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000
FXUS66 KSTO 190425
AFDSTO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
925 PM PDT Thu Sep 18 2014

.Synopsis...
Dry and warmer weather through the weekend except a slight chance of
afternoon thunderstorms over the Sierra Nevada. Cooling next week
with some precipitation possible around midweek.


&&

.Discussion...
Clearing skies this evening as offshore closed upper low is drifting
southward and modeled to be off the SoCal coast by Friday afternoon.
Upstream ridging will build over the West Coast through the weekend
bringing warmer temperatures. Highs expected to range from near to
upwards of 10 degrees above normal with upper 80s to upper 90s in
the Central Valley. Relatively weak delta breeze, currently, is
expected to gradually trend upwards through the weekend. Models
showing some moisture and instability over the Sierra Nevada to
support a slight chance of afternoon showers/thunderstorms. Surface
high pressure builds through the PacNW into the Great Basin as
thermal troughing deepens along the coast. This will increase
offshore flow late Friday into Saturday and bring increased
potential for smoke from the King fire to spread westward into the
Central Valley.

PCH

.Extended Discussion (Monday through Thursday)

Dry weather continues Monday into Tuesday as high pressure remains
over the Western US. This will bring a few days of above normal
temperatures.

The pattern changes again during the middle of next week as
another upper trough approaches again. Current progs suggest that
next week`s system may be a bit deeper and could tap into a decent
moisture plume. Feeling confident about the pattern change, but
less so with possible showery coverage and precipitation amounts.
With this forecast package, we`ve bumped up precipitation wording,
keeping the best chances generally north of Interstate 80. At the
very least, this pattern change will bring about some considerable
cooling for the middle of next week.

Dang


&&

.Aviation...
Ofshr upr low movs off SoCal cst Fri as upr rdg blds ovr NorCal. VFR
conds nxt 24 hrs exc lcl MVFR/IFR conds in FU vcnty of King fire.


&&

.STO Watches/Warnings/Advisories...
None.
&&

$$










000
FXUS66 KSTO 190425
AFDSTO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
925 PM PDT Thu Sep 18 2014

.Synopsis...
Dry and warmer weather through the weekend except a slight chance of
afternoon thunderstorms over the Sierra Nevada. Cooling next week
with some precipitation possible around midweek.


&&

.Discussion...
Clearing skies this evening as offshore closed upper low is drifting
southward and modeled to be off the SoCal coast by Friday afternoon.
Upstream ridging will build over the West Coast through the weekend
bringing warmer temperatures. Highs expected to range from near to
upwards of 10 degrees above normal with upper 80s to upper 90s in
the Central Valley. Relatively weak delta breeze, currently, is
expected to gradually trend upwards through the weekend. Models
showing some moisture and instability over the Sierra Nevada to
support a slight chance of afternoon showers/thunderstorms. Surface
high pressure builds through the PacNW into the Great Basin as
thermal troughing deepens along the coast. This will increase
offshore flow late Friday into Saturday and bring increased
potential for smoke from the King fire to spread westward into the
Central Valley.

PCH

.Extended Discussion (Monday through Thursday)

Dry weather continues Monday into Tuesday as high pressure remains
over the Western US. This will bring a few days of above normal
temperatures.

The pattern changes again during the middle of next week as
another upper trough approaches again. Current progs suggest that
next week`s system may be a bit deeper and could tap into a decent
moisture plume. Feeling confident about the pattern change, but
less so with possible showery coverage and precipitation amounts.
With this forecast package, we`ve bumped up precipitation wording,
keeping the best chances generally north of Interstate 80. At the
very least, this pattern change will bring about some considerable
cooling for the middle of next week.

Dang


&&

.Aviation...
Ofshr upr low movs off SoCal cst Fri as upr rdg blds ovr NorCal. VFR
conds nxt 24 hrs exc lcl MVFR/IFR conds in FU vcnty of King fire.


&&

.STO Watches/Warnings/Advisories...
None.
&&

$$











000
FXUS66 KSTO 182231
AFDSTO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
331 PM PDT Thu Sep 18 2014

.Synopsis...
Temperatures cooling to below normal today with a chance of
showers and thunderstorms. Warmer and drier weather returns for
the weekend.

&&

.Discussion...
An upper trough will shift further onshore this afternoon and bring
light showers to portions of interior northern California. The
base of the 571mb upper trough is directly along the northern
coast of California extending from the North Bay to Eureka. The
upper low is forecast to dig southeast towards Southern California
and transition into a closed low before ejecting into the Great
Basin via the westerlies late in the weekend.

Overnight precipitation brought light accumulations to portions
of the coastal range, extreme northern Sierra, and Shasta county.
Minor additional accumulations occured earlier today over the
coastal range as showers pushed further inland. Latest composite
radar imagery continues to show light returns over the Coastal
range this afternoon, however the event appears to be winding
down. A report of a funnel cloud near Chico came in late this
morning when shear profiles supported such an event, so most
likely a valid sighting.

