Hermiston, Oregon 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

030
FXUS66 KPDT 152338
AFDPDT

Area Forecast Discussion
National Weather Service Pendleton OR
438 PM PDT Fri May 15 2026

.KEY MESSAGES...
- An upper low and trough will move across the region through
  early Sunday.

- Mountain snow tonight, with the highest amounts over the
  Cascades.

- Mountain thunderstorms Saturday afternoon.

- Dry weather from Monday onward.

&&

.DISCUSSION...
An upper level low and trough was moving into the Pacific
Northwest. On Saturday, it will be over the region and then by
Sunday it will be moving eastward and out of the area.

After the low departs the region, high pressure and dry weather
will move in for most of the upcoming week. By the end of the
week, high temperatures will average about 5 degrees above
normal.

As the low and trough move into the area tonight through
Saturday morning, snow levels will drop. By Saturday morning,
snow levels will be below 4000 feet across the Cascades and
below 3500 feet across the Washington Cascades. Therefore, some
snow is likely, with several inches possible even at pass
level, especially the higher passes like White Pass where there
could be 2 to 4 inches and possibly more. At the highest
elevations there could be locations that even more. During the
day, there would likely be a mix or a changeover to rain or at
least any snow that falls would not accumulate.

Additionally on Saturday, as the upper low moves across the
area, there will be enough instability for thunderstorms in the
mountains, though overall chances are generally <= 20 percent.

By Sunday, precip chances shift eastward mainly to eastern
Oregon, with the trough, and there is still at least low
thunderstorm chances.

Saturday looks breezy to windy once again, mainly along the
Cascade gaps, Kittitas Valley, Columbia Basin, central Oregon
and Blue Mountain Foothills. Wind gusts of 30 to 35 mph wind
guts with gusts to 40 mph are possible. Will have to see how
things develop to see if any wind headlines are needed, but
guidance overperformed today. NBM probabilities of wind gusts
>=47 mph is generally < 50 percent in these areas.

&&

.AVIATION /00Z TAFS THROUGH 00Z SUNDAY/...
VFR conditions expected to prevail over the next 24-hours. Main
highlights will once again be the breezy winds over the TAF
sites. Winds will remain breezy at 20-30 knots through the
evening hours, with decreasing strength going into the overnight
hours. In the mid to late morning hours, winds will once again
re-strengthen to 20-30 knots. Few showers are possible to
develop over DLS and ALW with SCT025 clouds. If showers are
heavier than expected, then we can expect to see a 10-20% chance
of some brief sub-3000 feet ceilings temporary developing.


&&

.Preliminary Point Temps/PoPs...
PDT  40  59  37  62 /  10  20  30  10
ALW  43  58  40  62 /  30  60  50  10
PSC  41  65  38  69 /  10  20  20   0
YKM  37  64  37  70 /  10  10   0   0
HRI  39  63  37  67 /  10  10  10   0
ELN  32  56  34  63 /  40  10  10   0
RDM  31  54  26  59 /  10  10  10   0
LGD  37  51  34  54 /  40  60  50  20
GCD  36  52  32  55 /  10  30  50  10
DLS  43  60  40  67 /  70  30  20   0

&&

.PDT WATCHES/WARNINGS/ADVISORIES...
WA...None.
OR...None.

&&

$$

DISCUSSION...77
AVIATION...95