Area Forecast Discussion
Issued by NWS Medford, OR

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700
FXUS66 KMFR 191055
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
355 AM PDT Sat Oct 19 2019

.DISCUSSION...Main significant changes to the forecast this
morning have been to lower the level of the Winter Weather
Advisory to 5000 feet over the Cascades, and to embed some High
Wind Warning areas near Summer Lake and far southeast lake County
within the existing Wind Advisory.

Latest road cams have indicated snow falling at Willamette Pass
and at the junction of highways 138 and 230 near Diamond Lake with
temperatures at or slightly above freezing at those locations. A
fair amount of orographic-driven rain and snow is still
anticipated in these areas through the morning with the arriving
trough before rates taper in the afternoon. Thus we feel good
about a slightly lowered advisory level today.

The GOES West mid-level water vapor channel indicates a jet
maximum pushing across northwest Oregon at this time with some
recent 700 mb derived motion wind vectors of 60-65 kts captured
over Lane County. Still expecting increasing winds east of the
Cascades this morning into afternoon as this strong upper flow
passes through. Summer Lake Raws measured a recent gust to 45 mph
and is on the increase. Guidance indicates winds there will
increase and persist for the next 6 hours or so. Have elevated
the advisory around highway 395 at Summer Lake and over highway
140 east of Adel to a warning for gusts to 60 mph today. Winds
will decrease later in the afternoon through this evening.

Ample clouds and rain will continue over the region Sunday,
mainly along and east of the Cascades, as a warm front lifts
northward. In the wake of the upper trough moving through today,
and with the thicker clouds, temperatures Sunday should be about
10 degrees below normal. Not so bad considering normals are 65-70
in the western valleys and near 60 east of the Cascades this time
of year.

Despite another weak cold front bringing a threat for additional
light rain at the coast and Umpqua Tuesday, confidence is good for high
pressure to keep the remainder of the warning area seasonable
and dry through the week. Stavish

&&

.AVIATION...For the 19/06Z TAFs...Along the coast and just
offshore... Wind shear has been added to the TAFs at the 06Z time
period. The directional shear was not large but given the large
change in wind speed the marginal risk was included. The directional
change will become minimal by Saturday morning but, strong winds
will still persist. Cigs didn`t lower as much as what was expected
and aren`t expected to drop too much further. MVFR conditions should
persist into the afternoon.

Inland westside... VFR conditions currently exist, but MVFR ceilings
are expected to occur come morning. The main concern tonight will be
wind speed shear at Roseburg and Medford and has been added to the
TAF`s until the early morning on Saturday.

East of the Cascades... VFR conditions should persist overnight.
Come early morning MVFR ceilings at Klamath Falls will likely settle
in. At the very least expect partial mountain obscuration for most
of the TAF period. Gusty winds will be a concern beyond the TAF
period Saturday afternoon. -Miles

&&

.MARINE...Updated 345 AM PDT Saturday 19 October 2019...Continued
long period west swell will continue to lower slowly. Winds will
diminish as the low moves inland early this morning, but swells will
still remain elevated enough for small craft conditions to continue
through Sunday afternoon.

High pressure builds in on Monday followed by a strengthening
thermal trough over the south coast from mid to late week resulting
in gusty north winds and steep wind-driven seas especially south
of Cape Blanco. -Sven

&&

.MFR WATCHES/WARNINGS/ADVISORIES...
OR...High Wind Warning until 5 PM PDT this afternoon for ORZ030-031.
     Wind Advisory from 8 AM this morning to 11 PM PDT this evening
     for ORZ030-031.
     Winter Weather Advisory until 5 PM PDT this afternoon above 5000
     feet in the for ORZ027.
     Wind Advisory until 5 PM PDT this afternoon for ORZ029.

CA...Wind Advisory from 8 AM this morning to 11 PM PDT this evening
     for CAZ085.
     Wind Advisory until 5 PM PDT this afternoon for CAZ084.

Pacific Coastal Waters...Small Craft Advisory until 5 PM PDT Sunday for
     PZZ350-356-370-376.

$$



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