The King Fire experienced aggressive growth on the
northern perimeter yesterday and expanded by over 50000 acres due
to low humidities and moderate winds. Conditions today will be
slightly better with higher humidities and lower winds, however
only minimal amounts of precipitation, if any, are expected to
fall over the fire for the rest of the day. Smoke from this fire
will continue to impact nearby communities and could sink into the
valley (mostly along the extreme eastern edge of the Southern
Sacramento and San Joaquin valleys) after Friday when the winds
shift following the trough. Additional resources are in the
process of being added to fight the fire.

Temperatures rebound closer to normal values for tomorrow and into
the weekend after todays dip.

DRP


.Extended Discussion (Monday through Thursday)

Dry weather continues Monday into Tuesday as high pressure remains
over the Western US. This will bring a few days of above normal
temperatures.

The pattern changes again during the middle of next week as
another upper trough approaches again. Current progs suggest that
next week`s system may be a bit deeper and could tap into a decent
moisture plume. Feeling confident about the pattern change, but
less so with possible showery coverage and precipitation amounts.
With this forecast package, we`ve bumped up precipitation wording,
keeping the best chances generally north of Interstate 80. At the
very least, this pattern change will bring about some considerable
cooling for the middle of next week.

Dang


&&

.Aviation...

Mainly VFR conditions the next 24 hours with isolated SHRA along
the Coastal Ranges. These showers will be dissipating this
evening. South to southwest winds 10-15 kt across the Valley will
become light this evening, then become northerly late tonight into
Friday. Local SW wind gusts to 40 kts will continue over Sierra
ridges through this afternoon.

Dang


&&

.STO Watches/Warnings/Advisories...
None.
&&

$$









000
FXUS66 KSTO 181844 CCA
AFDSTO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
938 AM PDT Thu Sep 18 2014

.Synopsis...
Temperatures cooling to below normal today with a chance of
showers and thunderstorms. Warmer and drier weather returns for
the weekend.

&&

.Discussion...
An upper trough will shift further onshore today and spread cooler
temperatures and light showers/thunderstorms throughout much of
interior northern California. The base of the 571dm upper trough
is directly along the northern coast of California extending from
the North Bay to Eureka. The upper low is forecast to dig southeast
towards Southern California and transition into a closed low before
ejecting into the Great Basin via the westerlies late in the
weekend.

Overnight precipitation brought light accumulations to portions
of the coastal range, extreme northern Sierra, and Shasta county.
Correlation coefficient radar imagery indicates light showers
moving in ahead of the base of the trough. Additional
accumulations are expected this afternoon as the showers push
further inland. Short-term model data suggests considerable
instability, shear, and lift for this time of the year, so
isolated thunderstorms throughout the area are possible beginning
mid-day and lasting into the late afternoon. The NAM is the most
aggressive, with widespread convective potential throughout the
region. The WRF is more conservative, and the more likely scenario,
indicating enhanced potential over the higher terrain of Shasta
county and the Sierra Nevada.

The King Fire experienced aggressive growth on the northern
perimeter yesterday and expanded by over 50000 acres due to low
humidities and moderate winds. Conditions today will be slightly
better with higher humidities and lower winds, however only
minimal amounts of precipitation, if any, are expected to fall
over the fire. The heat from the fire should cause lighter
precipitation to evaporate before it even reaches to ground, but
this process does increase the local relative humidity. The main
threat today is additional starts from any isolated lightning. Smoke
from this fire will continue to impact nearby communities and
could sink into the valley after Friday when the winds shift
following the trough. DRP

Previous Discussion... Upper level trough will be moving
inland today. Radar imagery overnight has shown shower activity in
Shasta County near I-5 and westward to the NorCal coastline. At 4
am, most of the showers were west and north of our CWA due to a
dry slot moving into our region. On water vapor imagery, moisture
offshore is digging slightly southward and should impact our
region later today. Once the trough moves inland, models are
indicating increased instability over NorCal which will result in
a slight chance to chance of showers and thunderstorms across much
of our CWA. In the morning and early afternoon hours, instability
looks best over the Coastal and Sierra mountains north of I-80
including the adjacent foothills into the valley. The WRF model
echoes this by showing shower activity across Lake County
northward along the coastal range...across Tehama & Shasta
counties...and from Chico & Oroville eastward into the Sierra. By
late afternoon into early evening, instability continues along the
Sierra and spreads southward of I-80, however, the WRF shows
showers diminishing in areal coverage. So have stuck with the
forecast of having isolated showers/t-storms south of I-80 and
scattered showers/t-storms north of I-80 today with showers
limited to higher terrain for tonight.

Daytime highs today will be cooler than normal. Our CWA will
generally range 5 to 15 degrees below average. This will translate to
valley highs in the upper 70s to low 80s with higher terrain
warming into the 60s and 70s. However, on Friday into the weekend,
temperatures will warm again to normal and above normal.

