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000
FXUS66 KMFR 150002
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
502 PM PDT Sun Apr 14 2024

.Updated AVIATION Discussion...

&&

.AVIATION...15/00Z TAFs...A band of showers and thunderstorms is
streaming over northern Lake County into central Klamath and eastern
Siskiyou County this afternoon. This is bringing an area of IFR
conditions under this precipitation, along with brief periods of
strong wind gusts, including at Klamath Falls. Elsewhere, showers
are more isolated, especially west of the Cascades, with a mix of
low end VFR and MVFR conditions and widespread terrain obscurations.

The overall trend for the remainder of the evening and into the
overnight hours is for decreasing shower activity with showers
expected to really diminish after 04z-06z tonight. Cloud cover,
however, will linger well into Monday morning. Conditions are likely
to remain MVFR for West Side Valleys, with a mix of IFR/MVFR
possible for areas east of the Cascades where more precipitation has
fallen today. MVFR conditions are possible along the coast as well
tonight, though confidence is lower. Lingering cloud cover Monday
morning is expected to clear by late morning/early afternoon and VFR
conditions are expected area wide after 18z-21z. /BR-y

&&

.PREV DISCUSSION... /Issued 237 PM PDT Sun Apr 14 2024/

SHORT TERM...Through Wednesday morning. The last broad band of
the main showers that were also related to the Winter Weather
Advisory in extreme northern California has mostly exited to the
forecast area. However, a very well defined line of thunderstorms
is moving southwest in Lake and Klamath counties that may bring
additional brief but heavy snow with them. Some of these
thunderstorms may also bring small hail and brief gusty winds this
afternoon.

The region begins to transition to a warming and drying trend into
mid week as the upper low that will move the remaining showers
slowly leaving the east side into Monday morning continues it`s
eastward trek. A weak upper ridge builds in from the west with a
thermal trough deepening along the southern coast with offshore
flow developing by early Tuesday morning. This thermal trough dry
pattern remains with around 5 degrees warning day by day into mid
week. -Sven

LONG TERM...Wednesday (04/17) through Sunday (04/21)...This
extended period starts as high pressure builds across the PNW
region, and the thermal trough building along the S. Oregon coast
peaks and begins to get displaced inland. A thermal trough moving
inland will lead to a rise in temperatures across the region. This
time there is no exception, and temperatures will build through the
end of the work week; peaking on Friday. Temperatures on Friday will
peak in the mid-to-upper 70s west of the Cascades and upper 60s east
of the Cascades. These temperatures are about 10 to 15 degrees above
normal. However, while the heat risk is very low, the sun will be
hot. Don`t be like me and venture into the mountains (or lakeshore)
without sunscreen and end up with burnt lips like I did (don`t
worry, my nose and ears were okay). Regularly applying sunscreen and
protective layers of clothing will be important!

Winds will setup in a typical summer-time diurnal pattern Wednesday
through Friday, with stronger up valley flows in the afternoon.
Meanwhile at night winds will be light to nearly calm. The light
winds and clear skies will support efficient radiative cooling at
night and freezing temperatures are forecast around the Illinois and
Applegate Valley, as well as more localized areas of the Rogue
Valley and Douglas County. Frost could be more widespread than the
freezing temperatures, too. While less widespread, there are low
chances for frost/freeze in the same areas on Wednesday
night/Thursday morning.

While this region experiences some summer-like warmth, a broad low
pressure system will be developing in the Gulf of Alaska. After a
few frosty mornings and warm days, this area of low pressure will
move across the Canadian Rockies. This will be enough to cause a
pattern change here, too, and cool the region back closer to normal
temperatures. But we are left wondering, will there be rain? Chances
are low, generally 30% or less across the Cascades, Douglas County,
and coast. So while we are confident that the warm pattern will
break by next weekend, there is still much uncertainty over how
much, if any, rain this region sees.

-Miles

MARINE...Updated 215 PM Sunday, April 15, 2024...Gusty winds
combined with a westerly swell will maintain steep seas with
conditions hazardous to small craft for all areas beyond 5 nm from
shore through the start of tonight.

Conditions improve briefly tomorrow morning as the upper low moves
further south and rain showers cease. Improved conditions will be
short lived because a thermal trough develops in the afternoon. This
pattern will bring another round of gusty north winds, along with
steep to very steep seas, especially south of Cape Blanco.

The thermal trough is expected to peak Tuesday evening through
Wednesday. At its peak, the strongest winds are expected to expand
north of Cape Blanco. There is uncertainty as to how far northward
this expansion of winds will be. As a result, we only have an
advisory in place from Monday morning through Tuesday morning for
the thermal trough driven winds. We do expect to need further
advisories after, though. The gusty north winds will persist into
Thursday, before conditions improve.

-Miles/Hermansen

&&

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

CA...None.

PACIFIC COASTAL WATERS...Small Craft Advisory until 2 AM PDT Monday
     for PZZ350-356-370-376.

&&

$$

SBN/MCB/ANH/BR-y