Alturas, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

976
FXUS66 KMFR 071612
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
912 AM PDT Mon Apr 7 2025

.DISCUSSION...Upper trough lifting north over the region this
morning in fast southwest flow. Seeing Extensive cloud cover and
scattered showers with visibilities in fog much improved over the
past couple hours. No updated needed to the grids. Marine
discussion updated below. MTS

&&

.AVIATION...07/12Z TAFs...A band of showers is moving across Klamath
and Siskiyou counties at the start of the TAF period, with scattered
post-frontal showers continuing behind this band. Flight levels have
generally stabilized, with MVFR to LIFR levels remaining along the
Oregon coast. Inland, levels are at VFR under high ceilings but
passing showers will occasionally locally lower ceilings and
visibilities. Periods of gusty winds are expected along the Oregon
coast and over east side terrain later this morning and into the
afternoon. Scattered showers will continue through the TAF period,
generally remaining west of the Cascades. -TAD

&&

.MARINE...Updated 800 AM Monday, April 7th...Gusty southerly winds
continue to build steep seas in all area waters this morning. Winds
calm this afternoon before strengthening again Tuesday. Localized
occurrences of gale gusts may be possible north of Cape Blanco and
within 30 nm from shore in the morning as the front approaches.
Currently, there is not enough confidence in widespread gale gusts
occurring to support a Gale Warning, but this period will be watched
closely as more guidance is available. A Hazardous Seas Warning has
been issued for all area waters to highlight expected wind-built
very steep and hazardous seas developing with this front.

Beyond Tuesday`s front, periods of unsettled weather and atmospheric
stability look to alternate but with nothing significantly impactful
in the current forecast. Seas look to improve on Tuesday night, with
below advisory conditions expected through Wednesday and into
Thursday. A weak front may bring a brief period of steeps seas
Thursday night before seas look to fall back below advisory levels
on Friday and Saturday. -TAD/Hermansen

&&

.PREV DISCUSSION... /Issued 453 AM PDT Mon Apr 7 2025/

A sprawling long wave upper trough over the Gulf of Alaska will
continue to send disturbances onshore into the PacNW this morning.
Early morning radar imagery is showing a band of frontal
precipitation extending from western Siskiyou County northward
across Jackson County to the Cascades/Foothills. This first front
will weaken as it moves inland, but another cold front off the
coast will move onshore. Satellite imagery shows a nice swirl
about 200 miles off Gold Beach associated with the mid-upper level
disturbance that will move inland this morning. Overall, this
will bring a continued risk of showers to most areas, with the
greatest probability of rain along the coast, in the coast ranges
and over to the Cascades. We have observed wind gusts in advance
of the first front east of the Cascades in the 40-45 mph range
this morning with some of the usual suspects (Summer Lake) even a
bit higher than that (50-55 mph). The main jet causing the
enhanced winds will shift east of the area in the next few hours
and winds should subside for a while. The air mass will become
more unstable today as colder air moves in aloft and could lead to
some low-topped convection. As such, we have a slight chance
(generally less than 25%) of thunderstorms over the coastal
waters, the coast and also areas from the Umpqua Divide northward.
While other inland areas will also become more unstable, there
isn`t enough CAPE to worry too much about thunderstorms, but this
will translate into a well-mixed boundary layer resulting in
breezy conditions this afternoon. Overall, wind gusts should be in
the 25-40 mph range, with the highest gusts expected east of the
Cascades. Snow levels are very high this morning, generally 5500
feet or higher and even though colder air will move in aloft
today, snow levels probably don`t really get below 5000 feet until
this evening. By then, showers will be tapering off in most
areas.

The atmosphere is expected to stabilize in all but the coastal
waters/immediate coast tonight in more/less zonal flow aloft. This
will result in an overall reduction in shower coverage at least
briefly. However, the flow over the Pacific is fast, so another
upper disturbance offshore will head toward western Washington
tonight into Tuesday morning. As such, PoPs will remain high
(70-90%) along the coast and NW portions of the CWA. While there
is a slight chance of showers here in Medford Tuesday, most hours
will be dry. Precipitation chances diminish to 10% or less across
south and east portions of the area, including the Shasta Valley,
Modoc County and most of Highway 140 from Klamath Falls eastward.
Breezy conditions develop again during the afternoon.

Thereafter, heights begin to rise over the Southwest Wednesday
with an upper ridge amplifying into the Great Basin and
Intermountain West Thursday. This will bring a couple of nice,
dry, mild spring days with temperatures about 10-15F above normal
for afternoon highs. Even a few areas east of the Cascades could
be up to 20F higher than normal on Thursday. Thursday is the
warmest day with widespread west side valley highs in the mid to
upper 70s. We are currently forecasting 77F here in Medford. With
the exception of the higher terrain, most east side areas will
also have highs in the 70s.

The next spring front will arrive at the coast Thursday evening,
then move inland overnight into Friday morning. The front looks
fairly weak at this time with most precipitation potential
remaining from the Cascades westward. Breezy winds may develop again
east of the Cascades. As is often the case with spring frontal
systems, we`ll see temperatures drop back to near normal levels,
perhaps even a few degrees below normal for the west side valleys on
Saturday. But, it does look like high pressure will return on Sunday
with highs here in Medford in the mid 60s. Upper ridging should
persist into early next week. -Spilde

&&

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

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

Hazardous Seas Warning from 5 AM to 5 PM PDT Tuesday for PZZ350-
     356-370-376.

&&

$$