255
FXUS66 KMFR 201808
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
1008 AM PST Fri Feb 20 2026

.DISCUSSION...Updated aviation discussion.


&&

.AVIATION...19/18Z TAFS...Fog and low clouds from earlier
this morning are lifting to VFR for west side valley TAF sites.
Still could be pockets of valley fog/low clouds, but conditions
should improve to VFR all areas this afternoon. An offshore front
will bring increasing mid and high level cloud cover area wide
through this evening with ceilings lowering to MVFR along the coast
and also some areas just inland overnight. We don`t think fog
will reform tonight in the valleys west of the Cascades since there
should be a ceiling in the 4000-6000 ft range initially. With
some light precip possible after 04Z from the Cascades west, there
could be terrain obscurations as well. Increasing winds aloft and a
low-level inversion present around 1500-2000 ft AGL will cause a
risk for low-level wind shear (LLWS) from the coast to the Cascades
late tonight into Saturday. Stronger south-southeast winds will
develop along the coast, from around Cape Blanco southward through
Saturday where a period of very strong winds are possible
Saturday night into Sunday. Breezy to windy conditions will also
develop over higher terrain, the Shasta Valley, southern Rogue
Valley and over to the East Side during the weekend.


&&

.MARINE...Updated 1000 AM PST Friday, February 20, 2026...A brief
period of lighter winds and lower seas is expected through this
afternoon. This improvement will be short-lived, however, as a
strong storm system will move southward over the eastern Pacific
from the Gulf of Alaska and linger over the eastern Pacific through
the weekend. This system will spin up multiple surface low pressures
along 130W, the strongest of which is expected Saturday
afternoon/evening.

Conditions will deteriorate this evening and overnight as the first
surface low impacts area waters. Advisory level winds are likely to
return late this afternoon, ramping up to gales overnight. As the
strongest low pressure deepens offshore on Saturday, gales are
likely to increase to storm force Saturday afternoon/evening,
especially for the outer waters. These strong winds will result in
very steep and dangerous seas late tonight through Saturday. Winds
ease just below gales late Sunday, but seas are likely to remain
very steep and hazardous well into early next week. Calmer
conditions are likely from Tuesday through the end of the week.


&&

.PREV DISCUSSION... /Issued 453 AM PST Fri Feb 20 2026/

DISCUSSION...Fairly quiet and cold morning today. Satellite
imagery shows some lingering stratus across portions of the East
Side with low clouds and freezing fog in some of the West Side
Valleys. It`s cold everywhere this morning, including along the
coast with low to mid 30s being observed and a Freeze Warning is
in effect. Elsewhere, temperatures are running around 5 to as much
as 15 degrees cooler than this time yesterday morning. Teens to
the mid 20s are quite common across the region this morning,
coldest east of the Cascades and also in areas where cloud cover
is absent like the Shasta Valley where it is currently 16 degrees
in Mt Shasta City. A Cold Weather Advisory is in place for the
valleys of central and western Siskiyou County through this
morning.

Overall, quiet weather is expected today as a shortwave ridge pushes
through the region. High temperatures will still be on the chilly
side today, running about 10-15 degrees below normal for this time
of year. We`ll see an increase in mid and high level cloud cover
later this morning and through the afternoon in advance of a pattern
transition. For the past few days, we`ve been in a cold/wet pattern
with low snow levels and that is expected to change over the weekend
as strong low pressure lingers over the eastern Pacific. This will
set up a "southerly flow" pattern over the region, bringing periods
of strong winds, moderate/heavy rain and mountain snow with
increasing snow levels. We`ll see southerly winds start increasing
this afternoon, becoming breezy in the Shasta/Scott Valleys as well
as the southern end of the Rogue Valley. Winds increase moreso
Friday night, and especially Saturday when a strong surface low
swings through offshore. We`ll likely be hoisting some wind
headlines for this system over the next shift or two, so stay tuned
for updates. Details on this weekend`s pattern can be found in the
previous discussion below.

AVIATION...19/12Z TAFS...Conditions vary across the region with low
end VFR/MVFR stratus across portions of the East Side and areas of
LIFR conditions in freezing fog in the Umpqua Basin, Illinois Valley
and Klamath River Valley. Widespread terrain obscurations are also
present and are likely to continue into the afternoon hours. There
could be brief period of LIFR conditions in freezing fog that
develop in the remainder of the West Side Valleys early this morning
right around sunrise, but it should be shortlived. Southerly flow
will increase across the region later this morning, and this should
bring improving conditions around 17-19z. Expect VFR conditions to
prevail area wide this afternoon, though with increasing mid and
high level cloud cover after 20z. Low level wind shear may also
become an increasing concern towards the end of the current TAF
period as a strong storm takes shape offshore.

MARINE...Updated 200 AM PST Friday, February 20, 2026...A brief
period of lighter winds and lower seas is expected through this
afternoon. This improvement will be shortlived, however, as a strong
storm system will move southward over the eastern Pacific from the
Gulf of Alaska and linger over the eastern Pacific through the
weekend. This system will spin up multiple surface low pressures
along 130W, the strongest of which is expected Saturday
afternoon/evening.

Conditions will deteriorate this evening and overnight as the first
surface low impacts area waters. Advisory level winds are likely to
return late this afternoon, ramping up to gales overnight. As the
strongest low pressure deepens offshore on Saturday, gales are
likely to increase to storm force Saturday afternoon/evening,
especially for the outer waters. These strong winds will result in
very steep and dangerous seas late tonight through Saturday. Winds
ease just below gales late Sunday, but seas are likely to remain
very steep and hazardous well into early next week. Calmer
conditions are likely from Tuesday through the end of the week.