The King Fire is still likely to cause smoky conditions as it
doesn`t look like there is a high probability for heavy rain to
dampen this wildfire. With southwest to westerly winds this
morning, smoke will spread towards the Tahoe region again. On
Friday, winds should be northerly in the morning which will spread
smoke southward. (See Previous Discussion below)
&&

.Extended Discussion (Monday through Thursday)

For Monday into Tuesday, weak ridging develops over our CWA which
will maintain dry weather with daytime highs near to above normal.
The extended models (ECMWF, GFS, and GEM) are in good agreement
that another trough will dig southward and swing into NorCal
Wednesday and Thursday. Have increased pops and lowered temperatures to
account for this cooler, wetter pattern.


&&

.Aviation...

Mainly VFR conditions next 24 hours with showers possible over
Shasta County and Coastal Range and spreading SE over the
northern/Central Sac valley, northeast foothills, and Sierra by
this morning. Local SWerly sfc gusts up to 30 to 45 kts over
higher mountain peaks today, decreasing by this evening.

&&

.STO Watches/Warnings/Advisories...
None.
&&

$$











000
FXUS66 KSTO 181844 CCA
AFDSTO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
938 AM PDT Thu Sep 18 2014

.Synopsis...
Temperatures cooling to below normal today with a chance of
showers and thunderstorms. Warmer and drier weather returns for
the weekend.

&&

.Discussion...
An upper trough will shift further onshore today and spread cooler
temperatures and light showers/thunderstorms throughout much of
interior northern California. The base of the 571dm upper trough
is directly along the northern coast of California extending from
the North Bay to Eureka. The upper low is forecast to dig southeast
towards Southern California and transition into a closed low before
ejecting into the Great Basin via the westerlies late in the
weekend.

Overnight precipitation brought light accumulations to portions
of the coastal range, extreme northern Sierra, and Shasta county.
Correlation coefficient radar imagery indicates light showers
moving in ahead of the base of the trough. Additional
accumulations are expected this afternoon as the showers push
further inland. Short-term model data suggests considerable
instability, shear, and lift for this time of the year, so
isolated thunderstorms throughout the area are possible beginning
mid-day and lasting into the late afternoon. The NAM is the most
aggressive, with widespread convective potential throughout the
region. The WRF is more conservative, and the more likely scenario,
indicating enhanced potential over the higher terrain of Shasta
county and the Sierra Nevada.

The King Fire experienced aggressive growth on the northern
perimeter yesterday and expanded by over 50000 acres due to low
humidities and moderate winds. Conditions today will be slightly
better with higher humidities and lower winds, however only
minimal amounts of precipitation, if any, are expected to fall
over the fire. The heat from the fire should cause lighter
precipitation to evaporate before it even reaches to ground, but
this process does increase the local relative humidity. The main
threat today is additional starts from any isolated lightning. Smoke
from this fire will continue to impact nearby communities and
could sink into the valley after Friday when the winds shift
following the trough. DRP

Previous Discussion... Upper level trough will be moving
inland today. Radar imagery overnight has shown shower activity in
Shasta County near I-5 and westward to the NorCal coastline. At 4
am, most of the showers were west and north of our CWA due to a
dry slot moving into our region. On water vapor imagery, moisture
offshore is digging slightly southward and should impact our
region later today. Once the trough moves inland, models are
indicating increased instability over NorCal which will result in
a slight chance to chance of showers and thunderstorms across much
of our CWA. In the morning and early afternoon hours, instability
looks best over the Coastal and Sierra mountains north of I-80
including the adjacent foothills into the valley. The WRF model
echoes this by showing shower activity across Lake County
northward along the coastal range...across Tehama & Shasta
counties...and from Chico & Oroville eastward into the Sierra. By
late afternoon into early evening, instability continues along the
Sierra and spreads southward of I-80, however, the WRF shows
showers diminishing in areal coverage. So have stuck with the
forecast of having isolated showers/t-storms south of I-80 and
scattered showers/t-storms north of I-80 today with showers
limited to higher terrain for tonight.

Daytime highs today will be cooler than normal. Our CWA will
generally range 5 to 15 degrees below average. This will translate to
valley highs in the upper 70s to low 80s with higher terrain
warming into the 60s and 70s. However, on Friday into the weekend,
temperatures will warm again to normal and above normal.

The King Fire is still likely to cause smoky conditions as it
doesn`t look like there is a high probability for heavy rain to
dampen this wildfire. With southwest to westerly winds this
morning, smoke will spread towards the Tahoe region again. On
Friday, winds should be northerly in the morning which will spread
smoke southward. (See Previous Discussion below)
&&

.Extended Discussion (Monday through Thursday)

For Monday into Tuesday, weak ridging develops over our CWA which
will maintain dry weather with daytime highs near to above normal.
The extended models (ECMWF, GFS, and GEM) are in good agreement
that another trough will dig southward and swing into NorCal
Wednesday and Thursday. Have increased pops and lowered temperatures to
account for this cooler, wetter pattern.


&&

.Aviation...

Mainly VFR conditions next 24 hours with showers possible over
Shasta County and Coastal Range and spreading SE over the
northern/Central Sac valley, northeast foothills, and Sierra by
this morning. Local SWerly sfc gusts up to 30 to 45 kts over
higher mountain peaks today, decreasing by this evening.

