330
FXUS66 KMFR 141734
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
1034 AM PDT Fri Jun 14 2024

...Updated AVIATION discussion...

.DISCUSSION...An update is not necessary. The focus in preparing for
this afternoon`s issuance will be upon the temperature and
probability of precipitation forecasts. Specifically, it will be
much cooler ahead of, and with the passage of a closed low Sunday
through Monday night. with the highest probability of
precipitation Sunday night through Monday night.

Temperatures will be coldest Saturday night. First, patchy east
side frost and a northern Klamath County freeze are likely
tonight. If supported by the incoming 12Z data, a freeze watch may
be necessary for portions of the east side, for Saturday night and
Monday night. Temperatures will also be cold on Sunday night, but
cloud cover would be likely to prevent frost formation.

Temperatures begin to rebound, and the air mass turns drier
Tuesday, with above normal temperatures likely from Wednesday
through the end of the week.

&&

.AVIATION...14/18Z TAFs...VFR conditions are present across northern
California and southern Oregon this morning, and are expected to
continue through the TAF period. High clouds will move over the area
this afternoon and evening, but nothing that will change any flight
levels. Gusty afternoon winds in the Rogue Valley and east of the
Cascades will calm into the evening. Guidance suggests a 20-30%
chance of MVFR ceilings over the Oregon coast north of Cape Blanco
near the end of the TAF period, but confidence is not high enough to
include those ceilings in this round of TAFs. -TAD

&&

.MARINE...Updated 830 AM Friday, June 14, 2024...North winds
and steep seas will linger today south of Cape Blanco. Conditions
will gradually improve Friday evening as a weak cold front
approaches. The front passes on Friday night. A thermal trough over
northern California may produce advisory strength north winds near
shore south of Gold Beach Saturday afternoon and evening.

By Sunday, there is a lot of uncertainty with model guidance, and
there is the potential for a strong low to pass later Sunday into
Monday. This could bring in a strong fresh swell in addition to
stronger wind speeds than we currently have forecast. We essentially
have a scenario where either an upper level low takes a northern
track or a southern track through the region. As the track becomes
clearer, we should have a much better idea of potential hazards (or
lack thereof) early next week. -CC

&&

.PREV DISCUSSION... /Issued 346 AM PDT Fri Jun 14 2024/

DISCUSSION...Two records for maximum temperatures were set
yesterday. At Mt. Shasta the old record of 88 degrees was beaten
when the temperature peaked at 90 degrees. At Montague, the
previous record of 94 degrees was tied. Following some record warm
temperatures, stratus has once again built into coastal valleys
of SW Oregon and is trying to spread up the Umpqua river valley,
too. Meanwhile, currently, stratus has returned in some coastal
valleys and is developing in some parts of western Douglas County.
The stratus is expected to lift and dissipate by this afternoon.

As a broad trough takes hold over the region the main impact over
the next few days will be in introducing cooler temperatures. The
most notable of which are temperatures near or below freezing
returning to the mountains and areas east of the Cascades. Frost is
also expected with these conditions. The cold overnight temperatures
are expected to peak Saturday and Sunday nights, with Monday
forecast to be the coolest day in this period.

Otherwise, we are expecting humidities to trend up and for the
afternoon diurnal winds to be enhanced a bit, but none of this is
expected to cause any impacts. Slightly more active weather is
possible early on Saturday as a decaying front brings a 10-30%
chance for less than 0.1" of an inch of rain to the coast and
Douglas County.

Models are continuing to point towards later Sunday and Monday as
being a period of being more likely to have more frequent rain
shower chances. There is a broad 10-15% chance across NorCal and SW
Oregon Sunday evening, with the chance for precipitation peaking
around 50% in the Cascades at the same time. Amounts are forecast to
generally be less than 0.1", except in the Cascades and eastern
Douglas County where amounts are forecast to be around 0.25".
Although both road and many rocky surfaces are likely too warm to
support holding new snow cover, there is snow in the forecast for
the higher peaks in the Cascades, with a 20% chance that up to 1"
falls. So, overall light amounts of both rain and snow, which should
have minimal impact beyond maybe causing some slick roads.
Thunderstorm activity still doesn`t look all that likely, too, but
is possible north towards the Willamette Valley and central
Cascades.

High pressure is expected to return through the end of next week,
but is generally characterized by warm, rather than hot,
temperatures, and regular diurnal wind cycles.
-Miles

&&

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

CA...None.

PACIFIC COASTAL WATERS...Small Craft Advisory until 11 PM PDT this
     evening for PZZ356-376.

&&

$$