Hazardous Seas Warning 46, NWS Medford, OR

Area Forecast Discussion
National Weather Service Medford OR
251 PM PDT Tue Jun 27 2017

.SHORT TERM...Nice thick marine layer is making for a slow burnoff
of clouds in Coos and western Douglas Counties this afternoon.
Otherwise, just some popcorn cumulus in the north half of Klamath
and Lake Counties this afternoon. Not expecting these cumulus to
do much more building before the sun sets and they quickly
dissipate. Tomorrow looks like a carbon copy of today with the
thick marine layer allowing a low overcast to redevelop over Coos,
most of Douglas, and a good portion of Josephine counties in the
morning. Clear skies for all other inland locations. Afternoon
highs again similar to today.

The westerly flow aloft continues on Thursday with a ridge
building over the eastern Pacific. Still a decent marine layer for
the west side valleys Thursday morning but it will be more shallow
by some 500 to 1000 feet. Thus, it may have a tough time getting
into Josephine county but have gone ahead and put some morning
cloudiness there. The overall airmass begins to warm so inland
areas not affected by the marine layer should see highs around 5
degrees warmer than on Wednesday.

.LONG TERM...Friday through Tuesday...A slow eastward progression
of ridge on Friday and Saturday followed by more westerly
flow Sunday through Tuesday. The ridge axis is over the I-5
corridor on Friday along with the thermal trough so Friday would
theoretically be the warmest day. However, models hint at Sunday
being warmest. There is only 2 to 4 degrees of difference from
Friday through Sunday so not really a big deal. The airmass
remains dry and stable. Afternoon humidities drop to below 20
percent east of the Cascades and to between 20 and 25 percent west
of the Cascades so fuels will continue to dry out.

&&

.AVIATION...27/18Z TAF CYCLE...
MVFR ceilings will erode to near the beaches this afternoon. MVFR
ceilings will then develop and spread inland after dark across the
Umpqua Basin and near the coast. By early Wednesday morning there
should be similar conditions to this morning with IFR/MVFR ceilings
and visibilities at the coast and across the inland valleys of
Douglas and Josephine counties. Elsewhere, VFR conditions will
continue except for brief IFR conditions at KLMT between 11z and 14z
Wednesday.

&&

.MARINE...Updated 300 PM Tuesday, 27 June 2017...
North winds will increase and seas will steepen through Wednesday
evening as high pressure rebuilds offshore and the thermal trough
deepens over California. Warning level seas are expected to develop
over a portion of the area south of Cape Sebastian and beyond 10 nm
from shore Wednesday into Thursday. Northerly gales are possible
south of Cape Blanco this weekend as cooler air pushes southeastward
from the Gulf of Alaska. BTL/JBL

&&

.MFR WATCHES/WARNINGS/ADVISORIES...
OR...None.

CA...None.

Pacific Coastal Waters...Small Craft Advisory from 11 PM this evening to 5 AM PDT
     Thursday for PZZ356.
     Small Craft Advisory for hazardous seas from 11 PM this evening
     to 11 AM PDT Wednesday for PZZ356.
     Small Craft Advisory for hazardous seas from 5 AM to 11 PM PDT
     Thursday for PZZ356.
     Small Craft Advisory for hazardous seas from 11 PM this evening
     to 11 PM PDT Thursday for PZZ350-370-376.
     Small Craft Advisory from 11 PM this evening to 11 PM PDT
     Thursday for PZZ376.
     Hazardous Seas Warning from 11 AM Wednesday to 5 AM PDT Thursday
     for PZZ376.

KRS/KRS/JBL