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000
FXUS66 KMFR 201015
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
315 AM PDT Sat Apr 20 2024

.DISCUSSION...The forecast remains fairly the same since
yesterday, with only a few minor changes, mainly in regards to
precipitation and thunderstorm chances midweek.

Dry conditions will continue today for most of the area. A weak
front will push into the region Saturday and flatten the ridge
Saturday night into Sunday. This front will run into a pretty dry
air mass, so not much precipitation is expected for the area. The
best chances for accumulating precipitation will be along the
coast (40%-70%), in the Umpqua Basin (20%-30%) and along the
Cascades from Crater Lake northward (20%-40%). Even the areas
that do receive precipitation are only expected to measure around
0.10"-0.20" west of the Coast Range with only a few hundreths
expected elsewhere. The remainder of the area will likely remain
dry with some increased cloud cover and gusty winds across the
region. Widespread gusts of 25 to 35 mph are expected east of the
Cascades with gusts of 15 to 25 mph expected for areas west of
the Cascades.

The front shifts east of the area Saturday night with high
pressure building in on Sunday/Monday. Frost/freezing conditions
are possible during this period of dry weather during the late
nights/early mornings in the valleys west of the Cascades. It will
only be nominally cooler on Sunday, with high temperatures closer
to normal across NW sections, but remaining at least a few
degrees above normal elsewhere. Monday will warm up substantially
(up 5-10 F over Sunday). Another thermal trough will strengthen in
NorCal resulting in another round of N-NE winds late Sunday
through Monday. This should even bring the milder weather to
portions of the SW coast (including Brookings). The remainder of
the work week looks more active.

Tuesday, the upper trough axis remains west of the forecast area,
but there`s enough evidence to suggest increasing instability
along with a weak trigger Tuesday afternoon and early evening and
could be enough to warrant a slight chance of thunderstorms in the
area, particularly over Siskiyou and Modoc counties and southern
portions of the Oregon East Side Tuesday afternoon into early
Tuesday evening.

We`ll catch a break Tuesday night with weak upper troughing over
our area, but energy is pretty weak so were not expecting
precipitation.

Wednesday, upper troughing remains and instability will once
again increase during the day. There remains quite a bit of
difference across the ensembles by this point, but the general
pattern suggests that showers and a slight chance of thunderstorms
will once again develop over northern California and the East
Side, with light showers mainly along northern Coos and northwest
Douglas counties as the upper level trough swings overhead and
onshore flow is enhanced.

Upper troughiness remains over our area the rest of next week
which will result in cooler temperatures and a higher chance for
showers over a good portion of the forecast area.
-BR-y/Petrucelli/BPN

&&

.AVIATION...20/06Z TAFs...VFR conditions under clear skies and with
light winds continue overnight and into Saturday morning. On
Saturday afternoon, a weak front will bring light showers along the
Oregon coast and gusty winds over higher elevations, especially east
of the Cascades. Periods of MVFR ceilings and impaired visibilities
under showers are possible, especially along the Oregon coast. VFR
levels will continue in other areas. -TAD

&&

.MARINE...Updated 300 AM Saturday, April 19, 2024...A weak cold
front will bring increasing south winds early this morning, but they
are expected to remain below small craft advisory levels. The front
will move inland by the afternoon with winds becoming westerly
behind it.

On Sunday, high pressure will be offshore and a thermal trough will
set up along the south coast. North winds increase across the waters
early Sunday with moderate to strong winds possibly reaching gale
force south of Cape Blanco Sunday afternoon into Monday. These gusty
winds will result in steep to very steep wind-driven seas across the
waters.

Conditions are likely to improve Tuesday into Wednesday, ahead of
the next cold front on Wednesday night into Thursday.
-DW/Hermansen


&&

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

CA...None.

PACIFIC COASTAL WATERS...None.

&&

$$