465
FXUS66 KMFR 300548
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
1048 PM PDT Sat Aug 29 2026

.Aviation discussion updated...

&&

.AVIATION...30/06Z TAFs...VFR prevails across the area. Onshore flow
may bring periods of MVFR/IFR ceilings to coastal areas, with a
slight chance of some isolated low ceilings reaching into the Umpqua
Valley near sunrise. These ceilings look to clear by midday. VFR
will otherwise prevail, with gusty afternoon winds along the coast.
-BPN


&&

.PREV DISCUSSION... /Issued 300 PM PDT Sat Aug 29 2026/

KEY MESSAGES...

* Typical summer weather is expected today and Sunday.

* Gusty southerly winds are bringing elevated fire weather
  concerns for the Scott and Shasta valleys and areas east of the
  Cascades on Monday. Winds ease on Tuesday, but warm temperatures
  continue.

* A cold front looks to bring cool temperatures across the area.
  Rainfall is expected west of the Cascades, with lower chances
  just east the Cascades. Precipitation chances decrease into
  Thursday and beyond.

DISCUSSION...A trough around a cutoff low is helping to bring
slightly cooler temperatures across the area today, as well as
elevated afternoon breezes. This trough is bringing some partial
cloud cover into Coos and Douglas counties, but rainfall is not
expected. The trough will move eastward into Sunday, bringing
typical summer conditions.

Temperatures look to rise a few more degrees on Monday, which looks
to be the warmest day of the forecast period. An approaching
shortwave trough is expected to bring elevated winds in the
afternoon and evening. These winds overlap with ongoing dry
conditions, bringing fire weather concerns. These concerns are
especially high in the Scott and Shasta valleys as well as across
broad areas east of the Cascades. A Fire Weather Watch has been
issued for these areas on Monday afternoon and evening to highlight
the chance of critical fire weather conditions.

With the shortwave trough drawing closer on Tuesday, daytime highs
are forecast to drop 5 to 10 degrees for inland areas. Elevated
afternoon breezes are expected again, but improving humidities and
lower wind speeds reduce fire weather concerns from Monday. Model
guidance is showing some chances for isolated thunderstorms, mostly
along the Cascades and into western Siskiyou County. However,
atmospheric moisture looks patchy and current CAPE values are
unimpressive (100-200 J/Kg). This keeps thunderstorm chances low (5-
15%), but the possibility is worth watching.

A pattern change is expected on Wednesday, with a wet cold front
following that shortwave trough. Daytime highs could be 10 to 15
degrees below seasonal norms on Wednesday and Thursday. Rainfall is
most likely on Wednesday, with west side areas having 70-90% chances
in the afternoon into early Thursday morning. These chances drop
east of the Cascades, with Klamath Falls having 60% chances of
measurable rainfall on Wednesday night while 30-50% chances get into
Lake and western Modoc counties. For Wednesday morning into Thursday
morning, Curry County could see 1.5 to 2 inches of rainfall. Coos
and northern Douglas County are forecast to see about an inch of
rain. The Illinois and Umpqua valleys

The details for Thursday and beyond lose some clarity. An upper
trough around a low pressure system lingers over the area, which is
what will keep temperatures cool on Thursday. In general,
precipitation looks to continue on Thursday, but at lower chances
(20-40%) and lighter amounts. Modeled "wobbling" in the system is
keeping those slight chances spread across the area, making a more
exact forecast difficult. Similarly, lingering slight precipitation
chances on Friday and Saturday depend on the behavior of that low. A
drier pattern may be in place to start the following week. -TAD

&&

MARINE...Updated 300 PM PDT Saturday, August 29, 2026...North winds
are increasing, with steep seas south of Port Orford. These steep
seas and gusty winds will persist through the weekend, with steep
seas extending into the waters north of Cape Blanco from late Sunday
morning into Monday morning. Winds will be strongest each afternoon
and early evening through Sunday. Conditions are likely to improve
Monday into Tuesday. A pattern change looks to bring marine showers,
gusty winds, and westerly swell for Wednesday and Thursday. Some
amount of unsettled seas is expected, but additional guidance will
help to determine the timing and areas of any needed hazard
products. -TAD

&&

FIRE WEATHER...Updated 200 PM PDT Saturday, August 29, 2026...

Gusty winds and dry humidities near critical levels will continue
east of the Cascades early this evening. Sunday will be a relative
lull in activity as a ridge briefly builds in with warmer
temperatures and lower minimum humidities, but much weaker winds. As
a trough approaches from the west, conditions are then likely to
reach critical levels Monday in the Scott and Shasta valleys and
east of the Cascades due to gusty winds and dry humidities.

A trough dominated pattern will follow for the remainder of the
week. Winds will be gusty again on Tuesday and Wednesday, but with
humidities trending higher and the start of a cooling trend. On
Tuesday into Saturday, there is a good chance for periods of rain,
especially on the west side with a focus on Wednesday and
Thursday.

&&

.MFR WATCHES/WARNINGS/ADVISORIES...
OR...Fire Weather Watch from Monday afternoon through Monday evening
     for ORZ624.

CA...Fire Weather Watch from Monday afternoon through Monday evening
     for CAZ280-281-284-285.

PACIFIC COASTAL WATERS...Small Craft Advisory until 5 AM PDT Monday
     for PZZ356-376.

     Small Craft Advisory from 11 AM Sunday to 5 AM PDT Monday for
     PZZ350-370.

&&

$$