Area Forecast Discussion
Issued by NWS Medford, OR

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FXUS66 KMFR 231527
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
827 AM PDT Mon Oct 23 2017

.UPDATE...No major changes are necessary this morning, other than
to bring sky and fog forecasts in line with the current
observations. The fog layer is quite deep this morning, deep
enough to produce areas of drizzle, but much of it should burn off
through the morning. Expect all areas of fog to clear by this
afternoon, then temperatures should warm up under the building
ridge aloft.

For more information on this and the rest of the ofrecast, see the
previous discussion below. -BPN


&&

.AVIATION...23/12Z TAF Cycle...We are transitioning into a dry and
warm pattern with areas of morning/late night valley fog and low
clouds.

Coastal fog/low clouds should clear by mid morning due to drying,
east flow. Areas of fog across inland valleys with IFR cigs/vis will
clear between 17-20z today.This afternoon should see VFR conditions
everywhere. Areas of IFR in fog are expected to redevelop in western
valleys tonight. -CC


&&

.MARINE...Updated 340 AM PDT Monday 23 October 2017...Steep seas
will persist across the waters through tonight. Winds will become
northerly today with strong gusty winds developing for areas from
Cape Blanco south beginning this afternoon. Small craft advisory
level winds and seas are expected to persist through Wednesday
morning for areas from Cape Blanco south, then gales are possible
beginning Wednesday afternoon. Areas north of Cape Blanco are
expected to maintain steep seas through Monday night, then areas of
small craft advisory level winds and seas are expected in the outer
waters beyond 10 nm from shore and near Cape Blanco Tuesday into
Wednesday morning. Small craft advisory level winds and seas may
spread over much of the waters north of Cape Blanco late Wednesday
into Thursday. Winds are forecast to lower Thursday night.

Friday into Saturday, the concern shifts to a long period swell
which is forecast to build into the waters. This swell is forecast
to reach 10 to 12 feet at 20 seconds by early Saturday morning.
-Sven


&&

.PREV DISCUSSION... /Issued 358 AM PDT Mon Oct 23 2017/

DISCUSSION...
The long wave trough will exit the forecast area this morning and
high pressure will begin to build in it`s wake. The main feature
in the forecast this morning will be the patchy fog, which has
resulted in some of the observation sites changing between 10
miles down to a 1/4 of a mile at times over Klamath Falls. That
fog will clear out later today and temperatures will warm up to
above average values for Monday. Roughly 10 degrees above average
for some locations like Brookings and Medford.

Eventually a thermal trough will build up along the coast Tuesday
morning. Some pretty nice off shore flow can be seen at 850 mb
and 700 mb along the Coastal Range, which should allow the Chetco
Effect to be in full swing. Have adjusted temperatures near
Brookings, and along the majority of the coast, towards the
highest guidance, which is showing 80 degrees for highs Tuesday.

After Tuesday, A short wave will make it`s way through Washington
state Wednesday bringing some scattered cloud cover Wednesday
night to Douglas county and Coos county.

Aside from that wave, above normal temperatures are the biggest
story after Tuesday. The biggest change on the night shift tonight
was warming up temperatures in the extended forecast, especially
east of the Cascades. -Smith

&&

FIRE WEATHER...Updated 350 AM PDT Monday October 23
2017...Confidence is high for a stretch of dry weather starting
today and could last through the weekend. Guidance continues to show
a tight pressure gradient as a thermal trough develops along the
coast tonight through Tuesday. This will result in moderate
northeast winds along with moderate to poor overnight recoveries on
the ridges. The east to northeast flow decreases mid week, but the
pattern remains with poor ridge recoveries and decreasing humidity
into the weekend. Sven

&&

.MFR WATCHES/WARNINGS/ADVISORIES...
OR...Beach Hazards Statement until 5 PM PDT this afternoon for
     ORZ021-022.

CA...None.

Pacific Coastal Waters...Small Craft Advisory from 2 PM this afternoon to 11 AM PDT
     Wednesday for PZZ350-356-370-376.
     Small Craft Advisory for hazardous seas until 5 AM PDT Tuesday
     for PZZ350-356-370-376.

$$

BPN/CZS/SBN/CC



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