Coos Bay, Oregon Weather Forecast Discussion

283
FXUS66 KMFR 301042
AFDMFR
Area Forecast Discussion
National Weather Service Medford OR
342 AM PDT Tue Sep 30 2025
.DISCUSSION...Satellite image clearly shows were in between systems
with some clearing that has developed over the area. Radar is
showing isolated showers along the Cascades and portions of the
eastside. Because the stable conditions, clearing and recent
rainfall, this has allowed low clouds and patchy fog to form for
many of the interior westside valleys and the Klamath Basin. This
will continue into at least the mid morning hours before the next
front pushes towards the coast, resulting in the lower clouds and
fog lifting. Models are in pretty good agreement with the timing of
the next front which is expected to reach the coast late this
afternoon. Until then, most of the interior could get away with dry
weather through at least mid afternoon before precipitation sneaks
in at the coast and coastal mountains.
The front will move inland early this evening and we`ll have
another period of steady light to moderate rainfall. However
rainfall amounts are expected to be less than what we had with the
previous front as the front will lose some of it`s punch as it moves
onshore. Post frontal showers are likely behind the front later this
evening and tonight, but rainfall amounts will be light.
It`s also worth mentioning, it will be windy again ahead of the
front along the coast, coastal mountains, Shasta Valley and east
ofthe Cascades for most of the day. Winds in the Shasta Valley will
gradually diminish later this evening and tonight. Wind advisories
remain in effect for the Shasta Valley, and portions of the
eastside.
Wednesday, upper troughing remains offshore with a southwest flow
aloft, with off/on showers expected through the day. However
rainfall amounts will be light. Isolated showers are likely
Wednesday nigh into Thursday, with most hours and locations dry as
we transition towards a dry and milder pattern late this week into
next weekend.
The models are in pretty good agreement showing dry and milder
weather Friday through the weekend. An upper trough axis will move
through Friday followed by weak ridging offshore. At the surface, a
thermal trough will develop with offshore flow setting up with dry
and milder weather with temperatures near seasonal norms starting
Friday. -Petrucelli
&&
.AVIATION...30/12Z TAFs...The region is in between systems, and due
to a combination of recent rainfall and stable conditions. Low
clouds and fog have developed over most of the valleys west of the
Cascades, including Roseburg and the Grants Pass area. These areas
will experience IFR conditions for most of the morning, then both
visibility and ceilings will improve late this morning and afternoon
as the next system approaches. Also rainfall east of the Cascades
has resulted in low clouds for some of the valleys, including
Klamath Falls.
The next front will result in moderate to occasionally strong winds
winds along the coast, Shasta Valley and portions of the eastside.
There could be a period of low level wind speed shear at North Bend
between 12-17z before the stronger winds surface there.
While ceilings will improve initially later this morning, they will
lower again late this afternoon and tonight as the next front moves
inland. -Petrucelli
&&
.MARINE...Updated 200 AM PDT Tuesday, September 30, 2025...South
winds will increase ahead of the next front this morning with winds
approaching gales at times late this morning through this evening.
One the front moves onshore this evening. winds will diminish and
shift to the southwest. However an increasing west swell will move
into the waters resulting in hazardous seas warning conditions for
the northern waters and small craft conditions for the southern
waters with swells expected to be less there. West swell will remain
elevated between 11-12 feet through Thursday night, before
diminishing Friday, therefore we have extended the end time for the
small craft advisory until 5 am Friday morning.
An upper trough will move from north to south in central Oregon and
in it`s wake will be a developing thermal trough resulting in
increasing north winds during the day Friday and could persist
through the weekend. -Petrucelli
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...Wind Advisory from 9 AM this morning to 11 PM PDT this evening
     for ORZ030-031.
CA...Wind Advisory from 9 AM this morning to 11 PM PDT this evening
     for CAZ081.
PACIFIC COASTAL WATERS...Gale Warning from 5 AM early this morning to
     11 PM PDT this evening for PZZ350-356-370-376.
Small Craft Advisory from 11 PM this evening to 5 PM PDT
     Wednesday for PZZ350-356-370-376.
Hazardous Seas Warning from 11 PM this evening to 5 AM PDT
     Wednesday for PZZ350-370.
&&
$$

NWS MFR Office Area Forecast Discussion