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000
FXUS66 KMFR 290531
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
1031 PM PDT SAT MAY 28 2016

.AVIATION...For the 29/06Z TAF cycle...Stratus with MVFR cigs has
reached the Coos coast (including KOTH) and will proceed inland
through the Umpqua Basin (including KRBG) overnight. It is unlikely
to proceed much south of Gold Beach. We may see IFR cigs with
drizzle by dawn Sunday at the coast, but the chance was low enough
not to include in TAF yet. Elsewhere, VFR conditions will continue
through the TAF period. -Wright

&&

.PREV DISCUSSION... /Issued 823 PM PDT SAT MAY 28 2016/

Discussion...No updates necessary this evening. A weak upper
trough and associated cool front will move into northwest Oregon
this evening and then dissipate over our area overnight. This will
enhance the marine layer and drive clouds into the coast and
across the Umpqua basin tonight. Some drizzle is possible as well,
but most areas will see little to no impact. This will affect
temperatures tomorrow, mainly in the Umpqua basin where it will be
cooler due to increased cloud cover. The thermal trough along the
south coast will strength, however, and as a result, places like
Brookings will probably be warmer tomorrow. -Wright

Marine...Updated 815 PM PDT Sat 28 May 2016...North winds will
continue over the waters tonight, but speeds will decrease as a
weak frontal system disrupts the pressure field. However, small
craft conditions will continue over portions of the southern
waters. The thermal trough will strengthen again later tomorrow
resulting in an increase in winds and seas, especially south of
Gold Beach. -Wright

PREV DISCUSSION... /Issued 232 PM PDT SAT MAY 28 2016/

SHORT TERM...

A pretty quiet weather pattern continues across the Pacific
Northwest for the short term. We`ll have a very weak cold front
sag towards the coast Sunday evening and produce some drizzle
given the moist air in the boundary layer, but it won`t push
inland and dissipate before the umpqua valley.

After that, we`ll have a thermal trough build with some weak off
shore flow into the start of next week. As a result, look for
anomalously warm conditions for daytime highs pushing into the
80`s and eventually the mid 90`s on Wednesday. Given the very dry
air aloft, we`ll efficiently loose heat during the night time.
Therefore, lows should still drop below 60 degrees in the
valleys, and stay around the lower 60`s on the ridges Tuesday
night. -Smith

LONG TERM...An upper level ridge is forecast to shift inland
slightly and remain over the region next Wednesday and Thursday.
Meanwhile a broad upper trough is forecast well offshore with a
closed low off the central and southern California coast. The
surface thermal trough is forecast to move inland during the day
Wednesday. This pattern will bring hot temperatures across inland
areas on Wednesday. Highs in the mid to upper 90s are expected on
Wednesday for inland valleys west of the Cascades, with highs in the
mid to upper 80s for eastern valleys. High temperatures are expected
to lower slightly on Thursday. Both Wednesday and Thursday, there is
also a slight chance for thunderstorms across inland areas as
southerly mid level moisture is also forecast to move into the area.
This moisture combined with weak instability and some weak
shortwaves is forecast to bring a slight chance for thunderstorms.
This pattern with a ridge over the area continues into Friday.
Instability is weaker on Friday though, so kept thunderstorms out of
the forecast and only have a slight chance of showers in for central
and eastern portions of the CWA.

Models differ on how quickly this ridge will shift eastward and the
strength of a Pacific low moving towards British Columbia and the
PACNW late Saturday into Sunday. The GFS transitions the ridge
eastward faster and is stronger with the low than the ECMWF. Given
the strength of the ridge, have leaned towards the slower ECMWF
solution. Of note, the low to the south may, bring another chance
for thunderstorms next weekend as it moves inland over southern and
central California. There is low confidence in the forecast track of
this low at this time.  /CC

&&

.MFR Watches/Warnings/Advisories...
OR...None.

CA...None.

