Marine Weather and Tide Forecast for Glendale, OR

AVIATION
17/00Z TAFs...A front is moving inland tonight bringing rain, mountain obscurations and MVFR and areas of IFR conditions. Along the coast, expect a mix of MVFR and IFR conditions with areas of LIFR through tonight, transitioning to MVFR Saturday morning. Inland, rain MVFR will spread inland around 05-11z and persist through Saturday morning. MVFR conditions will be widespread across much of southern Oregon along with local IFR and widespread mountain obscurations. Across northern California, expect a mix of VFR and MVFR conditions tonight through Saturday morning.

Isolated to scattered thunderstorms embedded with rain showers are expected tonight through Saturday afternoon across Lake County and Modoc County, including Lakeview and Alturas. This risk will reach a peak tonight and early Saturday morning, but continue into the afternoon. Chances for thunderstorms (15-20%) are also expected tonight into Saturday across Douglas County, for the Southern Oregon Cascades and northern and eastern Klamath County.

Ceilings will gradually lift to VFR Saturday afternoon, but expect areas of MVFR to linger in heavier showers. Showers decrease in coverage Saturday evening, becoming limited to the coast, Umpqua and Cascades, where some areas of MVFR conditions may persist.

PREV DISCUSSION
/Issued 811 PM PDT Fri May 16 2025/

DISCUSSION...A fairly vigorous upper trough offshore supported by a 150-kt jet will sharpen as upper level energy dives ESE into northern California overnight into Saturday morning. Showers will break out along the coast later this evening, but the best forcing is over the East Side where showers likely develop quickly between 1-3 am. This is a bit unique to have a sharpening upper trough to swing through in the middle of the night and also to have enough instability present east of the Cascades (about 300-500 J/KG) to support convection. As such, we expect isolated to scattered thunderstorms to develop within the band of showers that gets going (mainly east of Klamath Falls). Best shot for thunder (20-30%) is in Modoc and up into portions of Lake County overnight into Saturday morning. We don't expect severe weather, but some of the stronger cells could contain gusty winds and, of course, cloud to ground lightning. The main axis of instability shifts to the east during Saturday morning, but the cold pool aloft will move in, so we'll maintain scattered showers, most numerous near and north of the Umqpua Divide, over the Cascades and from around Winter Rim eastward over the East Side. There is also a risk of thunder in portions of Douglas County Saturday in any of the heavier showers, but isolated (15-20% chance) at best.
For the Rogue Valley, showers will be more hit-or-miss. Some areas may have brief downpours, while others miss out all together.
Locally breezy conditions develop too Saturday, especially east of the Cascades in the afternoon where non-thunderstorm wind gusts could be 30-40 mph. Overall, expect a cooler than normal day with highs generally in the 60-65F range for the west side and 55-60F east of the Cascades. Shower coverage diminishes Saturday afternoon/evening as warmer air aloft moves in, though some do linger near the Cascades due to moist onshore flow. -Spilde

MARINE
Updated 800 PM Friday, May 16, 2025
Rain showers with light to moderate winds and increasing west seas are expected tonight through Sunday morning. Another frontal system will move into the area on Monday with winds veering from south to northwest. Northerly winds will increase on Tuesday from the brief development of a thermal trough near shore. Meantime, building seas on Tuesday may possibly becoming high and steep with the combination of the higher wind waves and a building west-northwest swell at 13 seconds. Conditions are likely to improve slightly on Wednesday.

PREV DISCUSSION... /Issued 253 PM PDT Fri May 16 2025/

DISCUSSION...Cloud cover is rebuilding this afternoon ahead of an approaching upper trough. The first impacts from this approaching system will be thunderstorm chances developing east of the Cascades late tonight into early Saturday morning. The best chances (10-15%) will be across Modoc and southern Lake counties, with lesser chances (5-10%) covering eastern Klamath and northern Lake counties. Any thunderstorms that develop are likely to be isolated and remain below severe thresholds. Thunderstorm chances increase to 15-20% across Lake and Modoc counties on Saturday afternoon before decreasing through Saturday evening and night.
Other areas are expected to see at least light showers at some point between Saturday morning and Sunday afternoon. Overall amounts will be unimpactful. Coos County, the Cascades, areas around and east of Lakeside, and the Warner Mountains are expected to see between 0.25 and 0.50 inches of rainfall. Occasional snow showers are possible over the Cascades early Sunday morning, but accumulation is not expected. The Umpqua Valley may see 0.10 inches of rainfall, and other areas will have rainfall measured in the hundreths. Temperatures will cool through the weekend as the trough moves over the area.

Seasonal temperatures under zonal flow aloft look to continue through the week. A couple of weak disturbances may briefly affect conditions for certain locations. On Monday, a weak front could bring some clouds to Coos and eastern Douglas counties. Brief showers are possible over these areas on Monday morning and afternoon, but amounts will be one or two hundreths at most. On Wednesday or Thursday, a weak disturbance could bring gusty winds and isolated showers to the northernmost border of the CWA
Deterministic guidance for both the ECMWF and the GFS show some upper instability passing over the area, with some variation in timing and structure. Individual ensemble members for both the GFS and ECMWF are split on showing the disturbance or not, and those that show it do so with some variation in timing and location.

Zonal flow continues on Friday, with some uncertainty for the weekend. While both models show some amount of upper level ridging, the strength and position of the ridge vary. The general expectation seems to be additional warming on Saturday and Sunday, but little overall consensus on how warm next weekend will be. NBM probabilistic guidance echos this uncertainty, with daytime highs forecast to be from seasonal temperatures to 10 degrees above on next Sunday. -TAD

MARINE
Updated 200 PM Friday, May 16, 2025
A trough will produce light showers with moderate winds and moderate swell dominated seas tonight through Sunday morning. Northwest winds will be strongest Saturday evening south of Brookings. Another seasonable system will follow on Monday with winds veering from south to northwest. Northerly winds will increase on Tuesday from the brief development of a thermal trough near shore. Meantime, building seas on Tuesday may possibly becoming high and steep with the combination of the higher wind waves and a building west-northwest swell at 13 seconds. Conditions are likely to improve slightly on Wednesday.
-DW

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

CA...None.

PACIFIC COASTAL WATERS...None.