853
FXUS66 KMFR 282345
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
445 PM PDT Tue May 28 2024

.Updated Aviation Discussion.

.DISCUSSION...overall the weather should be fairly repetitive
this week, with weak high pressure dominating once the current
trough moves to the east.

The broad trough sitting offshore of Vancouver Island and has forced
a weakening front onshore. This has caused some weak showers, but
generally just dry cumulus, up over the terrain west of the Cascades
in the Coast ranges and Douglas County. East of the Cascades,
thunderstorms are beginning to form today in Lassen and Modoc
County. There is a 10-20% chance for further isolated
thunderstorm activity across Lake County as well as the front
moves through, but the better environment is in the eastern half
of Oregon into Idaho. Overall, these showers/thunderstorms should
cause no more than a nuisance level of impact.

Temperatures are expected to remain around the mid 70s to low 80s
for most places inland from the coast, which is near or at normal
for this time of year. The one exception would be in the Umpqua
Basin where if fog forms tonight, the forecast could be a few
degrees on the warm side.

Wednesday into Friday, a thermal trough will peak and this will
bring moderate recoveries to most places outside of Douglas, Coos,
or Curry County. The thermal trough will also cause strong north-
northwest winds in the coast range and a chetco effect, which will
lead to warmer temperatures around Brookings than elsewhere on the
coast. The strong winds at the coast should subside on the weekend.

The climate prediction center is hinting already at some higher than
normal chances for a heat wave in the extended range of the forecast
and it is worth taking a look at their outlook if you are concerned
about heat.
-Miles

&&

.AVIATION...28/18Z TAFs...Along the coast and just offshore. VFR
ceilings are currently being observed. However a weak disturbance
offshore will move inland later this evening resulting in increased
onshore flow with marine stratus with MVFR ceilings developing
between 4-5z and lasting into tomorrow morning, before improving to
VFR in the afternoon. The south coast should remain VFR through the
TAF period.

Inland, west of the Cascades, Ceilings are expected to remain VFR
through the TAF period. Winds will increase during the day, with
gusts up to 25 kts possible at Medford until 3z.

East of the Cascades, VFR conditions will continue through the TAF
period. The main concern is moderate to occasionally strong winds
with peak gusts possibly exceeding 30 kts at Klamath Falls into this
evening. The other concern is isolated thunderstorms over Lake,
Modoc, and eastern Siskiyou counties late this afternoon and
evening. However, they are not expected at the Klamath Falls
terminal. -Petrucelli

&&

.MARINE...Updated 230 PM Tuesday, May 28, 2024...Relatively calm
conditions are expected into Wednesday morning with light to
moderate winds and low seas. A thermal trough will develop during
the day Wednesday resulting in increasing north winds that will
reach Small Craft for all of the southern waters, except beyond 5
nm from shore west of Port Orford. The thermal trough will
strengthen further late Wednesday night through at least Friday
evening and this will result in Gale force winds for a good chunk
of the southern waters, except beyond 40 nm from shore west of Cape
Blanco. Meanwhile Small Craft Conditions will expand north over the
rest of the waters that will last into at least Friday evening.

The thermal trough will weaken overnight Friday into Saturday with
north winds diminishing as an upper trough approaches. Calmer seas
are expected by the weekend and into early next week. -Petrucelli

&&

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

PACIFIC COASTAL WATERS...Small Craft Advisory from 5 PM Wednesday to
     5 AM PDT Thursday for PZZ350-356-370-376.

Gale Warning from 5 AM Thursday to 11 PM PDT Friday for PZZ356-
     376.

&&

$$