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000
FXUS66 KPDT 251621
AFDPDT

Area Forecast Discussion
National Weather Service Pendleton OR
921 AM PDT WED MAY 25 2016

.SHORT TERM...Morning Update...An upper level trough will continue
to weaken and shift east today. Thus upper level flow will become
increasingly northwesterly and drier. Surface flow will become
increasingly onshore with breezy winds through the Cascade gaps,
particularly into the Gorge and the Kittitas Valley. These winds
will keep high temps slightly below seasonal in the Gorge, the
Kittitas Valley, and over north-central and central Oregon. There
will be enough instability and lingering moisture for isolated to
scattered showers from the Blue mountains east to Wallowa county and
south through Grant county. Instability over Wallowa county may be
sufficient for stray, brief thunderstorms from mid afternoon to
early evening. Elsewhere, a few showers may occur over mountain
ridges. Updates this morning included adding the mention of
thunderstorms in Wallowa county, adjusting shower coverages, winds
and high temps. 90

.LONG TERM...Previous Discussion...Weak upper level trough over
the region Saturday and Sunday with northwest flow aloft. Scattered
showers over the Cascades and Blues otherwise partly to mostly
cloudy skies. Temperatures near normal with highs in the 60s to mid
70s. Upper level ridge building into the area Monday and Tuesday
with partly cloudy skies and warmer temps. Highs in the 70s with
near 80 in the Columbia basin. No significant winds expected through
the extended period.

&&

.AVIATION...Previous Discussion...12Z TAFS...Sct-bkn 040-070 today
and tonight. Winds increasing late morning into the afternoon
becoming westerly 10-25kt.

&&

.PRELIMINARY POINT TEMPS/POPS...
PDT  74  48  69  46 /   0   0  10  10
ALW  74  52  70  50 /  10   0  10  10
PSC  80  52  76  50 /   0   0   0  10
YKM  79  48  72  44 /  10   0   0  10
HRI  78  51  73  49 /   0   0   0  10
ELN  73  48  65  46 /   0   0  10  10
RDM  66  38  65  36 /  10   0  10  10
LGD  69  44  65  42 /  20  10  10  10
GCD  69  42  66  41 /  20  10  10  10
DLS  72  52  68  51 /  10   0  10  10

&&

.PDT Watches/Warnings/Advisories...
OR...None.
WA...None.
&&

$$

90/94/91



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000
FXUS66 KMFR 251239
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
539 AM PDT WED MAY 25 2016

.AVIATION...For The 25/12Z TAF Cycle...Areas of stratus with MVFR
cigs is present mainly over the coast and Umpqua basin this
morning, and this will likely continue much of the day. Elsewhere,
conditions generally remain VFR and will through the TAF period.
-Wright

&&

.PREV DISCUSSION... /Issued 404 AM PDT WED MAY 25 2016/

DISCUSSION...There is little change in the expected weather
during the short term and increased confidence in the long term
portion this weekend into early next week.

The GFS and ECMWF solutions have trended toward each other
regarding the Memorial Day weekend and the forecast highs have
been raised by a few degrees in accordance with the updated model
data. It looks to be mostly though not entirely rain-free with
high temperatures near normal on Saturday trending warmer at least
into Tuesday. There will be an even wider than normal diurnal
range of temperatures with cool morning lows in the 40s in most
west side valleys and cold morning lows in the 30s at ridges and
across the east side.

First, a few showers are lingering in Lake, Siskiyou, and Modoc
Counties early this morning as a shortwave moves southeast across
southeast Oregon. Shower activity looks to increase slightly into
the early afternoon with a majority of the showers and also a
slight chance of thunderstorms over the Warner Mountains of Lake
and Modoc Counties. The probability of showers will diminish late
today into tonight as low pressure moves into the Great Basin and
a shortwave ridge builds into the west coast. This will strengthen
a thermal trough at the coast with weak easterly winds expected to
result in reduced cloud cover in southern Curry County Wednesday
night.

Our weather from Thursday through Sunday will be affected by a
series of very weak disturbances moving through the southern edge
of a longwave trough that will persist over western Canada. This
will produce an onshore flow at the coast with a few light day-
time showers and patches of late night and morning drizzle at the
coast north of Cape Blanco and into Douglas County. The
probability of light showers will be higher north of our area. It
warrants emphasis that any showers will not amount to much...a
likely only a trace to a few hundredths of an inch in all. More
notable is the expectation of Coastal and Douglas County night and
early morning low clouds. Otherwise...skies look to be mostly
sunny to sunny. Temperatures will remain very slightly below
normal through Friday then reach normal on Saturday and continue a
warming trend early next week.

There does remain some uncertainty regarding the possibility of
weak instability developing east of the Cascades on Sunday
afternoon and evening as a shortwave trough moves east across
northern Oregon. Once again, the best chance for a light shower
will be across the northern fringe of our area.

The models now show a strengthening ridge and thermal trough on
Memorial Day into Tuesday. There is moderate uncertainty in the
forecast for Tuesday and Wednesday. Both days still are likely to
be warmer than normal but the timing and track of the west coast
ridge and an approaching trough over the eastern Pacific are in
question. This could introduce instability into the air mass with
a possibility of showers and thunderstorms as early as Tuesday
afternoon...though possibly holding off until Wednesday afternoon
or even day 8/Thursday afternoon.

MARINE...Updated 230 AM PDT Wed 25 May...High pressure well
offshore and lower pressures over land will remain in place and
continue to drive north winds and mainly wind driven seas over the
waters through at least the next week. Winds will ramp up today
and peak on Thursday. Then, winds remain north but weaken a bit
Friday into the weekend as weak fronts move by to the north. Winds
are expected to increase substantially and may reach gale force
early next week as a strong thermal trough develops. Winds will be
strongest and seas highest over the southern waters throughout the
forecast period. -Wright

&&

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

CA...None.

Pacific Coastal Waters...Hazardous Seas Warning from 5 PM this
     afternoon to 11 PM PDT Friday for PZZ356-376.
     Small Craft Advisory for hazardous seas from 11 AM this morning
     to 11 PM PDT Friday for PZZ350-356-370-376.

$$




000
FXUS66 KMFR 251104
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
404 AM PDT WED MAY 25 2016

.DISCUSSION...There is little change in the expected weather
during the short term and increased confidence in the long term
portion this weekend into early next week.

The GFS and ECMWF solutions have trended toward each other
regarding the Memorial Day weekend and the forecast highs have
been raised by a few degrees in accordance with the updated model
data. It looks to be mostly though not entirely rain-free with
high temperatures near normal on Saturday trending warmer at least
into Tuesday. There will be an even wider than normal diurnal
range of temperatures with cool morning lows in the 40s in most
west side valleys and cold morning lows in the 30s at ridges and
across the east side.

First, a few showers are lingering in Lake, Siskiyou, and Modoc
Counties early this morning as a shortwave moves southeast across
southeast Oregon. Shower activity looks to increase slightly into
the early afternoon with a majority of the showers and also a
slight chance of thunderstorms over the Warner Mountains of Lake
and Modoc Counties. The probability of showers will diminish late
today into tonight as low pressure moves into the Great Basin and
a shortwave ridge builds into the west coast. This will strengthen
a thermal trough at the coast with weak easterly winds expected to
result in reduced cloud cover in southern Curry County Wednesday
night.

