FXUS66 KMFR 121046

AFDMFR



Area Forecast Discussion

National Weather Service Medford OR

246 AM PST Fri Dec 12 2025



.DISCUSSION...Satellite imagery early this morning shows some

spotty mid to high level clouds passing over the area, while

nearly all of the valleys west of the Cascades remain filled with

either fog or low stratus clouds as strong inversions persist. 



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. 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. The NBM is bringing rain into the coast as

early as Saturday night. This is too soon, especially considering

that all ensemble members are dry through Sunday night, so have 

backed off on the rain forecast until a more robust front arrives 

late Sunday into Monday. 



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

fronts moving through the area from Monday-Friday next week 

bringing more rain, mountain 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 next week as the overall pattern changes.

-BPN/Petrucelli





&&



.AVIATION...12/12z 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. These conditions will persist through Friday 

morning and some areas, such as Medford, are expected to see 

MVFR/IFR 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. Low flight conditions are likely to return, or will persist, 

for these areas tonight.  East of the Cascades, expect mainly VFR 

through the TAF period. -BPN



&&



.MARINE...Updated 200 AM PST Friday, December 12, 2025...Light to 

moderate north winds and moderate west swell will persist 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/BPN



&&



.MFR WATCHES/WARNINGS/ADVISORIES...

OR...None.



CA...Dense Fog Advisory until 9 AM PST this morning for CAZ081. 



PACIFIC COASTAL WATERS...None.



&&



$$