361
FXUS66 KMFR 060529
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
1029 PM PDT Sat Sep 5 2026

.Updated AVIATION Discussion...

&&

.AVIATION...06/06Z TAFs...VFR prevails across the region with
widespread high and mid level clouds and terrain obscurations. An
area of showers will persist tonight into Sunday morning, and a few
of these showers will be capable of producing lightning. VFR should
prevail for most areas overnight, though brief periods of MVFR
conditions are possible under heavier showers/precipitation.
A period of IFR/LIFR conditions is possible along the coast late
this evening before showers become more widespread, with ceilings
expected to lift to at least MVFR. Increased shower activity will
persist into Sunday afternoon, with thunderstorm chances increasing
after 18z for areas along and east of the I-5 corridor.

&&

.PREV DISCUSSION... /Issued 446 PM PDT Sat Sep 5 2026/

KEY MESSAGES...

* Rain shower and thunderstorms remain in the forecast for Sunday
  east of and along the Cascades, with lighter activity farther
  west.

* A warming trend and dry conditions are expected from the start
  of the week into Wednesday or Thursday.

* Substantial model variability exists for the end of the week.
  PRecipitation chances have trended downward but remain at
  20-30%. In the absence of precipitation, gusty west winds are
  possible east of the Cascades.

DISCUSSION...Warmer temperatures remain in the forecast today as a
cutoff low within an upper trough lingering over the area weakens,
although highs remain 5 to 10 degrees below seasonal norms. Flow
over terrain is allowing cumulus to develop, but little activity has
been noticeable on radar. Observations across the area show a few
hundreths over remote areas but little of specific interest. Calmer
conditions continue through the rest of the day. Clear skies tonight
may allow for enough radiative cooling to bring local frost
conditions (overnight lows of 33-36 degrees for at least 3 hours)
for lower elevation areas east of the Cascades, but no Advisories
will be issued this afternoon as meeting the duration threshold is
generally questionable.

Late tonight into early Sunday morning, the trough starts to swing
inland. This motion will bring another 5 to 10 degrees of cooling
from today`s daytime highs. Wraparound flow from the cutoff will
bring the best rain shower chances along and east of the Cascades.
Rainfall amounts of 0.25 to 0.50 inches are possible over northern
parts of Lake and  Klamath counties as well as along the Cascades.
Lighter amounts, mostly 0.10 inches or less, are possible for other
east side areas and along the western Cascades foothills. Isolated
showers are possible farther west. Afternoon and evening
thunderstorm chances follow a similar pattern, with 30% chances over
and north of Crater Lake. East side areas have 15-25% chances, while
chances to the west are 15% or less. Shower and thunderstorm chances
dissipate into Sunday night.

Warm and dry conditions remain in the forecast for much of the week
ahead. Increasing influence from both Pacific and continental ridges
are bringing forecast temperatures up above seasonal norms for
Wednesday and Thursday. For Friday and beyond, model variability is
enough to keep substantial questions about any one outcome.
Deterministic imagery for both the GFS and ECMWF show an upper
trough helping to cool temperatures, while a sharp gradient may
bring gusty westerly winds east of the Cascades. Turning to ensemble
guidance, precipitation chances have trended downward but 20%
(ECMWF) to 30% (GFS) chances for precipitation remain for the end of
the week. -TAD

MARINE...Updated 230 PM PDT Saturday, September 5, 2026...Light,
northerly winds will continue this evening and later tonight. Low
seas along with a few showers will persist through Sunday night. A
thermal trough develops Monday and persists through Monday night,
with gusty north winds and steep seas likely south of Port Orford
through mid-week.

&&

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

PACIFIC COASTAL WATERS...Small Craft Advisory from 8 AM Monday to 5
     AM PDT Tuesday for PZZ356-376.

&&

$$