&&

.STO Watches/Warnings/Advisories...
None.
&&

$$










000
FXUS66 KSTO 181638
AFDSTO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
938 AM PDT Thu Sep 18 2014

.Synopsis...
Temperatures cooling to below normal today with a chance of
showers and thunderstorms. Warmer and drier weather returns for
the weekend.

&&

.Discussion...
An upper trough will shift further onshore today and spread cooler
temperatures and light showers/thunderstorms throughout much of
interior northern California. The base of the 571mb upper trough
is directly along the northern coast of California extending from
the North Bay to Eureka. The upper low is forecast to dig southeast
towards Southern California and transition into a closed low before
ejecting into the Great Basin via the westerlies late in the
weekend.

Overnight precipitation brought light accumulations to portions
of the coastal range, extreme northern Sierra, and Shasta county.
Correlation coefficient radar imagery indicates light showers
moving in ahead of the base of the trough. Additional
accumulations are expected this afternoon as the showers push
further inland. Short-term model data suggests considerable
instability, shear, and lift for this time of the year, so
isolated thunderstorms throughout the area are possible beginning
mid-day and lasting into the late afternoon. The NAM is the most
aggressive, with widespread convective potential throughout the
region. The WRF is more conservative, and the more likely scenario,
indicating enhanced potential over the higher terrain of Shasta
county and the Sierra Nevada.

The King Fire experienced aggressive growth on the northern
perimeter yesterday and expanded by over 50000 acres due to low
humidities and moderate winds. Conditions today will be slightly
better with higher humidities and lower winds, however only
minimal amounts of precipitation, if any, are expected to fall
over the fire. The heat from the fire should cause lighter
precipitation to evaporate before it even reaches to ground, but
this process does increase the local relative humidity. The main
threat today is additional starts from any isolated lightning. Smoke
from this fire will continue to impact nearby communities and
could sink into the valley after Friday when the winds shift
following the trough. DRP

Previous Discussion... Upper level trough will be moving
inland today. Radar imagery overnight has shown shower activity in
Shasta County near I-5 and westward to the NorCal coastline. At 4
am, most of the showers were west and north of our CWA due to a
dry slot moving into our region. On water vapor imagery, moisture
offshore is digging slightly southward and should impact our
region later today. Once the trough moves inland, models are
indicating increased instability over NorCal which will result in
a slight chance to chance of showers and thunderstorms across much
of our CWA. In the morning and early afternoon hours, instability
looks best over the Coastal and Sierra mountains north of I-80
including the adjacent foothills into the valley. The WRF model
echoes this by showing shower activity across Lake County
northward along the coastal range...across Tehama & Shasta
counties...and from Chico & Oroville eastward into the Sierra. By
late afternoon into early evening, instability continues along the
Sierra and spreads southward of I-80, however, the WRF shows
showers diminishing in areal coverage. So have stuck with the
forecast of having isolated showers/t-storms south of I-80 and
scattered showers/t-storms north of I-80 today with showers
limited to higher terrain for tonight.

Daytime highs today will be cooler than normal. Our CWA will
generally range 5 to 15 degrees below average. This will translate to
valley highs in the upper 70s to low 80s with higher terrain
warming into the 60s and 70s. However, on Friday into the weekend,
temperatures will warm again to normal and above normal.

The King Fire is still likely to cause smoky conditions as it
doesn`t look like there is a high probability for heavy rain to
dampen this wildfire. With southwest to westerly winds this
morning, smoke will spread towards the Tahoe region again. On
Friday, winds should be northerly in the morning which will spread
smoke southward. (See Previous Discussion below)
&&

.Extended Discussion (Monday through Thursday)

For Monday into Tuesday, weak ridging develops over our CWA which
will maintain dry weather with daytime highs near to above normal.
The extended models (ECMWF, GFS, and GEM) are in good agreement
that another trough will dig southward and swing into NorCal
Wednesday and Thursday. Have increased pops and lowered temperatures to
account for this cooler, wetter pattern.


&&

.Aviation...

Mainly VFR conditions next 24 hours with showers possible over
Shasta County and Coastal Range and spreading SE over the
northern/Central Sac valley, northeast foothills, and Sierra by
this morning. Local SWerly sfc gusts up to 30 to 45 kts over
higher mountain peaks today, decreasing by this evening.

&&

.STO Watches/Warnings/Advisories...
None.
&&

$$








000
FXUS66 KSTO 181638
AFDSTO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
938 AM PDT Thu Sep 18 2014

.Synopsis...
Temperatures cooling to below normal today with a chance of
showers and thunderstorms. Warmer and drier weather returns for
the weekend.

&&

.Discussion...
An upper trough will shift further onshore today and spread cooler
temperatures and light showers/thunderstorms throughout much of
interior northern California. The base of the 571mb upper trough
is directly along the northern coast of California extending from
the North Bay to Eureka. The upper low is forecast to dig southeast
towards Southern California and transition into a closed low before
ejecting into the Great Basin via the westerlies late in the
weekend.

