419
FXUS66 KMFR 072327
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
427 PM PDT Sat Jun 7 2025

.DISCUSSION...Updated Aviation Section...

&&

.AVIATION...07/00Z TAFs...The marine stratus at the coast has
started to move in for the night with IFR/LIFR ceilings returning.
Gusty winds also continue through the next couple of hours before
weakening more into the evening. Inland areas will remain under VFR
levels. -TAD/Hermansen

&&

.PREV DISCUSSION... /Issued 220 PM PDT Sat Jun 7 2025/

DISCUSSION...Satellite image shows marine stratus along the coast
with the exception for areas just south of Cape Blanco to Port
Orford. Elsewhere it`s clear with the exception for developing
cumulus over the higher terrain at Mount Shasta and areas east to
northeast of Mount Shasta. The expectation is for more cumulus
development to occur over the higher terrain in northern Cal, the
Siskiyous and southern Cascades during the course of the afternoon
into early this evening.

Temperatures for the interior are between 3-5 degrees higher
compared to this time yesterday as of this writing and we are likely
to have hot afternoon temperatures for the next few days (today-
Monday). Triple digit values are likely for the interior westside
valleys the next few days (including today), with warmer overnight
lows. Because of this, a Heat Advisory remains in effect. Please see
NPWMFR for more details.

It will be dry most of the time and for most locations into early
next week. However there`s some evidence suggesting mid level
moisture creeping into northern California as a weak upper low
creeps closer to the area Sunday. Instability parameters are
marginal and there could be enough of a trigger for isolated
thunderstorms to pop up Sunday afternoon and lasting into Sunday
evening for portions of norther Cal, southern Cascades and portions
of the eastside. Although current data suggest instability will be
most favorable in western Siskiyou County.

Any storms should fizzle out later Sunday evening with dry weather
Sunday night into Monday morning.

It will be slightly more unstable Monday along with increasing mid
level moisture that could set the table for isolated thunderstorms
Monday afternoon into Monday evening. The rigger is weak, but given
the amount of instability, it won`t take much of a trigger to get
storms to develop. The best chance for storms are expected to be in
portions of Siskiyou county which could also result in some
precipitation due to higher water content in the column of the
atmosphere.

Of the three days (Sunday, Monday and Tuesday afternoon and early
evening). Tuesday is the one of most concern in terms of
thunderstorms. A stronger upper trough will approach from the west
and there`s good agreement the upper trough axis will still be
just offshore late Tuesday afternoon. This will put the area in a
favorable position for isolated to scattered thunderstorms along
and east of the Cascades and northern Cal, with the instability
parameters greatest in Western Siskiyou County. Given the position
of the upper trough axis and stronger trigger ahead of it could
bring a heighten threat for isolated strong to severe storms. The
one element that could put a cap on the amount of storms Tuesday
will be the amount of cloud cover from Monday night into Tuesday
morning. Keep in mind, this is still a ways out and the details
could change, so stay tuned for the latest updates.

There`s some evidence pointing towards storms lingering into the
overnight hours Tuesday, but they are likely to be isolated and
confined to portions of Lake and Klamath County.

Beyond Tuesday night, the ensemble means  and clusters are all
pointing towards upper troughing to set up over the area for the
latter part of next week into Fathers Day weekend, with temperatures
near normal. Odds are it will be dry during this time, However,
precipitation chances will be be zero as a small number of
individual ensemble members show some precipitation -Petrucelli

MARINE...Updated 200 PM Saturday, June 7, 2025...Steep seas
continue in all area waters, with areas of gusty northerly winds
continuing between Coos Bay and Gold Beach. These winds will
decrease through the evening and night, with seas will be below
advisory levels early Sunday morning.

Far north of our area, a broad area of gusty winds will build
northwest fresh swell that will move into the area through the day
Sunday. Swell-built steep seas are forecast for all waters by Sunday
night, and will continue through the day Monday. Gusty northerly
winds will build across area waters on Monday as well, with the
highest speeds south of Cape Blanco. Areas of very steep and
hazardous seas may be possible on Tuesday especially south of Cape
Blanco. Unsettled seas look to continue for all area waters through
the week. -TAD

&&

.MFR WATCHES/WARNINGS/ADVISORIES...
OR...Heat Advisory from 11 AM Sunday to 8 PM PDT Monday for ORZ024-
     026.

CA...Heat Advisory from 11 AM Sunday to 8 PM PDT Monday for CAZ080-
     081.

PACIFIC COASTAL WATERS...Small Craft Advisory until 11 PM PDT this
     evening for PZZ356-376.

     Small Craft Advisory from 5 PM Sunday to 5 PM PDT Monday for
     PZZ350-356-370-376.

&&

$$