Our weather from Thursday through Sunday will be affected by a
series of very weak disturbances moving through the southern edge
of a longwave trough that will persist over western Canada. This
will produce an onshore flow at the coast with a few light day-
time showers and patches of late night and morning drizzle at the
coast north of Cape Blanco and into Douglas County. The
probability of light showers will be higher north of our area. It
warrants emphasis that any showers will not amount to much...a
likely only a trace to a few hundredths of an inch in all. More
notable is the expectation of Coastal and Douglas County night and
early morning low clouds. Otherwise...skies look to be mostly
sunny to sunny. Temperatures will remain very slightly below
normal through Friday then reach normal on Saturday and continue a
warming trend early next week.

There does remain some uncertainty regarding the possibility of
weak instability developing east of the Cascades on Sunday
afternoon and evening as a shortwave trough moves east across
northern Oregon. Once again, the best chance for a light shower
will be across the northern fringe of our area.

The models now show a strengthening ridge and thermal trough on
Memorial Day into Tuesday. There is moderate uncertainty in the
forecast for Tuesday and Wednesday. Both days still are likely to
be warmer than normal but the timing and track of the west coast
ridge and an approaching trough over the eastern Pacific are in
question. This could introduce instability into the air mass with
a possibility of showers and thunderstorms as early as Tuesday
afternoon...though possibly holding off until Wednesday afternoon
or even day 8/Thursday afternoon.

&&

.AVIATION...For The 25/06Z TAF Cycle...Areas of MVFR cigs with local
IFR cigs will return to the coastal waters...coast...and Umpqua
Basin later tonight with higher terrain becoming obscured.  The
lower conditions will clear back to the coast by Wednesday
afternoon...but will remain over the coastal waters into Wednesday
night. All other locations will remain VFR through Friday
night...but isolated to scattered showers will develop Wednesday and
some isolated thunderstorms may develop over Modoc and southern Lake
County Wednesday afternoon.

&&

.MARINE...Updated 230 AM PDT Wed 25 May...High pressure well
offshore and lower pressures over land will remain in place and
continue to drive north winds and mainly wind driven seas over the
waters through at least the next week. Winds will ramp up today and
peak on Thursday. Then, winds remain north but weaken a bit Friday
into the weekend as weak fronts move by to the north. Winds are
expected to increase substantially and may reach gale force early
next week as a strong thermal trough develops. Winds will be
strongest and seas highest over the southern waters throughout the
forecast period. -Wright

&&

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

CA...None.

Pacific Coastal Waters...Hazardous Seas Warning from 5 PM this
     afternoon to 11 PM PDT Friday for PZZ356-376.
     Small Craft Advisory for hazardous seas from 11 AM this morning
     to 11 PM PDT Friday for PZZ350-356-370-376.

$$

DW/TRW




000
FXUS66 KPDT 251037
AFDPDT

Area Forecast Discussion
National Weather Service Pendleton OR
324 AM PDT WED MAY 25 2016

.SHORT TERM...Today through Friday night...Weak flow aloft
today is associated with a broad long wave mid/upper level trough.
Very marginal shallow layer of instability will yield scattered rain
showers in the Blue Mountains eastward to Idaho this afternoon.
Elsewhere, dry conditions expected through this afternoon. Tonight
and Thursday westerly flow aloft will occur across forecast area
ahead of a large upper low digging southeast over British Columbia.
This flow pattern will produce dry conditions across the region
through Thursday afternoon. Thursday night and Friday the
aforementioned low opens up to a broad upper level trough, which
covers British Columbia as well as WA/OR. Forecast area will remain
on the southern flank of the trough thus giving us westerly flow
aloft and therefore dry conditions through Friday afternoon, except
for slop over showers along the east slopes of the WA/OR Cascades.
Friday night the same synoptic scale flow pattern continues in place
for a continuation of dry conditions, but with a chance of showers
near the crests of the Cascades.  polan

.LONG TERM...Saturday through Tuesday. Weak upper level trough over
the region Saturday and Sunday with northwest flow aloft. Scattered
showers over the Cascades and Blues otherwise partly to mostly
cloudy skies. Temperatures near normal with highs in the 60s to mid
70s. Upper level ridge building into the area Monday and Tuesday
with partly cloudy skies and warmer temps. Highs in the 70s with
near 80 in the Columbia basin. No significant winds expected through
the extended period. 94

&&

.AVIATION...06Z TAFS...VFR conditions expected to prevail over the
next 24 hours at all terminals. SCT-BKN clouds around 5k ft AGL will
continue to affect KBDN and KRDM for the next several hours before
gradually lifting/scattering out. Otherwise just a FEW to SCT mid
level clouds expected...mainly between 5k to 10k ft AGL through the
period...with the greatest cloud cover percentage expected during
the afternoon hours Wednesday as diurnally induced clouds develop(CU)
...especially over and INVOF the mountains. There will be a chance
for showers or even a thunderstorm Wednesday afternoon over the Blue
Mountains and into Wallowa County. It will remain dry elsewhere.
Winds stay generally light overnight...mainly less than 12 KTS at
all TAF sites. Then winds increase after 25/18z to between 10-20
KTS...except KDLS which will have WNW winds of 15 to 30 KTS
Wednesday afternoon. 77

&&

.PRELIMINARY POINT TEMPS/POPS...
PDT  73  48  69  46 /   0  10  10  10
ALW  75  52  70  50 /  10  10  10  10
PSC  81  52  76  50 /   0  10   0  10
YKM  78  48  72  44 /   0  10   0  10
HRI  79  51  73  49 /   0  10   0  10
ELN  72  48  65  46 /   0  10  10  10
RDM  67  38  65  36 /  10  10  10  10
LGD  67  44  65  42 /  20  10  10  10
GCD  68  42  66  41 /  10  10  10  10
DLS  73  52  68  51 /   0  10  10  10

&&

.PDT Watches/Warnings/Advisories...
OR...None.
WA...None.
&&

$$

99/94/94



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000
FXUS65 KBOI 250918
AFDBOI

Area Forecast Discussion
National Weather Service Boise ID
318 AM MDT WED MAY 25 2016

.SHORT TERM...Today through Thursday...Elongated upper level trough
will continue to impact the region today with scattered to
numerous light showers developing mainly over the higher terrain.
Convection under this pattern has been weak in the last few days
with limited thunderstorms observed, therefore included only a
slight chance over the Idaho high terrain and along the OR- NV
border. Temperatures today will be near normal. Showers will taper
off overnight and Thursday as the trough transitions east and the
flow becomes northwesterly. Looking for showers over the Idaho
high terrain with a slight chance of thunderstorms in the
afternoon. Temperatures will warm slightly under increased
heights and clearing skies.