Pacific Coastal Waters...Small Craft Advisory until 11 PM PDT Monday
     for PZZ356-376.
     Small Craft Advisory from 2 PM Sunday to 11 PM PDT Monday for
     PZZ350-370.
     Hazardous Seas Watch from Monday afternoon through Monday
     evening for PZZ376.
     Hazardous Seas Warning from 2 PM to 11 PM PDT Sunday for PZZ376.

$$





000
FXUS66 KMFR 281538
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
838 AM PDT SAT MAY 28 2016

.UPDATE...


&&

.DISCUSSION...

No changes for the update today as the models are pretty much on
track for the low impact weather pattern. We`ll see mainly clear
skies and temperatures pushing toward seasonal averages. -Smith

&&

.Aviation...For the 28/12Z TAF cycle...VFR conditions are expected
today and tonight with local MVFR near KOTH early this morning.
-FB

&&

.Marine...Updated 200 AM PDT Sat 28 May 2016...Offshore high
pressure and a thermal trough near the coast will continue to bring
moderate to strong north winds and steep wind dominated seas to the
waters through the middle of next week.

It should be noted that the sea state will be a chaotic mix of wind
wave and very fresh swell. Thus, while seas are fairly steep and
choppy in all areas, they are only 3-6 feet north of Cape Blanco. On
Saturday winds will diminish and the strongest winds and highest
seas will shift a bit more west of the coast. Additionally,
conditions are expected to fall below warning levels to advisories
south of Cape Blanco for today and Sunday with no advisories north
of the Cape. Numerical models do generally indicate winds and seas
will ramp upward again from the north Sunday into Monday with the
strongest winds and highest seas in the southern coastal waters area
beyond 5 nautical miles of the coast. Seas will be at a minimum on
this morning and at a maximum on Monday evening. -FB


&&

.PREV DISCUSSION... /Issued 500 AM PDT SAT MAY 28 2016/

UPDATE...See the Aviation Discussion below.

AVIATION...For the 28/12Z TAF cycle...VFR conditions are expected
today and tonight with local MVFR near KOTH early this morning.

PREV DISCUSSION... /Issued 339 AM PDT SAT MAY 28 2016/

Discussion...The upper level pattern today features a trough
along the British Columbia coast and a ridge building out along
140 West. Northwest flow aloft will transition to westerly this
afternoon, with 850 temperatures warming by around 5C compared to
yesterday. So, we`ll see high temperatures get back above normal
by a few degrees in most areas (up around 80 here in Medford).
Some cumulus clouds will probably develop over the Cascades,
northern California and over the east side this afternoon, but the
air above 600mb is very dry, so these will have little, if any
vertical extent. Fairly typical north to northwest breezes will
also develop this afternoon.

The trough along the BC coast will send a weak cold front through
the PacNW tonight into Sunday, serving to briefly deepen the
marine layer. Models are showing some very light QPF with this
marine push along the coast north of Cape Blanco and into lower
portions of the Umpqua valley north and west of Roseburg. Along
with an increase in stratus, we have also added a slight chance of
drizzle to these areas. Most folks won`t even notice the frontal
passage Sunday as temperatures will be similar to or even a
degree or two higher than today. It could be slightly cooler
though north and west of the Umpqua Divide just due to more cloud
cover in the morning.

Sunday night into Monday, the trough will shift into Montana
allowing the ridge offshore to set up along the West Coast. This
will allow a thermal trough to develop in northern California and
SW Oregon with offshore flow. This will bring another 5-10
degrees of warming to the area, including the coast south of Cape
Blanco, where offshore flow will be strongest. Brookings will
probably be up around 80 degrees. Most of the west side valleys
will have highs in the 80s, with upper 80s here in Medford.

