720
FXUS66 KMFR 101800
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
1100 AM PDT Wed Jul 10 2024

.Updated Aviation Discussion.


.DISCUSSION...

There is plenty of smoke/haze on satellite imagery this morning with
the Shelly and Salt Creek fires burning with a little intensity.
Heat signatures from the GOES satellite shows the Shelly fire in
Siskiyou County putting out more heat and smoke at this time,
although that could change into the day with planned burn
operations. Otherwise, hot temperatures are still lingering
around, although we`re trending a few degrees cooler today and
into the rest of the week. Even with the relatively cooler
temperatures this afternoon, major HeatRisk will linger.

For more information beyond today, read the previous discussion
below.

-Smith

&&

.AVIATION...10/18Z TAFS...Along the coast and just offshore,
satellite image shows marine stratus from about Bandon north,
including North Bend and from Brookings south. The marine stratus
should peel back west of North Bend in the next hour or two
resulting in VFR conditions that will persist for the rest of the
afternoon before marine stratus reforms between 1-2z with IFR
ceilings returning. Visibility could also drop later tonight to 4
miles or even less at North Bend. Meanwhile the marine stratus is
expected to persist at the coast and just offshore. Marine stratus
with IFR ceiling at Brookings and offshore is expected to persist
through at least 21z, then there`s some indications ceilings could
improve to VFR, but confidence is low on the timing and if it will
clear out at all.

Inland, west of the Cascades, VFR conditions will continue through
the TAF period with gusty breezes late in the afternoon into early
this evening. The exception will be MVFR visibility in the vicinity
of the Salt Creek and Shelly Fires, and in Medford tonight as the
smoke from the Salt Creek Fire could drift into the airfield.

East of the Cascades, VFR conditions will continue through the TAF
period, except for Klamath Falls where smoke from the Salt Creek
fire could get transported into the area late this afternoon into
tonight resulting in MVFR visibility. -Petrucelli

&&

.MARINE...Updated 200 AM Wednesday, July 10, 2024...A thermal
trough will strengthen today through Thursday resulting in
stronger north winds and increasingly hazardous seas. While
areas north of Cape Blanco will remain OK today, Small Craft
Advisory conditions with moderate north winds and steep wind-driven
seas are expected through this afternoon for areas south of Cape
Blanco. North winds and seas will increase this evening through
Thursday. Gales and very steep, hazardous seas develop this
evening from Gold Beach south, then expand north to around
Cape Blanco Thursday afternoon and night. North of Cape Blanco,
winds will gradually increase as well this evening through
Thursday with steep seas becoming likely. Moderate to strong north
winds and steep to very steep seas continue Friday. Then, winds
and seas are expected to gradually lower Saturday and Sunday. -
Spilde

&&

.FIRE WEATHER...Issued 200 AM Tuesday July 9, 2024...

....Near critical fire weather conditions possible all week...

Our trend of hot, breezy, low humidities, and occasionally unstable
afternoon conditions will persist through this weekend. Our
afternoons are forecast to be above normal with deep mixing.
Fortunately the wind speeds are not too crazy this week, but they
certainly will be on the breezy side around 10-15 mph. Very low
humidities, some reaching single digits east of the Cascades are
also forecast during the afternoon hours this week. These factors
during this prolonged drying stretch will result in near critical
fire weather conditions nearly every day this week. At this point,
however, it does not appear as if there is a large overlap between
the gusty winds and critically low humidity. Additionally,
afternoons and evenings may continue to become unstable with Haines
5s and 6s painted across much of the area, including some area
wildfires in Jackson and Siskiyou Counties over the next several
days. However, with conditions generally improving; will allow a
headline to continue for now and implore the day shift to coordinate
with area agencies and IMETs.

The attention then shifts to the weekend where a threat of
thunderstorms exists at around a 15% chance, particularly east of
the Cascades. The thunderstorms will be isolated in nature, although
some guidance is suggesting the potential for a more scattered
thunderstorm outbreak. Most guidance, is showing that for areas
northeast of our area. However, it would stand to reason that
lightning efficiency would be pretty good with the prolonged hot,
dry, and windy spell we just had. We will continue to monitor the
situation and hope that the thunderstorm threat pushes away from our
area. -Schaaf

&&

.PREV DISCUSSION... /Issued 414 AM PDT Wed Jul 10 2024/

DISCUSSION...Satellite imagery shows marine stratus across most
of the southern Oregon coast and inland into the Coquille Basin.
Elsewhere remains cloud free. Our "groundhog" day of summer
continues with a ridge of high pressure continuing to dominate the
the western United States, including southern Oregon and northern
California. However, the ridge is beginning to break down
somewhat, and afternoon high temperatures today should be a few
degrees less, particularly across the West Side Valleys. That
being said, temperatures inland from the coast will be in the 90s
to 100s with higher temperatures in the West Side Valleys. At the
coast, temperatures will still be warm relative to their
climatological normals, but temperatures will be in the 70s. Will
continue to our plethora of heat products through this evening.

The main difference, however, is that with the ridge breakdown,
temperatures will be allowed to cool off at night providing some
relief from the hot temperatures. The caveat to this statement is
that this will be where smoke is not present in large
concentrations. Not that the smoke will keep things warmer, but
that the smoke will prevent people from being able to open their
windows. Now, smoke will largely be downwind (toward the
southeast) of area wildfires, with Siskiyou and Modoc Counties
forecast to receive the highest concentrations. However, portions
of Jackson County--especially downwind of the Salt Creek Fire,
have degraded air quality as well. As such, the Oregon Department
of Environmental Quality has issued an an air quality advisory
for Jackson County. Info about the air quality can be found on the
Oregon smoke blog: https://oregonsmoke.org

Despite the ridge slowly breaking down, temperatures will be
similar over the next few days with highs in the low 100s and lows
in the upper 50s to low 60s. This pattern will repeat through the
weekend.

Then, over the weekend, a low pressure system will develop off the
coast and California and shift northward while remaining offshore.
This may indeed break our streak of 100 degree temperatures for
portions of our area. Additionally, this will also bring in some
monsoonal moisture and additional energy that could mean
thunderstorms. The general thought at this point is that isolated
to potentially scattered storms will be limited to areas east of
the Cascades, but there are ensemble members that do show a
farther west extent while others show a more eastward extent
missing us completely. The threat begins Saturday afternoon with
Sunday looking to be the more favorable afternoon and evening for
thunderstorms. With everything being said and done,

Beyond that, we return to a more stable southwest flow pattern
with above normal temperatures for interior locations. -Schaaf

&&

.MFR WATCHES/WARNINGS/ADVISORIES...
OR...Excessive Heat Warning until 9 PM PDT this evening for ORZ024-
     026.

     Heat Advisory until 9 PM PDT this evening for ORZ029>031.

CA...Excessive Heat Warning until 9 PM PDT this evening for
     CAZ080>082.

     Heat Advisory until 9 PM PDT this evening for CAZ083>085.

PACIFIC COASTAL WATERS...Small Craft Advisory until 8 PM PDT Friday
     for PZZ356.

     Small Craft Advisory from 8 PM this evening to 8 PM PDT Friday
     for PZZ350-370.

     Gale Warning from 8 PM this evening to 8 PM PDT Friday for
     PZZ356-376.

     Small Craft Advisory until 11 AM PDT Thursday for PZZ376.

&&

$$