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000
FXUS66 KMFR 192341
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
441 PM PDT Fri Apr 19 2024

...Updated AVIATION Discussion...

.DISCUSSION...This afternoon through Monday morning...High pressure
is in control today, leading to sunny skies and dry conditions.
Afternoon temperatures will be on the warm side again today,
running about 10 to 15 degrees warmer than normal for late April
and more on par with early June.

Dry conditions will continue into Saturday and through the day
Saturday for most of the area. A weak front will push into the
region Saturday and flatten the ridge Saturday night into Sunday.
This front will run into a pretty dry air mass, so not much
precipitation is expected for the area. The best chances for
accumulating precipitation will be along the coast (40%-70%), in the
Umpqua Basin (20%-30%) and along the Cascades from Crater Lake
northward (20%-40%). Even the areas that do receive precipitation
are only expected to measure around 0.10"-0.20" west of the Coast
Range with only a few hundreths expected elsewhere. The remainder of
the area will likely remain dry with some increased cloud cover and
gusty winds across the region. Widespread gusts of 25 to 35 mph are
expected east of the Cascades with gusts of 15 to 25 mph expected
for areas west of the Cascades.

The front shifts east of the area Saturday night with high pressure
building in on Sunday/Monday. Frost/freezing conditions are possible
during this period of dry weather during the late nights/early
mornings in the valleys west of the Cascades. It will only be
nominally cooler on Sunday, with high temperatures closer to normal
across NW sections, but remaining at least a few degrees above
normal elsewhere. Monday will warm up substantially (up 5-10 F over
Sunday). Another thermal trough will strengthen in NorCal resulting
in another round of N-NE winds late Sunday through Monday. This
should even bring the milder weather to portions of the SW coast
(including Brookings). The remainder of the work week looks more
active as we head into the extended period. /BR-y


.Extended Discussion (Monday through Friday)...Dry weather will
continue through Monday with upper ridging building into the area
albeit not a strong upper ridge that will quickly push east as an
upper trough approaches from the west. Tuesday, the upper trough
axis remains west of the forecast area, but there`s enough evidence
to suggest increasing instability along with a weak trigger Tuesday
afternoon and early evening and could be enough to warrant a slight
chance of thunderstorms along the Cascades, portions of the Eastside
and western Siskiyou County Tuesday afternoon into early Tuesday
evening.

We`ll catch a break Tuesday night with weak upper troughing over our
area, but energy is pretty weak so were not expecting precipitation.

Wednesday upper troughing remains and instability will once again
increase during the day. The operational ECMWF and GFS differ with
respect to the strength of the upper trough. The upper trough is
more pronounced and shows more convective feedback in terms of QPF.
However the individual ensemble members paint a different picture
with the majority showing a weaker solution. The GFS shows a weaker
upper trough and thus less in the way of QPF. Therefore the forecast
will lean towards the weaker ECMWF ensembles and operational GFS
solution with showers mainly along and east of the Cascades and
northern Coos and northwest Douglas County.

Upper troughiness remains over our area the rest of next week which
will result in cooler temperatures and a higher chance for showers
over a good portion of the forecast area. -Petrucelli


&&

.AVIATION...20/00Z TAFs...VFR conditions under clear skies and with
light winds continue through the evening and into Saturday morning.
On Saturday afternoon, a weak front will bring light showers along
the Oregon coast and gusty winds over higher elevations, especially
east of the Cascades. -TAD

&&

.MARINE...Updated 200 PM Friday, April 19, 2024...North winds have
generally calmed across the waters today, and relatively calm
conditions will continue through tonight. A weak cold front will
bring increasing south winds early Saturday morning, but they are
expected to remain below small craft. The front will move inland
late Saturday morning with winds becoming westerly behind it.

A thermal trough will set up along the south coast Sunday with north
winds increasing across the waters and moderate to strong winds
south of Cape Blanco Sunday afternoon. Associated with this, there`s
areas with a 50% chance for gale force gusts in the southwest outer
waters (areas about 20 NM from shore south of Gold Beach). These
gusty winds will result in steep to very steep wind-driven seas
across the waters, with conditions depreciating to the south.
Moderate to strong north winds and steep to very steep seas will
persist into early next week.
-CSP


&&

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

CA...None.

PACIFIC COASTAL WATERS...None.

&&

$$