403
FXUS66 KMFR 040846
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
146 AM PDT Sun Oct 4 2026

.KEY MESSAGES...

* Night and morning low clouds and fog (patchy light drizzle) at
  the coast north of Cape Blanco, and locally from Gold Beach
  south this morning and again tonight/Monday morning.

* Inland high temperatures well above normal (10-20 degrees)
  through Thursday. Heat Risk is elevated for sensitive groups or
  those spending extended time outdoors without adequate
  cooling/hydration.

* Very warm and dry conditions bring elevated fire weather
  concerns due to near summer-like dryness. But, with weak winds,
  critical fire weather conditions are not expected.

* A weak upper level disturbance moves in Sunday night and early
  Monday morning with an increase of high clouds. For Modoc
  County...some virga along with a low chance (~5%) for showers
  and a very low chance (<5%) of thunderstorms.

* Late next week, Friday into Saturday, gusty SW->NW winds
  accompany a cold front with a 10-25% probability of rain
  showers. Temperatures trend sharply lower, getting back to near
  or perhaps even below normal values by Saturday.

&&

.DISCUSSION...A ridge of high pressure will remain over the area
through Thursday bringing well above normal temperatures (10 to 20
degrees above normal) to inland areas. Along the coast, cooler
temperations with periods of overnight/morning low clouds or fog
are expected, especially today and Monday.

With this ridge pattern in place, expect dry humidities for the
ridges during the nighttime periods through Thursday. Winds will
remain light though. During the day, low humidities in the teens
are expected in the afternoons, especially for areas from the
Casacades east and across northern California but also into
valleys in Josephine and Jackson counties. Winds  will be
generally light through Thursday. So, we are not expecting
critical fire weather conditions.

Heat and dryness are the main concerns this week. With the late-
summer like temperatures and dryness, dry grasses and leaves will
be present in many areas. Please be cautious if you`re planning
any activities that could create a spark. Additionally, the above
normal temperatures this weekend will bring elevated HeatRisk to
inland areas. HeatRisk is generally in the minor category, or
elevated for those sensitive to heat and without
cooling/hydration. If you are sensitive to heat or spending
extended time outdoors, take precautions. Seek shade and stay
hydrated. Overnight/morning temperatures are expected to lower in
the mid-50s for valleys west of the Cascades and in the 40s for
valleys east of the Cascades which will help moderate HeatRisk.

It is worth noting, the high pressure does weaken slightly
tonight and early Monday as a weak shortwave moves into Northern
California and another shortwave trough moves inland well to the
north. With the shortwave moving into Northern California, expect
some high clouds to move into the area this afternoon and tonight.
Model guidance continues to show a potential for virga with
isolated high based showers late tonight and early Monday morning
in Modoc. There is a very low chance (3-5%) for showers or
thunderstorms as well for Modoc. Otherwise, this will bring little
change and the high pressure strengthens again late Monday and
Tuesday then remains in place into Thursday.

By the end of the week and into next week, expect a change towards
cooler weather. Friday into next weekend, models are showing a
decided end to the hot pattern with virtually all ensemble members
showing a significant cooling trend, perhaps even sharply cooler
(by Saturday). A strong upper trough and cold front will move in
from the northwest. This could lead to a breezy to windy day
Friday, especially in Northern California and east of the
Cascades. A combination of strong winds/low RH could also result
in an elevated fire weather concern. Models are still showing
enough uncertainty in the timing and strength of the front, so
PoPs for rain remain fairly low (mostly in the 10-25% chance
range).

The majority of GFS and ECMWF ensembles keep moisture/energy from
Hurricane Rachel well to the south with only a few ensemble
members showing moisture edging into far southeast portions of
the CWA next weekend. While this scenario remains in the envelope
of possibility, the probability that this moisture/energy reaches
this far north is <5%. The vast majority of ensemble solutions
keep the system well to our south. But, it`ll be interesting to
watch over the coming days.

&&

.AVIATION (06Z TAFs)...

Low ceilings and visibility restrictions are still anticipated
along the coast resulting in LIFR/IFR conditions through much of
this cycle. Additionally, drizzle may be realized tonight into
Sunday morning. Expecting periods of relief through the afternoon
which could bring VFR to KOTH at times. For inland TAFs, expecting
mostly clear skies combined with light wind speeds through much of
this cycle.

-Guerrero


&&

.MARINE...Updated 130 AM PDT Sunday, October 4, 2026...A
persisting thermal trough will bring gusty northerly winds and
steep seas for much of the week ahead. Winds have trended ligher
tonight into early Sunday morning. This will bring below advisory
seas to inner waters while outer waters remain steep. The thermal
trough strengthens Monday, bringing more widespread gusty winds
and steep seas to all waters.

Fluctuations in the thermal trough`s strength and position may bring
changes to where steep seas are through the week, but there is an
agreement in guidance that some amount of steep seas will be present
through at least Thursday. A pattern change may bring active
weather towards the end of the week, with some guidance also
showing incoming long period westerly swell arriving at some point
over the weekend. Confidence is not high enough in theses
outcomes to predict the sea state, but as this is the first signs
of possibly meaningful long-period swell for the season,
acknowledging it is worthwhile.



&&

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

PACIFIC COASTAL WATERS...Small Craft Advisory from 11 PM this evening
     to 11 PM PDT Monday for PZZ350-356.

Small Craft Advisory until 2 AM PDT early this morning for
     PZZ350-356.

     Small Craft Advisory until 11 PM PDT Monday for PZZ370-376.

&&

$$