350
FXUS66 KMFR 162350
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
450 PM PDT Thu Jul 16 2026

...Updated AVIATION discussion for 00Z TAFs...

.KEY MESSAGES...

* Temperatures trend warmer Friday into the weekend, peaking on
  Sunday with highs in the 90s to low 100s across inland valleys.

* Gusty winds and low humidities will bring elevated fire weather
  conditions today and Friday. Critical fire weather conditions
  are expected on Friday in portions of southeast Klamath, Lake
  and Modoc counties.

* Hot, dry and breezy weather this weekend.

* Unstable with potential for thunderstorms Monday through
  Wednesday, mainly from the Cascades east and Siskiyous south.

* Smoke from the East Evans Creek Fire will result in continued
  impacts downwind of of the fire.

&&

.DISCUSSION...An upper low just off the coast will gradually move
northward tonight then inland over British Columbia late Friday.
As this low gradually moves northward along the PacNW coast,
breezy to gusty winds are expected for many inland areas this
afternoon/evening and again Friday afternoon and evening,
strongest east of the Cascades and in the Shasta Valley. The
combination of gusty winds and low humidities will result in
elevated fire weather conditions. Please see the fire weather
discussion below for details.

High pressure will build across the area late Friday through
Sunday, with a upper trough staying further north. A significant
warm up is expected on the weekend with highs peaking on Sunday 5
to 10 degrees above normal. Inland valleys are expected to reach
the 90s to low 100s on Sunday. The National Blend of Models
indicates a 60% chance for reaching 100 degrees at Medford and a
25% chance for reaching 100 degrees at Yreka.

High pressure remains in place across the region Monday and
Tuesday. Meanwhile, a low well off the coast of Baja and southern
California is forecast to move northward on Monday. Ensembles
show significant variability in the track and strength of this
low. The operational GFS is stronger with the low and brings it
northward off the coast of northern California Monday night into
Tuesday. This would result in more southerly moisture aloft moving
into the area Monday and Tuesday with chances (10-20%) for
thunderstorms. The operational ECMWF keeps the low further south
and as a result shows a drier pattern. However, even under this
pattern, monsoonal moisture may move up the Sierra crest and into
eastern portions of the area, bringing a slight chance for
thunderstorms. The track of this low and the amount of moisture
and cloud cover will factor into whether thunderstorms develop as
well how hot temperatures will be early next week. We are
continuing to monitor this pattern for the potential of
thunderstorms and ongoing heat.

Smoke from the Evans Creek Fire is expected to continue to bring
impacts to air quality across portions of southwest Oregon, and
potentially into areas in Northern California. Smoke impacts have
been greatest downwind of the fire in northern Jackson, eastern
Douglas and Klamath Counties as west to northwest winds spread
smoke to the east and southeast. The Rogue Valley near Medford and
Ashland may seen daily pushes of smoke, especially in the
evenings. This pattern will likely continue through Friday. On the
weekend, some light northeast winds during the overnight and
morning periods may allow additional smoke to spread into the
Rogue Valley. Otherwise, daytime northwest to west winds from the
Cascades west are likely to allow smoke from the fire to continue
to impact areas in southwest Oregon (including northern Jackson,
eastern Douglas and Klamath counties).

&&

.AVIATION...17/00Z TAFs...VFR levels are present across most of
northern California and southern Oregon at the start of the TAF
period. Northwest winds will move smoke from the East Evans Creek
fire towards Medford and Klamath Falls later this evening, which may
bring periods of lower visibility. Marine stratus is expected to
develop later tonight, bringing MVFR levels along the coast and
possibly into the Umpqua Valley. Anything that develops overnight
looks to clear out before Friday afternoon, leaving VFR levels and
normal diurnal breezes for the end of the TAF period. -TAD

&&

.MARINE...Updated 200 PM PDT Thursday, July 16, 2026...Below
advisory levels continue in area waters, 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. Steep seas spread
to northern waters by Saturday afternoon. Winds and seas are
expected to diminish on Monday. -TAD

&&

.FIRE WEATHER...Updated 200 PM PDT Thursday, July 16, 2026...
The slightly cooler temperatures today will be followed a warm up
Friday through Sunday. The main concern in the near term, will be
breezy to gusty winds and low daytime RHs today and Friday. The
strongest winds and lowest RHs will be east of the Cascades and in
the Shasta Valley. Conditions may near critical levels late this
afternoon and early this evening in the southern Shasta Valley, in
southeastern zone 624 (southeast Klamath and southwest Lake) and
zone 285 (Modoc). Then, conditions peak on Friday afternoon and
evening, with critical conditions likely for southeast zone 624 and
zone 285. A Red Flag Warning has been issued for Friday afternoon
into the evening in Fire Weather Zone 285 and the southern
portion of 624 for gusty winds and low RHs. This covers southeast
Klamath, southwest Lake, and Modoc counties. In the Shasta
Valley, a brief period of critical fire weather conditions is
possible in the late afternoon and early evening on Friday.

Hot, dry, and breezy conditions are expected Saturday and Sunday.
Temperatures of 5 to 10 degrees above normal are expected through
the weekend. Afternoon wind speeds will trend back to typical values
by Sunday. Humidities will remain very low on Saturday then trend
slightly upward on Sunday.

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 until Monday
afternoon, continuing on Tuesday. Chances for those Monday
thunderstorms have trended down, with very slight (5-10%) chances
lingering in northern Lake and Klamath counties as well as near the
Warners. On Tuesday, 10-15% chances cover most of the east side. For
areas where thunderstorms do not develop, this instability added to
continuing hot and dry conditions can lead to elevated critical
condition concerns.

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...Red Flag Warning from 2 PM to 8 PM PDT Friday for ORZ624.

CA...Red Flag Warning from 2 PM to 8 PM PDT Friday for CAZ285.

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

&&

$$