683
FXUS66 KMFR 132352
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
452 PM PDT Mon Oct 13 2025

...Updated AVIATION discussion for 00Z TAFs...

.DISCUSSION...Low pressure continues to move southward just
offshore this afternoon, maintaining precipitation across the
region, with even a few lightning strikes in Modoc County. Snow
levels have risen, and area webcams now show wet roads for the
Cascade Passes, so wintry travel is less of a concern compared to
this morning. Steady rainfall has been ongoing across portions of
Jackson/Josephine/Siskiyou Counties since early this morning, but
the trajectory is now shifting to more southeast to northwest as
this low pressure continues southward. So far, under the steadier
precipitation today, observations show between 0.30"-0.50" since
this morning with more widespread amounts up to 0.75" across
portions of Jackson County including here at the Medford Airport
where we`ve received 0.76" since midnight. Given that
precipitation is shifting westward, it`s not likely that we`ll
break the record rainfall for the date (1.33" set in 2016), but
the current amount does set 2025 solidly in place for the 2nd
wettest daily rainfall total for October 13th; prior 2nd place
total was 0.47" set in 1980.

Ongoing precipitation will gradually lighten/taper off as the
afternoon progresses with the highest precipitation chances shifting
south of the OR/CA border by this evening and then really
diminishing for most areas overnight. Additionally, as the flow
transitions, gusty east to northeast winds are expected across the
Cascades and other north/south oriented terrain this evening and
overnight. Wrap around moisture combined with this east to
northeasterly flow could result in some isolated showers east of the
Cascades late tonight into early Tuesday morning. As low pressure
pulls eastward, wraparound moisture could maintain additional shower
activity across southern Lake and Modoc counties Tuesday afternoon
and overnight. For the most of the region, however, expect drier
conditions tonight and likely through the remainder of the week.

Cloud cover will linger tonight, with the greatest coverage east of
the Cascades. Drier air moving in behind this trough will result in
less cloud coverage west of the Cascades, but with all this recent
rain, it`s very likely that fog/low clouds will develop in West Side
Valleys. Despite a cloudy start on Tuesday, expect to see some sun
for areas west of the Cascades, but less so east of the Cascades.
This cloud cover will limit how cold low temperatures get tonight
and again Tuesday night. As high pressure nudges in and northerly
flow sets in on Wednesday, expect more widespread clearing of skies
for Wednesday night, and this is when temperatures will drop for
areas east of the Cascades (mid-upper 20s) and across northern
California (low to mid 30s). We`ll keep an eye on this for any
potential for frost/freeze in northern California. Guidance does
show the potential for some low temperatures to near frost
thresholds in the colder portions of the Rogue/Illinois/Applegate
Valleys Tuesday night and again Wednesday night, but this is greatly
depend on the extent of any lingering cloud cover those nights and
whether or not low clouds develop instead.

Otherwise, quiet weather is in store for much of the week with
afternoon highs staying on the cool side and hovering around 5
degrees below normal (upper 60s for the West Side/upper 50s across
the East Side). Temperatures trend slightly warmer on Friday and
even more so on Saturday as high pressure moves over the Pacific
Northwest. Active weather returns late in the weekend with models
and ensemble guidance in rather good agreement on the next system
arriving at the coast late Saturday night/early Sunday morning.
/BR-y


&&

.AVIATION...14/00Z TAFs...A low pressure system has moved just south
of the Oregon/California border. While cloud cover remains in many
areas, ceilings are generally staying at VFR or MVFR levels.
Circulation around the low is bringing showers across areas east of
Cascades. These showers are moving eastward and generally breaking
up as they hit the Cascades. Activity will continue to ease from
north to south as the low drifts farther south through the night.
While some lightning strikes were observed earlier today, convective
activity seems to have eased.

Lingering surface moisture is supporting fog remaining in the TAFs
for inland terminals, although with only slight to moderate
confidence. Lingering cloud cover over Roseburg and Medford as well
as continuing breezes at Klamath Falls could affect the chances of
stratus or fog developing. Anything that does develop overnight or
early Tuesday morning should clear up before Tuesday afternoon. -TAD

&&

.MARINE...Updated 200 PM PDT Monday, October 13, 2025...Low pressure
will move south of the area tonight and showers will end, but seas
will remain steep to very steep into Tuesday, highest over the outer
waters. Lighter winds and lower seas should return Wednesday into
Thursday morning. North winds increase Thursday afternoon into
Friday with possible small craft advisory level conditions again
south of Cape Blanco. Long period swell could arrive Friday.
-Spilde

&&

.BEACH HAZARDS...Updated 200 PM PDT Monday, October 13, 2025...We`re
heading into the time of year where distant storms generate swells
with long periods. These long-period swells harbor more energy than
a typical set of waves and have the ability to run up much farther
on the beaches. Model guidance is showing a long-period swell (6-8
ft at ~17-19 seconds) arriving later this week, probably sometime
Friday and lasting into Saturday before decaying. This could pose a
threat for sneaker waves at area beaches. We call them "sneaker
waves" because they aren`t particularly large or even high waves,
but because they exhibit such high energy, they can suddenly wash
over rocks, logs and jetties without much warning. We`ll be
evaluating this potential and a beach hazards statement may be
necessary at some point. -Spilde

&&

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

PACIFIC COASTAL WATERS...Small Craft Advisory until 5 PM PDT Tuesday
     for PZZ350-356-370-376.

Hazardous Seas Warning until 5 PM PDT Tuesday for PZZ370-376.

&&

$$

MNF/MAS