159
FXUS66 KMFR 192233
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
233 PM PST Wed Nov 19 2025

.DISCUSSION...Satellite image shows a persistent low cloud deck in
most of Lake, portions of Klamath County, Modoc, and southern
Siskiyou County, including Mount Shasta City. These areas may not
break out at all today. Meanwhile, low clouds have burned off in the
Umpqua Basin, Illinois and Rogue Valley. High and mid level clouds
are increasing ahead of an approaching front. This will only thicken
up more during the afternoon and early evening.

There`s good agreement with the timing of the next front with
precipitation arriving at the coast late this afternoon, then moving
inland this evening and tonight. Most of the precipitation will be
along and just behind the front, then precipitation rates will drop
off as the upper trough moves in behind the front with post frontal
showers. Snow tonight into tomorrow morning is- expected to be
confined to the mountains. Even then 24 hour snowfall accumulation
will be 1-2 inches along the Cascades and around Mount Ashland and
less than an inch over the higher terrain east of the Cascades.
Meanwhile snowfall amounts will be higher at Mount Shasta Ski area.

Thursday, the upper low will split and weakens, with precipitation
diminishing during the day Thursday will diminish. Most hours and
locations in Oregon could end up dry Thursday afternoon, but will
tend to linger longer in Northern California.

The upper low will move south into California Thursday night with
dry weather likely. However, low level moisture from Wednesday night
and Thursday morning precipitation will be high, thus setting the
table for low clouds and fog again for the interior west
side valleys, and east side valleys.

Friday through the weekend is likely to be dry as upper ridging
nudges in from the west as the cutoff low moves towards southern
California. The upper flow will likely remain westerly with the
ridge remaining over the area Saturday through Sunday. This will
likely keep the storm track farther north, this keeping our area
dry. There`s good agreement among the operational models with the
overall pattern this weekend. The operational models, the majority
of the individual ECMWF, and all of the GFS ensemble means show no
precipitation in our area Sunday. Although the extreme northwest
part of the forecast area could be a bit of a grey area late Sunday
afternoon, odds are it will remain dry. Additionally, the clusters
are also in good agreement into Sunday with upper ridging over our
area and the storm track farther north. As is typical, the NBM
solution for the weekend is too high, too far south, and inland,
especially given the above mentioned. So while we have a slight
chance to chance pops in the forecast for some locations Sunday, the
reality is we`ll end up dry.

Now it won`t be until Sunday night into Monday morning where a weak
upper trough will swing north of the area and this will send a
weakening front into our area. The front will weaken as it moves
through the area Monday, therefore it`s possible most of the
precipitation (and it will be light) will be in the morning with
most areas dry Monday afternoon.

A cooler and drier airmass will follow Monday night and could
possibly last into the peak travel day for the Thanksgiving Holiday
weekend. However a small majority of the individual ensemble members
cast some doubt on Wednesday with precipitation moving into the
area. -Petrucelli


&&

.AVIATION...19/18z TAFs...Along the coast and just offshore, VFR
conditions will continue for most locations through 0z, the
exception will be at Brookings where VFR ceilings are present and
should remain there into tonight. Ceilings will trend lower this
evening into tonight as a front approaches the coast. As the front
moves inland, convective showers will follow and with an unstable
atmosphere, should allow ceilings to improve to VFR early Thursday
morning.

Inland, VFR conditions are likely to start, but will lower as the
front moves inland later this evening and tonight with MVFR ceilings
and visibility for the terminals with the higher terrain at least
partly obscured. In the wake of the front, there`s some indications
suggesting precipitation will end later tonight in portions of the
interior westside valleys resulting stable conditions with low
clouds and fog at the Medford and possibly Roseburg terminals.
-Petrucelli


&&

.MARINE...Updated 200 PM PST Wednesday, November 18, 2025...A
frontal system is moving across the waters this afternoon and
evening with gusty winds and steep wind- driven seas. Models show a
potential for localized gales and for seas to briefly reach
hazardous seas warning levels in the late afternoon and evening,
mainly for the waters beyond 10 nm from shore and for the inner
waters from Port Orford northward to Florence.

Behind the front, winds diminish and large long period swell arrives
Thursday afternoon and night. This will result in continued steep
seas. Guidance is showing the swell peaking in the 15-18 foot range
at 15 seconds Thursday afternoon through Thursday night. Seas will
remain steep through at least Friday. Then, another west-northwest
swell is expected to build into the waters Saturday with seas of 10
to 15 feet at 15 seconds. Steep, elevated seas at or above 10 feet
may persist Sunday and Monday.


&&

.BEACH HAZARDS/HIGH SURF...Updated 200 PM PST Wednesday, November
19, 2025...Guidance is showing a long period swell arriving
Thursday morning and persisting through Friday morning. With
swells peaking in the 16-19 foot range (15 sec period) Thursday
evening, this will result in 20-24 foot breaking waves in the surf
zone. A high surf advisory has been issued.


&&

.MFR WATCHES/WARNINGS/ADVISORIES...
OR...High Surf Advisory from 10 AM Thursday to 4 AM PST Friday for
     ORZ021-022.

CA...None.

PACIFIC COASTAL WATERS...Small Craft Advisory until 7 PM PST Friday
     for PZZ350-356-370-376.

&&

$$