555
FXUS66 KMFR 181114
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
414 AM PDT Sat May 18 2024

.DISCUSSION...Model agreement is very good into Friday, with the
main points of uncertainty being the strength of a
seasonable/relatively weak trough Tuesday afternoon into Wednesday
night, and (with a larger extent of uncertainty) another at the
end of the forecast, around Friday night into next Saturday.

Today looks to be the warmest out of the next 7 days, with
readings near to several degrees above normal, which will be near
the levels reached yesterday. After a solid week of much warmer
and drier than normal weather, the shift to seasonable conditions
for the next week will be noticeable. The other main
characteristic, at least through Wednesday, will be continued
stronger than normal afternoon into evening breezes, with winds
mainly out of the west to northwest. Winds this afternoon will be
stronger than yesterday (with gusts at 15 to 30 mph), almost as
strong late in the day Sunday through Tuesday, then possibly at a
slightly stronger peak for Wednesday.

Regarding precipitation, the chances will be late tonight into
Sunday morning for Coos and northern Douglas counties with a few
hundredths of an inch possible, then first and most significantly
in that same area with the aforementioned cold front Tuesday
afternoon into Tuesday evening, extending across at least southern
Oregon Tuesday night into Wednesday with amounts mainly up to a
tenth of an inch. Some break between systems is likely Thursday,
then the next trough will move southeast into the Pacific
Northwest. There is a wide variety of solutions regarding the
southern extent and strength of this trough, with the possibility
of either a quick glancing blow of minimal impact or the necessity
of raising the current slight chances of precipitation. At the
least, temperatures Friday into the start of the Memorial Day
weekend are likely to be slightly below normal to near normal with
coastal highs near 60, lower 70s on the west side, lower to mid
60s on the east side, and mainly 50s in the mountains.

&&

.AVIATION...18/06Z TAFs...Clear skies and VFR conditions across the
forecast area will continue through most of the TAF period. Some
higher cirrus may filter in from the north, especially in Oregon.
The main concern tonight will be LIFR ceilings along the coast later
tonight as the boundary layer compresses, however; guidance is not
showing this potential, and Satellite currently does not show the
indications yet. Will put this at a 40% chance, and will leave it
out of the TAFS for now.

Then, Saturday, higher clouds may filter in from the north,
mostly staying confined to Oregon. The bigger concern will be
gusty northwest to north winds 20 to 30 kts across most of Oregon
and California, impacting all terminals in the afternoon. Breezy
winds are most likely to occur between 2pm and 11pm PDT.
-Schaaf

&&

.MARINE...Updated 200 AM Saturday, May 18, 2024...A thermal
trough pattern will maintain gusty north winds and steep to very
steep seas through the weekend into early next week. Seas will be
highest south of Cape Blanco around Brookings with waves up to 10-12
feet today. Meanwhile, areas near Florence and Coos Bay will see
waves around 5 to 7 feet. Seas will be a combination of fresh swell
out of the northwest and wind waves.

Seas will remain hazardous to small craft through the weekend and
into early next week. The thermal trough will weaken slightly early
Sunday morning through the afternoon, but seas will remain steep
through the majority of the waters. It will then strengthen again
late Sunday into Monday, with yet more steep to very steep waves.
Waves will then subside to around 4 to 6 feet across all the waters
around Tuesday and Wednesday of next week. -CSP

&&

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

PACIFIC COASTAL WATERS...Small Craft Advisory until 5 PM PDT Sunday
     for PZZ350-356-370-376.

Hazardous Seas Warning until 2 AM PDT Sunday for PZZ356-376.

&&

$$