.LONG TERM...Thursday Night through Thursday...
The northward shift of the southward moving upper low on Friday
and Saturday, noted by the earlier forecaster, continues in the
06z run. Front still expected to slide into eastern Oregon
Thursday evening and then into the Boise and McCall region after
midnight and the Twin Falls area around sunrise Friday. Not real
impressed with any of the convective parameters as best
instability generally across the Frank Church Wilderness region.
Have also removed mention of showers across the Nevada/Idaho
border area for Friday and Saturday. A weak trough slides across
the region Sunday evening bringing a mention of showers and
thunderstorms to the north. Models continue to hint that a rapid
warmup is on its way after the Memorial Day weekend. Southwest
flow aloft with 500 mb heights over 580 dm...well above normal
temps possible by mid next week.

&&

.AVIATION...VFR. Scattered showers and isolated thunderstorms over
the higher terrain mainly over Idaho will diminish this evening.
Gusty winds to 30 kts are possible near showers and storms. Away
from showers and storms, northwest winds to 10 kts at the surface.
Winds at the 10 kft level Northwest around 10kts...shifting North by
sunset and increasing 10 to 20kts.

&&

.BOI WATCHES/WARNINGS/ADVISORIES...
ID...None.
OR...None.

&&

$$

www.weather.gov/Boise
www.facebook.com/NWSBoise
www.twitter.com/NWSBoise

SHORT TERM...AB
LONG TERM....CR
AVIATION.....CR




000
FXUS66 KPDT 250421
AFDPDT

Area Forecast Discussion
National Weather Service Pendleton OR
920 PM PDT TUE MAY 24 2016

.UPDATE...Only minor adjustments made to PoPs, sky cover, temps and
winds as the short term forecast appears to be generally on track.
Sky cover was lowered some over the Columbia Basin tonight as the
diurnal clouds dissipate quickly. Sky cover was also lowered
tomorrow in the Columbia Basin as the brisk westerly flow and mid
level dry air should inhibit cloud development here. Temperatures
were raised 1-3 degrees over the Lower Yakima Valley and Columbia
Basin as the latest guidance indicated highs reaching into the lower
80s here Wednesday afternoon. Still expecting CU build up with a
chance of showers and a slight chance of thunderstorms over the
Eastern Mountains and Wallowa County again Wednesday afternoon
...PoPs were massaged to between 20-40 percent here in the
afternoon...except near 60 percent over the Eagle Caps. Instability
is looking marginal...with MUCAPE between 200-500 J/Kg and LIs
between 0 and minus 2.5 so continued with only a slight chance of
thunder. The other story for Wednesday will be the increasing winds
over the Columbia Gorge, Kittitas Valley and into the Lower Columbia
Basin. At this time winds look to stay under advisory criteria on
Wednesday afternoon...with west to northwest winds of 20-30 MPH and
gusts to near 40 MPH in the above mentioned locations. Winds are
still looking a bit stronger heading into Thursday for much of the
same areas and extending into the foothills zones...winds could push
advisory criteria at times on Thursday for parts of the area. Will
also need to watch for patchy blowing dust in the Lower Columbia
Basin with the stronger winds developing. On another note...
although fuels are still generally moist and min RHs are only
forecast to be in the 25-35 percent range any grass fires that may
start (human caused) have the potential to spread quickly both
Wednesday and Thursday afternoon in the breezy/windy conditions. 77

&&

.PREV DISCUSSION... /issued 345 PM PDT TUE MAY 24 2016/

SHORT TERM...tonight through Friday...weak cyclonic flow will be
over the region through Friday transitioning to a strong upper low
passing just north of the forecast area Thursday night and Friday.
For this evening there will be a few showers over the eastern
mountains with a very slight chance of a thunderstorm over Wallowa
County. On Wednesday the short term models depict a bit more
instability over the eastern mountains so have maintained a slight
Chance of thunderstorms for the afternoon and evening. Winds will
pick up in the Kittitas Valley and Columbia Gorge during the
afternoon and evening and could push advisory levels. High
temperatures Wednesday will be mostly in the 70s lower elevations
with 60s in the mountains. On Thursday expect mostly dry and
slightly cooler conditions but there will be some wind impacts.
Winds in the Columbia Gorge and Kittitas Valley could reach advisory
levels. For Friday the upper low will be passing to the north. The
trajectory of the low does not lend itself to much airmass
destabilization or moistening of the airmass. Thus just expect a few
mountain showers and continued breezy/windy conditions in the
Cascade gaps. 78

LONG TERM...Friday night through Tuesday. Previous forecast
discussions focused on the cool and unsettled weather for the first
half of the Memorial holiday weekend, but latest runs are showing
less amplitude of the upper level trough and more of a westerly flow
aloft than a cyclonic flow over WA/OR. Therefore, showers and
thunderstorms do not appear to be strong with heavy downpours like
what was observed last weekend. The threat of thunderstorms on
Friday evening and Saturday will be slight chance at best and mainly
from the Blue Mtns eastward. The first shortwave trough will exit
the region Friday night, and high pressure building behind the
system will result in gusty winds, especially through the Kittitas
Valley and the Eastern Columbia River Gorge. Another shortwave
trough will follow on Memorial Day with similar weather conditions.
The biggest concern for the holiday weekend will be the unseasonably
cool temperatures, mainly at night. There could also be light snow
accumulations above 5000 feet Friday evening. Wister

AVIATION...00Z TAFS. VFR conditions will prevail with sct-bkn
layers of stratocumulus and cumulus through Wednesday afternoon.
Winds will be less than 15 knots but NW winds 15-25 knots can be
expected at KDLS this afternoon and again after 20Z/25th.  Wister

&&

.PRELIMINARY POINT TEMPS/POPS...
PDT  50  73  48  70 /  10  10  10  10
ALW  52  76  51  71 /  10  10  10  10
PSC  51  81  52  76 /  10   0  10   0
YKM  48  80  48  72 /  20   0  10   0
HRI  51  80  50  74 /  10  10  10   0
ELN  49  74  47  67 /  10  10  10  10
RDM  40  68  37  65 /  10  10  10  10
LGD  45  68  44  65 /  20  20  20  10
GCD  43  70  42  67 /  10  10  10  10
DLS  54  73  52  69 /  10  10  10  10

&&

.PDT Watches/Warnings/Advisories...
OR...None.
WA...None.
&&

$$

77/85/77




000
FXUS65 KBOI 250233
AFDBOI

Area Forecast Discussion
National Weather Service Boise ID
833 PM MDT TUE MAY 24 2016

.DISCUSSION...The current satellite and radar imagery shows there
is plenty of cumulus development over the area with some isolated
showers, mainly along the ID/NV border. This convection is
expected to dissipate after sunset. The forecast was updated to
remove the mention of thunderstorms from much of the area that
has not seen any strikes in the last 12 hours, except in the
Magic Valley and areas south. Otherwise, the rest of the forecast
looks on track.

&&

.AVIATION...VFR. Isolated showers and thunderstorms, mainly along
the Nevada border, will diminish after sunset. Otherwise scattered to
broken mid-level clouds. Surface winds westerly 5-15 knots. Winds
aloft northwesterly 10-20 knots up through 10K feet MSL.

