057
FXUS66 KMFR 251834
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
1134 AM PDT Wed Jun 25 2025

.UPDATE...Updated Aviation Section.

&&

.AVIATION...25/18Z TAFs...Some MVFR marine layer cloudiness
remains along the coast north of Cape Blanco in Coos and NW
Douglas counties late this morning. IFR stratus is impacting areas
near Brookings and southward. Expect some improvement in ceilings
this afternoon. Elsewhere, VFR will prevail, though scattered
afternoon cumulus buildups are expected, mainly from the Cascades
eastward. Gusty WNW breezes (20-30kt) will impact Medford and
Klamath Falls from 21-05Z.

Deep marine layer will re-establish in Douglas, Coos and
Curry counties again tonight into Thursday morning with MVFR
stratus in most places, though IFR/LIFR is likely again south of
Gold Beach. Ceilings are probably VFR around Roseburg and any
spillover into the Rogue Basin should be VFR as well.  -Spilde

&&

.PREV DISCUSSION... /Issued 359 AM PDT Wed Jun 25 2025/

DISCUSSION...

The main weather feature for today will be a shortwave pushing
through the region during the evening hours. Cloud cover will
increase with a mix of high, mid and low level clouds. The
atmosphere still appears too dry to support widespread
precipitation, although some models do have a 15 to 25 percent
chance of rain along the coast this morning, while the NBM is
drier around 5 percent. There is also about a 5% chance of a weak
thunderstorms near the Mt. Shasta area this evening into tonight.
In any case, it will be dry for most of us today away from the
coast with some breaks in sunshine to warm most locations up to
the 80`s.

As we move into Thursday, the pattern continues to show a
persistent low in the Gulf of Alaska with a trough extending down
into the Pacific Northwest through Friday. It looks more like
zonal flow for us. Even with the zonal flow, temperatures remain
near normals or slightly above for late June with dry weather
persisting into Friday.

Things become more interesting towards the end of the weekend into
Monday as models are picking up on an upper level low off the
California coastline. This type of pattern usually results in some
thunderstorms developing across the region. The vast majority of
ensemble members are picking up on some light precipitation
somewhere over Oregon Monday evening, so confidence is pretty good
for some thunderstorm activity within Oregon on Monday. For what
it`s worth, the GFS does have pretty widespread 500 j/kg area of
CAPE Monday afternoon, which is good enough for some thunderstorm
activity around Oregon.

That upper level low and all the moisture will head eastwards
around Tuesday before conditions become more uncertain into the
middle of next week. Some ensemble members bring in another upper
level low while others do not. So uncertainty remains pretty high
middle of next week.

-Smith

AVIATION...25/12Z TAFs...LIFR to IFR ceilings will persist along
the coast tonight as a thick marine layer pushes into the coast
and other coastal valleys. There is a low chance these ceilings
will make it into Roseburg this morning. Ceilings will likely rise
into the afternoon hours, although MVFR ceilings will probably
persist along the coast.

Elsewhere, VFR conditions will continue through Wednesday evening,
with some slightly stronger than typical afternoon and early evening
breezy winds (with gusts of 15 to 30 kt), and scattered afternoon
cumulus buildups east of the Cascades. -DW/Smith

MARINE...Updated 230 AM Wednesday, June 25, 2025...Light winds and
seas are expected today into Thursday. A weak thermal trough
develops late Thursday then strengthens Friday through the weekend.
Strong north winds may bring steep seas south of Cape Blanco by
Friday afternoon. Then, steep seas possibly extend across the
northern waters during the weekend with gales and very steep seas
possible south of Cape Blanco. The outlook is for the thermal trough
to remain strong and persist next week. -DW/Smith

&&

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

CA...None.

PACIFIC COASTAL WATERS...None.

&&

$$