456
FXUS66 KMFR 191134
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
434 AM PDT Sat Apr 19 2025

.Updated AVIATION Discussion...

&&

.AVIATION...19/12Z TAFs...Marine stratus is resulting in MVFR
conditions along the coast from Cape Blanco northward, and LIFR
conditions south of Gold Beach. VFR conditions persist for all other
areas and will do so through the TAF period. A weak front is pushing
the region this morning, bringing some high level cloud cover mainly
north of the Umpqua Divide. The lower conditions along the coast
will improve to VFR this afternoon, but expect the return of these
lower conditions early this evening. Expect the return of typical
afternoon breezes today, strongest along the coast. /BR-y

&&

.PREV DISCUSSION... /Issued 232 AM PDT Sat Apr 19 2025/

DISCUSSION...

The overall forecast remains at a low impact level for weather
hazards. We have a weak front coming through today that will bring
light rainfall chances mainly north of the Umpqua Divide and
across our northern Cascade locations. Not expecting any further
notable rain chances until late next week starting around Thursday
when we could have a pattern change with more active weather
through next weekend. Too early to say with much confidence the
threat for widespread hazards, but early indications point towards
the chance for thunderstorms as the main threat. Otherwise,
seasonable temperatures expected through this forecast.

Further Details:

Satellite imagery indicates a frontal boundary with high clouds
along the leading edge. Water vapor shows mostly dry air behind
the front, and model analysis further indicates limited moisture
associated with this front. That said, as the front comes onshore,
there may be just enough moisture to squeeze out some light
rainfall amounts across some of our northern zones before the
front "washes out". Dynamics are not impressive at all, so not
expecting any convection or widespread hazards.

Behind the front, we will be under a zonal to northwesterly flow
pattern for several days with no notable disturbances expected
until Thursday. At this time, a broad area of cyclonic flow will
develop off British Columbia, and this will usher in a couple
rounds of rainfall as a cut-off low meanders over this area. At
this time, MUCAPE values are limited to around a few hundred J/kg
(upwards near 400 J/kg), and this pattern would be conducive for
thunderstorms, but its too early to say with much confidence the
overall threat level. That said, bulk shear is low, so
thunderstorm updrafts would struggle in this environment.

Lastly, we will have a couple breezy afternoons most notably on
Sunday and Friday at this time, but we fall short of any advisory
or warning level wind speeds at this time.

MARINE...Updated 200 AM Saturday, April 19th...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
this 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 tonight into Sunday, but steep to
very steep seas are likely to continue into early next week,
especially south of Cape Blanco. /BR-y

&&

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

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

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

     Gale Warning from 8 AM this morning to 11 PM PDT this evening
     for PZZ356-376.

&&

$$