Small Craft Advisory 49, NWS Medford, OR

Area Forecast Discussion
National Weather Service Medford OR
215 PM PDT Mon May 4 2020

.DISCUSSION...It will be a fairly quiet week for the forecast
area, with only a couple of weak fronts over the next few days,
and a possible more significant system next week. Currently,
clouds are beginning to overspread the area and a few showers have
moved onshore along the coast ahead of the first weak front
expected to pass through the region today. Light rain amounts are
expected along the coast and into the Umpqua Basin before the
front lifts north and dissipates this evening. All other areas
should remain dry, with nothing more than increased clouds and
breezy winds to mark the front's passage. Temperatures tonight
should be noticeably warmer than this morning, so frost will not
be a major concern, although some isolated pockets are possible in
the usual colder spots.

The next front arrives late tomorrow, with a bit more of a west-
to- east trajectory than the previous system. Rain is possible
over a wider area as well, including almost all of the West Side
and even northern portions of Lake and Klamath counties. With the
front progressing into a rather strong ridge and a dry air mass,
it will be difficult to produce much more than light rain amounts.
Wedensday will be a cooler day due to the cold air behind the
front, but this will be a short lived trend.

An upper level ridge will build along the West Coast by Thursday,
then become amplified as large scale troughing deepens over the
eastern US and over the northeastern Pacific. As a result, we
will see a warming and drying trend, along with the development of
a thermal trough along the coast. Each day should be a bit warmer
than the day previous, with the warmest day expected to be
Saturday (highs in the upper 80s and low 90s should be common
across the region) as the thermal trough pushes inland. As typical
with this type of pattern, generally east winds are likely, and
this will produce a Chetco effect in he Brookings area, where
temperatures should remain relatively warm throughout the latter
half of the week.

Warm temperatures and dry conditions will continue through the
weekend, with the ridge remaining firmly in control, despite
nudging east slightly as the Pacific trough gradually digs east
towards the coastline. The operational models, as well as the
majority of their respective ensemble suites, show a more robust
front arriving early next week as a portion of the Pacific trough
splits off and swings right up against the coast of the Pacific
Northwest. Should events unfurl as the models depict, widespread
rain and cooler temperatures are on tap around Monday or Tuesday
next week. Another feature to watch will be the possible formation
of a blocking pattern in the Westerlies just upstream of the
forecast area around the same time. Should this form, the pattern
could become quiet stagnant for the rest of the next week, but
what that stagnant pattern is will depend on where the forecast
area is in relation to the ridge. Time will tell. -BPN

&&

.AVIATION...For the 04/18Z TAF Cycle...Over the coastal waters,
along the coast, and over the Umpqua Basin...VFR conditions will
prevail initially, then areas of MVFR cigs with scattered
showers and obscuration of higher terrain will develop Monday
afternoon and evening as a dissipating front moves onshore.  The
lower conditions will clear to VFR Tuesday morning.

Over the remainder of the area...VFR conditions will prevail through
Tuesday, but there will be some obscuration of higher terrain Monday
afternoon into Tuesday morning.

&&

.MARINE...Updated 200 PM PDT Monday 4 May 2020...A front will
bring small craft seas to the outer waters this evening. Westerly
swell will become high and steep in the outer waters as it peaks
Tuesday morning. A weak front will move onshore Tuesday night.

High pressure will then build offshore Wednesday afternoon with a
thermal trough near the coast. This will likely bring advisory
level north winds and steep seas through Thursday night with the
strongest winds south of Cape Blanco. The thermal trough will
weaken Friday.

&&

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

CA...None.

Pacific Coastal Waters...Small Craft Advisory until 11 PM PDT this evening for
     PZZ370-376.
     Small Craft Advisory from 5 AM to 11 AM PDT Tuesday for
     PZZ370-376.