Hermiston, Oregon 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

980
FXUS66 KPDT 060534
AFDPDT

Area Forecast Discussion
National Weather Service Pendleton OR
1034 PM PDT Fri Sep 5 2025

.UPDATED AVIATION...06Z TAFs...VFR conditions are forecast for
all sites through the forecast period. Temporary 6SM VSBYs in
showers & thunderstorms are forecast briefly tonight at BDN/RDM,
and confidence in VSBYs in FU/HZ at YKM/PSC overnight and Saturday
is high (>80%) with PSC seeing MVFR at 4SM due to HZ starting
around 12Z and lasting through 02Z. However, confidence in the
length of time at MVFR is low (<40%). CIGs will remain 15-25 kft
across all sites with winds being below 10 kts with only DLS
seeing gusts to 15 kts through 11Z. Bennese/90


&&

.PREV DISCUSSION... /issued 521 PM PDT Fri Sep 5 2025/

AVIATION...00Z TAFs...Predominantly VFR conditions are forecast
for all sites through the valid period. Temporary sub-VFR VSBYs
in showers/thunderstorms are forecast this afternoon and evening
at BDN/RDM, with lower confidence in sub-VFR VSBYs in FU/HZ at
YKM overnight and Saturday. Confidence is low (<30%) in sub-VFR
VSBYs at other sites in FU/HZ, due to uncertainty in low-level
smoke concentrations.

Winds will be mostly 10 kts or less, except in thunderstorm
outflow. Thunderstorms will be capable of producing strong, gusty
outflow winds of up to 50 mph.

Mostly mid- and high-level clouds are forecast for all sites,
except for temporary CIGs of around 5 kft in heavier showers
and/or thunderstorms. Plunkett/86

PREV DISCUSSION... /issued 203 PM PDT Fri Sep 5 2025/

DISCUSSION...An upper low off the coast will gradually move
eastward through Monday, with the broader upper trough impacting
the area over the weekend.

Showers and thunderstorms will affect the Pacific Northwest over
the next few days...mainly over central Oregon today, then central
Oregon and the Cascades on Saturday. A Red Flag Warning remains in
effect through this evening. Thunderstorms look to become more
wet through the weekend and some areas, especially the mountains
and central Oregon could end up getting some decent rainfall
amounts.

The biggest question remains about cloud-to-ground lightning
strikes, and how many in a given area and what that impact will
be on any new fire starts, especially on Saturday. Other questions
are what impact smoke will have on thunderstorm development and if
rain will alleviate concerns from lightning, at least in some
areas. Will need to keep watch on this to see if any fire weather
headlines become necessary.

By Wednesday, more generally low (<=30%) precipitation chances
are expected as an upper trough remains over the western CONUS.

High temperatures will cool each day through the weekend and into
early next week and will return to seasonal normals by early next
week. High temperatures are expected to remain near normal
through the week. The cooler temperatures will also help increase
RH values.

&&

.PRELIMINARY POINT TEMPS/POPS...
PDT  66  89  61  85 /  20  30  40  30
ALW  70  91  66  85 /  10  20  30  40
PSC  63  91  63  88 /  10  20  20  20
YKM  68  93  63  86 /  10  30  30  30
HRI  66  91  63  87 /  10  30  30  30
ELN  63  91  61  82 /  10  30  30  50
RDM  54  86  50  79 /  50  40  40  40
LGD  60  88  56  84 /  10  30  40  40
GCD  60  87  54  83 /  30  40  40  20
DLS  68  88  64  82 /  20  50  40  30

&&

.PDT WATCHES/WARNINGS/ADVISORIES...

WA...Red Flag Warning from 4 PM Saturday to 3 AM PDT Sunday for
     WAZ690-695.

&&

$$

SHORT TERM...77
LONG TERM....77
AVIATION...90