Gale Watch 35, NWS Medford, OR

Area Forecast Discussion
National Weather Service Medford OR
121 PM PDT SAT SEP 10 2016

.SHORT TERM...A very dry and warm air mass is over the area today.
A dry front will move into the area from the north by this
evening and expect breezy north to northwest winds from the
Cascades west during the late afternoon and into the evening.
Tonight and Sunday an upper level trough will shift southward
over the region and bring a cooler air mass. A shortwave will move
around the trough and down into the area on Monday, followed by a
cut off low developing over Southern Oregon and Northern
California on Tuesday.

Today, the main concern is with the dry and breezy conditions
expected late this afternoon and this evening. Winds are expected
to be strongest from the Cascades west. The combination of breezy
winds and very dry conditions will bring an increased risk for
fire danger. A red flag warning is in effect for western locations
in Southern Oregon including portions of Josephine, Jackson, and
western Klamath counties. See the RFWMFR for details.

Tonight and Sunday, expect a marine push of low clouds to spread
from the coast, across the Umpqua Valley and to the Southern
Oregon Cascades. Low clouds are also expected to spill over the
Umpqua Divide and into portions of the Rogue, Illinois and
Applegate Valleys on Sunday morning. Also areas of drizzle or
very light rain are possible over the higher terrain from the
coastal mountains in Coos County to the Umpqua Divide and into the
western foothills of the Southern Oregon Cascades in Douglas
County. With the upper trough shifting south into the area on
Sunday, expect another day with breezy northwest winds. However,
conditions will be cooler and not as dry as today. Daytime high
temperatures are expected to be 10-15 degrees lower than today
with highs in the upper 70s to mid 80s for most inland locations.

Monday, expect cool temperatures along with gusty north to
northeast winds across the area. High temperatures are expected
in the lower 80s for western valleys and in the upper 60s to near
70 for eastern valleys. Gusty northeast winds are expected over
the mountains Sunday night and Monday morning with gusty north to
northeast winds developing over all areas in the afternoon and
evening. Dry conditions are expected for most areas. However,
models continue to show a slight chance for showers and
thunderstorms for Modoc County in Northern California Monday
afternoon and evening.

As the low cuts off over Southern Oregon and Northern California
on Tuesday, and brings some wrap around moisture into the area,
along with weak instablity, expect a slight risk for showers and
thunderstorms for areas east of the Cascades, mainly in Lake and
Modoc counties.

.LONG TERM...Models continue to show the upper low shifting east
of the area on Wednesday with an upper level ridge building into
the region from the west. This will bring warming and drying
conditions to  the area on Wednesday. The warming and drying
trend continues through late in the week with an upper level ridge
building over the area Thursday and Friday. Another upper trough
may begin to lower into northern portions of the Pacific
Northwest late Saturday but expect continued dry and warm
conditions across Southern Oregon and Northern California through
Saturday.

&&

.AVIATION...10/18Z TAF CYCLE...VFR conditions should continue
for nearly all areas through this afternoon. However, smoke will
continue to be a problem across northwest Siskiyou County with
reduced visibilities in the valleys. Some of this smoke may creep up
across SW Oregon at times, but it is not expected to reduce flight
conditions. MVFR/IFR is likely to develop late this afternoon or
early this evening along the coast, then spread inland into the
Umpqua Basin and perhaps the lower Rogue Valley overnight. -BPN/FB

&&

.MARINE...Updated 815 AM PDT Saturday 10 September 2016...
Due to the persistent thermal trough pattern, strong north winds and
steep to very steep seas will continue through the weekend. North
winds should be a factor again this afternoon and we are likely to
see Gales in the usual areas south of Cape Blanco this afternoon and
potentially again on Sunday. This pattern will remain in place until
Monday night, then conditions should improve by midweek. -BPN/FB

&&

.FIRE WEATHER...Updated 100 PM PDT Saturday 10 September 2016...The
thermal trough along the coast continues to provide for warm and dry
air across southwest Oregon and western Siskiyou County today. The
atmosphere is still very dry, and afternoon relative humidity today
will drop to around 10 percent in the Southern Oregon Cascades and
most of the West Side. A dry cold front will pass over the region
today as well, and should produce breezy winds across much of the
region this afternoon through tonight. The combination of low
humidity and breezy winds has prompted the issuance of a Red Flag
Warning for portions of the Cascade and Siskiyou mountains, as well
as the Applegate and upper Rogue valleys. For more information on
this, see the fire weather hazard message, or PDXRFWMFR.

An upper level trough is forecast to move southward over the region
Sunday and will bring cooler temperatures to the region. Again,
afternoon winds could become gusty at times, especially east of the
Cascades, but relative humidities will be higher, so no fire
weather warnings are expected at this time.

The trough will develop into a cutoff low late Monday into Tuesday.
Gusty northeast winds are expected over the area Monday with a
slight chance for thunderstorms in zone 285. Latest model guidance
suggests that the northeast winds will produce a downsloping effect
on the western to southwestern slopes, and this could result in very
low humidities for portions of the West Side, all the way down to the
coastline. Therefore, there is the potential for a fire Weather
Watch to be issued over the next day or so, when the details become
more apparent and confidence increases.

&&

.MFR WATCHES/WARNINGS/ADVISORIES...
OR...Red Flag Warning from 4 PM this afternoon to 9 PM PDT this
     evening for ORZ620>623.

CA...
Pacific Coastal Waters...Small Craft Advisory from 11 PM this evening to 11 PM PDT Sunday
     for PZZ350-356-370-376.
     Small Craft Advisory for hazardous seas from 5 PM this afternoon
     to 11 PM PDT this evening for PZZ350-356-370-376.
     Gale Watch from Sunday morning through Sunday evening for
     PZZ356-376.
     Gale Warning from 5 PM this afternoon to 11 PM PDT this evening
     for PZZ356-376.
     Hazardous Seas Warning from 5 PM this afternoon to 11 PM PDT
     this evening for PZZ356-376.

CC/BPN