932
FXUS66 KMFR 101312
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
612 AM PDT Mon Aug 10 2026

.KEY MESSAGES...

* Elevated Fire Weather Concerns continue through Wednesday due to
  hot, dry, and breezy conditions. Gradual, very slight
  improvement day-to-day while temperatures remain above normal,
  humidities drier than normal, and afternoon/evening breezes
  slightly stronger than normal. More seasonable conditions follow
  late in the week.

* Periods of smoke accumulation, especially for the morning
  hours, over Klamath, Lake, eastern Siskiyou, and Modoc counties.

* Afternoon thunderstorm chances remain in the forecast for
  Thursday through Sunday, and appear overall as a slight chance
  for portions of the area each day. But, with low confidence for
  now in where activity will be focused.

* Patchy low clouds and fog in The Coquille Valley this morning,
  with slightly greater coverage expected north of Cape Blanco
  overnight into Tuesday morning, then extending into portions of
  Umpqua Valley (to include patches near Roseburg) on Wednesday
  and Thursday mornings. Stratus is likely to cover more of the
  Coast during early mornings late in the week.

&&

.DISCUSSION...Confidence is high in the forecast through
Wednesday, and still reasonably high through Thursday. In the
short term, a weak trough over the Pacific Northwest into far
northern California will sharpen at mid-week. The result is a dry
air mass with a west-southwest flow aloft and a trend of very
slightly and very gradually improving (cooler, more humid)
conditions. Meantime, afternoon breezes will show the least
improvement...remaining slightly stronger than normal each day.
Gusty winds will be north to northwest for most of our area,
except southwest to west in Modoc County into southern Lake
County.

In spite of the elevated breezes, smoke will remain trapped in
some low-lying areas. With westerly to southwesterly flow aloft
and decreased fire activity, additional smoke reaching west side
valleys is not expected. But, light winds overnight look to allow
for periods of mainly night and morning smoke accumulation over
Klamath, Lake, eastern Siskiyou, and Modoc counties.

Weak instability could allow a thunderstorm to push into far
southeast Modoc County on Wednesday afternoon. Thereafter, late
in the week, the pattern will shift to a deeper trough. There is
an important, wide range of solutions in how it will evolve while
a stronger trough shifts southeast from near the Aleutian Islands.
This trough may become the driver of, or at least a more
significant contributor to our weather early next week. A sharper
trough, with a more southerly component to the flow aloft is
expected to allow an influx of mid-level moisture and the
development of instability. This looks most likely to be a modest
producer of lightning, although with a few days in a row with some
activity in our area, and a potential for at least one of those
days to have thunderstorm activity on both the west side and the
east side. This is most likely to start on Thursday with a slight
chance of thunderstorms (around 15%) for the Warner Mountains in
far eastern Modoc County into Lake County, with a lesser
probability of around 10% also for Siskiyou County into Klamath
County. Any of Thursday, Friday, Saturday, or Sunday could take
the prize as our most active thunderstorm day of this stretch,
though there is still a general trend to shift the region of
instability northward, into northern Oregon, for Sunday.

&&

.AVIATION...10/12Z TAFs...Smoke will be concentrated south and east
of the Wright`s Spring Wildfire, across southern portions of Klamath
and Lake counties, eastern Siskiyou County, and Modoc County. This
includes a potential for MVFR ceilings and visibility reductions at
Klamath Falls this morning. Meantime, smoke is not expected to be as
concentrated at Lakeview and Alturas.

Also, coverage of patchy IFR in marine stratus in the Coquille
Valley will be at a maximum around 13Z this morning, possibly
extending to North Bend through around 15Z. Strong, north wind gusts
up to 35 kt will occur along the coast, including at North Bend,
this afternoon and evening. Areas of IFR are likely north of Cape
Blanco later this evening into early Tuesday morning.

Otherwise, expect VFR conditions with locally breezy winds this
afternoon and evening (gusts of around 20 kt).

&&

.MARINE...Updated 230 AM PDT Monday, August 10, 2026...Gusty north
winds will continue through Wednesday evening, with gales and very
steep seas south of Port Orford and within 40 nm of shore.
Elsewhere, steep seas are expected. Winds will begin to ease
Thursday, and diminish more noticeably on Friday into the weekend.
But, steep seas are likely to linger into Friday.

&&

.FIRE WEATHER...Updated 200 AM PDT Monday, August 10, 2026...The
outlook has changed little from yesterday afternoon. Perhaps with a
slightly higher confidence in isolated late week, late day
thunderstorms occurring over portions of the area east of the Coast
Range. But, it is still too early to be confident in where activity
will be focused each day.

We`ll stay in a pattern of very warm, very dry, and breezy
conditions today through Wednesday. This pattern includes overnight
breezy east to northeast winds at ridge tops of SW Oregon and NW
California (most notably the Coast Range and Kalmiopsis Wilderness)
along with poor to moderate RH recovery this morning and Tuesday
morning, trending to improved but still moderate recovery in
subsequent mornings. A channeling of winds down the Chetco could
result in some drier/warmer conditions along the SW Oregon coast as
well.

Upper level ridging shifting back toward the Four Corners will allow
westerly zonal flow aloft to bring lower heights and modest cooling
to inland areas. Generally, the trend will be to lower daytime MaxTs
down by a degree or two each day, and this should subsequently allow
daytime MinRHs to be slightly higher. Even so, it`ll be dry and
unstable, so any fires on the landscape will still have the ability
to grow significantly, especially during the peak burning periods
during the afternoons/evenings. Overnight RH recoveries haven`t been
good the last couple of nights, generally only in the 20-35% range
for some of the upper slopes and ridges. There should be slight
nightly improvement in recoveries from NW to SE through the period.
Things trend toward normal after Wednesday, but temperatures still
probably remain a few degrees above normal for most locations.

Models and ensemble guidance continue to show a weakness or upper
trough developing near or just off the California coast Wed/Thu and
also show an increase in monsoonal moisture coming up from the south
late week. Right now, after around a 10% probability of a
thunderstorm extending into southeast Modoc County on Wednesday
afternoon, models still bring isolated lightning chances up into
NorCal around Thursday with the best chance for showers and isolated
thunderstorms Fri/Sat from NorCal up the Cascades and across
portions of the East Side. But, given plenty of uncertainty in
strength of forcing mechanisms and overall instability, confidence
is low in the locations where activity will be focused. Keep
checking back for updates since any lightning brings with it the
risk of new fire starts. -Spilde/DW

&&

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

PACIFIC COASTAL WATERS...Gale Warning until 11 PM PDT Wednesday for
     PZZ356-376.

Small Craft Advisory until 11 PM PDT Wednesday for PZZ350-356-
     370-376.

&&

$$