textproduct: Medford

Updated AVIATION Discussion

AVIATION...27/18Z TAFs

A trough is moving through areas near and west of the Cascades late this morning with most of the precipitation occurring in SW Oregon. Light to moderate rain, MVFR ceilings and higher terrain obscuration will accompany this disturbance with local IFR conditions at times in areas of heavier precipitation. As this system shifts east of the Cascades this afternoon, precipitation will become more sparse/showery and conditions should improve. Conditions should mostly remain VFR in south central Oregon and far northern California, though may briefly lower to MVFR in any shower. Conditions should improve to VFR all areas this evening.

Late tonight into Wednesday morning, after 09Z, another weaker trough will bring light rain to the coast north of Cape Blanco with a similar mix of IFR/MVFR for Coos and Douglas counties. VFR will persist elsewhere, except there is a 20-30% possibility of IFR fog in some valleys around sunrise. -Spilde

PREV DISCUSSION

/Issued 559 AM PDT Tue Oct 27 2026/

KEY MESSAGES...

* Persistent low pressure this week brings seasonably active weather with mainly low impacts.

* The most significant rainfall of the remainder of the week will be mainly along and west of the Cascades this morning. Snow levels around 5000-5500 ft, with a couple of inches of snow possible around the Diamond Lake/Crater Lake area. A few lighter showers linger this afternoon.

* Temperatures relatively steady through the week, fluctuating in a range from around 10 degrees below normal to near normal.

* Excellent model agreement through Friday with occasional light shower chances, mainly for Coos and Douglas counties northward during Wednesday and also Thursday night.

* Either a weak or very weak system moves inland on Saturday. Light shower chances on Saturday will be highest at the coast, possibly extending inland during the afternoon or evening.

* High pressure will likely bring drying and modest warming for Sunday through Tuesday.

DISCUSSION...Low pressure off the central Oregon coast will track eastward today. Rainfall will be focused on southwest Oregon through around 10 AM this morning, then lighter showers taper off during the remainder of the day. Around a quarter to half inch of rain is expected for Coos and Douglas counties, with up to a quarter of an inch for Curry County, up to a tenth of an inch for Josephine and Jackson counties, and a measureable amount for northern Klamath and far western Siskiyou counties. This includes up to 2 inches of snow for the southern Oregon Cascades with a snow level around 5500 feet falling to 5000 feet.

A broader area of low pressure, now over northern British Columbia, will retrograde slightly, tracking south-southwest toward Vancouver Island by tomorrow/Wednesday. Associated showers in the onshore flow pattern will be focused north of our area. But, Coos and Douglas counties should receive a measureable amount of showers under persistent cloud cover. Elsewhere, breaks in the cloud cover are expected and should allow for high temperatures to reach a few to several degrees higher than today.

The low will meander a bit farther south on Thursday, with our region likely to be between shortwaves for a reduced chance of light coastal showers. Compared to the GFS, the ECMWF does indicate a bit more low level moisture that would be sufficient to generate very light showers north of Cape Blanco. The blended 40% probability of rain and trace to a barely measureable hundredth or so is appropriate.

The low is expected to remain offshore of Washington and northern Oregon, with a slight backing to more of a due southwest flow aloft on Thursday night through Friday night. This will keep the more favorable dynamics and deeper moisture aimed north of our area. The result is a Friday that should resemble Thursday.

For now, the story for Saturday is much the same as it was yesterday. Uncertainty increases a bit, enough to make the difference between whether light or very light showers remain confined to the coast, or extend to the Cascades with a slight chance possibly warranted for the east side. For the daylight hours, the probability will be highest for (and possibly limited to) the coast. The ECMWF suite of solutions indicating a higher probability of west side focused rain, a sharper trough, than the GEFS. This would mean around 0.05 to 0.10 inches for the coast rather than a trace to 0.02 inches. Toward sunset into the evening, rain chances could spread farther inland. This uncertainty is expressed by 20-30% rain chances being mainly west and north of Jackson County for the afternoon, ahead of a more widespread slight chance to chance for the evening.

Despite the differences in strength, models are in good agreement on slight rain chances lingering east of the Cascades late Saturday night ahead of ridging early next week. The ridge will provide drying and modest warming Sunday into Tuesday. From late day 7 through day 10, model uncertainty quickly increases with a near even split between whether ridging will linger into mid-week, or shift to the Rockies with a return to wet weather for the Pacific Northwest.

MARINE...Updated 130 AM PDT Tuesday, October 27, 2026...Unsettled weather with occasional showers will continue through the week. Winds are expected to remain below advisory strength. A series of seasonably weak disturbances will produce the strongest northwest winds in the Washington and northern Oregon offshore waters, which will push fresh swell into the southern Oregon waters. Wave heights will be just high enough and steep enough to reach Small Craft Advisory criteria. Fresh west-northwest swell dominated seas continue for our area through this evening. The active pattern is expected to persist late in the week with slight, gradual improvement in conditions. The outlook is that a long period west- northwest swell may build from 2 ft at 21 seconds late Sunday to 6-8 ft at 17 seconds on Monday.

MFR WATCHES/WARNINGS/ADVISORIES

OR...CA...None.

PACIFIC COASTAL WATERS...Small Craft Advisory until 5 PM PDT this afternoon for PZZ350-356-370-376.