Langlois, Oregon Weather Forecast Discussion

874
FXUS66 KMFR 280542
AFDMFR
Area Forecast Discussion
National Weather Service Medford OR
1042 PM PDT Sat Sep 27 2025
.Updated AVIATION Discussion...
&&
.AVIATION...28/06Z TAFs...There are 3 items of particular interest.
The first is coastal stratus with IFR north of Cape Blanco,
including at North Bend/KOTH, expected to spread into the Coquille
and lower Umpqua valleys, as well as much of the Curry County coast
overnight. This stratus is expected to dissipate during Sunday
morning.
Second, smoke from the Moon Complex in northeast Curry County
extends southeast into portions of the Illinois, Rogue, and
Applegate valleys. MVFR visibilities are present in Josephine County
and spreading into Jackson County. MVFR reduction of visibility is
expected at Medford/KMFR through around 17Z Sunday morning.
Thereafter, a shift in winds aloft is expected to bring improvement
for Josephine and Jackson counties, but deteriorating conditions for
Douglas County. This will include MVFR smoke at Roseburg/KRBG from
around 19Z Sunday afternoon into early Monday morning.
Lastly, gusty south to southwest winds of 15 to 30 kt are expected
to develop over much of the area Sunday afternoon into Sunday
evening. Winds will be strongest at the coast and in the Shasta
Valley. This includes Montague/KSIY. -DW/BR-y
&&
.PREV DISCUSSION... /Issued 752 PM PDT Sat Sep 27 2025/
Updated the marine sections...
MARINE...Updated 800 PM PDT Saturday, September 27, 2025...Seas
will remain below advisory level overnight into Sunday afternoon.
Then, an approaching front will bring gusty southerly winds, with
steep to very steep and hazardous seas from early Sunday evening
into Monday morning. A Gale Watch has been issued for Sunday night
into Monday morning for the outer waters. Active weather with a
second front Monday night into Tuesday could produce gales as
well.
-TAD/Hermansen
PREV DISCUSSION... /Issued 225 PM PDT Sat Sep 27 2025/
DISCUSSION...The main weather feature this weekend will be smoke
from the Moon Complex. The fire was burning fairly hot yesterday,
maintained it`s heat last night, and is continuing to be quite
active today. We`ll see some of that smoke which previously blew
offshore push inland later this afternoon and evening into Sunday
when the easterly flow turns westerly. Grants Pass and Josephine
will observe the most dense smoke with hazy skies generally west
of the Cascades. Otherwise, skies across the area are mostly
clear, with warm temperatures today cooling towards more seasonal
normals on Sunday.
A significant pattern change then occurs Sunday night into
Monday, that will feel like someone hit a button that suddenly
switches the area from summer to fall. On Sunday, a strong upper
level trough develops over the Gulf of Alaska, which will then
dig south over the northeastern Pacific, sending a cold front
into the Pacific Northwest Monday. Another front follows on Tuesday,
then the upper level low swings overhead Wednesday into Thursday.
This will result in cool, windy, and rainy weather across the
region, with temperatures dropping to 5 to 10 degrees below
normal and wetting rains expected across nearly the entire
forecast area.
Rain will arrive at the coast late Sunday evening, then spread
across the area Sunday night into Monday. The front passes to the
east by Monday evening, then post-frontal showers are expected
overnight into early Tuesday. A quick break is possible midday
Tuesday as pressure rises behind the first front, then the next
front arrives Tuesday afternoon into Tuesday night with additional
rain. The forecast is showing 1-2 inches of rain along the coast
and over the coastal mountains, with 0.25 to 0.50 inches for
other locations along and west of the Cascades. East Side areas
are expected to receive between 0.1 and 0.25 inches. Debris flows
over burn scars shouldn`t be a concern as hourly rainfall rates
will be under critical values.
