722
FXUS66 KMFR 210548
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
948 PM PST Thu Nov 20 2025

.Updated AVIATION Discussion...

&&

.AVIATION...21/06z TAFs...Generally VFR conditions prevail across
the region this evening with some areas of low end VFR ceilings in
the Umpqua Basin and eastern Modoc/Lake Counties. Areas of LIFR
conditions are impacting the Coquille Basin, including North Bend,
but conditions should improve to VFR tonight as offshore flow kicks
in. Clear skies are expected overnight, providing for prime
conditions for fog and low clouds to develop in valleys tonight,
including in the Klamath Basin. With offshore flow in place, there
is some uncertainty regarding the extent of LIFR conditions as
breezy winds could limit fog development. Despite this uncertainty,
decided to keep the LIFR conditions in the forecast for inland TAF
locations. Any lower conditions should improve by late Friday
morning. /BR-y

&&

.PREV DISCUSSION... /Issued 816 PM PST Thu Nov 20 2025/

Update MARINE and BEACH HAZARDS Discussions...

MARINE...Updated 800 PM PST Thursday, November 20, 2025...Heavy
long period swell is impacting the waters this evening, resulting in
high and steep seas for all areas. Seas could occasionally become
very steep and hazardous through the overnight hours, but are
generally reaching a peak this evening in the 16 to 18 ft range at
14 to 16 seconds. Seas gradually lower some by Friday afternoon, but
another long period, but lower, northwest swell arrives late Friday
into Saturday. This will maintain steep seas into the weekend and
likely into early next week.

Meanwhile, gusty north winds will approach advisory criteria south
of Cape Blanco through Saturday morning. Winds turn southerly on
Sunday ahead of weak front, but should remain below advisory
criteria. Overall improving conditions are expected around mid-week
next week. /BR-y

BEACH HAZARDS/HIGH SURF...Updated 800 PM PST Thursday, November
20, 2025...Heavy, long period swell of 16 to 18 ft at 14 to 16
seconds is resulting in hazardous beach conditions this evening that
will continue overnight. Large breaking waves of 20 to 25 ft will
maintain hazardous conditions along and within the surf zone, and
could inundate beaches and low lying shorelines. Beach erosion is
possible, and exposed infrastructure may be damaged. Conditions
improve early Saturday, but breaking wave heights of 15 to 20 ft
will continue through the weekend as another long period swell moves
into the waters on Saturday. Stay away from the surf zone and off of
jetties. NEVER turn your back on the ocean!

PREV DISCUSSION... /Issued 232 PM PST Thu Nov 20 2025/

DISCUSSION...Satellite image shows instability clouds along with a
few isolated showers over Curry County. Any showers will end late
this afternoon.

The upper low will move south into California tonight with dry
weather likely. However, low level moisture from Wednesday night and
Thursday morning precipitation will be high, which could lead to
favorable conditions for low clouds and fog formation for the
interior west side valleys, and east side valleys later tonight and
probably lasting through most, if not all of Friday morning.

Friday through Saturday is likely to be dry as upper ridging nudges
in from the west as the cutoff low moves towards southern
California. The upper flow will likely remain westerly with the
ridge remaining over the area Saturday. This will likely keep the
storm track farther north, this keeping our area dry.

As mentioned in the morning update, the previous operational models
and ensembles runs were suggesting an earlier arrival of
precipitation. The latest run continues to show this along with some
of the higher res models showing evidence of this towards the end of
the model period. This is a change from the last few days.

The general consensus is for the front to move into the northwest
part of the forecast area late Sunday morning, then move southeast
Sunday afternoon. So while the timing of the front is now sooner,
the amount of moisture has not varied that much. Most of the
precipitation will be Sunday afternoon, then the front is expected
to weaken as it moves southeast Sunday evening and night. This will
keep rainfall amounts in check, even for the more favorable areas.

The front will weaken further as it as it moves through the area
Monday morning, and it`s possible it could dry out Monday afternoon.

A cooler and drier airmass will follow Monday night and could
possibly last into the peak travel day for the Thanksgiving Holiday
weekend. However, the peak holiday travel day (next Wednesday) could
be a bit of grey area with some of the operational models and
ensemble members suggesting there will be precipitation Wednesday
afternoon and night. So far it looks like snow levels will be high
enough to keep snow concerns limited to the higher passes, but the I-
5 corridor at Siskiyou Summit should be okay. However, it`s a ways
out and details could change in the coming days, so stay tuned for
updates. -Petrucelli

&&

.MFR WATCHES/WARNINGS/ADVISORIES...
OR...High Surf Advisory until 4 AM PST Friday for ORZ021-022.

CA...None.

PACIFIC COASTAL WATERS...Small Craft Advisory until 10 PM PST
     Saturday for PZZ350-356-370-376.

&&

$$