZ with
around 30% confidence they could see MVFR at 4-5SM as the HZ
thickens through the period. Winds will be light and variable
under 10kts except for DLS which will see 10-16kts with gusts to
25 beginning around 18Z. CIGs will be 15-25kft. Bennese/90
&&
PREV DISCUSSION... /issued 118 PM PDT Sat Sep 6 2025/
DISCUSSION...Our wet, active pattern continues as a parent low
spinning off the PacNW coast continues to circulate a series of
upper-level waves through the region. For today, this wave shows up
very clearly on visible satellite imagery as a cloud shield envelops
the northern half of the forecast area while some clearing takes
place over central Oregon. Given the moisture and lift supplied by
this wave, this will allow another round of storms to fire off this
afternoon and evening, sweeping northward into the Basin, as well as
riding along the spine of the Cascades. Latest CAMs suggest these
storms will flare up at around 3-5 PM this afternoon, replacing the
ongoing light showers riding up through the Blues, into the Basin
and up into the WA Cascades.
Convective parameters suggest that the main limiting factor to these
storms is shear, which has been the case over the last several days,
however should note that latest CAMs are hinting at a developed line
of storms once everything kicks off this evening, capable of strong
outflow winds as high as 50 mph, as well as small hail. Confidence
in anything severe forming is low (20-30%) given the cloud cover
over much of the forecast area stemming from the activity this
morning as well as the lack of bulk shear, but would not be
surprised if some storms flirt with severe criteria.
Storms are once again expected to be wetting in nature as they have
over the last few days. Did issue a Red Flag Warning last night for
the central WA Cascades for storms this evening and overnight, as
wetting rains may be spottier up there where the fuels are drier.
Once we start heading into next work week and this parent low begins
pushing onshore, however, wet and cool conditions will dominate,
hindering storm development and thus dampening any fire weather
concerns. Monday and Tuesday look to be particularly cool and wet,
with high temps struggling to climb over the mid 70s across even the
lower Basin. Cannot rule out an isolated thunderstorm, especially
over the mountains, but the convective threat overall looks to be
maximized today, steadily decreasing over successive days. Evans/74
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT  61  86  58  81 /  30  40  20  30
ALW  66  87  62  83 /  20  40  30  20
PSC  61  89  58  84 /  10  20  10  10
YKM  63  87  56  82 /  30  40  10  20
HRI  63  88  60  83 /  20  30  10  30
ELN  59  82  54  81 /  30  50  20  20
RDM  50  79  50  74 /  40  40  10  60
LGD  56  84  52  83 /  40  50  30  30
GCD  55  83  52  81 /  40  30  10  20
DLS  64  82  61  80 /  40  30  10  50
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...None.
WA...Red Flag Warning until 3 AM PDT Sunday for WAZ690-695.
&&
$$
SHORT TERM...74
LONG TERM....74
AVIATION...90

NWS PDT Office Area Forecast Discussion