505
FXUS66 KMFR 271132
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
432 AM PDT Fri Sep 27 2024

.DISCUSSION...Warm to very warm and dry to very dry conditions
are expected through Thursday/Day 6, and with the highest
probability that they will continue next weekend/Day 7 through
Day 10.

With that said, the pattern will not be stagnant. This will result
in some day-to-day variation in temperatures, winds, and
humidities.

The first and likely the weakest of the disturbances affecting our
weather during the next week is focused north of our area, and
will dissipate over western Oregon. It will merely bring an
increase of clouds to Coos and northwest Douglas counties and
northward this morning, including the Coquille and lower Umpqua
valleys, roughly west and north of Roseburg. Emblematic of its
weakness, rather than cooler today, a thermal trough will set up
along the south Oregon coast resulting in a warmer day than
yesterday inland, though also increasing north winds along the
coast.

Excepting the continued gusty northerly winds at the coast, the
next dry trough will bring afternoon and evening breezes at 10 to
15 mph with gusts at 15 to 25 mph this weekend (westerly on
Saturday and northerly on Sunday), strongest east of the Cascades.
Highs on Saturday will similar to those of today, perhaps up to a
few degrees warmer, then the trough passage will bring some high
clouds across the area and coastal low clouds Saturday night,
followed by several degrees of cooling of highs for Sunday.

The thermal trough will return and strengthen early in the week.
Easterly winds will accompany poor to moderate ridge top humidity
recoveries early next week, with critical conditions possible
over the Coast Range. The hottest and driest conditions are
expected on Tuesday.

A weak, dry trough on Wednesday and another stronger trough
around Friday will briefly trend conditions closer to normal, and
kick up afternoon wind speeds to breezy again. There has been and
still remains some hope of the latter trough, arriving around
Friday or Saturday, bring some rain chances. The 06Z GFS is
stronger than its previous few runs in regards to the trough.
The probability is highest to the west and north. But, the
overall trend in the broader cadre of models has been weaker/drier
with around 10% to 20% of ECMWF and GEFS ensemble members in the
00Z suite of data indicating rain in our area. So, for now we will
roll with a blended solution and stay tuned for updates.

&&

.AVIATION...27/06Z TAFS...A weak front will push into the region
tonight, but will dissipate as it moves onshore. MVFR ceilings are
possible along the coast, over the coastal waters, and into the
Umpqua Basin, although most areas will remain VFR. Skies should
clear through the morning, then gusty north winds are expected along
the coast and over the waters through the rest of the day.

Elsewhere, VFR conditions will continue through the TAF period.
-BPN


&&

.MARINE...Updated 200 AM, September 27, 2024...Area waters are calm
to start the morning, but elevated westerly swell is approaching
the area. A thermal trough will also start to develop today,
bringing gusty northerly winds to all waters and stronger gusts
south of Cape Blanco. The combination of swell and winds will build
steep seas in all waters later this morning. Very steep and
hazardous seas will be present in most waters south of Cape Blanco,
with sheltered areas near the coast remaining at steep sea states.

Currently, Small Craft Advisories and Hazardous Seas Warnings are in
place through Sunday evening. For Sunday evening into Monday
morning, the thermal trough is expected to strengthen and possibly
add gale winds for waters south of Gold Beach. Current guidance
suggests winds generally near or at gale strength, but confidence in
the timing is lacking. Additional hazards are certain for Sunday
evening into the day Monday, but better clarity will help to make
better products.

Unsettled seas look likely to continue through at least midweek as
the thermal trough remains in place, with another period of combined
wind wave and westerly swell possible on Wednesday afternoon and
evening. -TAD

&&

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

PACIFIC COASTAL WATERS...Small Craft Advisory from 8 AM this morning
     to 5 PM PDT Sunday for PZZ350-356-370-376.

Hazardous Seas Warning from 8 PM this evening to 5 PM PDT Sunday
     for PZZ356-376.

&&

$$