Small Craft Advisory 59, NWS Medford, OR

Area Forecast Discussion
National Weather Service Medford OR
933 AM PDT Mon Jun 25 2018

.UPDATE...A cold has made its into the East Side and continues to
shift towards the southeast out of the Medford CWA today.
Afternoon temperatures will be 10 to 15 degrees lower than
yesterday over most of the area. Marine stratus has made its way
over the Umpqua divide and some scattered clouds have spilled into
Grants Pass. Expect stratus to scatter this afternoon, likely
likely along the coast, and then the Umpqua Basin. A thermal
trough is starting to strengthen along the coast, and fog/low
stratus has receded south of Brookings. Later this afternoon, a
strong pressure gradient will likely bring breezy to gusty winds
over portions of the East Side. Otherwise, today will be a benign
weather day. -McAuley

&&

.AVIATION...For the 25/12Z TAFs...The marine push has brought
stratus to the coast and is edging it's way into the Coquille and
Umpqua Basin. Along the coast, we'll continue to see LIFR cigs near
the Brookings area and the southern coast.  As the cold front moves
onshore,  this should destabilize the atmosphere allowing for CIGS to
rise above MVFR thresholds.  However, the marine layer is quite
deep, so CIGS should hover around MVFR for the remainder of the
morning hours before burning off around 17 to 18Z.

Aside from cigs associated with the marine push, VFR conditions will
prevail for the remainder of the area. Expect gusty winds to develop
in the afternoon as a weak front moves through the area. -Smith

&&

.MARINE...Updated 800 AM PDT Monday 25 June 2018... Low end
small craft conditions are expected to continue south of Cape Blanco
through Tuesday. These somewhat calmer conditions will be short
lived as the thermal trough quickly redevelops this week. Hazardous
seas will develop south of Nesika Beach by Tuesday morning. The
thermal trough will continue to strengthen on Tuesday and gales
could be possible south of Cape Blanco by Tuesday evening. Small
craft conditions are expected to spread north of Cape Blanco by late
Tuesday afternoon.

Seas look to improve Wednesday night into Thursday as an upper level
trough moves through and disrupts the thermal trough pattern. Winds,
however, may continue to reach small craft advisory levels through
the end of the week. -BPN

&&

.PREV DISCUSSION... /Issued 354 AM PDT Mon Jun 25 2018/

DISCUSSION...Temperatures take a plunge today as the tail end of
a mostly dry cold front sweeps east of the forecast area. Behind
the front stratus has spilled into the Umpqua basin and is butting
up against the Umpqua Divide at this time. This stratus is
expected to spill over into the Grants Pass area and over into
southern end of the eastern Rogue basin around sunrise or a little
after. A thermal trough will deepen on the coast again later today
into Tuesday morning with off shore flow developing in the
southern coastal ranges by Tuesday morning. With the moist stable
onshore flow and the stratus deck temperatures will be 15 degrees
cooler or more than yesterday over the west side. East of the
Cascades winds will be gusty with low humidity over the far east
side, especially in Lake and Modoc counties ahead of and just
behind the exiting front.

A zonal flow pattern returns Tuesday and the newly deepened
thermal trough moves inland Wednesday as a weak upper level
trough moves into the region. However, the thermal trough will
move inland early Wednesday, and what would normally make this the
warmest day will be reduced by an early onshore push and bring a
cooler stable air mass in before max heating. An upper level
ridge begins to build into the region Thursday with temperatures
slowly increasing into the weekend. Sven

&&

.FIRE WEATHER...Updated 300 PM PDT Sunday 24 June 2018...The thermal
trough will shift east and lie over Lake and Modoc counties by late
this afternoon.  This thermal trough location will result in the
peak of warmth and dry conditions inland. By very late this
afternoon and early evening the winds will become a bit gusty west
of the Cascades as marine air spills inland with a dry cold front.

Breezy, cooler and more humid conditions are expected Monday as a
dry cold front, except for some drizzle early on the coast and coast
range, moves through.  The strongest winds will occur east of the
Cascades by Monday evening.
Sandler

&&

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

CA...None.

Pacific Coastal Waters...Gale Watch from Tuesday afternoon through Wednesday evening for
     PZZ356-376.
     Small Craft Advisory until 5 PM PDT Tuesday for PZZ356-376.
     Hazardous Seas Warning from 5 AM to 5 PM PDT Tuesday for
     PZZ356-376.

MSM/SBN/CZS