478
FXUS66 KMFR 161857
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
1157 AM PDT Thu Jul 16 2026

.KEY MESSAGES...

* Slight cooling today with highs around normal. High temperatures
  then trend to 5 to 10 degrees above normal on Friday, and likely
  remain near that level each day for the following week. Heat is
  forecast to peak on Sunday in the 90s to low 100s for inland
  valleys.

* Gusty winds and low humidities are expected to bring elevated
  fire weather conditions on Friday afternoon and evening,
  especially east of the Cascades and in the Shasta Valley. Though
  less critical, dry, hot, and breezy weather is also expected
  today and during the weekend.

* Smoke from the East Evans Creek Fire will result in continued
  impacts downwind of of the fire. Conditions improve from late
  morning into early afternoon. But, late today into tonight,
  smoke impacts may spread into a larger portion of the Rogue
  Valley and areas east and southeast, including Klamath County as
  well as into eastern Siskiyou and western Modoc counties.

* A slight chance of thunderstorms is expected on Monday and
  Tuesday, mainly east of the Cascades Monday, then again but
  possibly also including the Cascades on Tuesday. There is a
  wider variation in model solutions for Wednesday onward, but a
  potential for continued convective activity.

&&

.DISCUSSION...Yesterday, our region was between a trough offshore
and a ridge centered over the Rockies. Today, the trough will
track toward the Washington coast. This will be enough of a shift
to bring slight cooling, with a stable air mass of maritime
origin. Also, a stronger push than typical of low clouds from the
coast into the coastal valleys and central portion of the Umpqua
Valley, including Roseburg. A marine push is also expected during
subsequent nights into Sunday morning, but trending just slightly
weaker for Friday morning, and more noticeably so during the
weekend.

With a break from convective concerns, the focus shifts to hot,
very dry, and breezy weather today through Sunday. Breezy to
locally windy afternoon and evening winds are expected. Winds will
be strongest today and Friday, and especially for the Shasta
Valley and East Side. Humidity levels will be driest on Friday
and Saturday, while temperatures are likely to trend back to 5 to
10 degrees above normal for the weekend...peaking on Sunday at
values similar to those of the past few days.

Air mass moisture amounts are expected to rise starting on Sunday,
likely initially beginning with high clouds streaming into the
East Side. The GFS indicates some slight possibility of shortwave
induced thunderstorms developing Sunday night or Monday morning.
But, the higher probability is for the ingredients to come
together on Monday afternoon for isolated thunderstorms on the
East Side with a higher risk for the eastern portion of our area.
This pattern has some similarity to what occurred yesterday into
this morning, with a trough expected to track northeast toward
Washington.

In the long term, beginning Wednesday, the 00Z GFS and its
ensemble members are leaning toward a slower solution with
continued convective activity. Meantime, a majority of ECMWF
ensemble members (around 90%) indicate a shift on Wednesday to a
stable air mass resembling today`s transition. The NBM covers this
uncertainty well with a modest 5% to 10% risk from the Cascades
eastward on Day 6 and Day 7.

&&

.AVIATION...16/18Z TAFs...Thunderstorm chances are absent in the
forecast as dry air aloft moves over the area. Marine stratus is
clearing over Roseburg and is expected to clear over North Bend this
afternoon but looks to return early Friday morning and bring MVFR
levels through the end of this TAF period. Smoke from the East Evans
Creek Fire will move over the Rogue Valley this evening, possibly
affecting visibilities but MVFR levels are not expected. -TAD

&&

.MARINE...Updated 200 AM PDT Thursday, July 16, 2026...Improved
conditions are expected today, though with an area of gusty winds
this afternoon in the inner waters near Brookings. Increasing north
winds will build steep seas south of Cape Blanco Friday afternoon
under a thermal trough pattern. These thermal trough winds will be
strongest during the afternoon and evening hours, with the
possibility of spreading to all waters by Saturday afternoon before
seas reach a peak on Sunday. Winds are expected to diminish on
Monday with seas dominated by fresh swell early next week.

&&

.FIRE WEATHER...Updated 200 AM PDT Thursday, July 16, 2026...
We will transition to a stable air mass today, with a shift in focus
to hot, very dry, and breezy to windy conditions through Sunday.
A Fire Weather Watch remains in effect for Friday afternoon in Fire
Weather Zone CA285 and the southern portion of OR624. This covers
southeast Klamath, southwest Lake, and Modoc counties.

It will be a bit cooler today, but winds and relative humidity this
afternoon and evening look to be near, but just below critical
levels, with gusts in the 20 to 25 mph range. Winds today and Friday
are expected to be strongest in the area roughly south and east of
Klamath Falls, to include Lake and Modoc counties, and eastern
portions of Klamath and Siskiyou counties. Winds will be southwest
in that area, but generally west to northwest elsewhere. The
combination of gusty winds and low relative humidity is likely to
reach critical levels on Friday afternoon for southeast Klamath,
southwest Lake, and Modoc counties.

With one exception, winds will be at a similar level of strength on
Friday afternoon, but minimum humidities will be even lower. The
exception is that breezy south winds in the Shasta Valley early
this afternoon are expected to shift to north winds late in the
afternoon (with gusts up to 25 mph), and then have stronger south
winds in the Shasta Valley (with gusts up to 30 mph) for Friday
afternoon.

Though backing off slightly from critical levels, hot, dry, and
breezy conditions will continue across our area on Saturday and
Sunday. Temperatures 5 to 10 degrees above normal are expected
Friday through the weekend. Humidity recoveries will be at a peak
on Friday morning, then trend lower again. Afternoon wind speeds
will trend back to typical values by Sunday, while humidities
remain very low on Saturday then on Sunday will trend higher, to
very near to barely higher in comparison to today`s values.

The air mass will begin to moisten on Sunday with an increase of
high clouds, and perhaps some east side cumulus buildups.
Instability could develop as early as late Sunday night into Monday
morning, but the risk of thunderstorms is not expected to rise to a
mentionable slight chance for thunderstorms until Monday afternoon,
continuing on Tuesday. The probability on Monday is highest for Lake
County, secondarily into eastern Siskiyou, Modoc, and Klamath
counties. The model variance in solutions increases Tuesday, though
with the highest probability again on the east side.

Model uncertainty increases further beginning Wednesday with
differences in whether the unstable air mass will linger or shift
east of our area.

&&

.MFR WATCHES/WARNINGS/ADVISORIES...
OR...Fire Weather Watch from Friday afternoon through Friday evening
     for ORZ624.

CA...Fire Weather Watch from Friday afternoon through Friday evening
     for CAZ285.

PACIFIC COASTAL WATERS...Small Craft Advisory from 11 AM Friday to 11
     AM PDT Saturday for PZZ356-376.

&&

$$