Klickitat, Washington Weather Forecast Discussion

768
FXUS66 KPDT 211053
AFDPDT
Area Forecast Discussion
National Weather Service Pendleton OR
353 AM PDT Sun Sep 21 2025
.OVERNIGHT UPDATE...Radar is showing a few scattered showers over
the area this early morning with ground observations showing a few
of the higher terrain areas along the Blues receiving some
accumulated rain amounts of up to 0.01 while other areas like here
in PDT receiving a trace. Other than that, no real change from
the current forecast. The upper level trough will continue to move
in from the NW bringing increased chances of rain through the
morning through early afternoon before teetering off in the
afternoon with 20-40% probabilities of up to 0.03 inches of
accumulation. Winds will also increase to between 20-25 mph
through the Gorge and along the Horse Heaven Hills (45-70%). With
that cold front, temperatures behind the passage will be between 5
to 10 degrees cooler than seasonal average with most areas seeing
upper 60s to low 70s with a few isolated locations within the
Columbia Basin seeing mid 70s (80%). Also, this cold front will be
followed by a slot of cold and dry air which will cause overnight
temperatures to dip to near freezing 32-36 degrees (50-80%) in
lower central OR through the eastern mountains and into Wallowa
Valley. Confidence in reaching below freezing is low to moderate
at this time (30-60%). Bennese/90
&&
.UPDATED AVIATION...VFR conditions forecasted to prevail through
the period. A cold front passage tonight through tomorrow will
bring rain impacts to all sites through 2 PM with slight chances
(15%) for BDN/RDM and chance(20-40%) rain for YKM/PDT/PSC/DLS/ALW.
Winds will also see an increase through all sites seeing winds
between 10-20 kts with gusts to 20-30 kts beginning at 13Z for
DLS/BDN, and after 15Z at the remaining sites. Bennese/90
&&
PREV DISCUSSION... /issued 156 PM PDT Sat Sep 20 2025/
DISCUSSION...Satellite imagery reveals multiple features of
interest in the Pacific. A closed low centered off the coast of
central California is advecting remnants of tropical moisture
northward into the Blue Mountains region, leading to PWATs of
150-200% of normal. To the northwest, a closed low is churning in
the Gulf of Alaska, and water vapor imagery shows a shortwave
diving southeast towards the Pacific Northwest. Ahead of the
shortwave, a frontal boundary is draped from Vancouver Island
southwest into the Pacific.
Today, there is a slight chance (10-15%) of isolated showers and
thunderstorms across the Blue Mountains, roughly from the Bend
metro area eastward. Cross-Cascade pressure gradients will drive
breezy winds through the Cascade gaps into wind-prone areas of the
Columbia Basin today. While some areas will approach Red Flag
thresholds for wind and low relative humidity, confidence was too
low (

NWS PDT Office Area Forecast Discussion