&&

.PREV DISCUSSION...
SHORT TERM...Tonight through Thursday...a large and complex upper
level trough covers much of the northern rockies and west coast
this afternoon. There are several centers of vorticity within
this trough, however, none appears to be in position to be a
significant source of weather for our area this afternoon and
evening. We will see isolated to scattered showers and storms this
evening, with activity dropping off to just isolated after
Midnight MDT. Overnight and tomorrow, the overall trough axis
will slowly shift eastward as a closed low positioned at the south
end of the trough moves more rapidly eastward through southern
California. As the upper trough axis passes overhead Wednesday,
we will see a chance of showers and slight chance of thunderstorms
at lower elevations, with showers likely and a slight chance of
thunderstorms in the mountains. As the upper trough axis
continues to move to the east Thursday, the chance for showers and
thunderstorms will decrease and move east with it, remaining
mainly in the higher terrain of our southwest Idaho area.
Temperatures will remain a few degrees below normal Wednesday and
then rise up to very near normal Thursday.

LONG TERM...Thursday night through Tuesday...Dryer conditions
early in the period, especially across the lower valleys as dry air
wraps into the Interior Northwest. The 12z models have trended
northward with the next low pressure system during the weekend,
keeping it centered along the U.S/Canadian border. This would keep
the  focus afternoon shower and thunderstorm development over the
east-central Oregon and west-central Idaho mountains. The Snake
Plain and much of southeast Oregon would remain dry with only a
slight chance in the higher terrain towards the NV border. This
northward shift in the low center would also result in warmer
temperatures Sat/Sun. Have moved the forecast in this direction
for the weekend. The low kicks eastward early next week which will
increase precip chances across the mountains as it swings through.

&&

.BOI WATCHES/WARNINGS/ADVISORIES...
ID...None.
OR...None.

&&

$$

www.weather.gov/Boise
www.facebook.com/NWSBoise
www.twitter.com/NWSBoise

DISCUSSION...EP
AVIATION.....JA
PREV SHORT TERM...SP
PREV LONG TERM....DG/WH




000
FXUS66 KPDT 242245
AFDPDT

Area Forecast Discussion
National Weather Service Pendleton OR
345 PM PDT TUE MAY 24 2016

...Updated Aviation Discussion...

.SHORT TERM...tonight through Friday...weak cyclonic flow will be
over the region through Friday transitioning to a strong upper low
passing just north of the forecast area Thursday night and Friday.
For this evening there will be a few showers over the eastern
mountains with a very slight chance of a thunderstorm over Wallowa
County. On Wednesday the short term models depict a bit more
instability over the eastern mountains so have maintained a slight
Chance of thunderstorms for the afternoon and evening. Winds will
pick up in the Kittitas Valley and Columbia Gorge during the
afternoon and evening and could push advisory levels. High
temperatures Wednesday will be mostly in the 70s lower elevations
with 60s in the mountains. On Thursday expect mostly dry and
slightly cooler conditions but there will be some wind impacts.
Winds in the Columbia Gorge and Kittitas Valley could reach advisory
levels. For Friday the upper low will be passing to the north. The
trajectory of the low does not lend itself to much airmass
destabilization or moistening of the airmass. Thus just expect a few
mountain showers and continued breezy/windy conditions in the
Cascade gaps. 78

.LONG TERM...Friday night through Tuesday. Previous forecast
discussions focused on the cool and unsettled weather for the first
half of the Memorial holiday weekend, but latest runs are showing
less amplitude of the upper level trough and more of a westerly flow
aloft than a cyclonic flow over WA/OR. Therefore, showers and
thunderstorms do not appear to be strong with heavy downpours like
what was observed last weekend. The threat of thunderstorms on
Friday evening and Saturday will be slight chance at best and mainly
from the Blue Mtns eastward. The first shortwave trough will exit
the region Friday night, and high pressure building behind the
system will result in gusty winds, especially through the Kittitas
Valley and the Eastern Columbia River Gorge. Another shortwave
trough will follow on Memorial Day with similar weather conditions.
The biggest concern for the holiday weekend will be the unseasonably
cool temperatures, mainly at night. There could also be light snow
accumulations above 5000 feet Friday evening. Wister


&&

.AVIATION...00Z TAFS. VFR conditions will prevail with sct-bkn
layers of stratocumulus and cumulus through Wednesday afternoon.
Winds will be less than 15 knots but NW winds 15-25 knots can be
expected at KDLS this afternoon and again after 20Z/25th.  Wister

&&

.PRELIMINARY POINT TEMPS/POPS...
PDT  50  74  48  70 /  10  10  10  10
ALW  54  75  51  71 /  10  10  10  10
PSC  54  80  52  76 /  10  10  10   0
YKM  51  77  48  72 /  10  10  10   0
HRI  53  79  50  74 /  10  10  10   0
ELN  49  72  47  67 /  10  10  10  10
RDM  42  68  37  65 /  10  10  10  10
LGD  46  68  44  65 /  20  30  20  10
GCD  44  69  42  67 /  10  20  10  10
DLS  54  73  52  69 /  10  10  10  10

&&

.PDT Watches/Warnings/Advisories...
OR...None.
WA...None.
&&

$$

78/85/85




000
FXUS66 KPDT 241727 AAA
AFDPDT

Area Forecast Discussion
National Weather Service Pendleton OR
1027 AM PDT TUE MAY 24 2016

Updated Aviation Discussion

.UPDATE...Region will be in weak flow regime between upper low over
California and upper low over sw Canada. A weak disturbance will
rotate sewd across mainly Wallowa County today and will likely
trigger a few showers. Have confined thunderstorm chances this
afternoon and early evening to Wallowa County where latest NAM model
shows 200-300 J/KG of CAPE. Examination of the forecast soundings
show that the CAPE is rather shallow so it may be difficult to get
much lightning activity today. 78

&&

.AVIATION...18Z TAFS...VFR Conditions will prevail through the
forecast period. there will be scattered stratocumulus at 4-7
thousand feet today with mid cloud above. There will be a tendency
for decreasing clouds this evening and overnight. Winds will be 5 to
15 kt except westerly at 15 to 25 kt at KDLS this afternoon and
evening. 78

&&

.PRELIMINARY POINT TEMPS/POPS...
PDT  71  48  72  44 /  10  10  10  10
ALW  73  52  73  50 /  20  10  10  10
PSC  77  53  81  50 /  10  10  10  10
YKM  76  49  80  46 /  10  10  10  10
HRI  76  51  79  49 /  10  10  10  10
ELN  72  52  74  48 /  20  10  10  10
RDM  67  38  69  33 /  10  10  10  10
LGD  66  43  69  43 /  20  20  30  20
GCD  67  41  70  40 /  10  10  20  10
DLS  75  53  72  50 /  10  10  10  10

&&

.PDT Watches/Warnings/Advisories...
OR...None.
WA...None.
&&

$$

78/78




000
FXUS66 KPDT 241458
AFDPDT

Area Forecast Discussion
National Weather Service Pendleton OR
758 AM PDT TUE MAY 24 2016

.UPDATE...Region will be in weak flow regime between upper low
over California and upper low over sw Canada. A weak disturbance
will rotate sewd across mainly Wallowa County today and will
likely trigger a few showers. Have confined thunderstorm chances
this afternoon and early evening to Wallowa County where latest
NAM model shows 200-300 J/KG of CAPE. Examination of the forecast
soundings show that the CAPE is rather shallow so it may be
difficult to get much lightning activity today. 78

