textproduct: Medford

UPDATE

Aviation Discussion updated.

AVIATION...12/06z TAFs

Much like yesterday, strong high pressure is in control and low level moisture is persisting in valleys. Areas of low stratus and fog are present in valleys west of the Cascades, including IFR in the Rogue Valley at Medford and Grants Pass and LIFR in fog in the Shasta Valley as well as patchy fog in the Umpqua and Coquille valleys. Overnight, expect ceilings and visibilities to lower in the Rogue Valley, down to LIFR conditions. Elsewhere in valleys west of the Cascades, expect LIFR/IFR conditions to become widespread. These conditions will persist through Friday morning and for some areas, such as Medford, are expected to see low clouds into the afternoon on Friday. Along the coast, areas of fog with IFR/LIFR are present (including at North Bend). These conditions will persist into Friday morning, before lifting to VFR. East of the Cascades, expect mainly VFR through the TAF period.

PREV DISCUSSION

/Issued 439 PM PST Thu Dec 11 2025/

MARINE...Updated 100 PM PST Thursday, December 11, 2025...Long period WNW swell is causing seas about 8-10 feet currently, but conditions should improve the rest of this afternoon into Saturday as high pressure builds and seas subside. Mostly light to moderate north winds can be expected tonight through Friday night. Gradually, winds shift to southerly Saturday and increase into Sunday, but still probably remain below small craft advisory levels.

Low pressure then deepens over the north Pacific and a cold front will swing through the waters Sunday night into Monday. This will bring a high probability of gales (>70%) and a period of steep to very steep hazardous seas. A series of frontal systems is likely to keep the weather active with elevated winds and seas much of next week. -Spilde

PREV DISCUSSION... /Issued 226 PM PST Thu Dec 11 2025/

DISCUSSION...Satellite image shows low clouds persisting in the Rogue, Illinois, and Shasta Valleys. Low clouds are gradually burning off in the Klamath River and Scott Valleys and the Umpqua Basin. Elsewhere it's clear and will remain clear through this evening. It's possible it will remain socked in the Rogue and Illinois Valley through the afternoon and tonight. What this will do it limit or even prevent fog from forming in these areas later tonight. However low clouds and fog are likely again in the valleys in Douglas county, Scott, Klamath River, and Shasta Valley late this evening through Friday morning.

The overall pattern is not going to change much through Saturday with strong upper ridging keeping the storm track well north of the forecast area. This means continued dry and mild weather (where low clouds and fog are absent). The low clouds and fog for the areas mentioned above will keep afternoon temperatures in check Friday and Saturday and they have been adjusted lower to reflect this. It's not out of the question low clouds in the Rogue and Illinois Valley will persist through Friday afternoon as well.

The upper ridge will weaken slightly as a weak front moves in from the west Sunday. given the weak shortwave and surface front will be running into the stronger upper ridging, the most likely scenario is the front will weaken and dissipate as it reaches the coast Sunday afternoon. Per the usual the NBM solution is too bullish (meaning pops are too high and too far inland) which does not add up given the above mentioned. To further support this thinking, the majority of the individual ensemble members also show the front weakening and dissipating as it reaches the coast and inland.

Basically Sunday is likely to end up being the last quiet day of the forecast period. The operational models and ensembles have been showing for the past few days a more active pattern setting up by the start of next week. In a relative sense, it will seem like a significant change with bouts of moderate to heavy rain and mountain snow along with moderate to strong winds possible at the coast, and east of the Cascades on Monday. However, it's not all that unusual to have active weather of this magnitude this time of the year.

The change in the pattern is one where we'll see a parade of front moving through the area from Monday-Friday next week bringing more rain, mountains snow and moderate to occasionally strong winds.

The main issue will be the timing of each individual system which is likely to vary in the days to come.

Looking beyond next week leading up to Christmas Holiday, there's increasing evidence that's being supported by the ECMWF, GEFS ensemble means and clusters, we'll be heading into a colder and wet pattern with storms originating from the Gulf of Alaska. These typically result in colder temperatures, and precipitation with lower snow levels. The pattern shows below normal 500 mb anomalies with a stronger upper troughing in the western U.S. with ridging and above normal 500 mb anomalies in the northeastern part of the U.S. the anomalies being shown are pretty significant this far out which is unusual since they tend to "wash out" and lean more towards climatology.

This is a almost the opposite of the pattern we have experienced the last couple of weeks. In other words, the switch basically gets flipped as the overall pattern changes. -Petrucelli

MFR WATCHES/WARNINGS/ADVISORIES

OR...None.

CA...Dense Fog Advisory until 9 AM PST Friday for CAZ081.

PACIFIC COASTAL WATERS...None.