Overnight precipitation brought light accumulations to portions
of the coastal range, extreme northern Sierra, and Shasta county.
Correlation coefficient radar imagery indicates light showers
moving in ahead of the base of the trough. Additional
accumulations are expected this afternoon as the showers push
further inland. Short-term model data suggests considerable
instability, shear, and lift for this time of the year, so
isolated thunderstorms throughout the area are possible beginning
mid-day and lasting into the late afternoon. The NAM is the most
aggressive, with widespread convective potential throughout the
region. The WRF is more conservative, and the more likely scenario,
indicating enhanced potential over the higher terrain of Shasta
county and the Sierra Nevada.

The King Fire experienced aggressive growth on the northern
perimeter yesterday and expanded by over 50000 acres due to low
humidities and moderate winds. Conditions today will be slightly
better with higher humidities and lower winds, however only
minimal amounts of precipitation, if any, are expected to fall
over the fire. The heat from the fire should cause lighter
precipitation to evaporate before it even reaches to ground, but
this process does increase the local relative humidity. The main
threat today is additional starts from any isolated lightning. Smoke
from this fire will continue to impact nearby communities and
could sink into the valley after Friday when the winds shift
following the trough. DRP

Previous Discussion... Upper level trough will be moving
inland today. Radar imagery overnight has shown shower activity in
Shasta County near I-5 and westward to the NorCal coastline. At 4
am, most of the showers were west and north of our CWA due to a
dry slot moving into our region. On water vapor imagery, moisture
offshore is digging slightly southward and should impact our
region later today. Once the trough moves inland, models are
indicating increased instability over NorCal which will result in
a slight chance to chance of showers and thunderstorms across much
of our CWA. In the morning and early afternoon hours, instability
looks best over the Coastal and Sierra mountains north of I-80
including the adjacent foothills into the valley. The WRF model
echoes this by showing shower activity across Lake County
northward along the coastal range...across Tehama & Shasta
counties...and from Chico & Oroville eastward into the Sierra. By
late afternoon into early evening, instability continues along the
Sierra and spreads southward of I-80, however, the WRF shows
showers diminishing in areal coverage. So have stuck with the
forecast of having isolated showers/t-storms south of I-80 and
scattered showers/t-storms north of I-80 today with showers
limited to higher terrain for tonight.

Daytime highs today will be cooler than normal. Our CWA will
generally range 5 to 15 degrees below average. This will translate to
valley highs in the upper 70s to low 80s with higher terrain
warming into the 60s and 70s. However, on Friday into the weekend,
temperatures will warm again to normal and above normal.

The King Fire is still likely to cause smoky conditions as it
doesn`t look like there is a high probability for heavy rain to
dampen this wildfire. With southwest to westerly winds this
morning, smoke will spread towards the Tahoe region again. On
Friday, winds should be northerly in the morning which will spread
smoke southward. (See Previous Discussion below)
&&

.Extended Discussion (Monday through Thursday)

For Monday into Tuesday, weak ridging develops over our CWA which
will maintain dry weather with daytime highs near to above normal.
The extended models (ECMWF, GFS, and GEM) are in good agreement
that another trough will dig southward and swing into NorCal
Wednesday and Thursday. Have increased pops and lowered temperatures to
account for this cooler, wetter pattern.


&&

.Aviation...

Mainly VFR conditions next 24 hours with showers possible over
Shasta County and Coastal Range and spreading SE over the
northern/Central Sac valley, northeast foothills, and Sierra by
this morning. Local SWerly sfc gusts up to 30 to 45 kts over
higher mountain peaks today, decreasing by this evening.

&&

.STO Watches/Warnings/Advisories...
None.
&&

$$









000
FXUS66 KSTO 181149
AFDSTO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
449 AM PDT Thu Sep 18 2014

.Synopsis...
Temperatures cooling to below normal today with a chance of
showers and thunderstorms. Warmer and drier weather returns for
the weekend.

&&
.Discussion...
Upper level trough will be moving inland today. Radar imagery overnight
has shown shower activity in Shasta County near I-5 and westward
to the NorCal coastline. At 4 am, most of the showers were west and
north of our CWA due to a dry slot moving into our region. On
water vapor imagery, moisture offshore is digging slightly
southward and should impact our region later today. Once the
trough moves inland, models are indicating increased instability
over NorCal which will result in a slight chance to chance of
showers and thunderstorms across much of our CWA. In the morning
and early afternoon hours, instability looks best over the Coastal
and Sierra mountains north of I-80 including the adjacent
foothills into the valley. The WRF model echoes this by showing
shower activity across Lake County northward along the coastal
range...across Tehama & Shasta counties...and from Chico &
Oroville eastward into the Sierra. By late afternoon into early
evening, instability continues along the Sierra and spreads
southward of I-80, however, the WRF shows showers diminishing in
areal coverage. So have stuck with the forecast of having isolated
showers/t-storms south of I-80 and scattered showers/t-storms
north of I-80 today with showers limited to higher terrain for
tonight.

Daytime highs today will be cooler than normal. Our CWA will
generally range 5 to 15 degrees below average. This will translate to
valley highs in the upper 70s to low 80s with higher terrain
warming into the 60s and 70s. However, on Friday into the weekend,
temperatures will warm again to normal and above normal.

