Area Forecast Discussion
Issued by NWS Medford, OR

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FXUS66 KMFR 222156

Area Forecast Discussion
National Weather Service Medford OR
256 PM PDT Mon May 22 2017

.SHORT TERM...Today through Thursday...The ridge aloft has
strengthened and progressed eastward slightly. Temperatures in
many valleys west of the Cascades have already reached the
90s...including Medford...Merlin...Somes Bar...and Dunsmuir.
Temperatures will continue to warm over the next few hours.
Offshore winds along the coast will persist until late
tonight...then expect patchy fog in onshore flow along the coast
early tomorrow morning. Mostly clear skies will persist in areas
east of the Coastal Range tonight. Tomorrow will start out similar
to today...with patchy fog and low stratus along the coast
clearing in offshore flow mid to late morning...and highs across
the area again 10 to 20 degrees above normal with mostly clear

The ridge aloft will weaken Tuesday night into Wednesday morning as
a low passes over British Columbia and northern Washington. This
will bring onshore flow Wednesday...and highs Wednesday afternoon
should be 5 to 10 degrees above normal. As that low moves inland
over the northern Rockies, it will spin a few waves over the
PacNW, bringing increased cloud cover and gusty winds over the
east side Wednesday afternoon. Cool low level air should prevent
most thunderstorm development...however could not completely rule
out thunderstorms in Modoc County and eastern Siskiyou County.

Temperatures Thursday will be several degrees cooler than
Wednesday, as pressure aloft drops and onshore flow continues.

.Long Term...Friday through Monday...The ridge will regain control
of the area by Friday night, and this will produce another period of
warm and dry weather through the holiday weekend. There will be a
slight chance for daily afternoon thunderstorms, mainly along the
Cascades and in the mountains of Northern California through Monday,
but these will depend greatly on the presence of shortwaves within
the flow aloft. Any shortwave will be extremely hard to predict at
this time range, but the models suggest there could be some during
the weekend. With this in mind, have changed the timing and
placement of convection to more general terms, and only in those
locations where we typically see development. For most areas,
Memorial Day and the weekend should be warm and mostly clear with no
significant threat for rain. -BPN


.AVIATION...22/18Z TAF CYCLE...VFR conditions across the area
will continue for the duration of the TAF period. A return of IFR
conditions is possible this evening and overnight near KOTH, but
is not expected. -BPN


.MARINE....Updated 210 PM PDT Monday, 22 May 2017...The thermal
trough pattern will strengthen today with gales expected to begin
south of Cape Blanco Tuesday afternoon. Gales are expected to begin
for portions of the area north of the cape Tuesday night into
Wednesday. Fog will continue to be an intermittent concern...mainly
beyond a few miles from shore. Gales are currently expected to
subside Thursday morning as the thermal trough pattern weakens.




Pacific Coastal Waters...Small Craft Advisory until 11 AM PDT Thursday for
     Gale Warning from 5 AM Tuesday to 11 AM PDT Thursday for
     Hazardous Seas Warning from 5 AM Tuesday to 11 AM PDT Thursday
     for PZZ350-356-370-376.
     Small Craft Advisory until 5 AM PDT Tuesday for PZZ376.


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