641
FXUS66 KMFR 132349
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
449 PM PDT Sun Jul 13 2025

.Updated AVIATION Discussion...

&&

.AVIATION...14/00Z TAFs...VFR conditions prevail across the region
this afternoon, and will do so through the TAF period for most
locations. The marine layer remains just offshore north of Cape
Blanco as well as from Gold Beach southward. Meanwhile, widespread
cumulus buildups are present east of the Cascades and across
northern California. Isolated showers have developed and there`s
about a 10-30% chance of a thunderstorms east of the Cascades
through this evening. Otherwise, gusty winds will persist in the
Umpqua Basin and along the coast before easing some after sunset.
Marine stratus is expected to return to coastal locations much like
previous nights. However, guidance shows the potential for gusty
winds to persist overnight along the coast and this may keep
visibilities from reaching LIFR conditions. Regardless, LIFR
ceilings are expected to return later this evening.

Strong north winds return to the coast and Umpqua Basin fairly early
on Monday (between 16z-18z), and gusts up to 35 kts are possible at
North Bend. Additionally, another round of isolated showers
thunderstorms will be possible across northern California and
southern Lake/Klamath Counties Monday afternoon. /BR-y

&&

.PREV DISCUSSION... /Issued 237 PM PDT Sun Jul 13 2025/

DISCUSSION...It will be another warm afternoon with locations
reaching 99-104 degrees. Taking the warmer morning in the 65-70
degree range today and the expected highs, the Rogue and Shasta
Valleys and Umpqua Basin are under a significant heat risk. This
will impact anyone that does not have effective cooling and/or
adequate hydration. An Extreme Heat Warning and Heat Advisory is
in effect through Tuesday evening for this heat risk. Details can
be found in NPWMFR.

This afternoon a shortwave will be moving through which could
develop some thunderstorms. There is now a 30-40% probability of
thunder in portions near central Klamath and Lake counties, so have
added this to the 5-8 PM time frame. However as noted in the
previous discussion, convective temperatures will need to be met to
kick off these storms, and this could be a factor that limits
development if it`s not warm enough. Forecast soundings have
forecast convective temperatures in the 91-94 degree range this
afternoon, and temperatures around that time are expected to be
around 90-92 degrees.

In terms of overnight temperatures, forecast lows will be in the 60s
for more locations including east of the Cascades. There is an 80-
85% probability to see lows at or above 65 degrees in Medford and
Roseburg tonight. The northerly/northwesterly flow we`ll have the
next few days will bring near surface smoke to central Lake and
Klamath counties and Siskiyou and Modoc counties. Higher
concentrations of smoke from the Green Fire is forecast in Modoc
County Monday afternoon because of a more westerly flow there. Smoke
higher in the atmosphere will create hazy skies for more parts of
southern Oregon the next few afternoons.

Monday afternoon`s temperatures will still be in the 90-100 degree
range for most locations. There will be another 10-20% chance of
thunderstorms Monday afternoon as another shortwave passes through.
This will be concentrated in far eastern Siskiyou and Lake
counties. Tuesday`s temperatures will be similar to today, but
conditions are forecast to stay dry.

Long Term...Wednesday through Sunday...Wednesday`s heat risk has
been under review for the need to extend the current heat products.
On Wednesday there is still a 70-90% probability to see triple
digits in the Medford area with a 60-80% probability for other spots
in the Rogue Valley and in the Umpqua Basin. Areas east of the
Cascades will likely not be under the risk for the heat, so the Heat
Advisory for that side will be finished Tuesday evening. The likely
scenario is that Monday afternoon`s update will include having a
Heat Advisory for west side locations in Southern Oregon. This has
been included in the details section of the NPWMFR.

Ridging continues through the rest of the work week with
temperatures 5-10 degrees above normal for this time of year. After,
a low starts to develop into western Canada. This will help "cool"
temperatures back to below the 99-101 degree mark for more west side
locations. Looking to still favor drier conditions next weekend and
the week after will have cooler temperatures back to near normal.
-Hermansen

MARINE...Updated 200 PM PDT Sunday, July 13, 2025...The thermal
trough pattern will continue through the middle of next week. This
will maintain strong gusty north winds and steep to very steep
wind- driven seas across all waters. Gales are expected in the
afternoons/evenings mainly south of Port Orford and beyond 5 nm
from shore. Conditions could begin to improve around mid-week next
week. Otherwise, daily conditions will remain quite similar for
the next several days.

FIRE WEATHER...Updated 200 PM PDT Sunday, July 13, 2025...
There are a few fire weather concerns this afternoon. First and
foremost is the thunderstorm potential this afternoon and Monday,
which is discussed in the discussion above.

Secondly, we`ll see a thermal trough build over locations west of
the Cascades through Tuesday with some easterly breezes over the
Cascades Tuesday evening and Wednesday morning. It looks like a dry
cold front does indeed make it down here behind an upper level wave
diving south from British Columbia. The fire weather risk here is
limited to moderate as the driest air seems to be above 7000
feet. One would expect some of that drier air to make it lower
with some easterly breezes Tuesday night. In any case, we did
lower humidities overnight 5 to 10 percentage points below current
guidance on the mid slopes west of the Cascades, although that
might not be enough.

The thermal trough hangs around on Wednesday and temperatures still
remain hot west of the Cascades with highs in the lower to mid
100`s. This hot and dry weather persists through the week,
although temperatures do trend a bit lower by the weekend.

&&

.MFR WATCHES/WARNINGS/ADVISORIES...
OR...Extreme Heat Warning until 8 PM PDT Tuesday for ORZ024-026.

     Heat Advisory until 8 PM PDT Tuesday for ORZ023-025-029>031.

CA...Extreme Heat Warning until 8 PM PDT Tuesday for CAZ080-081.

     Heat Advisory until 8 PM PDT Tuesday for CAZ082>085.

PACIFIC COASTAL WATERS...Gale Warning until 11 PM PDT Tuesday for
     PZZ356-376.

     Small Craft Advisory until 11 PM PDT Tuesday for PZZ350-370.

&&

$$