702
FXUS66 KMFR 132026
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
126 PM PDT Mon May 13 2024

.SHORT TERM...

Overview:

Outside of a very slim chance (<10%) for showers/thunderstorms
today, we are looking at a relatively quiet forecast today through
tomorrow night. Warm and dry weather is expected for nearly the
entire area outside of the small chance for showers in Siskiyou
County this afternoon. In the unlikely event a thunderstorm
develops, lightning would be the main threat.

Further Details:

We can see cumulus forming via visible satellite over northern
California and parts of Lake County. At 500mb, we do have a
disturbance passing with the vorticity field essentially making its
way east of the area. Being on the back side of this disturbance
now, we likely wont see much--if any--shower activity today. That
really is the only potential weather impact in the short term.
Otherwise, it will be warm again today, but slightly cooler than
yesterday, with breezy afternoon wind speeds. When we say breezy,
this is within a range of 15 to 25 mph sustained. This is really
only for our "typical" breezy spots as a lot of the area will
likely be under 15 mph today and tomorrow. Tomorrow will be
slightly warmer than today. Inland, there will be no shortage of
sunshine both today and tomorrow.

-Guerrero

.LONG TERM...Wednesday May 15th - Monday May 20th...The axis of the
upper-level ridge will remain offshore Wednesday, with continued
northerly flow aloft. This is a very similar pattern to the one we
saw earlier in this week, one which brings higher than average
temperatures to the area (more typical of June than May), dry
weather, and sunny skies.

Northeasterly flow at lower levels along the south OR coast will set
off the Chetco Effect, where air is funneled down the Chetco River
Valley and warms as its forced down towards sea level, which will
result in warm temperatures for Brookings and the surrounding
southern Curry County coast. Highs look to be in the high 70s to mid
80s through Thursday, with the warmest day on Wednesday before
thermal trough/heat low pressure helping produce these warm
temperatures starts to move inland. Farther north, more of a due
northerly flow will continue night and morning stratus for the
beaches from Cape Blanco northward.

The thermal trough along the south OR/northern CA coast will begin
moving inland Thursday, resulting in the warmest temperatures for
most inland areas that day while coastal areas begin cooling off
behind it.

Model differences increase Friday into the weekend, but generally
agree that the ridge will flatten and move east as a shortwave
trough approaches from the northwest Friday into Saturday. While
differences in the strength of the trough persist, very likely this
initial wave is too weak and too far to the north to have too much
of an impact on the local region, especially in terms of
precipitation, with more or less no chances for precip through the
region. This will result in temperatures cooling off for the region,
though they will remain warmer than average for this time of year.

Saturday into Sunday, a large closed low will move west towards
south-central CA as the trough in the PNW moves east out of the
region. However, dry weather will very likely (90%+ chance) continue
locally until another, stronger trough approaches from the NW late
Sunday into Monday. We`re generally sandwiched between these two
lows here in south OR/NorCal, a pattern than typically results in us
missing out on precipitation as there`s a lack of energy locally to
get anything off the ground. That said, 15-20% of models in the
National Blend of Models indicate measureable precipitation in
northern Douglas and Klamath counties and along the Cascade crest
late Monday.

-CSP

&&

.AVIATION (13/18Z TAFs)...

IFR and MVFR ceilings remain along the Oregon coast under
persisting marine stratus. These clouds will remain in place
through most of the TAF period, with the exception of a few hours
of VFR this afternoon before marine stratus returns this evening.
Inland areas will remain at VFR levels under clear skies through
the TAF period, with widespread breezy afternoon winds.

-BPN

&&

.MARINE...Updated 200 PM Monday, May 13, 2024...A thermal trough
will continue to produce gusty northerly winds and hazardous seas
across all of the southern Oregon coastal waters through the rest
of the week. Gales and very steep seas are forecast for all areas
south of Cape Arago, with Small Craft Advisory conditions to the
north. These hazards are likely to be extended through the week
and possibly into the weekend.

-BPN

&&

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

PACIFIC COASTAL WATERS...Gale Warning until 11 PM PDT Thursday for
     PZZ350-356-370-376.

Small Craft Advisory until 11 PM PDT Thursday for PZZ350-370.

&&

$$