465
FXUS66 KMFR 171646
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
846 AM PST Mon Nov 17 2025

.DISCUSSION...Rain showers continue across the area this morning.
Southerly flow will focus activity over southern Siskiyou County,
where road cams are showing lower visibilities at Siskiyou Summit.
Other areas of west side terrain may see moderate to heavy showers
as well. While there are no official hazards out, lower
visibilities and slick roads may complicate travel conditions and
extra caution is encouraged. Activity looks to ease in the
afternoon and evening ahead of an uneventful Tuesday.

Please see the previous discussion for more details on the short-
and long-term forecast. -TAD


&&

AVIATION (12Z TAFs)...

A passing trough will bring light rainfall through this afternoon
before we start to see diminishing trends this evening. Low level
saturation will lead to MVFR conditions at times, but VFR should
be more dominate through this cycle. Tonight could be a tricky
forecast as we see split flow develop, but generally speaking
expecting VFR conditions to dominate through this cycle.

-Guerrero

&&

.MARINE...Updated 800 AM PST Monday, November 17, 2025...West-
northwest swell of 10 to 11 feet at 12 seconds will combine with
wind seas today and bring steep to very steep seas, highest from
Cape Arago south.  North winds will peak this morning and early this
afternoon around 20-30 kts sustained with occasional gusts near 40
kts. Winds will gradually trend lower late today into tonight.
Combined seas will peak at 12-16 feet today, then gradually lower
late this afternoon and this evening. However, seas will still be
hazardous to smaller craft for all the waters tonight, and into
Tuesday for the waters south of Cape Blanco.

Conditions improve Tuesday night into Wednesday, then another
frontal system is expected late Wednesday into Thursday. However,
confidence is low on the trajectory of the next storm system. Some
guidance brings the system inland, while other guidance keeps it
farther offshore as it moves southward and these differences will
have implications on how strong winds will be. Despite the
uncertainty in wind strength, confidence is higher for a heavy long
period swell to build into the waters Thursday night into Friday.

&&

.PREV DISCUSSION... /Issued 252 AM PST Mon Nov 17 2025/

DISCUSSION...

Key Points:

* Overall, little to minimal impacts expected this week
* Light rainfall will continue today/tonight
* Light snowfall at higher elevations continues today/tonight
* Next round of light precipitation Wed through Thurs
* Lingering precipitation continues through end of week for
  coastal areas and Umpqua Basin

Further Details:

Precipitation will continue through today as a split flow pattern
develops. A cut-off low will split from the southern edge of a
passing through, and this will allow for lingering precipitation
through this evening mainly for northern California as this cut-off
low slowly meanders south/southeast through tonight. We will see a
brief break in activity tomorrow before another weak embedded
shortwave passes within the chaotic pattern. This will lead to
additional light precipitation, including light snowfall amounts for
higher elevations like the Cascades and western Siskiyou County.
Then a stronger low/shortwave will develop Wednesday afternoon, and
pass through the region on Thursday as a cut-off low as it splits
from the mean flow. This could bring another punch in regards to
precipitation amounts. Rainfall along and near the coast will be on
the order of 0.50"-1.00" through 24-36 hours Wednesday
afternoon/evening through Thursday. Through this stretch a couple
inches of snowfall could fall around Crater Lake and associated
elevations. Higher amounts possible for Mt Shasta. Not expecting any
impacts across these areas as amounts will be too low for areas that
are inhabited/traveled. Also not seeing any wind threats through
this stretch.

Perhaps the biggest impact these week could be frost/freeze
potential Wednesday morning for westside areas. However, uncertainty
does exist as fog could limit radiational cooling and hence low
temperatures may not be cold enough for some areas/elevations. On
the other hand, the low level moisture could bring a higher risk for
frost formation if we are allowed to maximize radiational cooling
overnight. At this time, not expecting widespread frost/freeze to
come to fruition, but will continue to monitor this threat,
especially isolated areas. Some elevations will have a greater risk,
but valley floors like Medford have a greater risk for fog and hence
limited frost/freeze.

-Guerrero

&&

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

PACIFIC COASTAL WATERS...Small Craft Advisory until 10 AM PST
     Wednesday for PZZ356.

Small Craft Advisory until 4 AM PST Tuesday for PZZ350-370.

     Hazardous Seas Warning until 4 PM PST this afternoon for PZZ350-
     356-370-376.

     Small Craft Advisory from 4 PM this afternoon to 10 AM PST
     Wednesday for PZZ376.

&&

$$