Area Forecast Discussion
Issued by NWS Medford, OR
FXUS66 KMFR 282132
Area Forecast Discussion
National Weather Service Medford OR
232 PM PDT SAT MAY 28 2016
A pretty quiet weather pattern continues across the Pacific
Northwest for the short term. We`ll have a very weak cold front
sag towards the coast Sunday evening and produce some drizzle
given the moist air in the boundary layer, but it won`t push
inland and dissipate before the umpqua valley.
After that, we`ll have a thermal trough build with some weak off
shore flow into the start of next week. As a result, look for
anomalously warm conditions for daytime highs pushing into the
80`s and eventually the mid 90`s on Wednesday. Given the very dry
air aloft, we`ll efficiently loose heat during the night time.
Therefore, lows should still drop below 60 degrees in the
valleys, and stay around the lower 60`s on the ridges Tuesday
.LONG TERM...An upper level ridge is forecast to shift inland
slightly and remain over the region next Wednesday and Thursday.
Meanwhile a broad upper trough is forecast well offshore with a
closed low off the central and southern California coast. The
surface thermal trough is forecast to move inland during the day
Wednesday. This pattern will bring hot temperatures across inland
areas on Wednesday. Highs in the mid to upper 90s are expected on
Wednesday for inland valleys west of the Cascades, with highs in the
mid to upper 80s for eastern valleys. High temperatures are expected
to lower slightly on Thursday. Both Wednesday and Thursday, there is
also a slight chance for thunderstorms across inland areas as
southerly mid level moisture is also forecast to move into the area.
This moisture combined with weak instability and some weak
shortwaves is forecast to bring a slight chance for thunderstorms.
This pattern with a ridge over the area continues into Friday.
Instability is weaker on Friday though, so kept thunderstorms out of
the forecast and only have a slight chance of showers in for central
and eastern portions of the CWA.
Models differ on how quickly this ridge will shift eastward and the
strength of a Pacific low moving towards British Columbia and the
PACNW late Saturday into Sunday. The GFS transitions the ridge
eastward faster and is stronger with the low than the ECMWF. Given
the strength of the ridge, have leaned towards the slower ECMWF
solution. Of note, the low to the south may, bring another chance
for thunderstorms next weekend as it moves inland over southern and
central California. There is low confidence in the forecast track of
this low at this time. /CC
.Aviation...For the 28/18Z TAF cycle...VFR conditions are
expected to continue through today and into tonight with diurnal
increase in afternoon winds much like yesterday afternoon. Local
MVFR cigs will be possible near KOTH late tonight around 06z with
MVFR cigs also possible into the Umpqua Basin, including KRBG, early
Sunday morning around 12z. /BR-y
.Marine...Updated 800 AM PDT Sat 28 May 2016...Offshore high
pressure and a thermal trough near the coast will continue to bring
moderate to strong north winds and steep wind dominated seas to the
waters through the middle of next week.
It should be noted that the sea state will be a chaotic mix of wind
wave and very fresh swell. Thus, while seas are fairly steep and
choppy in most areas, they are only 3-6 feet north of Cape Blanco.
Today winds will weaken slightly, especially in the morning. Expect
small craft advisory winds and seas from Cape Blanco southward for
today and Sunday with no advisories north of the Cape. Winds will
increase Sunday evening and Monday with the strongest winds and
highest seas in the southern coastal waters area beyond 5 nautical
miles of the coast. Seas will be at a minimum on this morning and at
a maximum on Monday evening. -FB/CC
Pacific Coastal Waters...Small Craft Advisory until 11 PM PDT Monday for PZZ356-376.