Wildfire in Oregon, September 8 to 16, 2024

Area Forecast Discussion
National Weather Service Medford OR
250 PM PDT Sun Sep 8 2024

.DISCUSSION...Marine stratus was stubborn in Coos and western Douglas
counties this morning, but it has receded to bring more sun to the
coast. Skies remain mostly sunny inland, but the surrounding
fires are bringing a haze and smoke to the area. The main areas
with smoke are Jackson and Klamath counties, central and eastern
Douglas County, and northern Lake counties. The smoke is expected
to move farther south closer to the California border tonight and
will continue overnight with the potential to retreat northward
tomorrow morning.

Temperatures the next few mornings will mainly be in the 50s and
tomorrow afternoon will be similar to today in the 80s/low to mid-
90s. A trough will start to move along the western Canada border
Tuesday and a cooling trend will begin with highs down into the 70s
and 80s.

The troughing will bring the next rain chance to the area later
Tuesday night into Wednesday starting near the coast. The
probability for 0.50" of rain from Wednesday to Thursday morning is
at 50-70% for more areas west of the Cascades including in the
Umpqua Basin and the Rogue Valley has a 35-50% probability for this.
Forecast soundings show CAPEs near 500-1,000 J/kg, although computed
CAPEs come in lower. There is a 15-25% probability for thunder east
of the Cascades and also in the Umpqua Basin Wednesday
afternoon/evening. The latest model runs are in better agreement
that there will be lingering showers into Thursday, so kept the
drying trend with the last spots in Douglas and Klamath counties
to become dry.

There's a 60-80% probability to see temperatures warm to at most 75
degrees in the Rogue Valley and Umpqua Basin both Wednesday and
Thursday afternoons. This will bring temperatures on average 10-15
degrees below normal for this time of year. Looking at record low
highs (the coldest highs a location has on record), Roseburg could
be close on Wedensday the 11th with a forecast of 68 and a record of
65 from 1941. Medford won't be nearly as close with a forecast high
Thursday of 73 and the record low high set at 61 from 1928. Either
way, enjoy the cold afternoons! After, temperatures average out
and dry conditions return for the start of the weekend. -Hermansen

&&

.AVIATION...08/18Z TAFS...Lower ceilings have started to clear off
the coast this morning with some ceilings still lingering along the
southern Oregon coastline near Brookings and Gold Beach.

Elsewhere, numerous fires are burning in the area. At this time, we
don't think they'll bring reduced visibility to the terminals, but
visibilities down to 1 to 2 miles are likely downwind of some of the
most active fires. The locations that will see the most visibility
restrictions will be in Lake and Klamath Counties this afternoon
through tonight.
-Smith

&&

.MARINE...Updated 230 PM Sunday, September 8, 2024...The low
ceilings will return later tonight over the coastal waters with some
fog and light drizzle. North winds will remain brisk enough to
produce conditions hazardous to smaller crafts mainly in the outer
waters south of Cape Blanco. The winds will become more widespread
on Monday afternoon and evening. Eventually, a low short period west
swell will become the more dominant wave Wednesday onwards.

-Smith

&&

.FIRE WEATHER...Issued 200 PM Sunday, September 8, 2024...Hot, dry,
and unstable conditions will continue through Monday. Areas in and
around the southern Scott and Shasta valleys could see a brief
period of gusty southerly wind and critically dry humidities this
afternoon/evening and again tomorrow afternoon/evening.
Additionally, it will be breezy over northeast California and in
general east of the Southern Oregon Cascades this afternoon/early
evening and again on Monday. This will be coupled with low RH, so we
are looking at near-critical fire weather conditions today and
Monday for a few areas, such as in southeast zone 624 and locally in
285. The window/duration of these variables is falling just short of
critical conditions today and tomorrow.

A trough and associated front will move through the region Tuesday
and Wednesday, departing Thursday evening. This will result in
chances for widespread rainfall, cooler temperatures, and a
potential for breezy to gusty winds. There is a chance (40%-80%) for
widespread light rainfall (0.10"+ on the eastside and 0.25" Cascades
west) Tuesday afternoon through Thursday afternoon. The main focus
for rainfall is expected Tuesday night through Wednesday evening.
Highest chances for wetting rain are from the Southern Oregon
Cascades west. There is a slight chance for thunderstorms  (~15-20%)
on Wednesday, including areas west of the Cascades in southwest
Oregon and from the Cascades east. Any thunderstorms that develop
will not be "dry" given the amount of moisture expected.

-CC

&&

.MFR WATCHES/WARNINGS/ADVISORIES...
OR...Small Craft Advisory from 2 AM Monday to 11 AM PDT Tuesday for
     ORZ021.

CA...None.

PACIFIC COASTAL WATERS...Small Craft Advisory from 2 AM Monday to 11
     AM PDT Tuesday for PZZ350-370.

     Small Craft Advisory until 11 AM PDT Tuesday for PZZ356-376.

&&