Small Craft Advisory 39, NWS Medford, OR

Area Forecast Discussion
National Weather Service Medford OR
1100 AM PDT Sat Apr 2 2022

Updated Aviation discussion.

.AVIATION...02/18Z TAFs...A few cumulus buildups will drift around
the west side today, but conditions are already VFR at all terminals
and it is expected to stay that way today. Tonight, LIFR stratus and
fog is likely redevelop along the coast with VFR continuing inland.
Relatively light diurnal winds (mainly NW-W during the day and
VRB at night) will continue through the TAF period. -Wright

&&

.PREV DISCUSSION... /Issued 842 AM PDT Sat Apr 2 2022/

DISCUSSION...Satellite imagery depicts mostly sunny skies across
the forecast area. Looking further out, a significant storm
system is pushing through the Northeast Pacific waters. It will
take a few days for the storm to arrive, and before it does, today
will be warm again (high temperatures 5 degrees above normal) and
mostly sunny. Clouds and winds will increase on Sunday, and
beneficial rain will arrive Sunday evening and overnight. Gusty
winds and mountain snow will be the main weather hazards that
we're communicating with this storm system, and we'll continue to
look at that today. Please see the previous discussion below for
more details on the upcoming wet weather and subsequent warm up.
Keene

MARINE...Updated 830 AM PDT Saturday 2 April 2022...Gusty north
winds will develop south of Cape Blanco later today, with lighter
north winds prevailing over the rest of the waters. Conditions
will improve tonight, then winds switch to southerly on Sunday and
increase throughout the day, particularly in the northern waters.
Gale force winds are possible Sunday night as winds continue to
increase. If gales do occur, they should be north of Cape Blanco
and around 3 to 30 nm from shore. Confidence in gale force gusts
along the front is around 60%. Outside of the potential area of
gales, winds will be hazardous to smaller crafts. In addition, a
rather large long period northwest swell will build into the
waters beginning Sunday night and persist through Tuesday night.

FIRE WEATHER...Updated at 345 AM PDT Saturday, April 2nd,
2022... We have begun issuing 7 Day NFDRS forecasts for 2022. Also
of note, we're expecting breezy to windy conditions across the
forecast area, strongest across the mountains and east of the
Cascades, on Monday. Winds are likely to be strongest in the
afternoon and evening hours. While much of the forecast area is
likely to receive wetting rainfall Sunday night through Tuesday
morning, some areas east of the Cascades are likely to receive
little to no rainfall. ~BTL

PREV DISCUSSION... /Issued 510 AM PDT Sat Apr 2 2022/

DISCUSSION...
Some light rain has been reported overnight along and near the
coast and into the Umpqua Basin. Light snow has been reported in
the Oregon Cascades north of Highway 140. Measurable water amounts
have been under a tenth of an inch. This precipitation was
associated with a mid-level trough that moved through behind a
weak lower level cold front that pushed through this past
afternoon and evening. Aside from a few flurries or sprinkles of
rain early this morning in upslope NW flow along and near hills
and mountain slopes, we're expecting dry weather the remainder of
the day today. In fact, KMAX is currently indicating no
precipitation returns at this time.

Clouds will continue to be on decrease today resulting in mostly
sunny skies this afternoon and evening. Daytime highs will be
close to what they were on Friday.

Then, tonight into Sunday, a strong, zonally oriented jet stream
will begin to push a leading shortwave trough into and then across
the area. Clouds and southwest winds will begin to increase.

A High Wind Watch has been issued for much of the east side,
including most of Lake County and the nearby higher terrain, valid
from 2AM PDT Sunday night through 8PM PDT Monday evening. Wind
there is expected to gust 55 to 65 mph. It will also be generally
breezy (gust 15 to 25 mph) west of the Cascades Monday afternoon
and evening, and windy across the mountains and the remainder of
the east side, with gusts 25 to 35 mph and higher. It's likely
that we'll end up with some wind advisories for many areas east of
the Cascades, in addition to the High Wind Watch that may become
a warning, for Monday.

As for precipitation, the window for that is generally Sunday
night through Tuesday morning. Expected water amounts in the
Cascades north of Highway 140 and along and near the coast range
are likely to be in the 1-2 inch range. Models have also trended a
bit wetter for NW California from the Marble Mountains and
Siskiyous westward, where amounts of a half inch to an inch of
water are generally expected. Amounts will be lighter in the
interior west side valleys not already mentioned, mostly in the
0.20-0.70" range. From the Shasta Valley and southeast of Klamath
Falls, water amounts are most likely to be a tenth of an inch or
less.

As for snowfall, elevations above 4.5kft to 5.5kft north of
Highway 140 are likely to see moderate to heavy snowfall Sunday
night into Monday morning, with 5 to 14 inches of new snow
expected. We're likely to need a Winter Weather Advisory for that
area. South and east of there, amounts are expected to be 4 inches
or less.

Cool weather will then follow the early week precipitation and
wind. Lows Tuesday and Wednesday mornings will be supportive of
frost and freeze in the Grants Pass and Medford areas Wednesday
morning.

A rapid warm-up will then ensue for Wednesday afternoon through
Thursday. Easterly winds during that time period will dry the air
mass and result in some downslope warming for many areas. Highs
Thursday are likely to be about 20 degrees above normal for some
west side valley locations such as Medford, which is expected to
be 84F. This will put us about 5 degrees short of record highs for
Thursday that were broken in 2016.

Ensembles continue to indicate an anomalously cold trough of low
pressure then moving in sometime next weekend resulting in colder
than normal and wet conditions for most or all of the area. While
details are still to be worked out, it looks like snow levels are
likely to come down into the 2kft to 4kft foot range with periods
of stratiform precipitation followed by convective showers from
that cold trough. ~BTL

&&

.MFR WATCHES/WARNINGS/ADVISORIES...
OR...High Wind Watch from late Sunday night through Monday evening
     for ORZ030-031.

CA...High Wind Watch from late Sunday night through Monday evening
     for CAZ085.

Pacific Coastal Waters...
     Small Craft Advisory from 5 PM Sunday to 5 PM PDT Monday for
     PZZ350-356-376.
     Gale Watch from Sunday afternoon through late Sunday night for
     PZZ350-370.
     Small Craft Advisory from 11 AM Sunday to 5 PM PDT Monday for
     PZZ370.