textproduct: Medford

DISCUSSION

Updated aviation discussion.

AVIATION...16/00Z TAFs

High pressure aloft just off the PacNW coast and a thermal trough along the coast are bringing mostly light to moderate offshore flow across interior SW Oregon and northern California. Most areas are VFR, but persistent LIFR low clouds and fog are impacting the Umpqua Basin, including Roseburg. These are also impacting portions of the Rogue Valley, including Grants Pass, and in the vicinity of Medford. The clouds did break here in the last hour or so, but we expect a repeat of last night with LIFR filling back in this evening/overnight. Satellite is showing if it doesn't dissipate in the next hour or so, it could fill in fairly quickly. We'll monitor and amend as necessary. The Illinois Valley had a reprieve with clouds breaking there today, but some probably redevelop overnight into Friday morning. Roseburg looks pretty socked in, so expect LIFR to continue through most of Friday.

With offshore flow, expect less cloud cover/fog along the coast compared to previous nights, though patchy fog or mist could develop around North Bend during the night. The rest of the area should remain VFR through Friday.

Model guidance indicates offshore flow easing as the thermal trough weakens Friday. This could lead to a southerly stratus surge up the coast or through the coastal waters later Friday or Friday night.

PREV DISCUSSION

/Issued 154 PM PST Thu Jan 15 2026/

DISCUSSION...An upper level ridge will remain in control over the area for several more days. Temperatures will be unseasonably warm outside of the west side valleys, especially in and around Brookings, where a Chetco Effect of downslope warming is expected. In fact, as of this writing, it is 65 degrees in Brookings, with clear skies and light winds, while fog is only beginning to clear in Medford at 34 degrees.

Persistence remains the appropriate description for the duration of the forecast. While areas outside of the inland valleys will be relatively warm, dry, and with clear skies, the interior valleys will continue to experience strong inversions and stagnant air. According to the NBM, there is only a roughly 30 percent chance for fog in the valleys west of the Cascades tonight, and less than a 10 percent chance of temperatures at or below freezing. Typically, this pattern results in persistent fog and freezing fog within the valleys, with some areas clearing in the afternoon, and others never clearing at all, before fog reforms and spreads out within the valleys once again after sunset.

An air stagnation advisory remain in effect out to Tuesday next week, and the Freezing Fog Advisory has been extended through Friday morning, where low visibility and/or icy surfaces are likely to develop.

There are some signs that the ridge breaks down about midweek next week, but as in past years, these ridges have been known to be rather resilient, and tend to stick around longer than initially expected,. Confidence in a return to a wet pattern is low, but possible by this time next week.

AVIATION...15/18Z TAFs...LIFR ceilings and visibilities remain in the valleys due to dense fog and freezing fog this morning. Satellite shows some of this fog eroding and it should pick up this afternoon like it has the last few days. Therefore, we should see a brief period of VFR conditions before the fog rolls back in this evening.

The coast is clearer than anticipated near North Bend with near 100% relative humidity, although there must be enough wind to keep a fog bank from building in over that location. Farther south, the drier air is indeed mixing down to the surface with 15% relative humidity and clear skies around Curry County. One would expect some fog to build back into North Bend later tonight.

-Smith

MARINE...Updated 230 PM PST Thursday, January 15, 2026... Seas will remain hazardous to smaller crafts through this evening. Seas will gradually improve overnight with wave heights becoming relatively low during Friday. Sea heights drop to 3 to 5 feet during the day on Friday and even part of Saturday. High pressure remains in control into early next week. There is a chance of some active weather arriving by Thursday.

-Smith

MFR WATCHES/WARNINGS/ADVISORIES

OR...Freezing Fog Advisory until noon PST Friday for ORZ023-024-026.

Air Stagnation Advisory until 10 AM PST Tuesday for ORZ023-024- 026-029>031.

CA...Freezing Fog Advisory until noon PST Friday for CAZ080.

PACIFIC COASTAL WATERS...Small Craft Advisory until 10 PM PST this evening for PZZ350-370.

Small Craft Advisory until 10 PM PST this evening for PZZ376.