The King Fire is still likely to cause smoky conditions as it
doesn`t look like there is a high probability for heavy rain to
dampen this wildfire. With southwest to westerly winds this
morning, smoke will spread towards the Tahoe region again. On
Friday, winds should be northerly in the morning which will spread
smoke southward. (See Previous Discussion below)

Previous Discussion...The interesting thing for Thursday night and Friday
morning will be with the spread of the smoke from the King
Wildfire. Places in the southern motherlode that have had pretty
good air quality will have smoke spread over their area. The far
eastern sections of the Northern San Joaquin valley may also get
some smoke. The Sacramento region can also expect and increase in
smoke during that time period as well.

Saturday the low will shift over Southern California. Some
afternoon showers and isolated thunderstorms near the crest will
continue for areas south of Tahoe. The flow pattern will shift
again to onshore, upvalley and upslope. Temperatures will remain
near seasonal normals.

&&

.Extended Discussion (Monday through Thursday)

For Monday into Tuesday, weak ridging develops over our CWA which
will maintain dry weather with daytime highs near to above normal.
The extended models (ECMWF, GFS, and GEM) are in good agreement
that another trough will dig southward and swing into NorCal
Wednesday and Thursday. Daytime highs should dip below normal
starting on Wednesday. Have increased pops and lowered
temperatures to account for this cooler, wetter pattern.


&&

.Aviation...

Mainly VFR conditions next 24 hours with showers possible over
Shasta County and Coastal Range and spreading SE over the
northern/Central Sac valley, northeast foothills, and Sierra by
this morning. Local SWerly sfc gusts up to 30 to 45 kts over
higher mountain peaks today, decreasing by this evening.

&&

.STO Watches/Warnings/Advisories...
None.
&&

$$









000
FXUS66 KSTO 180442
AFDSTO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
942 PM PDT Wed Sep 17 2014

.Synopsis...
Temperatures cooling to below normal Thursday with a chance of
showers and thunderstorms. Warmer and drier weather returns for
the weekend.

&&
.Discussion...
The low has spread some light rain along the northern coastal
range this evening. As it transitions inland late tonight and early
morning the amount of chances of light showers will develop over
the remainder of the interior. Unfortunately the models are not
indicating any precipitation over the Kings wildfire area again
this evening but do show some light amounts of precipitation over
the far northern fires in California. Instability looks the greatest
Thursday afternoon over the mountains. Isolated thunderstorms
may be possible as the system moves through with scattered
light showers...mainly for the mountains but some local showers
and sprinkles will be possible for the valley. The best chance
within the valley will be late tonight and early Thursday morning.

Temperatures will be cooler. Instability over the valley does not
look to good with the evening model runs for producing
thunderstorms.

The center of the low will move along the central coast for
Friday. Instability looks greatest over the sierra Nevada
mountains at this time. This might bring a slight chance for
showers and thunderstorms south of Tahoe for the afternoon and
evening hours. Winds will be shifting northerly and temperatures
in the valley will be rebounding closer to seasonal normals.

The interesting thing for Thursday night and Friday morning will
be with the spread of the smoke from the King Wildfire. Places in
the southern motherlode that have had pretty good air quality will
have smoke spread over their area. The far eastern sections of the
Northern San Joaquin valley may also get some smoke. The
Sacramento region can also expect and increase in smoke during
that time period as well.

Saturday the low will shift over Southern California. Some
afternoon showers and isolated thunderstorms near the crest will
continue for areas south of Tahoe. The flow pattern will shift
again to onshore, upvalley and upslope. Temperatures will remain
near seasonal normals.
&&

.Extended Discussion (Sunday through Wednesday)

Interesting long term forecast towards mid week. Early in the week
no strong synoptic features in place but toward day 7 and 8...both
ECMWF and GFS are now bringing in a large trough into Pacific
Northwest. ECMWF is wetter and more agressive at this point. Given
the better agreement of the operational models at this point seems
appropriate to insert to have at least a 20 percent chance of
moisture...mostly in northern zones...but still alot of
uncertainity with this system...thus pops closer to climotology
make more sense than dry. Rasch


&&

.Aviation...

Mainly VFR conditions next 24 hours with showers possible over
western Shasta County and Coastal range and spreading SE over
valley and into Sierra late tonight and Thu morning. Local SWerly surface
wind gusts up to 35 to 45 kts possible over higher mountain peaks
overnight.

&&

.STO Watches/Warnings/Advisories...
None.
&&

$$








000
FXUS66 KSTO 172114
AFDSTO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
214 PM PDT Wed Sep 17 2014

.Synopsis...
Temperatures cooling to below normal Thursday with a chance of
showers and thunderstorms. Warmer and drier weather returns for
the weekend. High uncertainity towards middle week but at least
some indications of a possible system Wednesday or Thursday.

&&
.Discussion...
Somewhat active but fairly low impact short tern forecast with 3
key things to concentrate on. Upper trough will into area late
tonight and across the area Thursday. This wave will be weakening
as it does so looks like biggest impact it will bring will be
clouds and cooler than normal temperatures. There should be some
showers but amounts look to be light. Can`t rule out a
thunderstorm or two with some instability but not too much to get
too worried about.

