674
FXUS66 KMFR 172109
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
209 PM PDT Mon Jun 17 2024

.SHORT TERM...A trough is swinging across the Pacific Northwest
today. More locations west of the Cascades in the valleys and at
the coast will see a warm up this afternoon, although temperatures
will still be 10 to 15 degrees cooler than normal. A thermal
trough has been building today, and this has brought breezy
conditions to the coast with gusts near 25 mph possible this
afternoon, especially on the Curry County coast.

The next area of concern will be tonight with colder overnight
temperatures. Tonight there is a 68% probability to reach 32 degrees
at Klamath Falls. There is a 65% probability for Chemult to reach 26
degrees or lower tonight. A Freeze Watch was out for tonight with
the concern of sub-freezing temperates as low as 24 degrees. This
has been upgraded to a Freeze Warning which will be in effect
from 1 AM through 8 AM Tuesday. This includes most of Klamath and
Lake counties and portions of Siskiyou and Modoc counties near
Macdoel and Alturas. Please see the NPWMFR for more information.
There was a concern for a Frost Advisory in parts of Siskiyou
County, but the probabilities are too low and isolated to bring
about another product, so the Freeze Warning will be the only land
product tonight.

As the trough moves off to the east, higher heights will be
present in Oregon on Tuesday, and this will be enough to bring a
return to near normal temperatures. Tuesday night into Wednesday
morning, temperatures east of the Cascades will be in the mid-
/upper 30s, putting an end to the freeze risk in most spots. WEst
side valleys will have lows in the mid-/upper 40s. Dry conditions
will be favored in the coming days as well.
-Hermansen

.LONG TERM...Wednesday through next Monday (June 19-24, 2024)...

Things will start to warm up more Wednesday with a return to
temperatures near 90F for the Rogue Valley. The Rogue Valley and
western Siskiyou valleys will be under a moderate HeatRisk
Wednesday/Thursday afternoons. In addition to the Rogue Valley,
moderate HeatRisk will spread into more of the Umpqua Basin and
Illinois Valley in the later part of the work week (Thu/Fri). The
warmest day of the week will be Friday for west side valleys and
Saturday for east side locations. High temperatures will peak in
the low/mid 90s for the west side valleys and in the upper 80s to
low 90s over the east side. The official forecast for Medford is
for 96/95F for both Fri/Sat, respectively, with a low chance
(~20%) of 100F. Best chance for >=100F (40-60%) will be in the
lower Klamath and Salmon river valleys (Happy Camp/Somes Bar), and
the Shasta and Scott valleys of western Siskiyou County. Breezy,
but fairly typical, afternoon W-NW winds will be present each day,
but will pick up into the weekend, especially east of the
Cascades. These areas will have wind speeds of 15-25 mph and
occasional gusts to 30 mph both Fri/Sat.

A mostly dry front/marine push appears likely over the weekend.
As mentioned, Saturday should be another very warm day over inland
areas. The front will push onshore Saturday night into Sunday.
This could deepen the marine layer just enough for some light rain
or drizzle at the coast, especially north of Cape Blanco and
perhaps into lower portions of the Umpqua Basin, but right now
PoPs are less than 15% in these areas. This trough/front should
at least drop temps back by a few degrees both Sun/Mon. Otherwise,
dry conditions will prevail through the long term.

-Hermansen/Spilde


&&

.AVIATION...17/18Z TAFs...A large shield of cumulus is sliding down
the coast and into the Umpqua Basin this morning. Ceilings within
this cumulus are largely VFR, but occasional dips into MVFR are
possible. This is especially true along the coast where low-topped
showers not seen by radar may be embedded. These clouds should stay
bottled up west of the Cascades and north of the Umpqua Divide
today, with only pop-up fair weather cumulus elsewhere.

Residual moisture may result in the return of stratus and fog in the
Umpqua Basin (including KRBG) tonight, similar to this morning. But
with the probability remaining relatively low (30% at most), have
opted to exclude from their TAF for now. VFR conditions should
prevail elsewhere tonight. -Wright


&&

.MARINE...Updated 200 PM Monday, June 17, 2024...A thermal trough
will remain along the coast through at least next weekend, and this
will keep north winds and wind driven seas going through the period.
Conditions will be worst south of Cape Blanco where winds and seas
hazardous to small craft will persist. The thermal trough
strengthens and expands northward a bit on Tuesday, and this will
bring small craft advisory conditions to the waters north of Cape
Blanco as well Tuesday afternoon into Wednesday morning.

The thermal trough will strengthen further later this week into the
weekend, and this may bring north gales to the waters south of Cape
Blanco. Mariners would be wise to stay tuned to updates as we move
through the week. -Wright


&&

.MFR WATCHES/WARNINGS/ADVISORIES...
OR...Freeze Warning from 1 AM to 8 AM PDT Tuesday for ORZ029>031.

CA...Freeze Warning from 1 AM to 8 AM PDT Tuesday for CAZ084-085.

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

&&

$$

ANH/MAS/TRW