543
FXUS66 KMFR 162158
AFDMFR

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

.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...(18Z TAFs)...A variety of changes at the terminals
are expected today as an upper level disturbance continues to move
over the west coast. This will bring widespread clouds (varying
levels) across the region, breezy afternoon winds, and a chance
for rainfall. The rainfall will first start impacting Klamath
Falls later this afternoon. Showers will be in more locations west
of the Cascades later tomorrow morning, so this will be included
in the next TAF update. The other concern are the potential of
IFR/LIFR ceilings after 12Z tomorrow, so that has been added to
the TAFs. -Guerrero/Hermansen



&&

.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.

&&

$$