Marine Weather and Tide Forecast for Yreka, CA

DISCUSSION
With an upper trough over the Pacific and a ridge over the southern United States, southwesterly flow persists over the area. This pattern will keep generally seasonal temperatures in the forecast across the area for much of the week ahead. Incoming air following this flow looks to stay fairly dry, limiting chances for precipitation. With passing shortwaves supporting breezy afternoons in addition to ongoing warm and dry conditions, fire weather concerns continue through the week ahead.

For this afternoon and evening, models are showing a little more support for isolated thunderstorms over northernmost Klamath County.
SPC CAM paintballs are showing a few stray cells in the ensemble's latest run. GFS imagery shows a small band of monsoonal moisture reaching westward from a larger plume, which could help fuel any activity. A lingering cirrus layer may work against these chances, as daytime heating would play a significant role in providing instability for these thunderstorms and reducing that heating would reduce already low chances for thunderstorms. Overall, thunderstorm chances near the Douglas/Klamath border is about 5-10%, but the slight trend upwards from past days is notable. Chances look to drop beyond today as the broader moisture plume moves eastward.

Temperatures will fluctuate a little through the forecast period.
The ridge over the southern US nudges westward in the middle of the week, adding a few degrees to forecast highs. Towards the end of the week, a cutoff low at the base of the Pacific trough moves towards the area. The effects of the low's approach are trending down, as its current path keeps it west then north of the area. With this path, thunderstorm chances decrease but are not completely absent.
Winds into the Shasta Valley and east of the Cascades look to increase, but currently look to stay below any Advisory levels.
This low would push the upper ridge back to the east, bringing temperatures a few degrees below normal into the weekend. -TAD

AVIATION
17/12Z TAFs...IFR/LIFR levels are present along the Oregon coast early this morning under marine stratus. This layer may reach into the Umpqua Valley and bring a brief period of MVFR ceilings, but this layer would likely last a few hours at most.
Coastal stratus looks to clear out briefly this afternoon before returning in the evening.

Other areas look to remain at VFR levels under high clouds early in the day then clear skies in the afternoon and evening. -TAD

MARINE
Updated 830 PM PDT Sunday, August 16, 2026...There will be brief, slight improvement overnight. But, due to gusty north winds, the Small Craft Advisory in effect for most of the area south of Cape Blanco (excepting near shore south of Brookings) has been extended to cover all of the southern waters Monday afternoon through Wednesday evening. The strongest winds are expected during Tuesday afternoon and evening. Conditions are expected to improve late in the week.

MFR WATCHES/WARNINGS/ADVISORIES
OR
CA
None.

PACIFIC COASTAL WATERS...Small Craft Advisory until 11 PM PDT Wednesday for PZZ356-376.