&&

.PREV DISCUSSION... /issued 300 AM PDT TUE MAY 24 2016/

SHORT TERM...Today through Thursday...The forecast area will remain
under the influence of an elongated upper trough that is stretched
from northeast to southwest from southern Canada. This trough is
causing some moisture to sag southward into the northern portions of
the CWA. This is mainly currently causing clouds...but there is also
some light rain showers over eastern Washington and the Idaho
panhandle. This moisture is expected to continue sagging southward
today into the eastern/northeast mountains of the CWA by this
afternoon. This combined with surface heating will trigger mainly
afternoon showers and isolated thunderstorms. There will also be
some residual moisture over the Cascade east slopes and in central
Oregon where isolated showers may also occur. This pattern will
persist into Wednesday but the focus of the showers and afternoon
thunderstorms will shift eastward as the upper trough weakens and an
upper ridge off shore tries to build into the Pacific Northwest. The
mid level flow over the CWA will become northwest on Thursday ahead
of the next upper low pressure system that is expected to move
southeast out of BC into the CWA on Thursday. The overall trend is
for decreasing showers on Thursday, with the showers then mainly
just over Wallowa County and the northern Blue Mountains. Some
showers may also develop along the Cascade east slopes on Thursday
as the next trough moves into the region. Thunderstorms are not
expected on Thursday. It will become breezy at times during the
afternoons and evenings...especially in the eastern Columbia River
Gorge...the Kittitas Valley and the Lower Columbia Basin of Oregon.
Temperatures will slowly warm by a degree or two today and Wednesday
to near normal, but then will cool back down on Thursday to slightly
below normal. 88

LONG TERM...Thursday night through Memorial Day...a mid/upper level
low will enter Pacific Northwest thursday night and move slowly
south across forecast area on Friday. scattered showers will be
possible over the eastern mountains Friday afternoon with a slight
chance of afternoon/evening thunderstorms in Grant County, southern
Union County and Wallowa County. Friday night through Memorial Day
the mid/upper low will meander and remain essentially stationary
over the region for a chance of showers over mountains and a slight
chance of afternoon/evening thunderstorms each day.  Polan

AVIATION....12Z TAFS...VFR conditions will occur through the
forecast period. SCT high clouds around daybreak this morning. then
cloud bases will lower to mid levels by late this morning and
persist through this afternoon. then some afternoon showers possible
over and near the mountains. Winds will be 5-15 kts peaking Tuesday
afternoon.  polan

&&

.PRELIMINARY POINT TEMPS/POPS...
PDT  71  48  72  44 /  10  10  10  10
ALW  73  52  73  50 /  20  10  10  10
PSC  77  53  81  50 /  10  10  10  10
YKM  76  49  80  46 /  10  10  10  10
HRI  76  51  79  49 /  10  10  10  10
ELN  72  52  74  48 /  20  10  10  10
RDM  67  38  69  33 /  10  10  10  10
LGD  66  43  69  43 /  20  20  30  20
GCD  67  41  70  40 /  10  10  20  10
DLS  75  53  72  50 /  10  10  10  10

&&

.PDT Watches/Warnings/Advisories...
OR...None.
WA...None.
&&

$$

78/78/78




000
FXUS66 KMFR 241153
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
453 AM PDT TUE MAY 24 2016

.AVIATION...For The 24/12Z TAF Cycle...IFR cigs and vis will
continue over the coast and Umpqua Basin through mid morning then
burn off. Elsewhere, conditions will remain generally VFR with
patchy MVFR cigs/vis this morning. Showers and isolated
thunderstorms will develop this afternoon, especially from the
Cascades and Siskiyous eastward. -Wright

&&

.PREV DISCUSSION... /Issued 409 AM PDT TUE MAY 24 2016/

DISCUSSION...The GFS and ECMWF models have trended toward better
agreement into Saturday. Temperatures are expected to remain near
normal through Saturday. Today looks to be the most active day of
showers and thunderstorms of the next week...though it may have
competition for that honor from Sunday and/or Monday of the
holiday weekend if the pattern ends up closer to the GFS solution.
There is a slight chance of thunderstorms this afternoon and early
evening from the southern Oregon Cascades and Siskiyous southward
and eastward. There is good agreement between the GFS and SREF
models with the GFS indicating that the probability of
thunderstorms will be highest over far eastern Siskiyou County
while the SREF is focused a bit farther east...over Modoc County
extending into south central Oregon to around the vicinity of Bly
and Quartz Mountain on Highway 140.

The axis of the broad trough over the west will shift east of our
area Tonight with a ridge far offshore that will track closer to
the coast. A weak shortwave in a weak northerly flow aloft will
bring coastal low clouds Tonight into Wednesday and a slight
chance of light coastal showers north of Cape Blanco. The offshore
ridge may retrograde slightly on Thursday with the next upper
level trough forecast to move southeast into British Columbia.
This will send a very weak cold front into the Pacific Northwest
with a continued onshore flow...coastal low clouds and a slight
chance of light showers from Coos and Douglas County northward.
The weather on both Friday and Saturday is likely to closely
resemble the conditions from Thursday. The upper trough will
continue its relatively slow progression into Washington during
Thursday night into Friday then will likely linger into Saturday.

As mentioned above...model solutions have notable differences
between them for early next week and differences compared to their
12Z run of yesterday morning. We will maintain a broad brush
model blend at this early juncture. The models have trended toward
a less progressive though not stagnant longwave pattern. There is
a low to moderate confidence that temperatures will remain around
normal. The ECMWF solution is drier and warmer...highs would be a
few to several degrees above normal with an offshore ridge nudging
into the region and the trough axis with the threat of showers and
thunderstorms over the northern Rockies. Meanwhile...the GFS
solution suggests highs of a few degrees below normal to near
normal with another shortwave following the recent track south-
southeastward and forming a closed low before tracking across our
area with scattered showers and isolated thunderstorms Sunday
through Monday. The model solutions come back into phase next
Tuesday with the idea of a warming and drying trend.

MARINE...Updated 200 AM PDT Tue 24 May...Weak low pressure has
already moved south of the area and winds have become north. As
this low pressure moves inland today and then high pressure to the
northwest strengthens, north winds will increase and persist at
least into early next week. Winds will reach small craft advisory
levels over the waters south of Cape Blanco late Wednesday and
remain at least that strong through the remainder of the forecast
period. Winds will peak, possibly reaching gales late this week
into the weekend. Seas will be wind driven with little
contribution from swell, thus sea state will closely follow wind
conditions. Lighter north winds and sea state will occur north of
Cape Blanco. -Wright

&&

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

CA...None.

