292
FXUS66 KMFR 221155
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
355 AM PST Fri Nov 22 2024

.DISCUSSION...The latest radar shows steady moderate to heavy
precipitation along and west of the Cascades. Satellite image shows
the deepening surface low just outside of 130W, however it will
slide in just inside of 130W and deepening in the next 6-8 hours.

Snow levels have also come up which will keep the snow at the
highest peaks, the trade off is rain will continue to deluge
portions of norCal and SW Oregon through the morning hours, although
there are indications rainfall rates will decline this afternoon
into tonight as the front moves on shore with the heavier core of
precipitation shifting back south into Northern Cal. We have an
areal flood warning for portions of SW Oregon and into western
Siskiyou County. With the focus of moderate to heavy precipitation
focused in northern Cal during the day, there is concern for
flooding in and around the Mt Shasta region as well with all the
rain on top of the snow that has already fallen.

Moderate to strong winds are expected to continue in portions of the
Scott and Shasta Valleys as well as over the east today, although
they could gradually diminish in the afternoon. 700mb winds pushing
towards 80 kts this morning which typically results in winds speeds
reaching high wind criteria. Given the strongest winds will be
between now and late this morning, there will be less mixing from
aloft, thus the stronger winds aloft may not reach the surface.
Despite this, the higher peaks east of the Cascades could still
experience strong winds. 700mb winds are then expected to diminish
this afternoon.

Moderate to heavy precipitation has also moved into the Rogue
Valley, a couple of hours ago, Medford airport was reporting gusty
southeast winds, but not quire to wind advisory, It has since calmed
down, but with the low expected to deepen, we could see an uptick in
winds this morning. We`ll continue to monitor the trends and should
the winds not materialize, adjustments or a cancellation of the wind
advisory for the Rogue Valley may be needed.  This evening and
tonight. Showers will continue with an upper trough moving into the
area. A colder air mass will move in resulting in snow levels
lowering back down to around 4000 feet with some (mostly) light
accumulations expected in the mountains (mountain passes) and over
portions of the east side. Amounts of 3 to 8 inches appear to be
most likely above 5000 feet (highest amounts near Crater Lake NP)

Active, but less impactful weather is expected into the start of
next week with an upper trough over the area resulting in continued
showers and mountain snow showers, but precipitation amounts are not
expected to be a lot which will limit the amount of snow for the
mountains and mountain passes. Snow levels Saturday and Sunday are
expected to be around 4000 feet Saturday, then around 3000 feet by
Sunday morning.

Next Tuesday will be a transition day with the upper trough moving
over the area and weakening with showers far and few in between.
After Tuesday, the holiday travel day (Wednesday) through the
holiday weekend is shaping up to be rather quiet with dry weather
expected from Wednesday through the holiday weekend. This is being
supported by the ECMWF and GFS ensemble means, individual members,
and operational ECMWF and GFS. -Petrucelli


&&

.AVIATION...22/12Z TAFS...Strong low pressure offshore is bringing
another round of strong winds to the region along with low level
wind shear (LLWS) concerns for all TAF locations. This system is
sending a front through the area this morning, resulting in a mix of
VFR/MVFR conditions with widespread terrain obscurations and
moderate to heavy precipitation. LLWS concerns  and gusty winds will
diminish late this morning (between 15-18z), but linger into the
afternoon (~21z) along the coast. A mix of MVFR/VFR conditions will
persist into the afternoon, with areas of IFR possible in the
heaviest of precipitation. Later this evening, another wave of
precipitation will move northward into the area, bringing widespread
MVFR conditions between 01-04z. /BR-y


&&

.MARINE...200 AM PST Friday, November 22, 2024... Strong low
pressure developing inside 130W is bringing another round of strong
southerly gales and very steep wind driven seas to the waters this
morning. Isolated areas could experience storm force gusts of 55 to
60 kt at times through sunrise today. Winds will ease late this
afternoon, but seas will remain high and very steep into Saturday.
Overall conditions will gradually improve beyond Saturday, though
the weather will remain unsettled into early next week. Seas are
likely to remain steep into Monday with a period of very steep and
hazardous seas possible again on Sunday when another front passes
through the area. Beyond Monday and through next week, confidence is
increasing for a period of quiet weather and relatively calm seas
with winds becoming northerly around mid-week. /BR-y


&&

.MFR WATCHES/WARNINGS/ADVISORIES...

OR...High Wind Warning until 10 AM PST this morning for ORZ029>031.

     High Wind Warning until 1 PM PST this afternoon for ORZ021-022.

     Wind Advisory until 10 AM PST this morning for ORZ026.

     Wind Advisory until 4 PM PST this afternoon for ORZ029>031.

CA...High Wind Warning until 10 AM PST this morning for CAZ081-084-085.

     Wind Advisory until 4 PM PST this afternoon for CAZ084-085.


PACIFIC COASTAL WATERS...Gale Warning until 4 PM PST this afternoon
     for PZZ350-356-370-376.

     Hazardous Seas Warning from 4 PM this afternoon to 4 AM PST
     Saturday for PZZ350-356-370-376.

&&

$$