785
FXUS66 KMFR 021800
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
1000 AM PST Sun Nov 2 2025

...Updated AVIATION forecast for 18Z TAFs...

.DISCUSSION (Today through Saturday)...

Key Points:

* Today: Break in activity
* Monday/Tuesday: Another weak front with light rainfall
* Tuesday through Friday: Weak to moderate atmospheric river
  event(s) leading to impacts from both rainfall and strong winds
* Not expecting snowfall impacts

Further Details:

A mostly zonal pattern aloft will remain in place through early next
week. There will be weak energy embedded within this zonal flow, and
as PVA spreads across the forecast area, there will be light
rainfall both Monday and Tuesday ahead of a deeper and strong low
pressure system coming Wednesday. Not expecting much if any impacts
here, but light rainfall will spread across westside areas with
lesser chances over the eastside. Areas in Curry County, western
Siskiyou County, and Cascades will likely see the highest rainfall
amounts. These areas have a 50%-85% too see 0.50/24hrs Monday into
Tuesday. This will be more of a warm front situation pushing north
from California before the main cold front comes in Wednesday. This
will result in high snowfall levels, so snowfall will not be a
concern. In fact, we are not expecting any snowfall impacts this
upcoming week.

An incoming atmospheric river event will lead to widespread rainfall
for much of the upcoming week Tuesday onward. The probability for
rainfall amounts of 0.50"/24hrs Tuesday afternoon to Wednesday
afternoon is about 85%-95% for areas along the Cascades and west to
the coast. This is where the brunt of the moisture will be as
eastside areas will see far less amounts, but northern California
has about 40%-95% chance for 0.50"/24hrs with the lesser amounts
being across Modoc County. This same stretch Tuesday afternoon to
Wednesday afternoon will likely be the highest 24 hours rainfall
amounts. The probability for 2.00"/24hrs is 50%-90% for western
Siskiyou County, Curry County, and southwestern parts of Josephine
County. At this time, we are not expecting thunderstorms.
Additionally, King Tides are expected Nov 4-9 which could bring
additional impacts to the coast as this system enters the region.

Additional rainfall is expected Thursday and Friday. Of note is the
72 hour period ending Friday morning when areas of Curry County
could end up seeing several inches of rainfall. The probability for
5.00" over 72 hours is 30%-70% with higher chances along/near the
coast. There will be a Marginal Risk of  excessive rainfall for
these areas. Again, rivers are not forecast to go into any
actionable stage so we are not expecting widespread river flooding.
Its going to be a rainy period and there will likely be nuisance
type flooding and ponding on roadways which could create hazardous
road conditions through this stretch of weather thanks to an
incoming atmospheric river event.

&&

.AVIATION...02/18Z TAFs...IFR and LIFR layers are starting to clear
out of the Rogue and Umpqua valleys, but may periodically return as
cloud layers shift. Once these stratus layers clear out, VFR levels
are expected across the area into this evening.

Persisting conditions may allow for IFR and LIFR visibilities to
return to the Rogue and Umpqua valleys, but the current layers
persisting may also limit those chances. Possible timing has been
included for development on early Monday morning, but with slight to
moderate confidence at the highest. An approaching atmospheric
disturbance may bring coastal showers that could affect flight
levels towards the very end of the TAF period. This disturbance
could also help to clear out valley development, if that occurs. -TAD

&&

.MARINE...Updated 800 PM PDT Saturday, November 1, 2025...Steep seas
will persist through at least Monday. Seas will be dominated by west-
northwest swell. However, wind seas will mix with swell on Sunday
afternoon and Sunday night as gusty northerly winds develop.
A strong front approaches late Tuesday, then moves across the area
Tuesday night and Wednesday. This is followed by another strong
front on Thursday. These fronts will bring the potential for gales.
Additionally, expect building west swell late Wednesday and Thursday
which combined with wind seas may result in dangerous and chaotic
high to very high seas. This may result in hazardous seas and
dangerous bar crossings. We will be monitoring this period and
updating as confidence increases in the timing and details.

&&

.BEACH HAZARDS...Updated 1030 PM PDT Saturday, November 1,
2025...Hazardous beach conditions are possible on Thursday as a
strong storm is expected to bring a large long period west swell to
the coast. This may result in large breaking waves of around 23 to
26 ft. High Surf conditions may be elevated by high "King" tides
during this time period. This situation may create hazardous
conditions along the Southern Oregon Coast on Thursday.

Impacts could include large breaking waves within the surf zone,
which could inundate beaches and low lying shorelines as well as
damage exposed coastal infrastructure. Waves could wash over rocks
and jetties, and sweep unsuspecting people out to see. During high
surf conditions, avoid area beaches and exposed coastal areas. Never
turn your back on the ocean! Additionally, low lying streets
susceptible to impacts from King tides and high surf may become
flooded. Never drive through flooded waters.

While there is still  some uncertainty in the exact details, this
looks to be a potentially dangerous situation setting up along the
coast. We will continue to monitor and update the forecast as this
storm near.

&&

.MFR WATCHES/WARNINGS/ADVISORIES...
OR...CA...None.

PACIFIC COASTAL WATERS...Small Craft Advisory until 4 PM PST Monday
     for PZZ350-356-370-376.

&&

$$