Cecilville, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

458
FXUS66 KMFR 312107
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
207 PM PDT Sat May 31 2025

.DISCUSSION...A strong upper ridge is over the Great Basin with an
upper trough moving into the PacNW. It`s still quite warm this
afternoon east of the Cascades, but some cooling is already
underway (compared to yesterday) over the west side as heights
fall ahead of the incoming trough. Afternoon breezes are picking
up as well -- peak gusts in the 25-35 mph range are expected
through this evening. The surface front associated with the
upper trough will move through the area tonight into Sunday.
Moisture is limited, so precipitation chances are low (generally
10% or less), though some clouds will push onshore into the coast,
the Umpqua Basin and bank up against the Umpqua Divide and the
Cascades, particularly the Cascade Foothills. While measurable
rainfall is unlikely, there could be a few sprinkles and/or some
drizzle from these clouds, beginning this evening and lasting
through the wee hours of Sunday morning. Some clouds may also bank
up against the Siskiyous overnight into Sunday morning.

Deep-layer N-NE winds will set up area wide tonight into Sunday
with increasing offshore pressure gradients. The strongest winds
will be focused in the SW Oregon/NW California mountains (coast
ranges/Siskiyous and, to a lesser degree, the Cascades), but also
at the coast. Return interval on expected H85 winds is 1 year in
the last 30 in terms of magnitude, so this is indicating a strong
offshore flow event with ECMWF EFI also showing unusual strength
in terms of "climatological rarity". Guidance continues to show
high probability (>70%) of wind gusts reaching 40 mph over the
higher terrain and a low chance (15%) at peak gusts exceeding 50
mph. Even coastal areas could observe wind gusts in the 35-45 mph
range. While an unusually breezy to windy event, it does not quite
elevate to issuing public wind products. Even so, some valleys
with flow oriented NE-SW (Illinois) could have stronger breezes
come Sunday afternoon (30-35 mph) when the upper trough moves
through. If this were a month later, we`d almost certainly be
talking about fire weather products since the wind will be coming
with a period of low humidity. However, fuels in the areas of
interest are still in mixed phase with green-up and curing
grasses. As such, we`ll maintain a headline in the Fire Weather
Forecast. The most noticeable change in terms of temperatures will
be the cooling over the East Side, where high temps will be down
15-20 F compared to today. However, with the flow offshore over
the west side in SW Oregon, it could be warmer as winds channel
through the Chetco to near Brookings. Expected highs will be in
the 70s there. Low 80s are possible if all lines up, but overall
air mass cooling should preclude temps that high.

It should be noted that a closed low is expected to form and move
southward along the NorCal coast Sunday, then toward the Bay Area
Sunday night. This will bring some mid-level moisture and
instability to portions of NorCal Sunday afternoon/evening. With a
front getting hung up in the northern Sierra, it might be able to
trigger an isolated thunderstorm or two in Lassen that could graze
southernmost Modoc County. This is a low probability (~15% chance)
event and most areas aren`t going to get anything at all.

We`ll maintain a dry, breezy pattern through mid next week with
minor disturbances pushing through at times. This should bring
marine pushes to the coast, especially north of Cape Blanco, but
also into portions of the Umpqua Basin along with enhanced breezy
conditions. But, no significant precipitation is expected.
Overall, temperatures during this period will be a bit above
normal, but not too warm (generally highs in the 70s/low 80s over
the east side and in the 80s over the interior west side valleys).
Model clusters are showing the offshore Pacific ridge edging
closer to the West Coast late next week into next weekend, which
would bring increasing mid-level warmth and an uptick in
temperatures.

With fire season beginning tomorrow, Sunday June 1st, we`d like
to remind everyone that with the dry weather expected, fuels will
continue to dry out quickly. Currently, we do not have any
widespread initial attack fire weather concerns, but as we have
seen in the past couple of weeks, local grass fires can spread
fairly easily given gusty wind conditions. Please use extra care
when participating in activities that may create sparks or embers.

-Spilde

&&

.AVIATION...31/18Z TAFs...The coast will be under a marine layer
which will result in MVFR ceilings through early parts of this
afternoon before improvements occur. This means the coast will
join inland sites for VFR conditions through much of the day and
early evening. Thereafter, the coast will likely see another
marine push overnight; however, there is enough of an offshore
component that may limit lower ceilings overnight. At this time,
confidence was high enough to keep all terminals VFR overnight.
Lastly, it will be breezy this afternoon for all sites.

-Guerrero


&&

.MARINE....Updated 200 PM Saturday, May 31, 2025...Strong
northerly winds will build steep seas south of Coos Bay through this
afternoon. Wind speeds will further strengthen this evening
resulting in gale force winds and very steep wind-driven seas
impacting areas from Coos Bay southward while steep seas continue to
the north. These strong northerly wind speeds will be relatively
long-lived, lasting through at least Wednesday before any signs of
easing. That said, areas south of Cape Blanco will likely experience
breezy to gusty winds through the remainder of the week with seas
likely hazardous to smaller craft.


&&

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

PACIFIC COASTAL WATERS...Small Craft Advisory until 5 PM PDT this
     afternoon for PZZ350-356-370-376.

Gale Warning from 5 PM this afternoon to 11 PM PDT Monday for
     PZZ350-356-370-376.

&&

$$

MAS/JWG