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628
FXUS66 KMFR 122352
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
452 PM PDT Wed Jun 12 2024

Updated AVIATION Section

.SHORT TERM...Central and southern Douglas and southern Coos
counties had more stratus this morning that has been thinning out
through the afternoon. It is overall another warmer day with highs
in the 80s east side, more 70s and 80s for west side and 90s in
northern California. The temperatures at Mount Shasta will need to
be watched as they are nearing record highs today and tomorrow.
The record high for Mount Shasta today is 92 from 2015 and
Thursday is 88 from 2019. Breezy conditions have returned with
gusts nearing 25-40 mph at the Coos County Coast. Inland winds
will be westerly (east side)/northerly (west side) at 10-20 mph
the next few afternoons.

Starting Friday there will be a trough moving southward from the
coast of Canada. This will bring a cooldown and a return to near
normal. Temperatures Friday will return to the 70s and low 80s
overall. There`s a 48% probability of reaching 80 degrees in Medford
Friday. After that, the probability is below 15% through the weekend
with below normal temperatures. In terms of PoPs with this
troughing, there will be an increase in PoPs starting Friday night
near northern Coos and Douglas counties. This will not be impressive
by any means as the 15-25% PoPs will likely equate to less than a
tenth of an inch of new rainfall. A trough will dig deeper into the
Pacific Northwest early next week, and these details will be
discussed in the long term. -Hermansen

.LONG TERM....An upper level trough will remain centered just
north of the area on Saturday as an upper low approaches the
Pacific Northwest. This low will move inland over Washington and
northern Oregon late Saturday into Sunday with a weak moving
onshore into the region. This pattern will bring continued mild
temperatures and breezy to gusty afternoon winds (with winds
gusting up to 20 to 25 mph during the afternoon and evening
Saturday). Chances for light rain (15 to 30%) are mainly limited
to Coos and Douglas counties Saturday and Saturday night.

Models show more variability with the forecast for Sunday into early
next week. There is high confidence that an upper trough will linger
over the area on Sunday as the upper low begins to shift eastward.
However, some models (30% of the ECMWF ensembles and <5% of the
GEFS) indicate the upper low to the north will deepen over the area,
rather than move east, as another disturbance moves down from the
north. This would bring a chance for more widespread precipitation
Sunday night through Tuesday morning. Current National Blend of
Models (NBM) forecasts indicate this solution is a lower chance,
showing low chances (10%) for precipitation during this period
though. This would also bring a cooler pattern with models
supporting snow levels lowering to 5500 to 6000 feet Sunday, and
possibly lower Sunday night into Monday. Additionally, a low deepening
over the area, would result in instability and a potential for
thunderstorms. While, ensembles currently favor a drier pattern with
the low shifting east of the area, this will be a period to watch.
We will continue to monitor and update as confidence increases.

Tuesday afternoon through Thursday, a weak, broad trough is forecast
over the area with a high pressure ridge just offshore. With this
pattern expect temperatures to trend warmer and mainly dry
conditions.


&&

.AVIATION...
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13/00Z TAFs...VFR prevails area wide currently. For most
of the area, it will remain that way for the next 24 hours. Patchy
MVFR ceilings may develop after sunset in portions of the Coquille
Valley and along the coast north of Cape Blanco. But, with the wind
slightly E of due north, the clouds may just hug the immediate
coastline. We`re going with a SCT010 at North Bend, with the idea
that perhaps it could go either way (BKN or SKC) overnight into
Thursday morning. Similarly, patchy MVFR ceilings are possible in
the Umpqua Basin, though again, confidence in a BKN ceiling is low.
As such, went with SCT020 at Roseburg for a couple of hours Thursday
morning. The gusty northerly winds this evening will subside
overnight, then redevelop Thursday afternoon, but won`t be as strong
as today. -Spilde
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&&

.MARINE...Updated 230 PM Wednesday, June 12, 2024...Elevated and
gusty northerly winds continue over waters off the Oregon coast
under a thermal trough. Wind-built chaotic seas are forecast to
continue through Friday morning. Currently, gale seas are expected
south of Ophir and with 40 nm from shore. Very steep and hazardous
seas will be present south of Lakeside, with steep seas in waters
farther north.

Please see MWWMFR for more details about existing hazard ares and
conditions. These products will be in place through Thursday at 11
AM.

Steep seas will continue in all waters into early Friday morning,
with areas of very steep seas continuing south of Gold Beach as the
thermal trough weakens. Calm seas are expected through Friday
afternoon and through Saturday morning. By Saturday afternoon, there
are hints of a thermal trough returning. However, long term guidance
shows 0-10% chance of waves over 9 feet through the weekend. Some
areas of steep seas around Brookings are possible, but confidence
in any broad areas of weekend hazards are currently low. -TAD


&&

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

PACIFIC COASTAL WATERS...Hazardous Seas Warning until 11 AM PDT
     Thursday for PZZ350-356-370-376.

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

     Gale Warning until 11 AM PDT Thursday for PZZ356-376.

&&

$$

CC/MAS