Alturas, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

441
FXUS66 KMFR 160521
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
1021 PM PDT Fri May 15 2026

...New Aviation Section...


.AVIATION (06Z TAFs)...

While ceilings may occasionally dip into MVFR realm, we are
expecting this to be a mostly VFR TAF cycle. There will be
isolated showers across the area tonight through tomorrow morning
with coverage diminishing by the afternoon. Its possible for
terminals west of the Cascades to briefly see some light rainfall,
but confidence was much higher to only mention vicinity at this
time given the isolated nature of these showers. Not expecting any
lightning. Lastly, breezy wind speeds are expected Saturday
afternoon, and these speeds may linger into the evening hours.

-Guerrero

&&

.PREV DISCUSSION... /Issued 823 PM PDT Fri May 15 2026/

..Updated the Aviation Section...

AVIATION...16/00Z TAFs...Conditions remain VFR early this
evening. But, low pressure will dominate the pattern later this
evening into Sunday morning. While energy will be focused upon
Washington and northern Oregon, this will bring light rain and
around an inch of Cascade snow to Coos, Douglas, northern Curry, far
northwest Klamath, and far northern Jackson counties (with snow
levels around 4000 feet msl). Those areas will also see areas of
MVFR ceilings and mountain obscuration.

Meantime, VFR will persist elsewhere, along with breezy, gusty
northwest to north winds of 15 to 30 kt.

MARINE...Updated 200 PM PDT Friday, May 15, 2026...Gusty north to
northwest winds and steep seas are expected for areas from Gold
Beach southward through this evening. Steep seas expand
northward to all areas by Saturday as an increasing swell builds
into the waters. North winds will also strengthen late Saturday.
Strongest winds and highest seas are expected from Gold Beach
southward.

Multiple northwest swell trains will move through area waters into
early next week with persistent gusty north winds. At a minimum,
this will maintain steep seas for much of the area through mid next
week. However, the sustained northerly fetch Sunday through Thursday
could build very steep seas south of Cape Blanco. North winds also
could approach gale force at times, especially during the late
afternoon/evening hours. We`ve added a hazardous seas watch south of
Cape Blanco since it looks like at least a 4-5 day period of
persistent northerly winds/very steep steep seas (starting Sunday
afternoon). We`ve run it into Monday evening for now, but probably
will need to extend it as confidence increases in the duration of
the event. -Spilde

PREV DISCUSSION... /Issued 213 PM PDT Fri May 15 2026/

KEY MESSAGES...

* Seasonable temperatures are expected this afternoon/evening with
  breezy to gusty winds.

* Two disturbances, one tonight into Saturday morning and another
  Saturday night into Sunday will bring cooler temperatures and
  enhanced WNW afternoon winds along with marine pushes along the
  coast and into the Umpqua Basin through the weekend.

* Light rain is possible along the coast and north of the Rogue-
  Umpqua Divide on Saturday. Snow levels down to around 4000 feet
  in the Cascades.

* Localized frost is possible Saturday night, but more likely
  Sunday night in some west side valleys. Highest chances are in
  the Illinois and Applegate valleys Sunday night, and portions of
  the lower Klamath River Valley in western-central Siskiyou
  County. Near and below freezing temperatures are likely in the
  Scott/Shasta valleys and east of the Cascades.

DISCUSSION...Last night`s marine push brought only a few
hundredths of rain to the coast/coast range mountains in
Coos/western Douglas counties with just some clouds across the
Umpqua Basin down to around the Rogue Valley this morning. Except
for a few cumulus hanging near the terrain, the lower clouds have
mostly dissipated here this afternoon, though they`ve been more
persistent N&W of Roseburg. Some high cirrus are moving in now
ahead of another fast-moving disturbance arriving in WNW flow
aloft. The main vort max with this disturbance will swing across
Washington into Idaho/NW Montana on Saturday. Another cold front
with a fairly deep marine push is expected with some light rain
along the coast and into the Umpqua Basin into Saturday morning.
The snow level Saturday morning is forecast to be around 4000
feet, so some wet snow could fall in the Cascades, especially near
and north of Union Creek Saturday morning. Again though, precip
amounts will be light, and generally just a couple of hundredths
(maybe a tenth in some lucky spots). Some models show a slight
chance of precip south of the Umpqua Divide Saturday morning (so
we can`t completely rule out a few sprinkles around the valley),
but, NBM probs are 10-25%. Probably no more than a trace of rain
here in Medford. Saturday will be cooler with more clouds than on
Friday and highs only 60-65F for the west side valleys. High temps
in the 50s to low 60s can be expected over the East Side. Expect
another breezy afternoon for most locations.

Saturday night into Sunday, the main upper trough will dig across
southern Idaho/NE Nevada and into northern Utah with back side
energy swinging southward through SW Oregon and into NorCal. This
could lead to some light precip again, especially near the
mountains, but it`ll remain dry elsewhere with a colder
continental air mass moving in on north-northeast flow. Snow
levels Saturday night will be down to valley floors east of the
Cascades, any precip should be snow. Even so, travel impacts are
unlikely with amounts generally an inch or less. The colder air
mass will remain in place Sunday into Monday, so we could be
looking a temperatures dropping into the low to mid 30s for some
of the typically colder west side valleys. Right now, this looks
like a set up for patchy frost in portions of the Illinois and
Applegate valleys, but also some of the colder spots in the Rogue
Valley (outlying areas of Medford). Lows both mornings (Sun/Mon)
look to be in the 33-37F range. It looks like too much cloud cover
and/or wind for Sunday morning and duration of temps that low
won`t be long enough. Better chance is Monday morning as the upper
trough moves east, heights rise and the air mass dries out.

Since upper level heights rise next week, we expect a mostly dry
pattern along with a warming trend. Temperatures rise to around
normal Monday, then back to above normal levels Tue-Thu. We`ll
remain in WNW flow aloft during this time period with weak
disturbances pushing by to the north every now and then. This
means that while it will turn warmer, no huge heat waves are
expected. Also, marine layer intrusions are likely to continue at
the coast during the nights/mornings; any of the deeper ones could
produce a little drizzle near the coast.

NBM has a dry forecast through at least next Friday and perhaps
even into next weekend, which would heighten fire weather
concerns due to rapidly drying fuels. Lightning risk during this
period though is low since moisture will be limited. Models are
hinting at the potential for a long wave trough to enter the
picture toward the last week of May with a potential cool down
back to normal and this is in line with the 8-14 day CPC forecast
at the moment. -Spilde

&&

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

PACIFIC COASTAL WATERS...Small Craft Advisory until 5 AM PDT Sunday
     for PZZ350-356-370-376.

Hazardous Seas Watch from Sunday afternoon through Monday
     evening for PZZ356-376.

&&

$$