Hermiston, Oregon 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

753
FXUS66 KPDT 252339
AFDPDT

Area Forecast Discussion
National Weather Service Pendleton OR
439 PM PDT Sat Jul 25 2026

.Updated Aviation Discussion.


.KEY MESSAGES...
- Critical fire weather conditions through this evening as
  breezy to locally windy conditions overlap with dry conditions

- Diurnally breezy winds with dry conditions persisting through
  the week

- Another weak cold front passage Tuesday will bring increased
  winds across the area, with elevated to locally critical fire
  weather conditions

&&

.DISCUSSION...
Satellite imagery this afternoon shows mostly
clear skies with elongated plumes of smoke coming from fires in
central and eastern OR. Cumulus have also been noted developing
within some the plumes emanating from the Shingle, Crosswhite,
and Bench fires. Otherwise water vapor imagery shows a shortwave
coming ashore in WA. At the surface, westerly winds are
increasing across the forecast area as the shortwave and an
accompanying cold front approach the forecast area.

Today, winds will increase (15-25mph with gusts 30-45mph)
across the forecast area as the shortwave and cold front push
inland. The cold front boundary will continue to push east
today, with winds shifting from southwest to west this
afternoon, then shifting again to the northwest late this
evening. Winds through the Cascade gaps will stay their usual
direction (west to northwest). These increasing winds will also
overlap with low relative humidities in the lower elevations,
resulting in critical fire weather conditions through this
evening. Winds will remain breezy post the cold front passage
tomorrow, but will be lighter (10-20 mph with gusts up to
35mph). Dry conditions will remain across the region, but will
increase slightly as afternoon temperatures lower slightly.
While fire weather conditions will remain elevated, localized
areas of central OR and the lower elevations in the eastern
mountains may see critical fire weather conditions develop for a
few hours in the afternoon (confidence 55-70%).

Through Friday, there is great agreement that the forecast area
will remain between upper level troughing in the northeast
Pacific and an upper level ridge over central and southwest
CONUS. This will place a dry, southwest flow aloft over the
PacNW that will keep temperatures near seasonable. That said, a
weak shortwave and cold front boundary will lift across
northwest WA, producing another round of breezy conditions and
slight cool down. The most recent run of the NBM shows low
probabilities (<20%) of wind/RH overlap Tuesday afternoon. That
said, confidence is mod- high that elevated fire weather
conditions will be present across the lower elevations.

Thursday through Friday, there is good agreement that while the
forecast area remains under southwest flow aloft, upper level
ridging over the central CONUS will gradually retrograde west,
which will allow temperatures to warm from the upper 80s to low
90s into the mid to upper 90s across the forecast area
(confidence 60-75%). Lawhorn/82

&&

.AVIATION /00Z TAFS THROUGH 00Z MONDAY/...
VFR conditions currently across all sites, which will stay the
course through the period. Widespread breezy winds of 15-25kts
with gusts of 20-30kts will continue through the afternoon,
tapering off in the evening under clear skies. 75

&&

.FIRE WEATHER...
A weak cold front passage will bring breezy to
locally windy westerly winds across the region, while afternoon
RHs are expected to be near to below critical levels. This has
resulted in Red Flag Warnings being issued across most of our
lower elevation locations through 8PM this evening. Breezy to
locally breezy winds will continue tomorrow while RHs will be
slightly higher due to cooler temperatures. That said, locally
critical fire weather conditions may be present tomorrow
afternoon. Elevated fire weather conditions will remain through
the week as diurnally breezy winds redevelop, with RHs near to
just above critical thresholds. Lawhorn/82

&&

.Preliminary Point Temps/PoPs...
PDT  54  88  55  88 /   0   0   0   0
ALW  60  90  61  90 /   0   0   0   0
PSC  59  92  59  92 /   0   0   0   0
YKM  57  90  58  90 /   0   0   0   0
HRI  58  90  59  91 /   0   0   0   0
ELN  53  84  54  84 /   0   0   0   0
RDM  49  88  50  88 /   0   0   0   0
LGD  55  92  56  90 /   0   0   0   0
GCD  54  93  54  91 /   0   0   0   0
DLS  60  86  60  88 /   0   0   0   0

&&

.PDT WATCHES/WARNINGS/ADVISORIES...
WA...Red Flag Warning until 8 PM PDT this evening for WAZ690-691.
     Air Quality Alert until 11 AM PDT Monday for WAZ028>030.
OR...Red Flag Warning until 8 PM PDT this evening for ORZ691-697-
     698-700-704.
     Air Quality Alert until noon PDT Monday for ORZ049-050-502-503-
     505-506-508-509-511.

&&

$$

DISCUSSION...82
AVIATION...75
FIRE WEATHER...82