Flood in Oregon, December 27 to 31, 2024

Area Forecast Discussion
National Weather Service Medford OR
321 AM PST Fri Dec 27 2024

.DISCUSSION...Low pressure north of the area will move onshore in
the next few hours and at the same time weaken. An upper trough
moving into the area will keep light showers going during the
morning, but we should see showers diminish this afternoon as weak
ridging builds into the area. Winds have diminished over the last
few hours, including the Rogue, Shasta Valley, and portions of the
east side. The exception is in easter Klamath and Lake County where
strong winds aloft will remain there into this morning. The net
result was to cancel the wind advisory for the Shasta Valley and
southwest Klamath County. Meanwhile webcams show light to
occasionally moderate snow along the northern part of highway 97. The
winter weather advisory is due to end at 4 am pst, with snow showers
expected to linger into at last the mid morning hours, but
additional snow should be limited to an inch or less, especially
once we get into the daylight hours and road temperatures warm up
some.

As with the other systems, the break in the action will be short
lived with another storm impacting the area this evening into
Saturday. Some evidence suggest the front tonight could get hung up
and stall over southwest Oregon and northern California late tonight
through Saturday resulting in a prolonged period of steady moderate
to occasionally heavy precipitation. There's some evidence the
stalled front will lift north Saturday night, but probably not
enough for precipitation rates to diminish. It won't be until the
upper trough moves in Sunday afternoon pushing the cold front east
of the area during the day Sunday, that we'll see precipitation
rates diminish.

Snow levels will rise this evening and tonight to around 7000 feet
and remain there through Saturday night. This will keep any snow
concerns confined to the Crater and Diamond Lake areas. Even then 24
hour snowfall accumulations are expected to be around 6-8 inches
around Crater lake and 2-4 inches around Diamond Lake.

Moderate to heavy precipitation will continue into Sunday morning,
then diminish Sunday afternoon as the cold front pushes inland as an
upper trough moves overhead. Showers will continue Sunday night with
snow levels lowering with minor road snow accumulation possible down
to highway 140 near Lake of the Woods and Siskiyou Summit. However
precipitation is expected to be light to occasionally moderate which
should keep road snow accumulations in check.

With all the moderate to heavy rain recently and yet to come today
through most of the weekend, this will result in rivers rising. The
Coquille River at Coquille is already at minor flooding and flood
warning remains in effect. The Rogue River at Agness, and Deer Creek
at Roseburg are also expected to reach minor flooding Sunday
evening. We'll keep a watch on these as additional flood products
may be needed in the coming days.

All signs are pointing to a less active weather pattern starting
Monday and possibly lasting into most of next week. Showers will
linger monday, with most along the coast and north of the Umpqua
Divide, followed by dry weather Tuesday and Wednesday. A front could
get close to the area next Thursday, with the best chance of
precipitation over the northwest part of the forecast area.
-Petrucelli

&&

.AVIATION...27/06Z TAFS...The next strong front has reached the
coast and will bring another round of strong winds, low level wind
shear, mountain obscuration, and light to moderate precipitation
with mainly IFR to MVFR. The front will spread inland overnight into
Friday morning, then conditions briefly improve during the late
morning into the afternoon. Gusty winds and precipitation look to
ending by early afternoon on the east side.

After the precipitation becomes less widespread late Friday morning,
mainly MVFR is likely to linger with a few light coastal and
mountain showers, and areas of mountain obscuration. The next
strong, warm system will reach the coast around 00Z early Friday
evening, spreading slowly inland Friday night through Saturday. It
will bring another round of low level wind shear to each of the
terminals by Friday evening with mountain obscuration, mainly light
to moderate rain, and mainly MVFR conditions.
-DW

&&

.MARINE...Updated 200 AM PST Friday December 27, 2024...Very steep
and hazardous seas continue in all waters early this morning.
Unsettled sea states will continue through the weekend and beyond,
especially as two more disturbances are forecast to move over the
area. The first is expected late tonight into Saturday morning, then
another late Saturday night into Sunday morning. These disturbances
will bring 30-60% chances of gale winds to area waters, with the
highest chances over coastal waters.

Steep to very steep seas continue into the start of next week.
Seas could fall below advisory levels midweek, with active weather
possibly returning near the end of the week. -TAD

&&

.BEACH HAZARDS...Updated 200 AM PST Friday December 27, 2024...
Swell dominated seas will continue to produce dangerous surf
through the weekend. Surf conditions will be occasionally worsened
by high winds and seas as fronts pass each day through Sunday.
Breaking waves in excess of 30 feet remain possible through the
weekend.

During these events, extremely large breaking waves will create very
hazardous conditions along beaches and area shorelines. Waves will
inundate beaches and surge into normally dry areas, especially at
times of high tide. Infrastructure damage and significant beach
erosion can be expected. Stay away from area beaches during this
period of active weather. -Wright/Petrucelli

&&

.MFR WATCHES/WARNINGS/ADVISORIES...
OR...Winter Weather Advisory until 10 AM PST this morning for ORZ027-
     028-030.

     High Wind Warning until 10 AM PST this morning for ORZ030-031.

     High Surf Warning until 7 AM PST Sunday for ORZ021-022.

CA...Winter Weather Advisory until 10 AM PST this morning for CAZ080-
     082-083.

     High Wind Warning until 10 AM PST this morning for CAZ085.

PACIFIC COASTAL WATERS...Gale Warning until 7 AM PST Sunday for
     PZZ350-356-370-376.

&&

Preliminary Local Storm Report
National Weather Service Medford OR
1206 AM PST Fri Dec 27 2024

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1206 AM     Rain             Port Orford             42.75N 124.49W
12/27/2024  M1.57 Inch       Curry              OR   Trained Spotter

            Trained spotter reported 1.57 inches of rain
            in past 24 hours.

&&

TAD