171
FXUS66 KMFR 240504
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
1004 PM PDT Thu Jul 23 2026

...New Aviation Section...


.AVIATION (06Z TAFs)...

Outside of KOTH where MVFR/IFR conditions are expected to start
later this evening/overnight, expecting VFR conditions elsewhere
for inland TAF sites. There is a chance (~30%) for RBG to see low
clouds Friday morning, but at this time have maintained a VFR
cycle with a SCT deck at 1500 ft. Otherwise, we will continue to
see diurnal trends in the wind speeds with enhanced breezes for
inland TAF sites Friday afternoon.

-Guerrero

&&

.PREV DISCUSSION... /Issued 244 PM PDT Thu Jul 23 2026/

KEY MESSAGES...

* A much drier air mass moves into the area this afternoon and
  will persist for at least the next 7 days.

* Overall, temperatures will be very warm, but should be pretty
  close to or just slightly above normal for late July.

* Other than daily intrusions of marine stratus along the coast
  (and perhaps a slight chance of drizzle at times), cloud cover
  will be minimal and precip chances will be near zero for inland
  areas.

DISCUSSION...

Pretty quiet weather has developed across the forecast area this
afternoon with some marine stratus along the coast and cumulus
build ups over higher terrain. A vertically stacked low remains
spinning about 200 miles off our coastline with very weak
southerly flow in the boundary layer. However, winds aloft around
7000 to 9000 feet remain fairly strong out of the southwest. By
Friday, this low will be gathered up by another approaching trough
in the Pacific. Weather impacts here at the surface are pretty
minimal with temperatures near seasonal normals, although winds
will definitely trend higher by Friday afternoon east of the
Cascades.

Our main concern will be stronger wind gusts up to 45 mph.
Forecast soundings show some stronger mid level winds above the
mixed boundary layer Friday afternoon. If we mix about 500-1000
feet higher than anticipated, then wind gusts will likely be
stronger than what is in the forecast. It seems pretty unlikely
this would happen as the NBM 95th percentile wind gust forecast
isn`t producing these really strong wind gusts. Also, the extreme
forecast index(EFI) isn`t picking up on these very strong wind
gusts.

By Saturday, a trough and surface low off the BC coastline and
high pressure to our east will keep us in this deeper south west
flow pattern. All the moisture is well to our north closer to the
low with the air significantly drier to the south.

Heading into next week, nothing really stands out except for a
short wave moving into Washington state by Tuesday. This should
bring some increased westerly flow which will push temperatures
down a bit. Overall, pretty quiet and dry summer weather for the
majority of the forecast period.

-Smith

AVIATION...23/18Z TAFs...VFR prevails across most of the CWA for
the next 24 hours. This includes Medford and Klamath Falls. Marine
stratus (mostly MVFR, but local IFR) is also present along the
coast. Think this will peel back to around the beaches this
afternoon, so there may be some VFR at times then, but expect the
MVFR/IFR to return tonight. Roseburg is tricky again tonight. Could
see brief MVFR late tonight into tomorrow morning, but should become
VFR by late morning. -Spilde/BPN

MARINE...Updated 230 PM PDT Thursday, July 23, 2026...Relatively
calm conditions and low, mixed seas are expected through Friday.
South winds increase Saturday ahead of a dry cold front, possibly
approaching small craft advisory levels. Winds shift back to north
and west Sunday, but wind wave dominated seas probably hold off
until the middle of next week. -Spilde/BPN

FIRE WEATHER...Updated 230 PM PDT Thursday, July 23, 2026...

Relative humidity has trended significantly lower compared to
yesterday and by almost 20% in some locations. These very dry
humidities will persist into Friday with RH values east of the
Cascades falling into the single digits. Winds will also increase
during this time, mainly east of the Cascades in Modoc, Lake and
Klamath Counties. We`re pretty confident with critical fire
weather conditions today and meeting red flag criteria east of
the Cascades Friday. West of the Cascades, it will be breezy,
although not quite dry enough for a red flag warning. In any case,
elevated fire weather risk will develop for locations west of the
Cascades around the Rogue Valley.

By Friday night, wind gusts die down with moderate recoveries
east of the Cascades and over higher terrain and ridges. Some
areas of poor recoveries will occur along the Warner mountains.

These dry and windy conditions will persist into Saturday,
although humidities might come up a few percentage points. Critical
fire weather conditions might even continue into Sunday, although
the areas of concern are notably smaller.

-Smith

&&

.MFR WATCHES/WARNINGS/ADVISORIES...
OR...Red Flag Warning from 1 PM Friday to 9 PM PDT Saturday for
     ORZ624-625.

CA...Red Flag Warning from 1 PM to 8 PM PDT Friday for CAZ280-281.

     Red Flag Warning from 1 PM Friday to 9 PM PDT Saturday for
     CAZ284-285.

PACIFIC COASTAL WATERS...None.

&&

$$