773
FXUS66 KMFR 122108
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
208 PM PDT Wed Aug 12 2026

.KEY MESSAGES...

* Seasonably warm, dry, and breezy conditions are the overall
  theme going forward

* Thunderstorm chances increase tomorrow continuing through the
  weekend and perhaps early parts of next week with the main risk
  being lightning and gusty erratic winds

* Areas of smoke remain possible due to nearby wildfires which
  could bring unhealthy air quality but latest trends show a
  decrease in smoke

&&

.DISCUSSION...

High pressure aloft that has been over the Four Corners Region
for several days has started to slide east and southwest over the
Gulf of America states. This has allowed a trough to form over the
western CONUS. A general trough pattern will remain over the west
coast for well into middle parts of next week. Beyond Wednesday
the pattern does show inconsistencies with the models out of phase
from one another. This has resulted in some uncertainty,
especially middle to later parts of next week.

This pattern will allow for several days of thunderstorm chances.
While uncertainty exists on coverage details due to the isolated
nature of these potential storms, the takeaway is that we`re not
anticipating these to produce a lot of rain, and lightning is
expected to be isolated. DCAPE values are rather high in some
model outputs, and this could lead to strong gusty outflows with
speeds potentially around 45-55 mph. In fact, some of the stronger
storms could potentially produce 60mph winds, but again the
isolated nature of these storms makes this forecast difficult. At
this time, favored areas are central/western Siskiyou County,
east/southeast Modoc County, Lake County, and portions of central
to northern Klamath County. Given the isolated nature of these
potential storms, we are not anticipated a Red Flag Warning at
this time, but if coverage and/or lightning intensity increases we
may have to reconsider this. That said, we are in peak fire
season, so any lightning over these dry fuels could produce some
initial attack starts.

Lastly, smoke will be the other factor as the diurnal wind
pattern continues to spread areas of smoke across the forecast
area. Smoke is very difficult to forecast with uncertainties
involved in fire activity/suppression and exactly how much smoke
will be introduced into the atmosphere. That said, recent model
output is showing a general decrease in smoke over the next couple
days which could be due to better fire suppression from better
overnight humidity recoveries and the cooler afternoon
temperatures.

-Guerrero

&&

.AVIATION (18Z TAFs)...

The marine layer is expected to continue to dissipate this
afternoon with VFR conditions through this evening, but we are
expecting the marine layer to reestablish overnight bringing
IFR/LIFR conditions. Otherwise, expecting VFR conditions for
inland sites with a couple nuances. Roseburg may see some of this
marine layer influence tomorrow morning similar to this morning,
but should remain in VFR as clouds should be thin. We may continue
to see smoke impacts for KLMT with haze and perhaps some ceiling
influence as well.

-Guerrero

&&

.MARINE...Updated 230 PM PDT Wednesday, August 12, 2026...Gusty
north winds continue through this evening, with areas of gales
and very steep seas south of Port Orford and steep seas to the
north. Winds will begin to ease Thursday, with north winds at
Small Craft Advisory strength south of Port Orford replacing the
Gale Warning. In fact, the combination of wind wave and fresh
swell will lead to steep seas continuing Thursday through Friday
morning. Weak winds and low seas are expected for the weekend and
into early next week.

&&

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

PACIFIC COASTAL WATERS...Gale Warning until 2 AM PDT Thursday for
     PZZ356-376.

Small Craft Advisory until 2 AM PDT Thursday for PZZ350.

     Small Craft Advisory until 11 AM PDT Friday for PZZ356-370-376.

&&

$$