079
FXUS66 KMFR 152131
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
231 PM PDT Sat Aug 15 2026

.KEY MESSAGES...

* Low chance of thunderstorms in the Cascades and northern Klamath
  and Lake counties this afternoon and evening.

* The potential for thunderstorms continues on Monday evening
  mainly east of the Cascades.

* Warm weather persist most of next week.

* Upper level energy could bring another round of thunderstorms
  Friday into next weekend.

&&

.DISCUSSION...

Satellite has a lot of weather features this afternoon with some
coastal stratus moving into the Umpqua Valley. In addition, there
is plenty of cumulus build ups over the higher terrain around the
valleys and northern Klamath County. Finally, smoke from fires in
northern California are spilling into Siskiyou County this
afternoon.

As for the forecast, The high resolution ensemble forecast(HREF)
system is showing convective activity in the higher Cascades
around Crater Lake later this afternoon and evening. This is the
area we have the highest confidence in thunderstorm activity. The
national severe storms laboratory(NSSL) model is predicting some
thunderstorm activity around Jackson County this afternoon.
However, that model is usual to ambitious with thunderstorms, so
we feel the probability of anything occuring is around 1-3
percent, so not impossible.

Otherwise, we`ll likely see another marine surge into the Umpqua
valley later tonight with models giving a 50% chance of it pushing
back into the Umpqua Basin later tonight. Heading into Sunday and
Monday, the upper level charts become fairly interesting. We
should see a short wave move into Oregon with two upper level lows
combining and moving around each other in the Pacific. In any
case, all this upper level energy will give us a small chance of
thunderstorms in northern Lake and Klamath Counties on Monday.

By Wednesday, the GFS has 500 mb heights building and temperatures
will trend slightly warmer into the mid 90`s for highs here in
Medford. This is right around our normal high for mid August. This
ridge remains in place through Thursday before the next upper
level wave pushes through around Friday into Saturday next
weekend. Once this wave moves through, the majority of ECMWF
ensemble members are keeping us dry. However, we see about 4 out
of 50 are excited about rain or convection over our section of
Oregon. Therefore, there is some disagreement about about how
much moisture and lift is around Friday. Odds are it will remain
dry.

Overall, the upper level charts are fairly interesting through the
forecast period, although on the ground impacts will likely
remain low for the public and the region through next week.

-Smith

&&

.AVIATION...15/18Z TAFs...

VFR conditions continue farther inland this morning and early
afternoon with cumulus build ups along the higher Cascades. MVFR
ceilings are continuing along the coast and are anticipated later
tonight. Those MVFR ceilings could push into Roseburg(KRBG)
overnight.

Aside from the cloud cover, there is a <5% chance of thunderstorms
in the vicinity of MFR later this afternoon evening.

-Smith


&&

.MARINE...Updated 330 PM PDT Saturday, August 15, 2026...Light
north winds will persist tonight before trending later tonight
into Monday. Conditions will become hazardous to small crafts with
gusts to 30 knots 10 to 20 nm offshore south of Cape Blanco.
Winds will ease a bit before increasing again Tuesday evening.
-Smith

&&

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

PACIFIC COASTAL WATERS...Small Craft Advisory from 2 PM Sunday to 2
     AM PDT Monday for PZZ356-376.

&&

$$