565
FXUS66 KMFR 221056
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
356 AM PDT Mon Jun 22 2026

.DISCUSSION...An upper ridge drifting from west to east will be in
control of conditions to start this week, with daytime highs 10 to
15 degrees above seasonal norms expected across northern California
and southern Oregon. This will put the Oregon coast in the low 70s
north of Cape Blanco and mid to high 70s to the south. Even with
models trending down slightly, most west side valleys look to be in
the mid to high 90s. The Umpqua Valley is expected to remain in the
low to mid 90s. A Heat Advisory remains in place for most west side
valleys and exposed areas for Monday afternoon through Tuesday
evening, with the Umpqua Valley excluded. To the east of the
Cascades, daytime highs will be in the mid 80s to low 90s.

On Tuesday, a short wave trough may bring just enough instability to
trigger isolated afternoon and evening thunderstorms. For the
moment, these slight ~15% chances are present in northern Lake and
Klamath counties as well as in Siskiyou County.

On Wednesday, the upper ridge`s influence will be reduced as it
starts to leave the area. Daytime highs will still be generally 5-10
degrees above normal, but this looks to be below hazardous
thresholds. Another shortwave trough may bring another round of
isolated afternoon/evening thunderstorms east of the Cascades. As
this timeframe is currently outside of high-res data, more detail on
if and where these thunderstorms may develop will be possible as
more accurate data becomes available.

Temperatures cool further on Thursday ahead of an upper trough`s
arrival. A cold front will reach the area early Friday morning,
bringing chances of light showers to the coast, Douglas County, and
the Cascades into the afternoon. A round of gusty afternoon and
evening winds will be possible east of the Cascades. There`s still
some disagreement in long-term imagery if a low pressure system will
dig low enough to bring widespread rainfall or if it will stay to
the north and minimize precipitation. Models do agree that daytime
highs look to fall below seasonal averages on Friday, Saturday, and
Sunday. -TAD



&&

.AVIATION...22/06Z TAFs...Onshore flow is producing LIFR at the
coast from Cape Blanco northward this evening. Beginning around 09Z,
LIFR is also expected along the south coast near Brookings. The
coastal LIFR is expected to begin to erode after sunrise, with VFR
expected from around 18Z late Monday morning through around 03Z
Monday evening. Coastal LIFR is then expected to surge back to the
coast for Monday night. Elsewhere, VFR will persist with mostly
clear skies.

&&

.MARINE...Updated 1000 PM PDT Sunday, June 21, 2026...North winds
will continue to strengthen through Monday evening. The result will
be strong northerly winds and very steep seas south of Cape Blanco
while steep seas remain across most of the northern waters. There
may be isolated areas of gale force gusts through Monday evening for
areas south of Cape Blanco. A pattern of northerly winds is likely
to continue through mid-week, with winds remaining at Small Craft
Advisory strength south of Cape Blanco while fresh swell continues
steep seas in the northern outer waters beyond 30 nm from shore.

Conditions briefly improve on Thursday. A cold frontal system is
likely to bring light rain and a modest increase in fresh west-
northwest swell Thursday night into early Saturday.


&&

.MFR WATCHES/WARNINGS/ADVISORIES...
OR...Heat Advisory from 11 AM this morning to 11 PM PDT Tuesday for
     ORZ024-026.

CA...Heat Advisory from 11 AM this morning to 11 PM PDT Tuesday for
     CAZ080>082.

PACIFIC COASTAL WATERS...Hazardous Seas Warning until 11 PM PDT this
     evening for PZZ356-376.

     Small Craft Advisory until 2 AM PDT Wednesday for PZZ356-370-
     376.

&&

$$

TAD/TAD/TAD