Gallagher Head Lake, Washington Weather Forecast Discussion

748
FXUS66 KPDT 162104
AFDPDT
Area Forecast Discussion
National Weather Service Pendleton OR
204 PM PDT Tue Sep 16 2025
.DISCUSSION...Today through Thursday: Quiet weather will prevail for
the next couple days with warm, dry conditions from the high
pressure system with a thermal trough. This will promote easterly
winds through this evening across mainly the WA/OR Cascades and the
Gorge as well. Thursday will have the shortwave approaching across
to the PacNW as the upper ridge moves further out of the area.
However, the deterministic models and ensembles are in favor of
dryness over the forecast area. That said, no showers will be
expected for Thursday. High temperatures are expected to reach the
mid-70s to low 80s today and mostly mid to high 80s Wednesday. NBM
suggests a 50-90% probability of temps at 85 degrees or higher for
Wednesday. Daytime RHs will be in the 30s for the lower elevations
through Thursday with overnight RH recoveries becoming moderate to
good.
Friday through Tuesday: Dry conditions will continue through
Saturday morning with a transient ridge moving over the forecast
area. Starting Saturday early evening into Sunday, we will have more
of a zonal pattern associated with a frontal system approaching the
PacNW. This may bring light showers along the WA/OR Cascades. The
raw ensembles has a 30-40% prob for precip up to 0.10". We might
have a break on Monday due to the passing transient ridge. However,
light showers may return Tuesday morning at the Cascades before
spreading to other mountain areas Tuesday evening (

NWS PDT Office Area Forecast Discussion