422
FXUS66 KMFR 190600
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
1100 PM PDT Wed Jun 18 2025

.DISCUSSION...Updated AVIATION Section.

&&

.AVIATION...19/06Z TAFs...VFR prevails this evening. Smoke from
the Upper Applegate Fire (south of Ruch) settled down after sunset
due to a combination of aggressive initial attack, increasing
humidity and lessening wind speeds. Even so, expect some of this
smoke to settle in underneath a low-level inversion tonight, so
locally reduced visibility can be expected in the immediate
vicinity of the fire.

Some lower stratus could reform in the Umpqua and spillover into the
Rogue Basin later tonight or early Thuresday morning, but these
clouds should be mostly VFR AOA 3000 feet. Some MVFR ceilings could
impact North Bend late tonight/Thu AM. Expect another round of gusty
N-NW winds for all TAF sites Thursday afternoon/evening. Peak gusts
again will be in the 20-25 kt range. A few afternoon/evening cumulus
buildups may occur in extreme SE portions of the forecast area,
out near the Warner Mtns. -Spilde

&&

.MARINE...Updated 800 PM Wednesday, June 18, 2025...Breezy north
winds continue all areas tonight and Thursday, with stronger winds
and steep, hazardous seas south of Cape Blanco. An unseasonably cool
and wet system arrives Friday and Saturday with showers and breezy
west-northwest winds. An isolated thunderstorm is also possible. A
thermal trough, along with north winds and steep seas, returns next
week. -BPN/Spilde

&&

.PREV DISCUSSION... /Issued 511 PM PDT Wed Jun 18 2025/

DISCUSSION...Updated AVIATION Section.

AVIATION...19/00Z TAFs...VFR prevails this evening, though
some lower clouds linger in portions of Coos and Douglas counties.
The Upper Applegate Fire is producing quite a bit of smoke south of
Ruch this evening, enough so that it could produce local IFR
conditions around the immediate vicinity of the fire, but especially
on the SE flank due to NW local surface winds. Wind gusts in the 20-
25 kt range will continue until around 04z, then subside thereafter.
SW winds aloft are carrying the elevated smoke off to the NE across
Medford.

Some lower stratus could reform in the Umpqua and spillover into the
Rogue Basin later tonight or early Thuresday morning, but these
clouds should be mostly VFR AOA 3000 feet. Some MVFR ceilings could
impact North Bend late tonight/Thu AM. Expect another round of gusty
winds for all TAF sites Thursday afternoon. Peak gusts again will be
in the 20-25 kt range. -Spilde

PREV DISCUSSION... /Issued 245 PM PDT Wed Jun 18 2025/

DISCUSSION...Daytime highs look to remain at or just above seasonal
norms today as zonal flow aloft remains in place. Marine stratus is
expected to return to the Oregon coast tonight, and could move into
the Umpqua Valley as well. Winds look to turn slightly offshore
early Thursday morning, which would limit how long any clouds endure
through the day. Temperatures cool on Thursday as the upper air
pattern starts to shift ahead of active weather arriving for the
weekend.

A low pressure system looks to move over the area through Friday and
Saturday. While the Oregon coast will cool slightly to reach the
high 50s to low 60s, inland temperatures will resemble April`s. West
side valleys are forecast to be in the mid 60s and east side areas
could reach the mid 50s to low 60s. Overnight lows will also cool
significantly east of the Cascades. Low temperatures are approaching
Frost Advisory thresholds (33-36 degrees for at least 3 hours) from
Friday night into Saturday morning as well as Saturday night into
Sunday morning for most areas of Klamath, Lake, and Modoc counties.
As of this discussion, conditions are just outside of those
thresholds so an Advisory will not be issued yet. But cool
temperatures are likely, even if an official product is not issued.
Gusty winds also remain in the forecast over east side terrain, but
are safely below Wind Advisory thresholds.

Widespread precipitation is expected, although amounts are non-
threatening. The highest forecast amounts remains over Coos County
and the Cascades, with 0.75 to 1.0 inches of precipitation forecast
from Friday morning to Sunday morning. Curry County and the Umpqua
Valley could get 0.25 to 0.5 inches. Other areas will get lower
amounts of rainfall. Upper level instability within the low pressure
system could trigger thunderstorms west of the Cascades on Friday
afternoon and evening, but chances remain slight (5-15%). Lesser
chances remain in the forecast for Saturday afternoon and evening.
Confidence in these possibilities are moderate, given that CAPE and
LI values remain low. Developing cloud cover on Friday morning could
also limit surface heating, which could also impact Friday`s
thunderstorm chances. These periods are just outside of high-
resolution data sources, so more clarity is expected as the weekend
approaches.

Scattered showers continue on Sunday, but activity decreases through
the day as conditions transition back to dry and stable to start
next week. Chances for Medford to hit 90 degrees early next week
(Monday-Wednesday) are at 60-75%. Long term clusters show an upper
trough may move over the area towards the end of next week, which
may bring cooler temperatures but additional precipitation is not
expected. -TAD

AVIATION...18/18Z TAFs...Marine clouds remain along the Oregon
coast and into the Umpqua Valley, but satellite imagery and local
observations show this layer is starting to clear out. VFR levels
are expected across the area this afternoon, with normal diurnal
wind changes. Marine stratus looks to return to coastal areas
tonight, but could clear out before Thursday afternoon. -TAD

MARINE...Updated 200 PM Wednesday, June 18, 2025...Areas of marine
fog, stratus, and drizzle will return tonight along the coast north
of Cape Blanco, while a thermal trough develops to the south. Expect
breezy north winds today and Thursday, with gusty winds and steep
seas south of Cape Blanco. An unseasonably cool and wet system
arrives Friday and Saturday with rain and breezy west winds, and
perhaps an isolated thunderstorm. The thermal trough, along with
north winds and steep seas, returns next week. -BPN

&&

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

CA...None.

PACIFIC COASTAL WATERS...Small Craft Advisory until 11 PM PDT
     Thursday for PZZ356-376.

&&

$$

MAS/MAS/MAS