022
FXUS66 KMFR 030545
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
1045 PM PDT Thu Oct 2 2025

...Updated AVIATION discussion for 06Z TAFs...


&&

.DISCUSSION...Updated to add a freeze watch for the east side
Friday night and Saturday morning. Freezing and subfreezing
temperatures are possible for many areas east of the Cascades,
with cooler temperatures following on Saturday night and Sunday
morning.

&&

.AVIATION...03/06Z TAFs...Marine stratus has settled over the Oregon
coast, bringing IFR to LIFR ceilings and visibilities. This layer
looks to stay in place through late Friday morning or early in the
afternoon. Lower levels look to return to coastal areas towards the
end of the TAF period.

Area valleys and basins may see periods of MVFR ceilings early
Friday morning. Ceilings reaching the Medford terminal will depend
on clouds banking up against the southern end of the Rogue Valley.
Any inland ceilings look to clear out later Friday morning, with VFR
levels expected through the rest of the TAF period. -TAD


&&

.PREV DISCUSSION... /Issued 305 PM PDT Thu Oct 2 2025/

DISCUSSION...Three upper level features will be the drivers of
our weather through Tuesday, and forecast confidence is high
through that time. The first is an upper trough now over the
Pacific Northwest and northern California coast area. The second
is a much weaker trough late Friday night into Saturday night, and
the third will be a strong ridge building in from the west early
next week.

The broadest coverage of showers during the short and medium term
period will be early this evening, with accumulations mainly from
the Coast Range eastward. This includes a low end slight chance
of thunderstorms early this evening from Siskiyou County north and
northeast to the Cascades and Cascade foothills (including
Jackson, Klamath, and southern and eastern Douglas counties), with
the highest probability for northeast Douglas County.
Precipitation amounts overnight of up to a tenth of an inch should
be common, with local amounts to a quarter of an inch possible.
Meantime, low clouds and patchy fog are expected overnight at the
coast.

With the end of day-time heating, the risk of thunderstorms will
end later this evening. But, the trough will continue track across
our area. The lower levels of the air mass will moisten overnight
in a north to northwest flow aloft. This will favor light showers
late tonight into Friday morning southward and eastward from
southern Douglas County near the Umpqua Divide, and particularly
southward and eastward from southern Jackson County near Ashland.
The coast and most of Douglas County will just have low clouds to
contend with for Friday`s morning commute, though a 10%
probability mention for 0.01 inches of drizzly sprinkles for
Roseburg through around 9 AM on Friday does look appropriate. All
in all, a dreary start to the day for most of our area.

During Friday, the trough will track southeast into Nevada and the
shower activity will also shift in that direction. After the
morning commute, expect showers to be most numerous for Modoc and
southern Lake counties while sunny breaks in the clouds gradually
developing on the west side and northern portions of south
central Oregon.

For Friday night into Saturday, there is better model agreement
with a stronger depiction of a weak shortwave and associated
weakening cold front in the northwest flow behind the trough. This
has resulted in the need to introduce a slight chance to a chance
of light showers to Coos, Douglas, and northern Curry counties.
This disturbance looks to have a shallow pool of moisture to work
with the highest probability of meager, barely measureable
showers late Friday night until shortly after sunrise on Saturday.
Meantime, morning low clouds are expected in Josephine and Jackson
counties. Cloud cover will be more sparse on the east side and
lead to a chilly start to Saturday with lows in the upper 20s and
lower 30s expected. Douglas County is likely to have lifting but
persistent low cloud cover later Saturday, while other areas are
expected to see increasing sun in the afternoon.

Lower clouds return to southwest Oregon late Saturday night into
Sunday morning with a northerly flow between ridging far offshore
and the trough, which will be centered over the Rockies.

High pressure aloft will be the dominant feature with a warming
and drying trend Sunday at least into Tuesday, possibly into mid-
week. After a week of cooler temperatures, inland highs by Monday
will be slightly above normal. This also includes light easterly
winds with Brookings joining in the slightly above normal
temperatures for Monday and Tuesday.

Model uncertainty quickly increases for Wednesday with a majority
of GFS and ECMWF ensemble members holding on to a weakening ridge.
About 20% of ensemble members bring showers to the coast by
Wednesday night. As time progresses into next Thursday, the
probability of the next trough pushing out the ridge increases.
But, the track and strength of the trough are in question. The
probability of showers Thursday into Friday looks to be highest
for northern portions of our area.  -DW

MARINE...Updated 200 PM PDT Thursday, October 2, 2025...Steep
northwest swell will gradually subside tonight with light winds.
Winds become northerly on Friday and increase, but should remain
below advisory levels. A thermal trough will strengthen along the
coast Saturday with moderate to strong north winds expected Saturday
night through Sunday night, strongest south of Cape Blanco. Steep,
hazardous seas will develop as well. -Spilde

&&

.MFR WATCHES/WARNINGS/ADVISORIES...
OR...Freeze Watch from late Friday night through Saturday morning for
     ORZ029-031.

CA...Freeze Watch from late Friday night through Saturday morning for
     CAZ084-085.

PACIFIC COASTAL WATERS...Small Craft Advisory until 11 PM PDT this
     evening for PZZ350-356-370-376.

&&

$$