PREV DISCUSSION... /Issued 245 PM PST Thu Feb 19 2026/

SYNOPSIS...

Cold weather will create minor impacts over the area tonight as
Mt. Shasta City comes close to a record low temperature. A strong
low will strengthen off our coast on Sunday and bring another
round of snow and rain to the region. There is a risk of flooding
along the coast and coastal rivers into early next week. Overall,
moderate weather risks continue for the region.

DISCUSSION...

There are lots of showers on the radar this afternoon as cooler
unstable air moves in with sufficient surface heating. The
showers have increased in coverage over the last few hours and
they should persist for a few more hours. Coverage should decrease
into the late evening hours as we loose surface heating and 500
mb heights build quickly behind the departing trough.

Cold weather is the main headline tonight. Temperatures were cold
last night, although those were occuring during a winter storm
warning. With the recent snow pack, partially clear skies and
some very light winds, there is minor cold weather risk according
to our criteria in northern California. It will frankly be cold
everywhere, but California is usually a bit warmer in the valleys.
We`re currently forecasting a record low temperature of 12
degrees in Mt. Shasta City with the old record of 15 set back in
2006. We might be a bit too cold in the forecast, but we should
come close to that record at the very least.

There was also some talk of fog forming in Umpqua Valley tonight,
although the soundings has ample moisture in the boundary layer
and the air isn`t that dry aloft. It`s unclear how much clearing
we`ll get tonight in some spots, although the high resolution
ensemble forecast(HREF) is pretty confident we`ll clear out in
some spots. Overall, there is a small chance some freezing fog
forms later tonight in the valleys tonight.

The focus then turns to the next storm system around late Saturday
into Sunday. The next trough dives out the Gulf of Alaska and a
surface low undergoes cyclogenesis and starts to spin up off the
Oregon coastline late Saturday. The low then strengthens as it
heads northwards along 130W and deepens further around 135W and
48N late Saturday night and Sunday morning. Ensembles are pretty
consistent in showing this low strengthening between 970MB to
980MB with significant winds in the outer waters. The extreme
forecast index(EFI) is showing winds values around 0.9 to 0.95 in
our outer waters with a shift of tales of 1. This hints at a
pretty strong wind event coming close to coastal shoreline and
producing high winds. Local MOS guidance based off the GFS
forecast is showing wind gusts up to 65 mph in the coastal
headlands. We didn`t issue a watch at this time, although it needs
to be revisited during future shifts.

We were a little more confident with the snow forecast as NBM
probabilities show a 50% chance of >10 inches over 5000 feet in
Siskiyou County through Sunday. Therefore, we issued a winter
storm watch as models show strong 700 mb flow up the Sacramento Valley.
The 12Z ensembles also appear to trend a little wetter with more
snow, so that added to our confidence.

Below the freezing level, there will be plenty of rain, especially
along the Oregon coast. Integrated Water Vapor Transport(IVT)
vectors/values are southerly around 500 for around 72 hours,
which could be considered a moderate atmospheric river(AR) for the
coast. The latest WPC QPF is showing 4 to 8 inches of rain along
the coast as snow levels hover around 4000 feet before increasing
to 6000 feet on Monday. When combined with the liquid in snow, we
felt there is risk of areal flooding in small streams and rapid
rises in rivers. Some of the latest hydro graphs near Myrtle
Point along the Coquille river show a 25% chance of reaching minor
flood stage by Tuesday.

By Wednesday, things start to quiet down a bit as the low
impacting us from Sunday through Tuesday weakens and rotates
farther west. Ensembles show higher surface pressure with almost
perfect zonal flow aloft, although the NBM has PoPs around 40
percent for most of Wednesday.

HYDROLOGY...A moderate atmospheric river will likely bring periods
of moderate to heavy rainfall later this weekend into early next
week. The first frontal system is forecast to arrive late Saturday
night into Sunday with multiple waves of precipitation continuing
Sunday night through Tuesday morning. Preliminary estimates are
showing widespread amounts of 4 to 6 inches along the coast with
locally 8 inches in the favored coast ranges of Curry County.
Amounts of 3 to 5 inches are possible in the Mount Shasta region and
also other favored areas of western Siskiyou County.

Small streams and creeks are likely to rise rapidly during this
event with nuisance flooding and ponding of water on roadways during
periods of heavy rain. Significant rises on main stem rivers and
flashier creeks are also expected. Given that rivers are still
running fairly low for this time of year, river flooding potential
is a bit lower than usual, but there is at least a low probability
of some flooding, especially in the Coquille Basin. We have issued a
Hydrologic Outlook (ESFMFR) to highlight this potential.

While the exact scenario for the heavy rainfall and potential
flooding remains uncertain, we will continue to monitor the
forecasts and update accordingly. Flood Watches may be issued by the
National Weather Service if this situation worsens.

&&

.MFR WATCHES/WARNINGS/ADVISORIES...
OR...CA...Winter Storm Watch from Saturday evening through late Sunday
     night for CAZ080-082-083.

PACIFIC COASTAL WATERS...Gale Warning from 10 PM this evening to 4 PM
     PST Sunday for PZZ350-356-370-376.

Storm Warning from 10 AM to 10 PM PST Saturday for PZZ370-376.

&&

$$