Winds will also be a concern. It will be breezy everywhere as
these fronts pass, but wind concerns will be concentrated along
our typically wind-prone areas: the coast, the Shasta Valley, the
East Side, and over higher terrain, where wind gusts could peak
up to 50 mph (as indicated by forecast 700 mb winds of 40-50 kt
and tight, but not especially strong MSLP gradients). Some of the
more exposed capes and headlands along the coast could gust as
high as 60 mph. Much consideration was given to the wind threat,
especially since this early in the season there remains plenty of
foliage on area trees, and after the long summer, area forests
could be weakened due to heat/drought and wildfire. Winds were
adjusted well above NBM fields and based more on high resolution
models, especially since the NBM does poorly with terrain. Wind
Advisories have been issued for the Shasta Valley, the coastal
mountains of Curry and Josephine counties (where wildfires
continue to burn), and portions of the East Side, such as in the
vicinity of Summer Lake. We may even see some blowing dust
downwind of Summer and Fossil dry lake beds on Monday as winds
increase before rain arrives.
After a brief break in between systems,gusty winds will return
Tuesday, and with the latest models, gradients have tightened,
indicating that winds could be stronger with the second front.
Additional wind headlines will likely be necessary for Tuesday.
The offshore upper level low tracks slowly southeastward
Wednesday, finally passing onshore Thursday. With this upper level
support and plenty of containing onshore flow, showers are likely
to continue through both days, with heavier showers possible
Thursday as the low/trough axis passes overhead.
This will be the first event of its type this season, and the
first significant front(s) to pass through the region since early
May. As a result of this, some additional concerns arise. Summer-
weakened trees could be more easily susceptible to damage, blocked
drainages could result in ponding of storm water, and rain could
combine with oil/residue buildup on area roads, making them
slicker than expected. Be aware of these hazards when out and
about early next week.
Fortunately, snow levels will remain above roughly 7000 feet, so
although some light snow is possible along the rim of Crater Lake,
no winter weather impacts are expected for area passes.
Also of note, this could be a wildfire season ending event, at
least for much of the area. That being said, dry and warm periods
are still possible and have occured during October in previous
years, so it may be only a significant season-disrupting event for
some locations.
Conditions dry out and warm slightly for next weekend as ridging
builds in over the northeastern Pacific and the trough exits to
our east, leaving the area under northwest flow aloft. There are
some pronounced differences in the models heading into early next
week, with the ridge either passing onshore, or building to the
north. Either way, the forecast remains dry, but temperatures
would be warmer with the first scenario, and remain more
seasonable with the second. -BPN
FIRE WEATHER...Updated 200 PM PDT Saturday, September 27, 2025...
Warm and dry conditions continue this afternoon. Recoveries into
Sunday morning increase with westerly flow tonight. Southerly winds
develop across the area Sunday, with gusty winds developing over
east side terrain, ridgelines and aligned valleys in Josephine
County, and into the southern Shasta Valley in the afternoon. These
winds are within Advisory levels. Widespread wetting rainfall is
likely as a couple of strong fronts move through the area, one late
Sunday night into Monday and another Tuesday through Tuesday night.
There is a 15-20% chance for thunderstorms Monday afternoon as the
front passes in some west side valleys east of the Umpqua Basin and
along the Cascades. In addition to the wind/rain, Mon-Wed will also
see higher than usual humidity and below normal temperatures.
-TAD/Hermansen
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...Wind Advisory from 1 PM Sunday to 5 PM PDT Monday for ORZ024-030-
     031.
CA...Wind Advisory from 1 PM Sunday to 5 PM PDT Monday for CAZ081.
PACIFIC COASTAL WATERS...Small Craft Advisory from 3 PM Sunday to 8
     AM PDT Monday for PZZ350-356.
Gale Watch from Tuesday morning through Tuesday evening for
     PZZ350-356-370-376.
Small Craft Advisory from 3 PM to 11 PM PDT Sunday for PZZ370-
     376.
Gale Warning from 11 PM Sunday to 8 AM PDT Monday for PZZ370-
     376.
&&
$$

NWS MFR Office Area Forecast Discussion