423
FXUS66 KMFR 191052
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
352 AM PDT Thu Sep 19 2024

.DISCUSSION...Generally benign conditions are expected through
the forecast period with near to occasionally above normal
temperatures and no precipitation chances outside of some light
marine layer drizzle. Skies are clear for most of the region this
morning with the exception of marine stratus over the waters and
draped along the coast into the Coquille Basin. Residual moisture
from recent rainfall is allowing for the development of patchy low
clouds in the Umpqua Basin, otherwise skies are clear across the
region.

Low pressure responsible for the recent rainfall will continue to
trek southward today and a thermal trough will develop along the
coast. To the west, high pressure aloft will linger over the eastern
Pacific Ocean, largely blocking the storm door for our area. The
storm track will remain to the north, but shortwaves will ride over
the top of the ridge, moving into the region on northwest flow over
the weekend. No precipitation is expected with these shortwaves, but
expect increases in afternoon breezes at times. This pattern will
lead to near normal temperatures for the interior with cool mornings
giving way to warm afternoons (low-mid 80s for West Side Valleys,
mid-upper 70s for East Side). With a thermal trough in place,
northeast flow will bring some warmer temperatures at times to the
Brookings area with upper 70s-low 80s possible through the weekend.
This northeast flow will also bring some gusty winds to the ridges
overnight, especially to the Kalmiopsis Wilderness area. Recoveries
will trend lower Saturday and Sunday mornings, but remain above
critical thresholds for fire weather concerns.

Early next week, ridging nudges into the region Monday and moves
overhead on Tuesday. This will bring the hottest temperatures of the
forecast period. Tuesday will be the hottest day as the thermal
trough moves inland and temperatures in West (East) Side Valleys
reach into the low-mid 90s (low-mid 80s). This warm up will be short-
lived, however, as the upper level pattern starts to transition on
Wednesday when a large scale trough approaches the region.
Temperatures trend cooler for the latter half of the week, but most
of the guidance maintains dry conditions into next weekend or
beyond. /BR-y

&&

.AVIATION...19/06Z TAFS...IFR/LIFR will impact coastal locations
overnight into Thursday morning, especially from Port Orford
northward, but also south of Gold Beach. Expect the stratus/fog
to break up around 18z, then gusty north winds (gusts of 25+ kt)
will develop at North Bend Thursday afternoon. IFR ceilings could
return to some areas Thursday night, but probably not as widespread
as tonight.

Inland, areas of MVFR ceilings are expected to develop in the Umpqua
Basin overnight into Thursday morning, including at Roseburg.
Highest probability of MVFR ceilings is from 12-18Z, then VFR will
return Thursday afternoon. Most of the remainder of the area will be
VFR for the next 24 hours, aside from patchy valley fog early
Thursday, especially in areas that had some rain on Tuesday. Any fog
will be short-lived though, only for a few hours at most. -Spilde

&&

.MARINE...Updated 200 AM Thursday, September 19, 2024...A thermal
trough has brought gusty northerly winds, building steep seas in
waters south of Cape Blanco. Steep seas will spread to waters north
of Cape Blanco later this morning, with very steep and hazardous
seas expected south of Pistol River through Friday afternoon.
Periods of very steep seas may be possible as far north as Gold
Beach today and Friday afternoon and evening. Occasional gale gusts
will be possible on the afternoon and evening as well.

The thermal trough looks to remain in place through the weekend and
into next week, with signs of calming by Tuesday evening. A
Hazardous Seas Warning is in place for waters south of Gold Beach
and beyond 5 nm from shore, and a Small Craft Advisory will cover
all other waters. Currently these hazards are in place through
Friday at 5 PM, bu are likely to extend through the weekend.
Additional guidance will help to determine the best areal coverage
for continuing chaotic seas. -Spilde/Hermansen

&&

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

PACIFIC COASTAL WATERS...Small Craft Advisory until 5 PM PDT Friday
     for PZZ350-370.

Small Craft Advisory until 5 PM PDT Friday for PZZ356-376.

     Hazardous Seas Warning until 5 PM PDT Friday for PZZ356-376.

&&

$$

MNF/ANH/MAS