Next concern shifts to Friday as this system passes...low level
winds will shift to down valley from the north. Once again...given
strength of the wind...not too much to worry about for fire
weather but it will allow temperatures to warm and humidities to
drop.

Friday night into Saturday will be interesting as far smoke
concerns as winds turn to the east. This could drag smoke from
KingFire westward into Valley floor. It likely will but westward
extent will be tricky to tell. NAM also showing fair instability
over night Friday into Friday night but GFS much less. Will
probably result in some mid level clouds but have kept some slight
chances of Sierra south of Highway 50.

&&

.Extended Discussion (Sunday through Wednesday)

Interesting long term forecast towards mid week. Early in the week
no strong synoptic features in place but toward day 7 and 8...both
ECMWF and GFS are now bringing in a large trough into Pacific
Northwest. ECMWF is wetter and more agressive at this point. Given
the better agreement of the operational models at this point seems
appropriate to insert to have at least a 20 percent chance of
moisture...mostly in northern zones...but still alot of
uncertainity with this system...thus pops closer to climotology
make more sense than dry. Rasch


&&

.Aviation...

Mainly VFR conditions next 24 hours with isolated
showers/thunderstorms possible over western Shasta County and
Coastal range beginning this afternoon and spreading SE over
valley and into Sierra by tonight. Local SWerly surface wind gusts
up to 35 to 45 kts possible over higher mountain peaks this
afn/eve and overnight. SWerly gusts up to 20-25 kts through delta
and Sac Valley this afternoon.

&&

.STO Watches/Warnings/Advisories...
None.
&&

$$









000
FXUS66 KSTO 172114
AFDSTO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
214 PM PDT Wed Sep 17 2014

.Synopsis...
Temperatures cooling to below normal Thursday with a chance of
showers and thunderstorms. Warmer and drier weather returns for
the weekend. High uncertainity towards middle week but at least
some indications of a possible system Wednesday or Thursday.

&&
.Discussion...
Somewhat active but fairly low impact short tern forecast with 3
key things to concentrate on. Upper trough will into area late
tonight and across the area Thursday. This wave will be weakening
as it does so looks like biggest impact it will bring will be
clouds and cooler than normal temperatures. There should be some
showers but amounts look to be light. Can`t rule out a
thunderstorm or two with some instability but not too much to get
too worried about.

Next concern shifts to Friday as this system passes...low level
winds will shift to down valley from the north. Once again...given
strength of the wind...not too much to worry about for fire
weather but it will allow temperatures to warm and humidities to
drop.

Friday night into Saturday will be interesting as far smoke
concerns as winds turn to the east. This could drag smoke from
KingFire westward into Valley floor. It likely will but westward
extent will be tricky to tell. NAM also showing fair instability
over night Friday into Friday night but GFS much less. Will
probably result in some mid level clouds but have kept some slight
chances of Sierra south of Highway 50.

&&

.Extended Discussion (Sunday through Wednesday)

Interesting long term forecast towards mid week. Early in the week
no strong synoptic features in place but toward day 7 and 8...both
ECMWF and GFS are now bringing in a large trough into Pacific
Northwest. ECMWF is wetter and more agressive at this point. Given
the better agreement of the operational models at this point seems
appropriate to insert to have at least a 20 percent chance of
moisture...mostly in northern zones...but still alot of
uncertainity with this system...thus pops closer to climotology
make more sense than dry. Rasch


&&

.Aviation...

Mainly VFR conditions next 24 hours with isolated
showers/thunderstorms possible over western Shasta County and
Coastal range beginning this afternoon and spreading SE over
valley and into Sierra by tonight. Local SWerly surface wind gusts
up to 35 to 45 kts possible over higher mountain peaks this
afn/eve and overnight. SWerly gusts up to 20-25 kts through delta
and Sac Valley this afternoon.

&&

.STO Watches/Warnings/Advisories...
None.
&&

$$








000
FXUS66 KSTO 171540
AFDSTO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
840 AM PDT Wed Sep 17 2014

.Synopsis...
Temperatures cooling to below normal Thursday with a chance of
showers and thunderstorms. Warmer and drier weather returns for
the weekend.

&&
.Discussion...
Forecast still on track. System is just off shore and will push
into the forecast area starting tonight. System then starts to
close off Thursday afternoon over NorCal. All the while the system
is weakening so any resultant activity should be pretty minimal.
Looks like biggest impact will be cooler temperatures and light
moisture chances. All this is covered very well in current
forecast. Next concern will be with upper low as it closes off
over southern California. This will turn winds around to the east
Friday into Saturday. NAM showing a fair amount of instability
wrapping around on back side of the upper low but GFS much weaker.
Will take a closer look at this for afternoon package but maybe
biggest impact with this would be possibility of winds blowing
some smoke down into valley areas during this time. Will also look
closer at this for afternoon run as well.  Rasch

.Previous Discussion...
Upper trough axis between 130-140W early this morning. Most of the
region is seeing some mid and high clouds ahead of the trough,
though the far southern portion of the forecast area remains
clear. The marine layer remains quite shallow and onshore
gradients are weak.For the most part, temperatures are a little
warmer than 24 hours ago with the increase in clouds and range
from the 50s in the cooler mountain valleys to the 60s in the
Central Valley.

