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578
FXUS66 KMFR 262320
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
420 PM PDT Sun May 26 2024

...Updated AVIATION Discussion...

.DISCUSSION...Satellite image shows clear skies over most of the
forecast area. Some fair weather cumulus exist in portions of
northern California, northern Klamath and northwest Lake County.

Any clouds in these areas will dissipate towards sunset with clear
skies and continued dry weather tonight.

Monday, weak upper ridging will move east and a southwest flow will
set up. Instability will increase some east of the Cascades Monday
afternoon, and this in combination with a slightly stronger trigger
could be enough to warrant a slight chance of thunderstorms and this
has been added to the forecast. Afternoon temperatures will trend
higher for the interior.

Any isolated storms will end early Monday evening with it will
remain dry Monday night with milder overnight low temperatures due
to increasing clouds ahead of the next upper trough and front.

An upper trough will approach from the west Tuesday and could bring
a few showers north of Cape Blanco, north of the Umpqua Divide and
northern Cascades. Additionally, instability will be on the increase
along with ample low level moisture and trigger east of the
Cascades resulting in another round of Isolated storms. Several
ofthe models show convection breaking out and orientated from
southwest to northeast from Mount Shasta northeast to southeast
Klamath and central Lake County. Afternoon temperatures for the
interior will be cooler and winds will be stronger east of the
Cascades Tuesday afternoon and evening, but not strong enough to
warrant any headlines.

Isolated storms will once again diminish and end early Tuesday
evening with not much more than a few showers in northern Coos and
Douglas County Tuesday night. -Petrucelli

.LONG TERM DISCUSSION...Models and ensembles continue to indicate
the upper trough will remain over the area on Wednesday, with
continued mild temperatures, breezy/gusty afternoon winds and a
slight chance for showers, mainly far northeast Douglas County.
There is moderate agreement (90% of the GFS ensembles and over 50%
of the EC ensembles) that the upper trough will begin to move
eastward Wednesday night, with a high pressure ridge building into
the area Thursday. This ridge is expected to remain in place through
Friday.  This would result in a warming trend and dry weather across
the area. Additionally, models indicate a surface thermal trough
developing along the coast late Wednesday, then peaking Thursday
into Friday, with gusty north to northeast winds along the coast and
over the coastal mountains. This pattern may also bring a warming
and drying trend to the Brookings area along the southern Curry
coast late in the week. Guidance the National Blend of Models (NBM)
supports temperatures in the mid 70s at Brookings Thursday and
Friday. -CC

&&

.AVIATION...
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27/00Z TAFs...VFR levels continue across northern
California and southern Oregon this afternoon, and look to continue
for most areas through the TAF period. Marine stratus will develop
tonight along the Oregon coast, with MVFR ceilings expected early
Monday morning and clearing out late Monday morning or early Monday
afternoon. -TAD
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&&

.MARINE...Updated 200 PM Sunday, May 26, 2024...Stable atmospheric
conditions are continuing to bring generally calm seas in all
waters. Elevated northerly winds will develop south of Cape Blanco
this afternoon, with sustained speeds up to 20 kts. Gusts of up to
25 kts are possible near Brookings. These winds will decrease
overnight before returning Monday morning. While local areas of
steep seas are possible, guidance suggests that constant steep seas
are not expected.

A weak upper trough will bring some slight (10-20%) chances for
showers north of Cape Blanco on Tuesday. An upper ridge will build
on Wednesday and remain in place through the rest of the week. Model
guidance suggests a strong thermal trough will develop, with gusty
northerly winds in all waters and near gale gusts south of Cape
Blanco. While the exact conditions and hazards need further time to
develop, some amount of chaotic seas will build from midweek to the
weekend. -TAD


&&

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

CA...None.

PACIFIC COASTAL WATERS...None.

&&

$$