Hermiston, Oregon 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

387
FXUS66 KPDT 302126
AFDPDT

Area Forecast Discussion
National Weather Service Pendleton OR
226 PM PDT Sun Mar 30 2025

.SHORT TERM...
Tonight through Tuesday...Precipitation is expected to increase
tonight in advance of an area of low pressure off the coast. The
precipitation chances will continue through the day Monday before
decreasing Monday afternoon/evening with most areas becoming dry.

The low off the coast will then come onshore in southwestern
Oregon late Monday night or early Tuesday morning and bring
another round of precipitation Tuesday afternoon, especially for
the mountains.

QPF tonight will generally be 0.50 to 1.0 inches along the highest
portions of the Oregon Cascades and much less less elsewhere.
Along the crest of the Blues and the rest of the higher terrain,
perhaps around 0.25 inches and in the lower elevations, generally
less than 0.10 inches, though some could get between 0.10 and 0.20
inches.

Snow levels will initially start out quite high...over 5000 feet,
but will fall to between 2500 and 3000 feet by Monday morning.
Snow amounts tonight should be no more than a couple of inches at
along the crests of the Cascades and less elsewhere.

QPF Monday into Tuesday (mainly beginning later Monday) will be
between 0.50 and 1 inch is possible along the crest of the Oregon
Cascades, around 0.50 inches along the crest of the Blue
Mountains. Most lower elevation locations will get less than 0.10
inches. Snow levels will rise from 2500 feet to 3500 feet by
Tuesday afternoon.

Snow amounts Monday into Tuesday will be higher along the Oregon
Cascades and Blue Mountains with several inches possible along the
crests. Will have to monitor for any needed headlines at a later
time but confidence is low due to time of year, warm ground and
will have to see the potential for snow accumulation at night.

There will be some diurnal breezes on Tuesday in the 20 to 25 mph
range. NBM probabilities of wind gusts >=25 mph are 70 to 90
percent. NBM probabilities of wind gusts >= 39 mph are generally
less than 50 percent.


.LONG TERM...
Tuesday Night through Sunday...

Key Messages:

1) Light mountain snow and low elevation rain.
2) Late week ridging with drier and warmer conditions.

Models are in great alliance that the ridge will be settling just
off the coast with the trough axis over the Rocky`s across Idaho,
Utah, and Nevada. Wrap around from the surface low pressure will
keep precip lingering for the next couple of days. QPF amounts are
not impressive looking at either snow or rain thanks to the
northward surface wind preventing an abundance of moisture entering
the region. NBM is displaying up to an additional three inches of
mountain snow through the long term period (50-70% confidence), with
a trace to up to a half inch in Central OR (60-80% confidence). QPFs
for the Basin and other parts of low elevations don`t leave a lot to
discuss as they remain tapered up to 0.05 inches.

Ridging begins to take place of the shortwave, introducing a dry,
warmer pattern for the PacNW. Clusters are in good agreement that
most precip will move out of the region by Thursday night, but 39%
would like to extend the precip until Friday morning. This will
hardly make a difference in the total QPF amounts we will receive
through Friday and will solely be a disagreement in the timing when
things dry out. Models for the remainder of the term have timing
disagreements when the ridge axis will take place over the region,
but the overall picture of a dry/warm weekend remain intact overall.

Temperatures will begin a warmer trend as we head into the weekend
thanks to the overhead ridging, with most areas receiving high
temperatures 5 to 15 degrees above normal.  The high temperatures
for this weekend will climb into the following ranges:

Friday: Mid to High 50s Foothills of the Blues and Central OR; Low
to Mid 60s Upper Columbia Basin; Mid to High 40s in Higher
Elevations.

Saturday: Low to Mid 60s Foothills of the Blues and Central OR; Mid
to High 60s Upper Columbia Basin; Low to Mid 50s in Higher
Elevations.

&&

.AVIATION...(Previous Discussion)
18Z TAFS...VFR conditions will extend through the period for all
sites. No CIG or VIS issues with the next system approaching the
PacNW, however rain and some gusty winds will be the primary
factors for this period. All sites are expected to receive rain at
some point, with the line starting at the BDN/RDM area at 20Z.
The rain line will continue to push NE throughout the CWA,
reaching DLS at 23z, then onwards to PDT/ALW/PSC at 05-06z. Rain
will last a few hours before a second round of precip affects the
area during the last few hours of the period. Winds remain light
for DLS/PSC with sustained winds up to 12 knots. Elsewhere will
see gusts up to 20-30 knots during the heaviest rainfall.

&&

.PRELIMINARY POINT TEMPS/POPS...
PDT  40  55  35  56 /  50  50  20  20
ALW  42  55  37  55 /  50  60  30  30
PSC  41  60  35  61 /  50  40  10  10
YKM  37  58  33  59 /  80  20  10  10
HRI  40  60  34  60 /  40  50  10  20
ELN  36  54  35  56 /  80  40  10  10
RDM  32  50  29  51 /  50  40  20  30
LGD  37  49  29  49 /  50  90  40  40
GCD  35  49  28  48 /  60  80  40  60
DLS  40  57  36  59 /  80  40  10  20

&&

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

$$

SHORT TERM...77
LONG TERM....95
AVIATION...95