Pacific Coastal Waters...None.

$$




000
FXUS66 KMFR 241109
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
409 AM PDT TUE MAY 24 2016

.DISCUSSION...The GFS and ECMWF models have trended toward better
agreement into Saturday. Temperatures are expected to remain near
normal through Saturday. Today looks to be the most active day of
showers and thunderstorms of the next week...though it may have
competition for that honor from Sunday and/or Monday of the
holiday weekend if the pattern ends up closer to the GFS solution.
There is a slight chance of thunderstorms this afternoon and early
evening from the southern Oregon Cascades and Siskiyous southward
and eastward. There is good agreement between the GFS and SREF
models with the GFS indicating that the probability of
thunderstorms will be highest over far eastern Siskiyou County
while the SREF is focused a bit farther east...over Modoc County
extending into south central Oregon to around the vicinity of Bly
and Quartz Mountain on Highway 140.

The axis of the broad trough over the west will shift east of our
area Tonight with a ridge far offshore that will track closer to
the coast. A weak shortwave in a weak northerly flow aloft will
bring coastal low clouds Tonight into Wednesday and a slight
chance of light coastal showers north of Cape Blanco. The offshore
ridge may retrograde slightly on Thursday with the next upper
level trough forecast to move southeast into British Columbia.
This will send a very weak cold front into the Pacific Northwest
with a continued onshore flow...coastal low clouds and a slight
chance of light showers from Coos and Douglas County northward.
The weather on both Friday and Saturday is likely to closely
resemble the conditions from Thursday. The upper trough will
continue its relatively slow progression into Washington during
Thursday night into Friday then will likely linger into Saturday.

As mentioned above...model solutions have notable differences
between them for early next week and differences compared to their
12Z run of yesterday morning. We will maintain a broad brush
model blend at this early juncture. The models have trended toward
a less progressive though not stagnant longwave pattern. There is
a low to moderate confidence that temperatures will remain around
normal. The ECMWF solution is drier and warmer...highs would be a
few to several degrees above normal with an offshore ridge nudging
into the region and the trough axis with the threat of showers and
thunderstorms over the northern Rockies. Meanwhile...the GFS
solution suggests highs of a few degrees below normal to near
normal with another shortwave following the recent track south-
southeastward and forming a closed low before tracking across our
area with scattered showers and isolated thunderstorms Sunday
through Monday. The model solutions come back into phase next
Tuesday with the idea of a warming and drying trend.

&&

.AVIATION...For The 24/06Z TAF Cycle...Along the coast, MVFR cigs
are expected to become widespread overnight through early Tuesday
morning with conditions gradually lifting to VFR in the late
morning. Inland, VFR cigs are expected through Tuesday except for
areas of MVFR cigs in the Umpqua Valley developing late tonight
and continuing Tuesday morning. Also areas of higher terrain will
be obscured tonight and Tuesday morning. In the afternoon,
isolated afternoon and evening thunderstorms are expected from the
Cascades east and Siskiyous south on Tuesday. -CC

&&

.MARINE...Updated 200 AM PDT Tue 24 May...Weak low pressure has
already moved south of the area and winds have become north. As this
low pressure moves inland today and then high pressure to the
northwest strengthens, north winds will increase and persist at
least into early next week. Winds will reach small craft advisory
levels over the waters south of Cape Blanco late Wednesday and
remain at least that strong through the remainder of the forecast
period. Winds will peak, possibly reaching gales late this week into
the weekend. Seas will be wind driven with little contribution from
swell, thus sea state will closely follow wind conditions. Lighter
north winds and sea state will occur north of Cape Blanco. -Wright

&&

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

CA...None.

Pacific Coastal Waters...None.

$$

DW/TRW/CZS



  [top]

000
FXUS66 KPQR 241027
AFDPQR

Area Forecast Discussion
National Weather Service Portland OR
327 AM PDT Tue May 24 2016

.SYNOPSIS...A broad area of low pressure is shifting south toward
California, allowing higher pressure to briefly build into the Pac NW
today for drier weather and near normal temperatures. However moist
onshore flow will continue Wednesday and Thursday, along with a deep
marine layer. This will probably result in some night and morning
drizzle or light rain in areas, transitioning to isolated showers
each afternoon. Another low pressure system is expected to drop down
the coast from Alaska later in the week, bringing showers and cooler
temperatures to the region for Memorial Day weekend.

&&

.SHORT TERM...(Today through Thursday)...Water vapor satellite
imagery continues to show a broad and fairly disorganized upper low
dominating much of the Western US and SW Canada. Several individual
circulations are swirling around within the broader upper low, but it
appears per latest guidance that the upper low is in the midst of
reconfiguring into one upper low near the CA coast. Meanwhile,
another somewhat-related upper low retrograding slowly southwestward
into Montana, but appears likely to stay there and unlikely to have
much of an impact on our weather in SW WA/NW OR. This will leave our
forecast area somewhat in between disturbances, while a shortwave
ridge of high pressure noses into WA/OR for milder and less showery
weather than the last few days.

While the synoptic-scale pattern looks rather dry and mild, models do
suggest onshore flow will continue. 11-3.9 um satellite fog product
appears to show enough mixing over the coastal waters to keep the
marine inversion weak, but this will change with warm advection
aloft. 00z/06z NAM and GFS soundings and cross-sections suggest this
will allow a deep marine layer to develop below the inversion by late
tonight, persisting through Thursday. With a deep and well-saturated
marine layer and onshore flow, some drizzle or light rain cannot be
ruled out each morning. 00z GFS also shows signs of a very weak
shortwave and warm front approaching the Pac NW coast Wed morning,
which could also enhance chances for -DZ/-RA.

With a poorly defined pattern the next few days, confidence will be a
little lower than usual with the overall forecast. However, given the
potential for a deep marine layer and onshore flow tonight through
Thursday the most likely scenario appears to be this: Thick morning
stratus will likely mix into SCT-BKN stratocumulus and isolated or
scattered showers each afternoon Wed/Thu, probably favoring the
higher terrain. It will be tough to get much in the way of shower
activity each afternoon with a strong capping inversion near 800-750
mb, but a few shallow showers cannot be ruled out. Unless cloud cover
ends up being considerably less than expected, high temps will likely
be stuck a few degrees below late May norms each day.Weagle

.LONG TERM...(Thursday night through Monday)...At first glance, the
extended forecast period appears to be cool and showery, much like
the past few days. Low pressure moving across Alaska today is
forecast by most models to drop down the west coast of Canada toward
the Pac NW Thu/Fri. Subtle differences emerge between models
regarding the placement of this system, for which 100-200 miles
either to the west or the east could have a significant impact on our
sensible weather. For example, the 00z GEM is further inland,
dropping the low into the Idaho Panhandle Fri night/Sat. This would
result in a considerably drier and milder Memorial Day weekend for
our forecast area due to northerly flow aloft and faster height rises
over the weekend. This solution was somewhat echoed by the 12z GFS,
which advertised a sharp warmup toward the tail end of the holiday
weekend. However the 00z GFS and, to some extent, the 00z ECMWF drop
the Alaskan low a little further south and west... resulting in a
cool and showery weekend under another stubborn cutoff low. Will take
the middle road for now, with generally slight chance or low-end
chance PoPs...and baby steps toward near-normal temps and drier
weather toward the end of the upcoming holiday weekend.  Weagle

&&


.AVIATION...VFR conditions currently prevailing across the
region, with cigs around 5 to 8 kft. But there are spots of
MVFR developing. Models show the onshore flow weakening early in
the morning and with some breaks in cloud cover suspect should see
an increase in MVFR cigs this morning but not become widespread.
Guidance indicates any MVFR cigs should be done by 16Z-18Z.
Cascades should see gradual improvement this afternoon with
decreasing obscuration then likely becoming obscured late tonight
into Wed.

