945
FXUS66 KMFR 082143
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
243 PM PDT Tue Oct 8 2024

.DISCUSSION...A slight eastward shift in an upper ridge is allowing
an upper trough to move closer, bringing cooler temperatures over
northern California and southern Oregon. Daytime highs will
generally stay about 5 degrees over seasonal normals. The Oregon
coast will be in the low 70s and west side valleys will be in the
mid 70s to low 80s. Areas east of the Cascades will see temperatures
in the mid to high 70s. Temperatures will be slightly cooler on
Wednesday as a weak trough passes north of the area.

With upper level stability, smoke from ongoing wildfires in eastern
Douglas and Lane counties will be guided to the east and settle when
winds decrease. For these reasons, Air Quality Advisories have been
issued for northern Lake and Klamath counties through Friday
afternoon. Intermittent smoke is also possible in eastern Douglas
County through this time.

Rainfall chances for this Friday and Saturday continue to decrease.
Deterministic guidance shows a cutoff low developing and generally
moving over northern California. Expected paths could bring light
showers over Brookings and parks of Siskiyou and Modoc counties. And
there are slight chances of this cutoff moving farther north and
bringing showers to west side valleys. Overall, any rainfall that
this cutoff does bring should be light wherever it falls.

Meteogram guidance from both ECMWF and GFS models show precipitation
chances starting next Tuesday and continuing throughout next week
but with very little agreement on the exact timing. Deterministic
imagery does show a front bringing rainfall to the Oregon coast and
possibly inland through the day Tuesday. With a low pressure system
sitting in the Gulf of Alaska spinning against that persisting upper
ridge, multiple frontal systems may develop at multiple times. This
results in widespread and constant low precipitation chances in the
forecast for next week. Showers are not expected every day next
week, but showers are possible at multiple points next week given
the possible variations in the forecast. -TAD


&&

.AVIATION...08/18Z TAF...A weak cold front will dissipate at the
coast or just inland today. Mixed IFR/MVFR will remain through
tonight into Wednesday at the coast along with a chance of light
drizzle. Inland, conditions will remain VFR through tonight, except
a deepening marine layer could bring MVFR ceilings to Roseburg.
While there is a chance (30%) the MVFR ceilings spill into the Rogue
Valley toward sunrise, confidence was too low to include in the
Medford TAF at this time. Klamath Falls is VFR through Wednesday
morning. -Spilde/BPN

&&

.MARINE...Updated 200 PM PDT Tuesday, October 8, 2024...Mostly
light winds are expected today with swell dominated seas through
Wednesday morning. North winds increase Wednesday with conditions
becoming hazardous to small craft during the afternoon. The stronger
north winds will build steep wind seas south of Cape Blanco that
will last into Thursday. Improving conditions will follow with seas
becoming swell dominated again late Thursday into early Saturday.
Small Craft Advisory seas are possible again Saturday, with
increasing southwest swell and increasing southerly winds.
-Spilde/BPN

&&

.FIRE WEATHER...Updated 200 PM Tuesday October 8, 2024...Dry
weather will continue for the week ahead.

Today, a weak front will move into the area resulting in cooler
afternoon temperatures for the interior and gusty breezes east of
the Cascades into this evening. Relative humidities will be on the
low side, but overall are expected to be a little higher compared to
yesterday. The combination of winds and low humidities could result
in brief periods of critical levels for areas east of the Cascades,
but overall we are not expecting to reach critical thresholds for
red flag. The front could bring a few showers over portions of Fire
zone 615 and northwest 616 this afternoon, otherwise it will likely
remain dry. Also expect recoveries over ridges to trend higher
across the ridges, especially along and west of the Southern Oregon
Cascades.

On Wednesday, a weak upper trough will move inland north of the
area. This will bring continued mild daytime high temperatures, dry
humidities and some continued afternoon breezes (especially east of
the Cascades). Then, stable southwest flow will persist over the
area the rest of the week. This will bring improving recoveries and
a subtle cooling trend with daytime humidities trending higher.

There`s good agreement among the operational models an upper low
will form and track east to southeast towards our area. There are
some timing differences of when the upper low will move into our
area, but it looks like it could bring some showers to northern Cal
and southwest Oregon Saturday into Saturday night. The operational
models suggest the upper low will weaken as it moves into southwest
Oregon, which means rainfall amounts probably won`t be significant.

The majority of clusters and ensemble means (ECMWF and GFS) show no
precipitation, and the members that do show limited rainfall amounts
in northern Cal.

It will be dry with seasonable temperatures for the start of next
week. The operational models and individual ensemble members show a
weak front bringing some precipitation to the coast next Tuesday.
Stay tuned. -Petrucelli

&&

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

CA...None.

PACIFIC COASTAL WATERS...Small Craft Advisory from 2 PM Wednesday to
     2 PM PDT Thursday for PZZ356-376.

&&

$$

TAD/MAP/BPN