A mild night is likely along the SW coast Monday night with dry
offshore flow and lower dew points. Mid slope and ridge top
recoveries will likely be quite poor. The ridge axis will be
overhead Tuesday. The surface thermal trough will be along the
coast Tuesday morning and though offshore flow will ease some,
this should be the warmest day there. It is a bit tricky for
Brookings as there may be a coastally trapped wind reversal
beginning around Cape Mendocino with stratus trying to round the
bend and come northward. Right now, think it holds off until
Tuesday night, but we`ll get a better idea in the next couple of
model runs. Inland, with 850 temps rising into the low 20s
Celsius, it will turn quite hot with highs well into the 90s over
the west side valleys. This will be the first 90+ degree day in
Medford in May and the first since April 18th. East side
locations will have highs in the low to mid 80s.

The thermal trough will shift inland Tuesday night into Wednesday,
allowing for onshore flow and cooler weather at the immediate
coast with perhaps an area of marine stratus pushing northward
along the coast. Inland, this will probably be the warmest day of
the stretch with highs in the upper 90s here in Medford. Record
highs may be challenged or set in one or two locations, but don`t
expect widespread record-breaking warmth.

Models diverge greatly from Thursday onward with respect to how
soon and to what degree the ridge breaks down. Run-to-run
consistency hasn`t been very good, so confidence for this time
frame isn`t all that high. The 00z ECMWF actually rebuilds the
ridge over the area Friday into the weekend, with an upper low
eventually cruising into California Sunday night. Meanwhile, the
GFS brings height falls to the West Coast late in the week with a
Pacific trough moving in over the weekend resulting in showers and
a cooling trend. Given the uncertainty, have not made any changes
to the forecast at this time. Spilde

It should be noted that the sea state will be a chaotic mix of wind
wave and very fresh swell. Thus, while seas are fairly steep and
choppy in all areas, they are only 3-6 feet north of Cape Blanco. On
Saturday winds will diminish and the strongest winds and highest
seas will shift a bit more west of the coast. Additionally,
conditions are expected to fall below warning levels to advisories
south of Cape Blanco for today and Sunday with no advisories north
of the Cape. Numerical models do generally indicate winds and seas
will ramp upward again from the north Sunday into Monday with the
strongest winds and highest seas in the southern coastal waters area
beyond 5 nautical miles of the coast. Seas will be at a minimum on
this morning and at a maximum on Monday evening. -FB

&&

.MFR Watches/Warnings/Advisories...
OR...None.

CA...None.

Pacific Coastal Waters...Small Craft Advisory until 11 PM PDT Monday for PZZ356-376.

$$

MAS/FJB/CZS





000
FXUS66 KMFR 272357 AAA
AFDMFR

Area Forecast Discussion...UPDATED
National Weather Service Medford OR
457 PM PDT FRI MAY 27 2016

.DISCUSSION...The aviation and marine sections have been updated.

&&

.AVIATION...For the 28/00Z TAF cycle...VFR conditions with clear
to partly cloudy skies are expected through Saturday afternoon...
except for local early morning MVFR stratus between around 11Z and
16Z in the Umpqua Valley. This stratus is most likely to form
in the southern portion of the valley near Canyonville. -DW

&&

.MARINE...Updated 330 PM PDT Fri 27 May 2016...Offshore high
pressure and a thermal trough near the coast will continue to bring
moderate to strong north winds and steep wind dominated seas to the
waters through the middle of next week.

It should be noted that the sea state will be a chaotic mix of wind
wave and very fresh swell. Thus, while seas are fairly steep and
choppy in all areas, they are only 3-6 feet north of Cape Blanco. On
Saturday winds will diminish and the strongest winds and highest
seas will shift a bit more west of the coast. Additionally,
conditions are expected to fall below warning levels to advisories
south of Cape Blanco for Saturday and Sunday with no advisories
expected north of the Cape after this evening. Numerical models do
generally indicate winds and seas will ramp upward again from the
north Sunday into Monday with the strongest winds and highest seas in
the southern coastal waters area beyond 5 nautical miles of the
coast. Seas will be at a minimum on Saturday morning and at a
maximum on Monday evening. -DW