PDX AND APPROACHES...Expect mainly VFR conditions to prevail
through Tue evening. There is a chance that cigs will lower to
around 2500 ft between 12Z and 18Z Tue, but not high enough of a
chance to include in the 12Z TAF package.  /mh

&&

.MARINE...Fairly stable pattern setting up for the remainder of
the week with high pressure centered over the northeast Pacific.
This will bring northwesterly winds across the waters through the
week. Winds should generally remain below 20 kt but gusts to 25 kt
are possible in the afternoon and evenings over the waters west of
20 nm. This persistent pattern of northwesterly winds will bring a
fresh swell into the waters from the north-northwest, which could
bring hazardously steep seas to the outer waters beyond 10 nm
Wednesday afternoon and evening. Seas will build to around 8 ft
with dominant wave periods dropping to around 8 seconds by
Wednesday evening. Outer waters beyond 10 nm from the Coast will
probably see steep seas around 7 to 8 ft with wave periods around
8 seconds through Friday, though there is a chance that seas will
be less steep around 6 ft during morning hours when winds will be
weaker. Over the weekend, an upper-level low may disrupt the
northerly wind pattern to our north, which could allow seas to
become less steep. Right now, though, much uncertainty exists with
the track of this upper low system. /mh

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...None.
WA...None.
PZ...None.

&&

$$

Interact with us via social media:
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This discussion is for Northwest Oregon and Southwest Washington
from the Cascade crest to 60 nautical miles offshore. The area is
commonly referred to as the forecast area.




000
FXUS66 KPDT 241000
AFDPDT

Area Forecast Discussion
National Weather Service Pendleton OR
300 AM PDT TUE MAY 24 2016

.SHORT TERM...Today through Thursday...The forecast area will remain
under the influence of an elongated upper trough that is stretched
from northeast to southwest from southern Canada. This trough is
causing some moisture to sag southward into the northern portions of
the CWA. This is mainly currently causing clouds...but there is also
some light rain showers over eastern Washington and the Idaho
panhandle. This moisture is expected to continue sagging southward
today into the eastern/northeast mountains of the CWA by this
afternoon. This combined with surface heating will trigger mainly
afternoon showers and isolated thunderstorms. There will also be
some residual moisture over the Cascade east slopes and in central
Oregon where isolated showers may also occur. This pattern will
persist into Wednesday but the focus of the showers and afternoon
thunderstorms will shift eastward as the upper trough weakens and an
upper ridge off shore tries to build into the Pacific Northwest. The
mid level flow over the CWA will become northwest on Thursday ahead
of the next upper low pressure system that is expected to move
southeast out of BC into the CWA on Thursday. The overall trend is
for decreasing showers on Thursday, with the showers then mainly
just over Wallowa County and the northern Blue Mountains. Some
showers may also develop along the Cascade east slopes on Thursday
as the next trough moves into the region. Thunderstorms are not
expected on Thursday. It will become breezy at times during the
afternoons and evenings...especially in the eastern Columbia River
Gorge...the Kittitas Valley and the Lower Columbia Basin of Oregon.
Temperatures will slowly warm by a degree or two today and Wednesday
to near normal, but then will cool back down on Thursday to slightly
below normal. 88

.LONG TERM...Thursday night through Memorial Day...a mid/upper level
low will enter Pacific Northwest thursday night and move slowly
south across forecast area on Friday. scattered showers will be
possible over the eastern mountains Friday afternoon with a slight
chance of afternoon/evening thunderstorms in Grant County, southern
Union County and Wallowa County. Friday night through Memorial Day
the mid/upper low will meander and remain essentially stationary
over the region for a chance of showers over mountains and a slight
chance of afternoon/evening thunderstorms each day.  Polan

&&

.AVIATION....12Z TAFS...VFR conditions will occur through the
forecast period. SCT high clouds around daybreak this morning. then
cloud bases will lower to mid levels by late this morning and
persist through this afternoon. then some afternoon showers possible
over and near the mountains. Winds will be 5-15 kts peaking Tuesday
afternoon.  polan

&&

.PRELIMINARY POINT TEMPS/POPS...
PDT  71  48  72  44 /  10  10  10  10
ALW  73  52  73  50 /  10  10  10  10
PSC  77  53  81  50 /  10  10  10  10
YKM  76  49  80  46 /  10  10  10  10
HRI  76  51  79  49 /  10  10  10  10
ELN  72  52  74  48 /  20  10  10  10
RDM  67  38  69  33 /  10  10  10  10
LGD  66  43  69  43 /  20  30  30  20
GCD  67  41  70  40 /  20  20  20  10
DLS  75  53  72  50 /  10  10  10  10

&&

.PDT Watches/Warnings/Advisories...
OR...None.
WA...None.
&&

$$

88/99/99




000
FXUS65 KBOI 240921
AFDBOI

Area Forecast Discussion
National Weather Service Boise ID
321 AM MDT TUE MAY 24 2016

.SHORT TERM...Today through Wednesday...Mean upper level trough
will continue to impact the region through Wednesday. Disturbances
moving through the flow, as well as diurnal heating, will
encourage scattered showers each afternoon (mainly over the higher
terrain), tapering off each evening. Instability parameters will
be better today and Wednesday, therefore have included a slight
chance of thunderstorms in the afternoon and evening forecast.
Winds will be light through the period, except gusty near
thunderstorms. Temperatures will be a few degrees below normal.

.LONG TERM...Wednesday night through Monday...The extended starts
with a brief break in the unsettled weather as the upper trough
that is over the region in the short term kicks east only to be
replaced by another upper low Friday. This next upper low will
last through the weekend and into early next week. Snow levels
are expected to lower to around 5500 feet across the north to
6500 feet along the Nevada border by Saturday morning.
Temperatures will remain below normal through the extended with
afternoon and early evening showers and thunderstorms mainly over
the higher terrain.

&&

.AVIATION...VFR. Scattered showers and isolated thunderstorms over
the higher terrain this afternoon with patchy mountain obscuration.
Activity tapering after sunset. Surface winds Northwest 5-10kt
with gusts up to 20kt near showers during the afternoon,
diminishing after sunset. Winds aloft at 10,000ft MSL North to
Northwest 10 to 15 kts.

&&

.BOI WATCHES/WARNINGS/ADVISORIES...
ID...None.
OR...None.

&&

$$

www.weather.gov/Boise
www.facebook.com/NWSBoise
www.twitter.com/NWSBoise

SHORT TERM...AB
LONG TERM....CR
AVIATION.....CR




000
FXUS66 KPDT 240524
AFDPDT

Area Forecast Discussion
National Weather Service Pendleton OR
1025 PM PDT MON MAY 23 2016

updated aviation discussion

.SHORT TERM...Tonight and Tuesday...Overall the Pacific Northwest
continues under a trough pattern with multiple shortwaves moving
trough the trough. Strongest one is over southern Canada which is
sending some moisture back into eastern Washington but just clouds
over the forecast area this evening. Otherwise there continues to be
a few lingering evening instability showers over central Oregon that
are coming to an end now that the heating of the day is over. The
other shortwaves are south and west of the forecast area which will
help drive the trough deeper into California overnight and Tuesday.
With the trough continuing to linger over the region Tuesday we
will again see some afternoon and evening instability showers mainly
over the mountains. Some of these could become thunderstorms over
far eastern and southern Oregon.

