Sneakerwave in Oregon, March 1, 2025

Area Forecast Discussion
National Weather Service Medford OR
838 PM PST Fri Feb 28 2025

.UPDATE...Updated Aviation and Marine Discussion.

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.AVIATION...01/00Z TAFs...Along the coast, stratus and fog is
expected to move onshore early this evening then persist through
Saturday morning. Low clouds and fog are currently just off the
coast and locally at North Bend (KOTH).

Inland, conditions are VFR. IFR/LIFR condition are expected to
develop in the Umpqua basin, including at Roseburg (KRBG) late
tonight and persist Saturday morning, before clearing to VFR.

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.MARINE...Updated 800 PM PST Friday, February 28, 2025...Steep,
westerly seas will build this evening into Saturday. Northerly winds
will weaken tonight, becoming southerly and strengthening on
Saturday, then shifting back to westerly Saturday evening. Moderate
northwesterly winds are expected on Sunday, then lower on Monday.
Steep westerly seas will persist through Monday morning. Improved
conditions are then expected Monday afternoon through most of next
week.

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.BEACH HAZARDS...Updated 200 AM PST Friday, February 28,
2025...Beginning this evening, models support a moderate to high
risk of sneaker waves along the southern Oregon coast south of Cape
Blanco as a long period westerly swell builds into the waters and
combines with existing swells. This risk of sneaker waves includes
all beaches along Curry County, although the highest risk will be to
west-facing beaches. A beach hazards statement is in effect tonight
into early tomorrow morning (CFWMFR). Those visiting or recreating
along the southern Oregon coast should take extra precautions.
Sneaker waves can run up significantly farther on beaches than
normal, including over rocks and jetties. These waves can suddenly
knock people off of their feet and quickly pull them into the cold
ocean waters, resulting in serious injury or death. Waves may also
lift driftwood logs, trapping anyone caught underneath.

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.PREV DISCUSSION... /Issued 150 PM PST Fri Feb 28 2025/

DISCUSSION...A strong upper ridge over northern California,
southern Oregon and into the Great Basin is providing wall to wall
sunshine for inland areas today with some stratus hugging the
beaches and just offshore. A closed low is also positioned off
the southern California coast. This blocking pattern has been
responsible for this period of unseasonably mild late February
weather. Temperatures this afternoon are running a degree or two
higher than yesterday at this time over inland areas. Highs
here in Medford will be in the low 70s again.

The blocking pattern will break down this weekend as an upper
level trough gets a kick eastward as a stronger jet arrives over
the Pacific. This trough will be off the PacNW coast Saturday, so
many inland areas will eke out one more nice, mild day (but
probably a bit cooler compared to today). With weak onshore flow
tonight into Saturday morning, there still will be some marine
layer cloudiness along the coast and into coastal valleys of Coos
County. There is also a chance for some drizzle out of the marine
layer, but only a hundredth or two here and there. Areas of fog
should once again develop in the Umpqua Basin and into the
Illinois Valley.

The upper trough will move onshore Saturday night with a period of
light to moderate frontal precipitation spreading from the coast
to the Cascades during the evening, then east of the Cascades
overnight into Sunday morning. Snow levels up around 7000 feet
Saturday evening will drop to 4000-4500 feet by Sunday morning.
Steadiest precipitation will move through the Cascades (including
Lake of the Woods on Hwy 140) during the overnight, with peak
snowfall rates generally 0.25-0.50"/hr, perhaps briefly up to
1"/hr (an hour or two) in the 11p-3am time frame. 2-5 inches of
snow is forecast for the Siskiyou/Warner Mtns. At Siskiyou Summit
on I-5 and over the east side, rain could briefly change to snow
before precipitation becomes more showery behind the front Sunday
morning.

Post-frontal showers will continue Sunday afternoon/night as the
cold pool aloft swings through SW Oregon and across NorCal. Snow
levels will drop to around 3500 feet Sunday night, but
precipitation will be most persistent over the mountains and will
diminish in coverage by MOnday morning as the trough/low moves
into the Great Basin.

It looks like we'll catch a break Monday night as a weak ridge
axis moves overhead, but the next trough will approach the coast
Tuesday. Expect precipitation associated with this system to
develop along the coast Tuesday morning, then spread inland to the
Cascades during Tuesday afternoon. Another upper trough will move
through Wednesday. While the weather pattern remains active, both
of these system will mostly feature some light rain/mountain snow
with only minor impacts. Remaining in the split flow regime late
next week (Thu/Fri), our area should be mostly in the dry region
between the northern and southern branches.

Beyond that, some model ensemble members are showing a risk for a
stronger front to arrive next weekend, March 8th or 9th, that
could bring a return of stormy weather. However, there are still a
large number of members that maintain a drier forecast. The 8 to
14 day forecast from CPC is indicating about a 60% probability of
above average precipitation and similar odds for below normal
temperatures. We'll continue to monitor this potential. -Spilde

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.MFR WATCHES/WARNINGS/ADVISORIES...
OR...Beach Hazards Statement until 7 AM PST Saturday for ORZ022.

CA...None.

PACIFIC COASTAL WATERS...Small Craft Advisory until 10 AM PST Monday
     for PZZ350-356-370-376.

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