Winter Storm Warning 2, NWS Medford, OR

Area Forecast Discussion
National Weather Service Medford OR
252 PM PST Thu Jan 5 2023

.DISCUSSION...Winds across the region have decreased below warning
and advisory levels, but gusty winds remain this afternoon.
Showers continue to taper off tonight into early Friday morning
ahead of the next front moving in Friday, This system is
indicating as another winds system, but not as windy as the last
system. the strongest winds are expected in the Shasta Valley and
mostly higher elevations east of the Cascades, Like the last
system, the Mount Shasta region will see the greatest snow
amounts, but with lower winds the precipitation rates are not
expected to start as strong, and with the lower precipitation
rates snow levels are not expected to start as low, with the
greatest amounts being above 4500 ft elevation, with sub advisory
amounts possible below that elevation. However, above 4500 ft
elevation, snow amounts are not expected to be much lower than the
last system. Watches for the the snow in Siskiyou County and the
winds in the Shasta Valley an portions of the east side have been
issued.

This front is expected to stall over the region as the closed
upper low slowly curves in towards the coast before swinging to
the northeast Saturday. Winds and snow coverage and amounts may
possibly be the same as Friday's, but models diverge quite a bit
with strength and confidence is not high enough to issue a watch
for this timeframe at this time. -Sven

.Discussion...(Sunday through Thursday). The pattern will
remain active for the foreseeable future with a parade of systems
moving through the area. The pattern that has set up over the
Pacific remains fairly consistent with systems lined up as far west
as the Aleutians.

The main challenge during this time will be the timing, intensity,
and track of each individual upper low trough, surface fronts and
surface low pressures. Unfortunately the individual ensemble members
show a great amount of variation, which makes it difficult to pin
down the details at this time. The one thing we do know is the wet
and windy pattern will continue, with additional systems moving
through the area about once every one or two days.

We'll have a system move into the area Sunday morning bring moderate
to occasionally heavy precipitation in northern California and the
coastal mountains in southwest Oregon. A front will move through
with precipitation generally diminishing, but not ending completely.
Moderate to occasionally strong winds are also expected along the
coast, eastside and portions of the westside, especially over the
higher terrain.

A "relative" break in the action is anticipated Sunday afternoon
into Sunday evening, then another system will bring another round of
moderate to occasionally heavy precipitation and moderate to strong
winds to similar locations late Sunday night into Monday morning
followed by a front Monday afternoon. Snow levels during this time
will fluctuate, especially during periods of when the warm front
moves through where they can end up around 5000 feet, followed by
the cold front where they could lower to around 4000 feet. Areas
above 5000 feet are likely to have some travel impacts. Thats' not
to day areas above 4000 wont't but the chances will be diminished
some. With that said, keep in mind the timing that's being
communicated in this discussion will likely change by this time
tomorrow. The best advice is to stay tuned for the latest updates.

There is "some" evidence supporting the continued wet and windy
pattern through at least the middle of the month, with a pattern
chance for the latter part of the month with troughing developing in
the eastern part of the U.S. with riding building over the Pacific
Northwest. However a different data set (showing the same
parameters) are not as convincing. The net result, the CPC outlook
for above normal precipitation for the entire forecast area through
the majority of the month remains valid. -Petrucelli

&&

.AVIATION...06/00Z TAFs...Rain and MVFR/IFR conditions will increase
in coverage from west to east this evening into tonight as the next
front approaches through the area. Ceilings should improve to VFR
for most areas by morning, although brief periods of MVFR could
continue for much of the day. Gusty winds, terrain obscurations, and
LLWS will also be concerns throughout the TAF period, mainly along
and west of the Cascades. -BPN/Petrucelli

&&

.MARINE...Updated 200 PM PST Thursday 5 January 2023...

Large breaking seas and exceptionally dangerous bar conditions are
ongoing this afternoon behind the departing front. Very high and
very steep seas will continue into tonight due to long period west-
southwest swell and residual fresh swell.

Yet another low will build up out of the south and strengthen as it
moves towards Canada around Friday.  Gale force winds and very steep
seas are expected once again during this period.  Beyond Friday, the
weather looks very unsettled with storms strengthening over the
Pacific into next week, impacting the area on a nearly daily basis.

-Smith/BPN

&&

.MFR WATCHES/WARNINGS/ADVISORIES...
OR...High Wind Watch from Saturday morning through Saturday evening
     for ORZ030-031.

     High Surf Warning until 4 AM PST Friday for ORZ021-022.

CA...Winter Storm Watch from Friday morning through Saturday
     afternoon above 4500 feet for CAZ080>083.

     High Wind Watch from Saturday morning through Saturday evening
     for CAZ081-085.

PACIFIC COASTAL WATERS...Hazardous Seas Warning until 4 AM PST Friday
     for PZZ350-356-370-376.

     Gale Warning from 4 AM to 7 PM PST Friday for PZZ350-356-370-
     376.

&&

SBN/SBN/SBN