077
FXUS66 KMFR 170006
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
506 PM PDT Mon Sep 16 2024

...Updated AVIATION discussion...

.SHORT TERM...Tonight (9/16) through Wednesday night (9/19)...
Satellite imagery is showing extensive cloud cover across portions
of southern Oregon and northern California. Above the lower cloud
layer is a second layer of higher clouds that are circulating anti-
clockwise indicative of a low pressure system traversing across
northern California and northwest Nevada. Meanwhile, RADAR imagery
is showing some showers pushing from northeast to southwest across
portions of Klamath, Siskiyou, and Modoc Counties. There may be
additional showers and thunderstorms later this afternoon and
evening, specifically for portions of Lake and Modoc Counties.

This low will traverse out of our area this evening and tonight
and the next low will approach the Pacific Northwest on Tuesday.
This will bring the next set of precipitation across the area,
mainly favoring West Side. In general, rainfall will be wetting
along and west of the Cascades. Temperatures will remain cooler
than normal as well.

Showers may linger on Wednesday, but gradually dissipate.
Temperatures will start to warm up on Wednesday as well. -Schaaf

.LONG TERM...Thursday (9/20)through Monday (9/23)...A ridge of
high pressure returns to the area, allowing conditions to dry out
and temperatures to warm up. Another front will push through the
Pacific Northwest over the weekend, and ensembles differ on the
strength and location of the front. That being said, the National
Blend of Models favors a 20 percent chance or less for
precipitation for the coast, Umpqua Basin and the Cascades from
Highway 140 northward. Stay tuned to the forecast as we are
entering the shoulder of fire season where wetter weather begins
to return. This is the case as ensembles suggest that another
system could return by midweek next week. Fire season is not quite
over, but it has slowed significantly by this point, and we will
continue to see how things play out. -Schaaf


&&

.AVIATION...17/00Z TAFS...Clouds continue to spin around an upper
level disturbance this afternoon. Showers are decreasing, and mostly
located over Siskiyou and Modoc counties.

Cloud cover from the disturbance will continue over Modoc and Lake
counties through the TAF period, with areas of MVFR and IFR
ceilings. Marine stratus is developing along the Oregon coast at
North Bend, with MVFR ceilings generally expected overnight and into
Tuesday morning. IFR ceilings are possible early Tuesday morning but
are not well supported in current guidance.

On Tuesday afternoon, another system will approach the area. Showers
are expected at North Bend and near Roseburg on Tuesday afternoon,
with further showers beyond the current TAF period. -TAD

&&

.MARINE...Updated 230 PM Monday, September 16, 2024... Strengthening
today will result in steep to very steep seas through tonight, with
the strongest winds and highest seas south of Cape Blanco where a
Hazardous Seas Warning is in effect through 5 AM.

An incoming front Tuesday will briefly turn winds to a southerly
component, while allowing seas to briefly diminish. During this
time, rain showers and isolated thunderstorms will also be possible
over the waters. The chance for rain is high (85+%), but
thunderstorm chances are only around 15-20%. That said, any
thunderstorm that develops will have the potential for strong
erratic gusty winds. Moderate to occasionally strong north winds and
steep seas will develop Wednesday, likely bringing the return of
conditions hazardous to small craft through the end of the week.

-Guerrero/Hermansen


&&

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

PACIFIC COASTAL WATERS...Small Craft Advisory until 5 AM PDT Tuesday
     for PZZ350-356-370-376.

Hazardous Seas Warning until 5 AM PDT Tuesday for PZZ356-376.

&&

$$