&&

.PREV DISCUSSION... /Issued 254 PM PDT FRI MAY 27 2016/

Short term...Temperatures are once again similar to the previous
day...with this being the last day of relatively constant weather
conditions. Afternoon high temperatures will once again be below
normal...and this makes 8 out of the past 9 days at or below
normal in terms of temperatures. Onshore flow is similar to
yesterday in terms of pressure gradients so expect some clouds to
make their way into the Umpqua Basin tonight, but coverage should
not be as much as yesterday. East of the Cascades, significantly
lower dew points are being observed today compared to yesterday,
and with mostly clear skies again tonight, freezing conditions are
likely in portions of the Klamath Basin. A freeze warning has been
issued for that area at NPWMFR.

Tomorrow marks the first significant warming of the air mass in more
than a week as 850mb temperatures increase by at least 5C.
Temperatures will be a few degrees above normal in most places, and
this trend will continue on Sunday but with only a slight warmup
because weak upper troughing will keep the ridge at bay for one more
day. This upper troughing has a slight potential of bringing some
drizzle to the coast and Umpqua Basin but have left it 10 percent
or less at this time. The next run of high resolution models may
have some more insight that could force a nudge upwards of POPs
Sunday morning.

The upper ridge axis moves overhead nearly overhead on Monday,
resulting in upper-80 degree temperatures west of the Cascades and
near-80 degree readings east of the Cascades. Additionally, moderate
offshore northeasterly winds will heat things up in Brookings,
making 80 degree temperatures within reach.

Long term...Tuesday through Friday. Models are in tight
agreement with all of the ensemble plots in line with an upper level
ridge over the west coast. Offshore flow is all the way across the
east side with a deep thermal trough on the coast Tuesday morning
with west side temps near 90 to the mid 90s. The thermal trough
moves inland Wednesday and the warmest day of the stretch will be on
Wednesday inland. Southerly flow begins to feed moisture into the
region Thursday with the GFS and ECMWF indicating LI`s in the -2
range. However, the 700-500 mb RH is less than 50 percent and cells
that will develop will fizz out at the top as the flow hits the dry
layer in the cells. The ECMWF has an upper low swinging up on Friday
with instablity and moisture indicating possible thunderstorms, but
this is an outlying solution and have gone only slight chance showers
due to uncertainty at this time. Sven

&&

.MFR Watches/Warnings/Advisories...
OR...Freeze Warning from 2 AM to 8 AM PDT Saturday for ORZ029.

CA...Freeze Warning from 2 AM to 8 AM PDT Saturday for CAZ084.

Pacific Coastal Waters...Small Craft Advisory for hazardous seas
     until 11 PM PDT this evening for PZZ350-356-370-376.
     Small Craft Advisory until 11 PM PDT Monday for PZZ356-376.
     Hazardous Seas Warning until 11 PM PDT this evening for
     PZZ356-376.

$$

SK/SBN/DW





000
FXUS66 KMFR 270025
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
525 PM PDT THU MAY 26 2016

Updated Marine and Aviation sections and marine headlines...

.Marine...Updated 515 PM PDT Thu 26 May 2016...
Strengthening high pressure over the eastern Pacific and low
pressure inland is bringing strong north winds and steep to very
steep seas to most of the coastal waters area south of Cape Blanco.
These winds will peak this evening with Gale and Hazardous Seas
Warning conditions for a portion of the area south of Cape
Sebastian. This pattern will remain in place through the holiday
weekend with steep seas continuing south of Cape Blanco, but winds
will be slightly weaker after today.

