407
FXUS66 KMFR 141141
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
440 AM PDT Tue May 14 2024

.Updated Aviation Discussion.

.SHORT TERM...An upper level ridge centered to the west will
remain in place. Meanwhile a surface thermal trough along the
coast will result in offshore flow today and Wednesday. This will
result in warm and dry weather across the area. Offshore
northeasterly winds will bring warm and dry air into the Brookings
area and southern Curry coast as well. High temperatures today
and Wednesday will be 10 to 15 degrees above normal for inland
areas and along the southern Curry coast. Breezy to gusty winds
are likely in the afternoons and evenings along the coast and
across much of Coos, Curry, Douglas and Josephine counties.

High pressure will remain in place into Thursday, weakening
slightly late in the day and Thursday night as a shortwave trough
moves into Washington and northern Oregon. The thermal trough
will shift inland during the day Thursday. This pattern will bring
continued warm and dry weather to inland areas but expect coastal
areas to see near normal or slightly above normal temperatures.
Breezy to gusty north to northwest winds are expected Thursday
across most the area.

Confidence is high for temperatures to remain well above normal
across inland areas through Thursday as well as above normal along
the southern Curry coast through Wednesday.


&&

.AVIATION...14/12Z TAFs...Along the coast and just offshore. IFR
ceilings are expected to remain confined to around Brookings and
west of Brookings out to around 6 nm from shore this morning with
the marine stratus burning off towards 18z. Elsewhere, VFR
conditions will prevail into this evening, but could not rule out
brief periods of shallow IFR ceilings at North Bend between 14-15z.
Moderate to strong winds gusting close to 35 kts at North Bend as
early as 20z. Marine stratus returns late this evening with IFR
ceilings lasting until the end of the TAF period.

Inland, VFR conditions will continue through the TAF period with
gusty afternoon and early evening breezes at the terminals.
-Petrucelli

&&

.MARINE...Updated 200 AM Tuesday, May 14, 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/Petrucelli

&&

.PREV LONG TERM DISCUSSION... /Issued 126 PM PDT Mon May 13 2024/

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.

&&

$$

CC/CC/CC