221
FXUS66 KMFR 182130
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
230 PM PDT Fri Apr 18 2025

.DISCUSSION...Dry weather is expected for most of the next week,
with high pressure dominating the area, and only a few exceptions
as weak systems moving through or nearby.  Heading into tonight
and Saturday morning, a mostly dry cold front will approach the
Oregon coast and then dissipate as it moves onshore. This will
bring some increased clouds, and perhaps some light precipitation
to the coast and the northern Cascades, but amounts will be low,
if measurable at all. The relatively cold air behind the front
will struggle to surge into southern Oregon and northern
California given the weak northwest flow late Saturday through
Sunday. As a result, temperatures will trend lower, although there
is no drastic 10 to 20 degree cool down. Otherwise, dry can clear
will be the rule through Monday

By next week, a trough will swing through southern Oregon around
Tuesday and bring a 10 to 20% chance of showers in Lake and Modoc
counties. There could thunderstorms as well as the NBM guidance is
showing a 15% chance of cloud to ground lightning in the
aforementioned areas, which is essentially GFS and ECMWF MOS at
this lead time. Forecast soundings are not that impressive,
although they do show a little convective available potential
energy west of Alturas.

Towards the tail end of the forecast period, ensembles are
hinting at more precipitation entering the forecast as a more
active pattern develops. In general, the probability of
precipitation is about 20 to 30 percent Thursday evening and
increasing slightly to 30 or 40 percent by Friday. There is still
a lot to sort out as some ensemble members are definitely on the
dry side through both days. -Smith/BPN


&&

.AVIATION...18/18Z TAFs...VFR prevails area wide late this morning
with local IFR near the immediate coast from Brookings southward.
Wind gusts this afternoon and early this evening will be strongest
along the coast (peaking in the 20-30 kt range), with gusts up to 15
kt for inland areas. Onshore flow will develop this evening and
overnight, bringing the return of MVFR ceilings to the coast. A cold
front will sweep through the area Saturday, but with little, if any
precipitation (low chance -- 15% or less -- along the coast and over
the Cascades). MVFR ceilings at the coast should break up Saturday
afternoon. /BR-y/Spilde


&&

.MARINE...Updated 200 PM Friday, April 18th...A thermal
trough will maintain gusty north winds and steep, hazardous seas for
all areas through this weekend. The strongest winds and steepest
seas will be south of Cape Blanco. North winds will reach gale force
Saturday afternoon from around Gold Beach southward and within 30 NM
from shore along with very steep seas up to 15 feet at 8 seconds.
Very steep and hazardous seas will spread north of Cape Blanco to
about Coos Bay and beyond 10 nm from shore, except in the vicinity
of Cape Blanco. Winds ease some Saturday night into Sunday, but
steep to very steep seas are likely to continue into early next
week, especially south of Cape Blanco. -Spilde/BR-y


&&

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

PACIFIC COASTAL WATERS...Small Craft Advisory until 8 AM PDT Saturday
     for PZZ350-356-370-376.

Hazardous Seas Warning from 8 AM to 11 PM PDT Saturday for
     PZZ350-356-370-376.

     Gale Warning from 8 AM to 11 PM PDT Saturday for PZZ356-376.

&&

$$