203
FXUS66 KMFR 262352
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
352 PM PST Tue Nov 26 2024

.Update AVIATION Discussion and added BEACH HAZARDS section...

&&

.AVIATION...27/00Z TAFS...VFR conditions prevail across the region,
though terrain obscurations persist along with scattered showers.
Areas of MVFR ceilings are occuring with these showers, but overall,
VFR conditions prevail. The air mass is slowly drying with clouds
generally dissipating. As skies clear tonight and stable conditions
develop, confidence is fairly high for LIFR conditions to develop in
low clouds and fog for inland terminals. These conditions are likely
to improve to at least IFR/MVFR late Wednesday morning, but
confidence is low on any further improvement. This is especially
true for portions of the Klamath Basin where guidance suggests low
clouds could linger well into Wednesday afternoon. /BR-y

&&

.BEACH HAZARDS...100 PM PST Tuesday, November 26, 2024...We`re
monitoring the potential for a high sneaker wave threat this holiday
weekend, particularly Saturday afternoon into Sunday (11/30-12/1).
Guidance indicates a long period northwest swell (6-7 ft @ 15-18
seconds) will build into the waters during this time. As this swell
first enters our local waters, swell heights are expected to be 2-5
ft at 19-22 seconds, which are ideal conditions for sneaker waves.
Combine this with it being a holiday weekend and quiet/calm weather,
and the threat for sneaker waves is greatly enhanced. Sneaker waves
can run up significantly farther on beaches than normal, including
over rocks and jetties. These waves can suddenly knock people off of
their feet and quickly pull them into the cold ocean waters,
resulting in serious injury or death. Waves may also lift driftwood
logs, trapping anyone caught underneath. Please stay tuned for
future updates if you have plans to visit area beaches this holiday
weekend. And remember, NEVER turn your back on the ocean! /BR-y

&&

.PREV DISCUSSION... /Issued 212 PM PST Tue Nov 26 2024/

DISCUSSION...With the upper trough out of the area and the last
showers dissipated, an expected substantial upper level ridge still
looks to dictate conditions in the short- and the long-term.

In the short-term (Wednesday and Thursday), clear daytime skies and
lingering surface moisture from recent rainfall is expected to bring
areas of fog and freezing fog to low-lying areas. This generally  Of
course, the main effect of any fog that develops will be making
morning commutes difficult. Persistent fog can also keep daytime
highs a little cooler than expected.

In the long-term (Friday and beyond), air stagnation may be a
concern. While confidence in these conditions are not high yet,
stable conditions east of the Cascades may affect air quality as
early as Friday. Continued high pressure aloft could cause air
stagnation in west side valleys over the weekend or early next week.
Morning fog may continue to develop into the long term, but may be
more patchy and limited in areal coverage.

Near-freezing temperatures along the coast are also a consideration
for the end of the week and into the weekend. NBM outcomes have a
25% chance of freezing temperatures around North Bend and other
localized coastal areas on Friday night and Saturday night. Looking
at individual models, those freezing temperatures are not common
which decreases confidence in the possibility.

Deterministic models for both the ECMWF and GFS models go as far out
as Friday, December 6th with an upper ridge remaining in place.
Ensemble members for both models do show activity returning to the
area as early as this coming Monday, with more ensemble members
showing rainfall reaching the Oregon coast on Wednesday or Thursday.
There`s very little organization in these outcomes though, which
gives a moderate confidence that active weather will return in the
middle of next week but low confidence on when and how it will
return. -TAD

MARINE...Updated 100 PM PST Tuesday, November 26, 2024...Isolated
showers are expected to persist north of Cape Blanco into Wednesday
afternoon. Otherwise, relatively calm conditions are expected
through much of Wednesday morning as high pressure builds in
overhead. A thermal trough will develop by Wednesday afternoon,
resulting in increased north winds and steepening seas for the rest
of the week. Conditions hazardous to small craft are expected south
of Cape Blanco by late Wednesday morning, then spread northward to
all areas from Cape Arago southward by Wednesday afternoon. Advisory
conditions persist for these into Thursday, with possible
improvement for the inner waters by late Thursday morning. Steep
seas, however, are likely to persist for the outer waters into the
weekend. -BPN/BR-y

&&

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

PACIFIC COASTAL WATERS...Small Craft Advisory from 10 AM Wednesday to
     10 AM PST Thursday for PZZ350-356-370-376.

&&

$$