719
FXUS66 KMFR 091039
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
339 AM PDT Wed Jul 9 2025

.DISCUSSION (Today through Tuesday)...

Overview:

Impacts revolve around the small thunderstorm potential later this
afternoon for mainly Klamath and Lake counties as well as the
heat risk starting this weekend when westside valleys could see
triple digits through early next week. After today, the
thunderstorm and rain chances diminish significantly with no
reasonable chances through the next seven days and likely beyond
that through at least middle of the month. There is a Red Flag
warning out to account for the lightning over dry fuels for
eastside areas this afternoon and early evening.

Further Details:

A shortwave trough will continue to pass over the forecast area
today leading to larger scale ascent for eastside areas this
afternoon with MUCPAE values approaching 800 J/kg in some instances.
This coupled with convective temperatures being reached will lead to
a chance (~20%) for isolated thunderstorms this afternoon and early
evening before chances diminish near/after sunset. Not expecting
severe weather, but a couple storms could produce gusty/strong wind
gusts as DCAPE values are progged to be around 1000-1200 J/kg. With
the passage of the trough, there could be some isolated gusty winds
this afternoon around 30 mph for eastside areas where deep mixing
will be present.

After today, a mostly zonal flow pattern aloft will be evident with
500mb heights generally rising this weekend through early next week.
This will likely lead to above normal temperatures and hot
conditions for some of our westside valleys where triple digits will
be possible. These conditions will be about 10 degrees above normal,
but will likely fall short of any records. We will need to consider
a potential heat advisory starting on Saturday. Additionally, low
temperatures may only drop to the low to mid 60s overnight, so we
wont see much relief overnight during this stretch of warm weather.
To put things into perspective, the probability for Medford to reach
at least 100 degrees is about 65%-75% each day Saturday through
Tuesday.

-Guerrero

&&

.AVIATION (06Z TAFs)...

LIFR conditions have returned to the coast and over the coastal
waters and will persist into Wednesday morning. As low pressure
moves inland late tonight into early Wednesday, the marine layer
will deepen and push into portions of the Umpqua Basin. Stratus
looks more likely to reach Roseburg tonight, with MVFR conditions
likely. These lower conditions will improve later Wednesday
morning with LIFR/IFR conditions along the coast improving to
IFR/MVFR, and VFR returning to the Umpqua Basin. Ceilings will
likely persist into the afternoon hours and beyond for the coast.

Elsewhere, VFR conditions are expected through the TAF period. Areas
of smoke in the vicinity of wildfires could lower visibilities to
MVFR at times. Gusty winds return to the area Wednesday afternoon
and another round of thunderstorms is expected across central
Klamath/Lake Counties.

/BR-y

&&

.MARINE...Updated 330 AM PDT Wednesday, July 9, 2025...The
thermal trough pattern will be disrupted today as an upper level
trough passes through the region. This will result in relatively
calm conditions, along with areas of reduced visibilities due to
marine layer fog/stratus. The thermal trough redevelops tonight
into Thursday, and is likely to persist through the weekend. Gusty
north winds will strengthen on Thursday, resulting in the return
of steep wind-driven seas south of Cape Blanco by Thursday
morning. Steep seas will likely expand north of Cape Blanco late
Thursday into Friday, with very steep seas and possible gales
south of Cape Blanco over the weekend.

&&

FIRE WEATHER...

Today, a low will move inland across northern California. This
will maintain a slight chance to chance of thunderstorms across
eastern portions of the forecast area, including eastern Klamath,
Lake, and northern Modoc counties. Models are continuing to
highlight eastern Klamath and Lake counties as well as areas to
the east as having the best chance (15-20%) for thunderstorms.
Additionally, with elevated bases and relatively low precipitable
water values, these storms may be on the dry side. We have
upgraded the Fire Weather Watch to a Red Flag Warning for eastern
portion of FWZ 624 and FWZ 625 (2-9 pm PDT) for abundant lightning
on dry fuels. The trough axis pushes east of the area fairly
quickly Wednesday evening and convection is expected to diminish
after 9pm.

Following the trough passage, drier westerly flow aloft moves in
Wednesday night and the thunder risk ends. Expect slight cooling
Wed/Thu over inland areas, but northeast winds provide warmer
weather to the south coast by Thursday. A return of hotter weather
is expected Friday into the weekend with fairly typical late-day
summertime breezes, but also dry afternoon humidity. Offshore
northeast flow over the coastal mountains and Siskiyou mountains may
result in moderate to locally poor RH recovery at night.

-CC/Spilde

&&

.MFR WATCHES/WARNINGS/ADVISORIES...
OR...Red Flag Warning from 2 PM this afternoon to 9 PM PDT this
     evening for ORZ624-625.

CA...None.

PACIFIC COASTAL WATERS...Small Craft Advisory from 5 AM to 5 PM PDT
     Thursday for PZZ356-376.

&&

$$