FXUS66 KMFR 091129
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
329 AM PST Thu Jan 9 2025

...New Aviation Section...


.AVIATION (12Z TAFs)...

Westside valley fog has returned this morning and is impacting
both KRBG and KMFR. Expecting the fog to lift late this
morning but could be as late as early this afternoon. Otherwise,
expecting a few high clouds across the region later today after
the fog lifts with generally light wind speeds.

-Guerrero

&&

.PREV DISCUSSION... /Issued 253 AM PST Thu Jan 9 2025/

DISCUSSION...Satellite shows clear skies across southern Oregon and
Northern California. Nighttime microphysics shows fog in more west
side valleys tonight including the Illinois Valley and Umpqua Basin,
and more of the Rogue Valley is filling in with fog as well. Current
observations and cameras show that these areas are under dense fog
conditions, so a Dense Fog Advisory has been issued. Yesterday
morning the fog did not lift until the late morning and forecast
soundings show that the inversion could break later this morning as
well, so have the Dense Fog Advisory out until 10 AM. Please take
extra caution and give yourself extra time for travel. There is also
still an Air Stagnation Advisory out for the stagnant air
conditions. Please see NPWMFR for more details on these hazards.

It's been a colder morning with inland temperatures overall into the
20s and 30s this morning. The warmest temperatures of the week will
come today with 60s at the coast, 50s inland west of the Cascades,
and 40s east. This is on average 5-10 degrees above normal for this
time of year with the largest difference at the coast and in western
Siskiyou County.

High pressure will continue to be the main weather factor in the
next week. However, a front makes its way into the picture Friday
and could bring some precipitation. The most likely time to see
precipitation will be Friday morning and afternoon. Only about a
tenth to a quarter of an inch is expected with less than an inch of
snow in the Cascades. The area with the most rainfall potential will
be in Coos county and central Douglas County into Roseburg and east.

By the time the front moves out of the area, high temperatures will
be a few degrees below normal this weekend and back to 40s and low
50s west and 30s east. Mornings will also be colder and
near/slightly below normal this weekend with teens east and 20s and
30s west. On Sunday another disturbance will come in to the east of
the ridge and will likely bring minimal impacts to the area other
than a few showers that could creep into Douglas County and parts of
the Cascades north of Crater Lake.

The disturbance tracks south of the ridge into Southern California
Monday and after the center of the ridge reaches the PNW Tuesday and
Wednesday of next week, and that is when afternoon temps will turn
closer to normal again. Dry conditions are favored other than the
disturbance this Friday.

AVIATION...09/00Z TAFS...Low clouds and fog have developed in
the west side valleys again tonight, reducing conditions to LIFR
at both Roseburg and Medford. These should break up again later
this morning or, at the latest, early this afternoon. VFR will
prevail elsewhere. -Spilde

MARINE...Updated 230 AM PST Thursday, January 9, 2025...Northerly
winds will slowly diminish today along with brief easing of the
seas. However, a cold front is expected to pass through the region
on Friday with another steep west swell; as a result, a small craft
advisory has been issued over all the waters Friday through
Saturday. North winds strengthen late Saturday into Sunday as high
pressure builds offshore and a thermal trough develops near the
coast. Winds could reach gale force south of Gold Beach late
Saturday into Sunday; however, current guidance is suggesting the
stronger winds may be south of our waters.

&&

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

     Dense Fog Advisory until 10 AM PST this morning for ORZ023-024-
     026.

CA...None.

PACIFIC COASTAL WATERS...Small Craft Advisory from 10 AM Friday to 4
     PM PST Saturday for PZZ350-356-370-376.

&&

$$