Likely, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

946
FXUS66 KMFR 040522
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
922 PM PST Tue Dec 3 2024

...Updated Aviation Section...


.AVIATION (06Z TAFs)...

Valley fog has returned to the westside valleys, and is expected
to impact both Roseburg and Medford tonight through tomorrow
morning with IFR/LIFR conditions. Expecting fog to burn off in a
similar fashion as today with return to VFR conditions across all
four terminals by tomorrow afternoon. Wind speeds through this
stretch will be mostly light and variable.

-Guerrero

&&

.MARINE...


&&

.PREV DISCUSSION... /Issued 845 PM PST Tue Dec 3 2024/

DISCUSSION...Made a few adjustments to tonight`s forecast based
on current satellite and the expectation of fog/low clouds to
redevelop in the valleys west of the Cascades. If you encounter
dense fog tonight or Wednesday morning, please slow down and take
some extra time. In areas where it`s near or below freezing, icy
spots may be on the roadways, especially bridges and overpasses.
The low visibility in areas of dense freezing fog and icy spots
will make driving conditions hazardous. Expect lows from the upper
20s to the mid 30s in these valley areas. East side areas should
remain mostly clear with lows in the teens and 20s, the exception
being the Klamath Marsh area, where temps could drop to the single
digits. -Spilde

AVIATION...04/00Z TAFS...VFR conditions prevail over most of the
area this evening. However, LIFR stratus and fog is reforming in
the Umpqua Basin, the Illinois Valley and also the Rogue Valley
near Grants Pass. Expect most of the valleys that had fog/low
clouds last night and this morning west of the Cascades will
fill in with LIFR fog and low clouds again this evening 05-08Z,
then persist into Wednesday morning. Clearing to VFR will occur
in most areas Wednesday afternoon, though the usual spots (Grants
Pass and the Illinois/Umpqua valleys could hold it most of the
day.

-BPN/Spilde

MARINE...Updated 800 PM PST Tuesday, December 03, 2024...Light
to moderate north winds and relatively calm swell dominated seas
will persist into Wednesday.

A weak front is expected to pass by just to the north, with winds
shifting to southerly. Seas will build, with west swell dominated
seas just shy of becoming steep as they peak on Thursday night.

A stronger front will move through Friday night into Saturday
morning with the highest winds and seas approaching advisory levels
north of Cape Blanco on Saturday. A third front is forecast to be
the strongest of the bunch with large and steep swell dominated seas
possible early Sunday into early Monday.

-BPN/DW

PREV DISCUSSION... /Issued 220 PM PST Tue Dec 3 2024/

DISCUSSION...Satellite image shows low clouds lingering in portions
of the Umpqua Basin Illinois Valley and in the Grants Pass area. The
low clouds are slowly burning off, but those areas should break out
late in the day before becoming socked in again early this evening.
Elsewhere, it`s clear.

We`ll have a rinse and repeat scenario with respect to the
development of low clouds, fog and freezing fog later this evening
through at least tomorrow morning impacting the same areas as this
morning. Areas that experience freezing fog (Illinois Valley, Grants
Pass area, Rogue, Shasta, and Scott Valley) will result in low
visibility along with slick driving conditions for the early morning
commute, especially on bridges and any other elevated roads because
of not warming from the ground below.

Dry weather is likely to continue through Wednesday night. A weak
warm front could bring a slight chance of precip along the coast,
north of Cape Blanco Thursday morning, but the front is likely to
weaken as it moves into the ridge. Therefore precipitation will be
limited to the north coast, and not make much if any headway inland.
Even then rainfall amounts should only amount to a few hundreths of
an inch at best. Thursday afternoon is likely to be dry as the
aforementioned front continues to weaken and dissipate.

The one thing the front will do is bring more cloud cover to the
area Wednesday night into Thursday morning, with the cloud cover
thickest in the Umpqua Divide. This should keep temperatures from
dropping down below freezing. Farther south, in portions of the
Rogue parts of the Illinois, Shasta, and Scott Valleys, the cloud
cover may not be sufficient enough to keep temperatures from dropping
below freezing, so we could be dealing with another round of
freezing Fog later Wednesday night into Thursday morning.

Dry weather is likely Friday with upper ridging building into the
area. The main variable will be the extent of cloud cover and will
it be sufficient enough to keep low clouds and fog from forming. For
now, kept it out of the forecast, but this will need to be looked at
again.

A stronger upper trough will approach the area Saturday, with a
surface front pushing into the area. This will bring light
precipitation primarily along and west of the Cascades. The
operational models and about a third of the ECMWF individual
ensemble members show some precipitation in the above mentioned
areas.

Upper troughing remain over the area Sunday with a few showers
possible west of the Cascades, then there`s good agreement among the
operational, ensembles and clusters showing upper ridging building
back in by the start of next week and could last into at least the
middle of next week with dry weather becoming more likely.

-Petrucelli

&&

.MFR WATCHES/WARNINGS/ADVISORIES...
OR...Air Stagnation Advisory until 4 PM PST Friday for ORZ023-024-026-
     029>031.

CA...None.

PACIFIC COASTAL WATERS...None.

&&

$$