111
FXUS66 KMFR 221802
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
1102 AM PDT Sat Jun 22 2024

.Updated AVIATION Discussion...

&&

.AVIATION...(22/18Z TAFs) Aside from some lingering LIFR ceilings
over portions of the marine waters and along the coast south of
Gold Beach, VFR conditions prevail across the region. Conditions
may improve briefly south of Gold Beach this afternoon but
confidence is low in the duration and extent. Otherwise, VFR will
prevail for all other areas through the afternoon. Expect the
typical increase in afternoon breezes today, though slightly
enhanced due to an incoming upper level trough.

Late this afternoon and overnight, this trough will push the
marine layer back along the coast and into the Umpqua Basin
overnight tonight. Expect the return of LIFR/IFR conditions along
the coast, especially north of Cape Blanco between 23z-03z, lifting
to IFR around 04-06z. Conditions in the Umpqua Basin are expected to
be MVFR, including at Roseburg (KRBG). The marine layer does not
look deep enough to "spill over" the Rogue-Umpqua Divide, but there
could be some scattered clouds that develop over the Illinois and
Applegate Valleys around sunrise Sunday morning. /BR-y

&&

.PREV DISCUSSION... /Issued 828 AM PDT Sat Jun 22 2024/

UPDATE...Updated marine discussion and small craft advisory. No
other changes were made this morning.

MARINE...Updated 825 AM Saturday, June 22, 2024...The thermal
trough will weaken today, but steep seas will persist south of
Cape Blanco into this afternoon. With the wind wave transitioning
into fresh swell and beginning to decay, we shortened the duration
of the small craft advisory. A weak front will bring a surge of
stratus late today into Sunday with light showers possible mainly
across the northern waters.

Sunday evening, the thermal trough will begin to build again and
steep to very steep seas are again expected. Steep, advisory seas
are possible for a wide area south of Cape Blanco, with the highest
confidence area for very steep seas being south of Brookings. This
next pulse in the thermal trough is expected to last through Monday
before another front disrupts it either Tuesday or Wedensday.
-Miles

PREV DISCUSSION... /Issued 348 AM PDT Sat Jun 22 2024/

DISCUSSION...Satellite imagery is showing some marine stratus
across portions of the coast and offshore. Meanwhile there is some
higher cloud cover occurring across portions of southern Oregon
while northern California is observing mainly clear skies. We are
the influence of a weak trough which is exiting the Pacific
Northwest, and another trough will pass through southern Oregon
later today into Sunday. This trough may cause a marine push to
bring light drizzle to portions of the Coos and Douglas County
Coast this morning, but all other areas will remain dry.

The main concern with this trough will be the breezy winds with
continued dry conditions. If this were taking place in August or
September, we might be a bit more worried; but local fire agencies
are generally reporting moderate fire danger with grass-like
vegetation more receptive to catching fire than leaves and other
shrubs at this point in time. That being said, we have seen some
fire activity over the last couple of days, but in general
conditions do not warrant additional products like a red flag
warning due to the moderate nature of the fire danger. That being
said, breezy winds may still impact ongoing fires like the Little
Applegate fire this weekend. Since the winds will be from the
northwest, smoke may push toward the southeast; but most of the
smoke will be relatively well-mixed and will only cause the
biggest impacts to areas immediately downwind and close to the
fire.

The weather remains somewhat unsettled as the parent low pushing
through the northern half of the Pacific Northwest. This will
bring increased rain chances to portions of the coast and Umpqua
Basin with very light rain showers possible. More aptly, this low
will keep temperatures a little bit cooler with today being the
hottest day. Temperatures will gradually cool down before dropping
several degrees closer to normal for the latter half of the work
week. -Schaaf

FIRE WEATHER...Updated 200 PM Friday, June 21, 2024...Previous
fire weather discussion issued 145 PM Friday...For areas west of
the Cascades, over the next couple days critical conditions are
not expected. This will be anchored by good humidity recoveries
(80% and higher) in valleys and moderate to good humidity
recoveries over upper slopes and ridges (50-70%) overnight.
Afternoon humidities in this area will bottom out in the mid to
upper teens to 20 percent, with these minimum humidity values
trending similar this afternoon to Saturday afternoon. Some
drizzle in the coast range and across Douglas County Saturday
night, will continue to keep concerns low.

East of the Cascades, weather conditions are a bit different, as
brief durations of critical wind & humidity conditions Saturday
and possibly Sunday are possible. These would be in eastern zone
624 between Bly and Lakeview, as well as around Alturas in Modoc
County. This will be caused by a dry front moving through late
Saturday into Sunday. The driest conditions are expected Saturday
near 10%, while the strongest breezes are expected Sunday
afternoon, with some areas gusting to 30 mph.

No lightning is expected over the forecast area through at least
Tuesday. -Miles

&&

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

PACIFIC COASTAL WATERS...Small Craft Advisory until 8 PM PDT this
     evening for PZZ356-376.

&&

$$

MCB/BMS/MNF