textproduct: Medford

Updated AVIATION and MARINE Discussions

AVIATION...09/06Z TAFs

A front remains aimed at the Oregon Coast just north of North Bend. This is bringing gusty winds to the coast and a variety of ceiling conditions across the region. Along the coast and just offshore, IFR and LIFR ceilings are expected to prevail through the TAF period, with visibility also lowering Tuesday morning as the front slowly sags south. VFR conditions generally prevail across the region, but LIFR conditions are developing in the Rogue/Illinois/Applegate Valleys, and these lower conditions will prevail into Tuesday morning. In the Umpqua Basin, the proximity of the front could limit fog development there, but MVFR conditions are still expected tonight into Tuesday morning.

Meanwhile, strong winds aloft will persist near the Cascades and over the east side in Oregon (north of Highway 140) tonight into Tuesday where higher terrain could experience gusts in excess of 50 mph. This could lead to some low-level wind shear over there (NE of Klamath Falls) since a low-level inversion probably doesn't allow these winds to mix all the way to the surface in some valleys. Even so, vertical mixing may improve Tuesday to allow surface wind gusts to 50 mph from around Summer Lake eastward.

MARINE...Updated 815 PM PST Monday, December 8, 2025

Gusty south winds and steep wind waves combined with westerly swell will maintain conditions hazardous to small craft through at least Tuesday. Winds subside, but west swell persists into Wednesday, especially north of Cape Blanco. Conditions improve for the latter half of the week as swell dominated seas gradually lower. Expecting showers over the waters through mid-week as well which could further reduce visibilities (fog/low clouds expected as well) over the next couple days.

PREV DISCUSSION

/Issued 335 PM PST Mon Dec 8 2025/

DISCUSSION...A strong upper ridge off the California coast this week will keep much of the moisture associated with a strong atmospheric river to our north. The frontal boundary associated with that moist plume will settle southward later tonight into Tuesday and this will bring increasing rain chances to NW sections of our forecast area and also the coast/coast ranges, but the impactful rainfall will largely stay to our north. In fact, many areas south of the Umpqua Divide and east of the Cascades won't see any rainfall from this system at all. As the front edges southward tonight through Tuesday evening, mid level winds will increase in NE portions of our area and this will bring occasionally gusty winds from the Cascades eastward in Oregon (primarily north of Highway 140). Limited vertical mixing could make it difficult for the winds to completely mix down to the surface, so the strongest winds will be over the higher terrain, but also possibly in some of the more typically channeled valleys (around Summer Lake). Please refer to our wind advisory for the details.

After the front briefly jogs southward, the upper ridge will re- strengthen at midweek and amplify as it heads into California and the West Coast late this week into the weekend. As such, moisture will shift well to our north and precip chances will diminish Wednesday to almost nil everywhere Thu-Sat. Overall, we're expecting yet another dry, mild period for this time of year, which isn't exactly a good thing since we're heading into (climatologically) our wettest time of the year and snowpack is pretty much non-existent. This pattern will probably bring more valley/basin low clouds/fog during the nights/mornings. Areas that remain clear will have cold mornings, but also milder afternoons. It's not out of the question that some of the climate sites in NorCal (Montague, Mount Shasta, Alturas) and perhaps even Klamath Falls challenge a mid-December record high or two late this week.

Beyond that, models show the upper ridge axis pushing east of the Cascades Saturday night with a Pacific frontal system approaching the coast and moving inland Sunday. Most ensemble members weaken this front as it moves onshore, so it remains to be seen just how much, if any precipitation it will bring. Will this be the system that opens the storm door for our area? While the CPC 8-14 day forecast gives hope for a wetter period next week (odds are shown to be 50-60% for above normal precip), model clusters and ensembles still show plenty of drier solutions within the membership and a tendency for upper ridging near or just off the California coast. If that ridge remains strong enough, this could keep the storm track to our north. -Spilde

MFR WATCHES/WARNINGS/ADVISORIES

OR...Wind Advisory until 10 PM PST Tuesday for ORZ030-031.

CA...None.

PACIFIC COASTAL WATERS...Small Craft Advisory until 1 AM PST Wednesday for PZZ356-376.

Small Craft Advisory until 10 AM PST Wednesday for PZZ350-370.