.AVIATION...06Z TAFS...VFR conditions will prevail through the
forecast period. SCT mid clouds with cirrus above can be
expected overnight then some possible afternoon showers over and
near the moutnains. Winds will be 5-15KT peaking Tuesday afternoon.

&&

.PREV DISCUSSION... /issued 232 PM PDT MON MAY 23 2016/

SHORT TERM...Tonight through Thursday...An upper level trough will
linger over the western U.S. tonight through Wednesday. Weak
disturbances will rotate through this trough causing varying chances
of showers. The best chances of showers will occur in the afternoons
and evenings. Instability during the afternoon into the early
evening Tuesday and Wednesday could be strong enough over for a few
thunderstorms. Thunderstorms will mainly occur over our eastern
mountain zones. Winds will be locally breezy through Wednesday,
especially through the Kittitas Valley and the Columbia River Gorge.
Another upper low will begin to move south through British Columbia
Thursday. This low will produce an increase in the west flow across
the region. As a result, will see winds across the area increase
with the winds in the Kittitas Valley and the Columbia Gorge
potentially reaching advisory speeds of 30 to 35 mph sustained.
Expect mainly dry conditions Thursday, though a few showers may
occur near the Cascade crest, and over the Blue mountains and
Wallowa county. Temperatures will run near seasonal through this
period. 90

LONG TERM...Thursday Night through Monday...Models in good
agreement in overall longwave pattern over the region. However...
there are temporal and spatial disagreements relating to the next
upper level system dropping down from Canada on Friday. GFS evolves
it into a cutoff low while the ECMWF is more progressive. At this
time...will lean more towards the GFS solution as the overall
pattern lends itself to producing cutoff lows. Overall...the
forecast area will be dominated by a troughy weather pattern through
much of the extended. As a result of the expected pattern...
unsettled weather will continue with showers forming in the
afternoon and dissipating overnight...especially over the northeast
Oregon. Daytime highs will be near to slightly above normal through
the period. Earle



&&

.PRELIMINARY POINT TEMPS/POPS...
PDT  47  71  49  74 /  10  10  10  10
ALW  51  73  53  74 /  10  10  10  10
PSC  51  77  54  81 /  10  10  10  10
YKM  46  76  50  80 /  10  10  10  10
HRI  49  76  52  79 /  10  10  10  10
ELN  48  72  53  74 /  10  20  10  10
RDM  36  67  39  69 /  20  10  10  10
LGD  41  66  44  69 /  10  20  30  30
GCD  40  67  42  70 /  20  20  20  20
DLS  52  75  54  72 /  10  10  10  10

&&

.PDT Watches/Warnings/Advisories...
OR...None.
WA...None.
&&

$$

91/91/91




000
FXUS66 KMFR 240328
AFDMFR

Area Forecast Discussion
National Weather Service Medford OR
828 PM PDT MON MAY 23 2016

.SHORT TERM...The forecast remains on track with showers expected
for the next couple days over inland areas. A broad upper trough
is over the region with a shortwave trough moving southward along
the Oregon and Northern California coast tonight. Scattered to
numerous showers are present over most inland areas this evening,
except for along the coast and Umpqua Valley, which are mainly
dry. Showers are forecast to decrease in coverage tonight and
become mainly isolated. On Tuesday the upper trough will deepen
southward and wrap around moisture will move into the area. This
pattern will bring showers with a slight chance to  chance of
thunderstorms Tuesday afternoon and evening. Models continue to
show the best chance for thunderstorms from the Cascades eastward
and over Northern California.


&&

.AVIATION...For The 24/0Z TAF Cycle...Over the coastal waters
and near the coast...areas of VFR cigs will continue into
early this evening, however brief MVFR cigs cannot be ruled out
between 0-2z. MVFR cigs are expected to be the predominate
condition after 2z into most of Tuesday morning. Elsewhere...VFR cigs
are expected for the next 24 hours. However some higher terrain
could end up being obscured near showers. There will
be isolated afternoon and evening thunderstorms from the Cascades
east and Siskiyous south on Tuesday. -Petrucelli


&&

.MARINE...Updated 230 PM PDT Mon 23 May...Weak low pressure over the
coastal waters will persist into Tuesday...then weaken as offshore
high pressure builds into the area. The models are in pretty good
agreement after Tuesday showing a thermal trough developing along
the Oregon coast Wednesday night and strengthen Thursday into
Friday.  This will bring a return of moderate north winds and choppy
seas to the area. It`s possible winds over parts of the southern
waters could reach gale force late Friday afternoon and persist into
next weekend. This will need to be monitored closely. -Petrucelli


&&

.PREV DISCUSSION... /Issued 234 PM PDT MON MAY 23 2016/

Short term...Cumulus clouds are filling the sky this
afternoon...and showers are now being observed on radar. Some of
these showers could develop into thunderstorms...mainly from the
Cascades eastward and over northern California. The HRRR shows
shower activity peaking late this afternoon and then diminishing
quickly after sunset.

Tomorrow will be similar to today in that broad troughing will still
support showers in the afternoon...and a slight chance to chance
of thunderstorms. Instability is greater tomorrow per the GFS, and
with shortwave activity moving from north to south near Modoc
County, I have increased the thunderstorm probabilities there.
This is supported by SPC lightning probabilities as well.
Temperatures will warm some tomorrow, likely due to more sunshine,
and also due to the overall air mass warming at 850mb.

Weak upper troughs will bring the chance for light rain to the coast
and Umpqua Basin Wednesday and Thursday, with the rest of the
forecast area dry. The exception will be parts of the East Side
Wednesday, where lingering troughing will maintain the chance for
showers there.

Overnight low temperatures will be cool this week, but we don`t see
any freeze concerns for agricultural interests.  The coldest
overnight lows will likely be Friday into this weekend with a
greater potential for clear skies.

Long term...Friday through Monday...Another low pressure is
forecast to drop into British Columbia on Friday. Both the GFS and
the ECMWF are very close on timing and confidence is high on the
position of this trough. The models output a few showers from NW
Oregon down to the Umpqua Valley with little or no showers. The
GFS is slower t moving this low out than the EC and thus generates
more instability east of the Cascades due to cold air aloft. On
Sunday, northerly flow strengthens and the atmosphere turns more
stable west of the Cascades. There could still be isolated showers
east of the Cascades. While the GFS tries to build a ridge from
the eastern Pacific into BC/Washington, there is still some
instability across our forecast area for mainly mountain showers.
Confidence is not very high on temperatures as the EC solution
shows a mostly NW flow into our area with a short wave trough
coming into NW Washington.

&&

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

CA...None.

Pacific Coastal Waters...None.

$$

CC




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