964
FXUS66 KMFR 292116
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
216 PM PDT Wed May 29 2024

.SHORT TERM...Rest of today through late Thursday night...At the
large scale, a midlevel trough is gradually moving off to the
east today as a low amplitude ridge builds in behind it. At the
moment, this has resulted in NW flow aloft in the local area as
we`re sandwiched between the two regimes, which has resulted in
cooler (relatively) temperatures and a little bit of cloud cover.
Per satellite imagery, cirrus is moving southeast across the
region, while some scattered cumulus is present in Douglas/Coos
and NW Curry/Josephine/Jackson counties this afternoon.

Overnight, temperatures will drop to levels similar to last
night/early this morning, if not a tad lower due to increased
radiational cooling with relatively less cloud cover. Tomorrow
will then see clearer, warmer weather with afternoon temperatures
in the high 70s to low 80s (western valleys and the Brookings
area), low to mid 70s (eastern valleys), and low to mid 60s
(mountains, remainder of the coast). We`ll have some seasonable
afternoon/evening breezes and dry weather through the entire
region. A little bit of cloud cover is expected in the morning
(stratus in Coos into inland Douglas counties as well as some more
upper level cirrus) that will clear over the course of the day.
Overnight temperatures will then be average for this time of
year, a couple of degrees warmer than tonight`s temperatures.

Finally, this will be my last AFD here at Medford, as this
forecaster is transferring to southern CA (please keep your boos
and hisses for after the AFD, please). Not very interesting
weather as a send off, but lovely conditions to move in, at least.
Thanks for everything Medford, I`ll miss you. -CSP


.LONG TERM (Friday through Tuesday)...

Overview:

The long term will be noted by slightly above normal temperatures
and generally dry conditions until Sunday night/Monday. The system
coming into the region end of the weekend/early next week will be
moisture rich but lacking some variables which could make this more
impactful. We will talk about this further below, but at this time
it does appear impacts will be limited at best. The coast could see
rainfall amounts approaching 2 inches in some isolated areas that
could cause minor nuisance issues. Interestingly enough, the
rainfall amounts have gone up each forecast over the last 24 hours,
so we could see changes to those amounts near the coast. Otherwise,
little to no impacts are expected inland as amounts drop off
significantly, and we are not expecting thunderstorms at this time.
Lastly, we will have several breezy days in the forecast, and Monday
looks to be the "windiest" of the days at this time (behind the cold
front), especially the eastside across our typical windy spots
where a wind advisory may come to fruition.

Further Details:

By Friday, it looks like the upper levels might resemble a general
zonal (west to east) type of flow downstream of the next trough.
There is a small discernible piece of energy embedded in this flow,
so expecting clouds to increase in coverage Friday and more so on
Saturday. By Sunday, appreciable upper level moisture will be
present with forecast soundings suggesting PWATs could be around
1.50" at KOTH with a very deep saturated column. This moisture will
coincide with a strong H3 jet nosing into the area. The left exit
region of the upper jet, and the 500mb vorticity max are both a
little farther north than one would like to see for high rainfall
rates. We will have to watch these variables because they will
coincide with the highest rainfall amounts if phased together
correctly, and at this time it does look like those amounts may be
highest just to our north along the central to northern Oregon
coast. Along our coastal waters of southern Oregon, the probability
for rainfall amounts to be 0.50" or more in 12 hours is around 30-40
percent ending Monday morning. This is of course a broad brush with
coarse resolution given this is Day 5/6. Total forecast rainfall
amounts currently put much of Curry County at 1.00-1.50" of rainfall
over 36 hours from early Sunday afternoon through Monday night. The
highest rates could be between Sunday night and Monday morning, so
the Monday morning commute may have nuisance issues with rainfall.
All that said, its the coast and it can inherently take a lot of
rainfall, so at this time we are expecting very limited impacts, but
it may not be a bad idea to plan for longer commutes on Monday
morning if you live along/near the coast.

-Guerrero


&&

.AVIATION...29/18Z TAFs...Along the coast north of Cape Blanco,
MVFR ceilings are currently being observed, with VFR conditions
elsewhere. These MVFR conditions will improve to VFR in the
afternoon.

Inland, west of the Cascades, Ceilings are expected to remain VFR
through the TAF period. While winds will be gusty (~15mph) in the
afternoon, they are not expected to be as strong as on Tuesday
(yesterday).

East of the Cascades, VFR conditions will continue through the TAF
period. The main concern will be moderate winds with peak gusts
possibly nearing 25 kts at Klamath Falls this afternoon.
-Miles

&&

.MARINE...Updated 200 PM Wednesday, May 29, 2024...A thermal trough
will develop this evening and tonight, resulting in increasing north
winds that will reach Small Craft Advisory conditions for all south
of Bandon by tonight. The thermal trough will strengthen further,
peaking Thursday evening, and persisting through at least Friday
evening; resulting in gale force winds for most areas south of Cape
Blanco and for isolated instances across the waters between Bandon
and Cape Blanco. Meanwhile small craft conditions will expand north
over the rest of the waters that will last into at least Friday
evening.

The thermal trough will weaken overnight Friday into Saturday and
north winds will diminish as an upper trough approaches. Calmer seas
are expected by the weekend and into early next week after the wind
waves have diminished.
-Miles

&&

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

PACIFIC COASTAL WATERS...Small Craft Advisory from 5 PM this
     afternoon to 5 AM PDT Thursday for PZZ350-356-370-376.

Gale Warning from 5 AM Thursday to 11 PM PDT Friday for PZZ356-
     376.

&&

$$