Area Forecast Discussion
Issued by NWS Medford, OR

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000
FXUS66 KMFR 211029
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
329 AM PDT Sat Oct 21 2017

.DISCUSSION...

Everything appears on track with the warm front currently pushing
eastwards. Precipitation has begun to fall west of the Cascades
along with some snow occuring along the Cascades. The big stories
that we continue to highlight for the next 24 hours will be...

*Snow: Along the Cascades an additional 2 to 6 inches above 4500
       feet.
*Winds: Still windy along the coast, yet not strong enough for a
        wind warning.  Winds east of the Cascades 20 to 30 mph in
the late afternoon and evening with gusts to 55 mph.

As for the snow forecast, the snow levels are still on track to
jump up from 4500 to 9000 feet as the front passes. The biggest
impact here will be when the front passes the Cascades. That
appears to still be on track for 15Z this morning. The only
modification here is we forced snow accumulation into the
forecast from 12z to 18z above 4500 feet along the Cascades. Some
locations from 4500 to roughly 6000 feet did not have any snow
accumulation in the previous forecast.

As for the wind forecast, the 700 mb winds will be roughly 50 to
65 knots with the strongest winds farther north near Central
Oregon. All models are pretty consistent with this picture, so
feel very confident with the strong and gusty winds on the east
side this afternoon.

Eventually, the warm front will pass to the east, yet the the
strong west to east flow will continue to impact Oregon. The
majority of the rain is forecasted to fall to our north as the
moisture axis shifts north throughout the day. Therefore, during
Saturday night and Sunday morning, some locations will actually be
dry or just be under a slight chance for some rain. That moisture
axis will eventually shift south again Sunday and give us some
more wetting rain especially over the Coastal and Cascade range.

Into the work week, high pressure will build bringing back a
rather quiet weather pattern. With the clearing skies and all the
added moisture in the valley, expect fog in the morning hours.
This may impact maximum temperatures to be on the cool side even
with all the sunshine.

-Smith

&&

.AVIATION...21/06Z TAF Cycle...Generally VFR ceilings
are present this evening ahead of a warm front. Precipitation will
increase late tonight with an approaching warm front. Ceilings will
likely lower to MVFR and occasional IFR and mountain obscuration is
expected with the warm front. South winds will increase through
tonight and into Saturday (southwest winds east of the Cascades),
and there is a chance for low level wind shear west of the Cascades
Saturday morning as south to southwest winds become moderate to
strong above the relatively light surface winds. Freezing levels
will rise Saturday morning behind the warm front. Ceilings will
likely lift to more of an MVFR/VFR mix Saturday afternoon, though
models suggest plenty of low level moisture continuing through the
day and into the night. SK

&&

.MARINE...Updated 1000 PM PDT Friday 20 October 2017...Heavy long
period northwest swell is subsiding to moderate tonight, but south
gales will develop tonight as a warm front approaches the area. This
front will bring heavy rainfall late tonight into Saturday morning.
Though winds will decrease slightly tomorrow afternoon, expect
another round of steep west swell, which will likely continue
through Sunday. A thermal trough will set up along the coast early
next week, and this will bring strong north winds and steep seas
south of Cape Blanco beginning Monday and continuing through
Tuesday. SK/MSC


&&

.MFR WATCHES/WARNINGS/ADVISORIES...
OR...Wind Advisory from 8 AM this morning to 11 PM PDT this evening
     for ORZ030-031.
     Winter Weather Advisory until 11 AM PDT this morning for
     ORZ025-027-028.

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

Pacific Coastal Waters...Small Craft Advisory from 5 PM this afternoon to 5 PM PDT Sunday
     for PZZ350-356-376.
     Gale Warning until 5 PM PDT this afternoon for
     PZZ350-356-370-376.
     Hazardous Seas Warning from 5 PM this afternoon to 5 PM PDT
     Sunday for PZZ350-356-370-376.

$$

CZS/BPN/BMS



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