Wildfire in Oregon, August 5 to 25, 2024

Area Forecast Discussion
National Weather Service Medford OR
458 PM PDT Mon Aug 5 2024

...Updated AVIATION discussion...

.DISCUSSION...Not much variation in the weather is expected for the
week ahead.

The latest satellite image shows the marine stratus burning off
along the coast, but still remains just offshore west of Cape
Blanco. Meanwhile, marine stratus just south of Gold Beach has been
slower to burn off, but we expect the clouds to burn off at the
coast late this afternoon. Elsewhere it will remain clear, except
for some cumulus clouds over the northern Cascades and northern
Klamath County. The marine stratus will return to the same areas
later tonight with patchy fog possible.

A dry, stable west to southwest flow will remain over the area
through Tuesday, with a weak upper trough remaining offshore.
Afternoon temperatures for the interior will be above normal and hot
in the afternoon, but were not expecting any heatwave. Overnight
lows will drop down enough to provide relief at night.

The weak upper trough will move through the area late tonight with a
portion of the four corners ridge nudging into the area Wednesday.
This will result in afternoon highs being a few degrees higher on
average compared to Tuesday. Another weak upper low southwest of the
forecast area will usher in some high clouds during the day
Wednesday, but the perception will still be mostly clear skies with
the high clouds expected to be thin enough for the sun to get
through.

It will be flat out dry this week with the typical gusty afternoon
and early evening breezes for the interior westside valleys and east
of the Cascades. A thermal trough will set up along the south Oregon
coast with breezy east winds near and at the ridges late in the
evening into the morning hours Tuesday and Wednesday.

This weekend, there's good agreement among the operational models,
ensemble means and clusters showing an upper trough settling into
the area bringing cooler afternoon temperatures for the interior.
It's expected to remain dry this weekend. There are some signs of
instability Sunday, but much will depend on the exact location and
strength of the upper low. -Petrucelli

&&

.AVIATION...06/00Z TAFS...The remnants of marine stratus are
clinging to the Brookings area, but a cloud layer is expected to
rebuild along the Oregon coast later tonight. Periods of MVFR and
IFR ceilings are expected, with current guidance suggesting
visibilities along the coast staying clear through the TAF period.

Inland areas will generally be VFR through the TAF period, with
normal afternoon winds. Wildfire smoke may cause some locally lower
visibility in eastern Douglas and northern Klamath counties, with
lighter smoke accumulation possible in the Rogue Valley as well. -TAD

&&

.MARINE...Updated 130 PM Monday, August 5, 2024...A developing
thermal trough will bring the return of strong gusty north winds and
steep to very steep and hazardous wind driven seas this week. Winds
will begin to increase and seas steepen today, especially south of
Cape Blanco. Conditions worsen Tuesday afternoon into Wednesday as
the thermal trough amplifies. Very steep and hazardous seas will
develop south of Gold Beach and beyond 5 nm from shore, and wind
gusts may briefly reach gales Tuesday and Wednesday afternoons.
Conditions will improve for the latter half of the week, but gusty
north winds with steep seas are likely to linger through much of the
week. /BR-y

&&

.FIRE WEATHER...Issued 200 PM Monday August 5, 2024...The week ahead
is shaping up to be dry with not much variation in the weather from
one day to the next. The only concern will be breezy mid to late
afternoon and early evening winds with low relative humidity east of
the Cascades today into Wednesday evening. The combination ofthe two
are not expected to result in critical conditions, but a few areas
in fire zones 625 and 285 could briefly touch critical conditions
due to winds and low relative humidity. We'll continue to headline
this in the fire weather forecast.

Meanwhile a thermal trough will develop along the south Oregon coast
Tuesday resulting in breezy east to northeast winds near and at the
ridges in Fire Zones 619, 620, 621 and western 280 starting Tuesday
night and lasting into Thursday morning. However, winds are not
expected to be strong and guidance shows relative humidities are not
expected to be low enough for concern. The exception is over the
higher elevations in Fire Zones 621 and 280 where guidance over
these areas show moderate to locally poor overnight recoveries, but
wind speeds just aren't strong enough to warrant any concerns. This
is something we'll continue to monitor.

West to northwest winds will increase mid to late afternoon into the
early evening hours in the vicinity of the Umpqua Fires in central
and eastern Douglas County for most of the week, but the combination
of winds and relative humidity are not expected to enough for
critical conditions to be met.

There's good agreement we'll have some cooling by next weekend as an
upper trough settles in over the forecast area. Odds are it will
remain dry this weekend. There's some evidence pointing towards
marginal instability Sunday, but much will depend on the exact
location and strength of the upper low. Stay tuned. -Petrucelli

&&

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

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

Hazardous Seas Warning from 5 PM Tuesday to 11 PM PDT Wednesday
     for PZZ356-376.

&&