Marine Weather and Tide Forecast for Yreka, CA

DISCUSSION

Key Points:

* Showers and chances for thunderstorms today.
* Additional showers on Wednesday. Gusty winds east of the Cascades Wednesday afternoon.
* Showers taper off Thursday * Dry and warm Friday, followed by a chance for showers on the weekend.

An upper low will remain over the region through Wednesday. This will bring a cool and showery pattern. Shower activity this morning will continue to be focused over Siskiyou County and west of the Cascades. A winter weather advisory remains in effect through late this morning for the higher mountains above 5000 ft near the Trinity Alps, south of Callahan. Showers will continue during the day but expect mainly light snow.

With the upper low moving inland today, expect an unstable and showery pattern to develop today. Widespread showers are likely across the area. Models also continue to support a chance for thunderstorms today with a 15-30% chance from the Cascades west and a 10-20% chance east of the Cascades. Chances for thunderstorms (5-10%) decrease on Wednesday. Winds will be breezy today. Then, on Wednesday, ensembles continue to support gusty winds (gusting to 25-40 mph) east of the Cascades.

The low will move eastward Wednesday night with diminishing showers on Thursday. Models and ensembles show warm and dry conditions develop on Friday.

On the weekend, a weak upper trough is forecast to move down from the north and into the region. However, there is still variability on the track of this low which will impact how much shower activity is expected. The National Blend of Models indicates a slight chance for light precipitation, mainly across the mountains and east of the Cascades (15-30% chance) with a 10% chance for showers in valleys west of the Cascades and a 10-20% chance for showers along the coast. Temperatures may trend cooler, especially on Sunday, if this trough settles over the area.



AVIATION
21/12Z TAFs...Low pressure moving inland today will bring showers, breezy winds, and lower ceilings (mixed VFR/MVFR) to much of the area. Areas of mountain obscurations are expected.
Southerly flow into Siskiyou County, including the Mt Shasta region, will cause lower ceilings (to MVFR) this morning along with rain and high elevation snow (above 5000 feet). Precipitation will be more showery north of the Siskiyous with a mix of VFR/MVFR. This afternoon, expect mainly VFR with areas of MVFR west of the Cascades and areas of mountain obscurations. There is also a chance of thunderstorms this afternoon. MVFR conditions increase this evening and tonight across the area.



MARINE
Updated 100 AM PDT Tuesday, April 21, 2026...Seas will continue to trend lower today as a low pressure system gradually moves inland. Increasing northwest swell follows Wednesday into Thursday, decreasing Friday into Saturday. Additionally, north winds will increase over the waters Thursday and Friday. This pattern may result steep seas and gusty winds, especially for the waters south of Cape Blanco Thursday evening into Friday.

MFR WATCHES/WARNINGS/ADVISORIES
OR...None.

CA...Winter Weather Advisory until 11 AM PDT this morning for CAZ080>082.

PACIFIC COASTAL WATERS...None.