142
FXUS66 KMFR 190539
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
1039 PM PDT Wed Sep 18 2024

.DISCUSSION...Tonight, mostly clear skies will prevail. However, a
thermal trough will set up along the south Oregon coast.
residual moisture from rain earlier in the week will bring marine
stratus to the coast north of Cape Blanco and south of Gold Beach.
Some stratus could also form in portions of the Umpqua Basin.

Thursday through early next week will be dry with afternoon
temperatures trending warmer for the interior. The thermal trough
will remain in place along the south Oregon coast and the pattern is
one where we could see afternoon temperatures at Brookings get into
the lower to mid 70s Thursday, then into the lower to mid 80s,
possibly the upper 80s Friday through the start of next week.
Tuesday, the thermal trough will build north and weaken some
allowing the flow to become weak onshore at Brookings, therefore it
should be cooler.

Upper ridging will build over the area Monday and Tuesday with
afternoon temperatures maxing out both these days, then the upper
ridge will flatten out some with the thermal trough shifting east of
the Cascades and being replaced with an onshore flow resulting in
cooler afternoon temperatures. -Petrucelli/Spilde

&&

.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 830 PM Wednesday, September 18, 2024...A thermal
trough will bring gusty northerly winds, building steep seas in
waters south of Cape Blanco this evening. Steep seas will spread to
waters north of Cape Blanco later Thursday morning, with very steep
and hazardous seas expected south of Pistol River. Periods of very
steep seas may be possible as far north as Port Orford on Thursday
and Friday afternoon and evening. Occasional gale gusts will be
possible in 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 Pistol River
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, but are likely to extend through the weekend.
Additional guidance will help to determine the best areal
coverage for continuing chaotic seas. -TAD/Spilde


&&

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

PACIFIC COASTAL WATERS...Small Craft Advisory from 5 AM Thursday to 5
     PM PDT Friday for PZZ350-370.

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

     Hazardous Seas Warning from 5 AM Thursday to 5 PM PDT Friday for
     PZZ356-376.

&&

$$

MAP/CZS/TAD/MAS