It should be noted that nearly all of the current sea state now
and through the weekend is and will be comprised of wind wave and
very fresh swell. Thus, while seas are fairly steep in all areas,
they are only 3-6 feet north of Cape Blanco. We expect similar sea
conditions Friday as compared to today. On Saturday winds will
diminish and the strongest winds and highest seas will shift a bit
more west of the coast. Additionally, conditions are expected to
fall below warning levels to advisories south of Cape Blanco for
Saturday and Sunday with no advisories expected north of the Cape
after Friday evening. Numerical models do generally indicate winds
and seas will ramp upward again from the north Sunday and Monday in
the southern coastal waters area beyond 5 nautical miles of the
coast. BTL

&&

.AVIATION...For the 27/00Z TAF cycle...
High pressure and nocturnal cooling will cause winds to turn a bit
northeasterly tonight through early friday along the coast and into
the umpqua basin. This net flow toward offshore areas should keep
coastal areas mostly vfr. In the umpqua basin mvfr is expected in
the 06z-18z time frame, with moderate confidence that roseburg will
be affected during a portion of this time period. Radiational
cooling is likely to again result in some patchy fog around sunrise
in portions of the upper Klamath Basin. All areas should see mostly
clear skies by noon local time. BTL

&&

.PREV DISCUSSION... /Issued 250 PM PDT THU MAY 26 2016/

Short term...This afternoon through Sunday...Temperatures are
similar to yesterday at this time, with high temperatures expected
to be slightly below normal for this time of year. Onshore flow
continues...stronger than yesterday...and will result in gusty
northwest winds later this afternoon. Marine layer low clouds
will affect the coast and Umpqua Basin this evening and overnight
again due to the continued onshore flow and plenty of stratus to
work with over the waters. Further east, freezing temperatures
are expected in portions of the Klamath Basin and a freeze warning
has been issued at NPWMFR. Model trends have been consistent in
showing temperatures tonight colder than last night, and given
that a few stations recorded freezing temperatures last night, we
have confidence in the freeze warning. Again, Friday night should
be the coldest night of the week mainly due to lighter winds and
cooler air mass, and we have maintained a freeze watch for that
time.

Temperatures will be similar Friday compared to today as an upper
trough to the north maintains the relatively cool air mass and
onshore flow. Saturday will begin the warmup that will last through
the weekend as temperatures reach above normal readings and then
bump into the 80s Sunday and Monday. We have removed the chance of
rain for Sunday due to good model agreement on little instability
and dry westerly flow.

Long Term...Monday through Thursday Night...Upper level ridging
will be in control of the area throughout much of the extended term.
as typical of the warmer season, thermal troughing will develop to
our south, and this will produce an extended period of offshore
easterly flow. Monday will be the warmest day at the coast, then when
the trough shifts inland, temperatures there will cool Tuesday into
Wednesday. Inland, warming will continue, with the warmest day
likely to be Tuesday or perhaps Wednesday before slight cooling by
the end of the term. Thursday, a large scale trough over the eastern
Pacific will approach the West Coast, shifting winds to a more
onshore southwesterly flow.

This pattern usually results in a dry period. However, models
solutions are showing a weak shortwave within the upper level flow
during the afternoon Wednesday, and this may be enough to produce
some convection along and west of the Cascades. Have introduced a
slight chance for afternoon and evening thunderstorms to cover this
thinking. Thunderstorms and showers are also possible Thursday
afternoon under a similar pattern, although the focus should be
slightly closer to the coast. Confidence in convection both days is
low, but should increase if models continue with this trend over the
next several runs. -BPN

&&

.MFR Watches/Warnings/Advisories...
OR...Freeze Watch from late Friday night through Saturday morning for
     ORZ029.
     Freeze Warning from 3 AM to 8 AM PDT Friday for ORZ029.

CA...Freeze Watch from late Friday night through Saturday morning for
     CAZ084.
     Freeze Warning from 3 AM to 8 AM PDT Friday for CAZ084.

Pacific Coastal Waters...
- Small Craft Advisory for hazardous seas until 11 PM PDT Friday
  for PZZ350-356-370-376.
- Small Craft Advisory until 11 PM PDT Sunday for PZZ356-376.
- Gale Warning until 11 PM PDT this evening for PZZ356-376.
- Hazardous Seas Warning until 11 PM PDT Friday for PZZ356-376.

$$

NSK/BPN/BTL





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