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000
FXUS66 KMFR 190938
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
238 AM PDT Fri Apr 19 2024

.DISCUSSION...High pressure will maintain very nice early spring
weather across most of SW Oregon and Northern California today.
Some high clouds will drift by at times, but overall, expect
mainly sunny skies with a mild afternoon. High temperatures will
be largely in the 70s in the valleys west of the Cascades and into
the 60s over the East Side. The air mass is quite dry, so humidity
this afternoon will drop into the teens and 20s in many areas --
keep the lip balm and skin moisturizer handy. This will also
likely prevent any potential pop-up sprinkles/showers from
reaching the ground over SE sections of the CWA (though there is a
about a 5-10% chance) due to some weak instability over there.
Better chance for this is over the Sierra/NW Nevada.

Dry weather is expected tonight into Saturday as a weak short wave
upper ridge swings through. However, a cold front will approach
the coast on Saturday. Some rain showers are likely to move into
the coastal waters during the morning, and then eventually move
onshore Saturday afternoon. Given the preceding dry air mass, it
will be difficult for these showers to get very far inland
Saturday afternoon/evening. This is evident in the PoP forecast
with PoPs not even reaching 15% here in Medford. PoPs will be
highest along the coast 18z Sat-00z Sun (50-70%), then lower to
20-40% Saturday evening. Farthest east precip chances (20-40%)
reach the Cascades north of Highway 140. It should be noted that
it will get breezy Saturday afternoon/evening in many areas from
the WSW, shifting to NW as the front moves through (peak gusts
25-35 mph).

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 (Brookings).

The next chance at precip won`t come until Tuesday of next week.
Some guidance is showing the upper trough offshore staying well to
our north and west with a bit of a moisture surge from the south.
This could cause some showers (thunder?) in parts of NorCal and
maybe from the Cascades eastward Tuesday afternoon/evening. Models
aren`t too bullish on this just yet with NBM PoPs only peaking up
around 20%. The upper trough should send a cold front onshore at
midweek with a bit of a cool down and a chance of showers.
-Spilde

&&

.AVIATION...Other than some high clouds at times and a slight
uptick in diurnal breezes this afternoon, VFR will prevail area
wide through the next 24 hours. Coastal areas won`t be nearly as
gusty as yesterday. -Spilde


&&

.MARINE...Updated 200 AM Friday, April 19, 2024...A weakening
thermal trough will maintain steep, hazardous seas through early
this morning. Steep seas will shift to beyond 10 NM from shore and
south of Cape Blanco by late morning, then subside below small craft
advisory levels this afternoon. Conditions improve tonight with
relatively light winds and low seas into Saturday, though a weak
cold front will move through on Saturday with some rain. Gusty north
winds and steep seas are expected to return later in the weekend
with possible gales and very steep, hazardous seas south of Cape
Blanco late Sunday into Monday. -Spilde


&&

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

CA...None.

PACIFIC COASTAL WATERS...Small Craft Advisory until 5 AM PDT early
     this morning for PZZ350-356.

     Small Craft Advisory until 11 AM PDT this morning for PZZ370.

     Small Craft Advisory until 2 PM PDT this afternoon for PZZ376.

&&

$$

MAS/MAS/MAS