537
FXUS66 KMFR 112105
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
205 PM PDT Sat Oct 11 2025

.DISCUSSION...The upper level low has opened up and passed
overhead, and is now moving to the east. An impulse dropping down
on the back side of the tough, along with persistent onshore flow
in the low levels, is producing some light shower activity across
the region this afternoon. Most of these showers are currently
resulting from some upslope flow along the western slopes of the
Cascades and the north slopes of the Siskiyous. Most of the
activity will stay along and west of the Cascades through tonight,
but some showers could make it to the East Side at times.

The next system arrives Sunday into Monday as a trough digs south
along the Pacific Northwest coast from British Columbia, then
turns back into the California coast near San Francisco Monday
night into Tuesday morning. Precipitation intensity will pick up
again along the coast and into the Umpqua Basin Sunday, then
spread to the rest of the area Sunday night into Monday morning,
before tapering off Monday afternoon. Guidance shows a band of
heavier precipitation forming up somewhere between the coast and
the Cascades Monday morning, but the exact location varies
depending on the track of the low across the various models. Areas
outside the band will see lighter rain totals, but another round
of wetting rains is expected for all of the forecast area.

Much of the area will dry out on the back side of the low
Tuesday, but precipitation chances will linger over Siskiyou and
Modoc counties, as well as far southern Klamath and Lake counties
through Tuesday afternoon and early Wednesday as the circulation
around the low pumps more moisture into those regions. Areas to
the west of the Cascades are likely to remain dry, as the east
winds produce downsloping effects from the Cascades.

Throughout this time, temperatures will remain below normal for
this time of year, and snow levels will lower from roughly 6000
ft this afternoon to about 5000 ft tonight, then after a brief
rise through the day Saturday, will lower to 5000 ft again
Saturday night. The same cycle repeats yet again Sunday into
Sunday night. This will be the lowest snow levels so far this
season, and will result in snow over the area peaks and our
higher mountain passes. However, as this is expected during
periods of more showery precipitation, and the ground remains
somewhat warm, accumulations of only a couple of inches is
forecast with little in the way of travel impacts. Higher
elevations, such as Crater Lake National Park rim drive at over
7000 feet, will see heavier snows of up to a foot total through
Monday evening, but are much more likely to stay at or below 6
inches. Otherwise, only a dusting to an inch of snow is expected
for the higher terrain of the East Side.

This low will finally push off to the east Wednesday, and upper
level ridging will attempt to build into the area from the west,
drying things out and allowing for some more seasonable
temperatures.

Models still diverge quite a bit for the latter half of the week,
but are overall trending drier and warmer, aside from some
sporadic shower chances as weak shortwaves attempt to push in on
the ridge overhead. Most guidance keeps the seasonable
temperatures and dry conditions in place until a larger trough
and associated surface front potentially arrive late in the
weekend. -BPN


&&

.AVIATION...11/18Z TAFs...The forecast area remains in broad
cyclonic flow aloft. The lower ceilings that formed in some areas
last night into early this morning are gradually lifting and expect
most areas to become VFR this afternoon and evening. Even so,
scattered showers remain and this could briefly result in lower MVFR
ceilings and/or terrain obscurations, especially for areas along and
west of the Cascades.

Tonight, a weak upper trough will move through this evening with
additional mostly west side showers, but clearing and stabilization
could occur in the low-levels behind these showers overnight. As
such, some lower conditions could redevelop. We`ve indicated local
IFR ceilings in some of the TAF locations (Roseburg and Klamath
Falls) that had it this morning and hinted at the possibility again
here in Medford. One thing going against it happening at KMFR is the
likelihood of a longer lasting higher ceiling, which would prevent
the low-level stabilization needed for IFR. As it stands, there`s
about a 30% chance of IFR, so we`ve shown SCT006 in the TAF and
we`ll continue to monitor and amend as necessary. Any lower
conditions Sunday morning should lift to VFR by early afternoon.

The next strong upper trough will bring widespread rain showers
along the coast, to the Umpqua Basin and the Cascades Sunday
afternoon along with lowering ceilings and terrain obscuration.
These conditions will spread SE across the area Sunday night. -Spilde


&&

.MARINE...Updated 200 PM PDT Saturday, October 11, 2025...Low
pressure will push inland tonight, though onshore flow will maintain
a few showers through this evening. Northwesterly swell will
continue to build into the waters tonight and will be steep enough
to bring small craft advisory conditions across the northern waters
and also beyond 10 NM from shore south of Cape Blanco.

Another low pressure system will move in late Sunday and last into
Monday evening. Similar to the last low, this one will bring
widespread showers and a chance of thunderstorms. We expect stronger
north winds to accompany this system, which will maintain steep
seas, especially over the outer waters through Tuesday. Lighter
winds and lower seas should return on Wednesday. -Spilde


&&

.MFR WATCHES/WARNINGS/ADVISORIES...
OR...None.

CA...None.

PACIFIC COASTAL WATERS...Small Craft Advisory from 11 PM this evening
     to 11 PM PDT Sunday for PZZ350-370-376.

&&

$$