The trough will continue to approach the region today, however it
looks like precip chances inland will likely hold off until
tonight. We`ll see a mix of clouds and sun today. Temperatures
will likely cool a bit further and winds will increase.

The bigger changes will hold off until later tonight and early
Thursday as the trough nears the coast and a weakening frontal
system moves onshore. Scattered showers can be expected across the
region Thursday along with a chance of thunderstorms in the
afternoon as the cooler air aloft moves overhead. Despite pretty
impressive TPW approaching 1.5 inches, overall QPF is forecast to
be light given the rather weak nature of the system. Some areas
may see a 1/4 inch or so, but most of interior NorCal will likely
see less than a tenth of an inch. The cooler airmass along with
the clouds and showers will result in considerably cooler
temperatures on Thursday.

System forecast to close off and drops south to off the SoCal
coast Friday and Saturday before lifting out to our east across
the Great Basin on Sunday. The eastern fringes of the forecast
area may see some clouds and a slight chance of showers and
thunderstorms, but the remainder of the region will warm up and
dry out.

Some considerable model differences develop next week with over
200m height differences forecast at 500 mb in the latest
operational runs over NorCal depending on which model you look at.
With ensemble means still favoring a ridge, will continue the dry
and warm/hot forecast for now.

&&

.Extended Discussion (Sunday through Wednesday)

Some considerable model differences develop next week with over
200m height differences forecast at 500 mb in the latest
operational runs over NorCal depending on which model you look at.
With ensemble means still favoring a ridge, will continue the dry
and warm/hot forecast for now.


&&

.Aviation...

Mainly VFR conditions next 24 hours with isolated
showers/thunderstorms possible over western Shasta County and
Coastal range beginning this afternoon and spreading SE over
valley and into Sierra by tonight. Local SWerly surface wind gusts
up to 35 to 45 kts possible over higher mountain peaks this
afn/eve and overnight. SWerly gusts up to 20-25 kts through delta
and Sac Valley this afternoon.

&&

.STO Watches/Warnings/Advisories...
None.
&&

$$








000
FXUS66 KSTO 171540
AFDSTO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
840 AM PDT Wed Sep 17 2014

.Synopsis...
Temperatures cooling to below normal Thursday with a chance of
showers and thunderstorms. Warmer and drier weather returns for
the weekend.

&&
.Discussion...
Forecast still on track. System is just off shore and will push
into the forecast area starting tonight. System then starts to
close off Thursday afternoon over NorCal. All the while the system
is weakening so any resultant activity should be pretty minimal.
Looks like biggest impact will be cooler temperatures and light
moisture chances. All this is covered very well in current
forecast. Next concern will be with upper low as it closes off
over southern California. This will turn winds around to the east
Friday into Saturday. NAM showing a fair amount of instability
wrapping around on back side of the upper low but GFS much weaker.
Will take a closer look at this for afternoon package but maybe
biggest impact with this would be possibility of winds blowing
some smoke down into valley areas during this time. Will also look
closer at this for afternoon run as well.  Rasch

.Previous Discussion...
Upper trough axis between 130-140W early this morning. Most of the
region is seeing some mid and high clouds ahead of the trough,
though the far southern portion of the forecast area remains
clear. The marine layer remains quite shallow and onshore
gradients are weak.For the most part, temperatures are a little
warmer than 24 hours ago with the increase in clouds and range
from the 50s in the cooler mountain valleys to the 60s in the
Central Valley.

The trough will continue to approach the region today, however it
looks like precip chances inland will likely hold off until
tonight. We`ll see a mix of clouds and sun today. Temperatures
will likely cool a bit further and winds will increase.

The bigger changes will hold off until later tonight and early
Thursday as the trough nears the coast and a weakening frontal
system moves onshore. Scattered showers can be expected across the
region Thursday along with a chance of thunderstorms in the
afternoon as the cooler air aloft moves overhead. Despite pretty
impressive TPW approaching 1.5 inches, overall QPF is forecast to
be light given the rather weak nature of the system. Some areas
may see a 1/4 inch or so, but most of interior NorCal will likely
see less than a tenth of an inch. The cooler airmass along with
the clouds and showers will result in considerably cooler
temperatures on Thursday.

System forecast to close off and drops south to off the SoCal
coast Friday and Saturday before lifting out to our east across
the Great Basin on Sunday. The eastern fringes of the forecast
area may see some clouds and a slight chance of showers and
thunderstorms, but the remainder of the region will warm up and
dry out.

Some considerable model differences develop next week with over
200m height differences forecast at 500 mb in the latest
operational runs over NorCal depending on which model you look at.
With ensemble means still favoring a ridge, will continue the dry
and warm/hot forecast for now.

&&

.Extended Discussion (Sunday through Wednesday)

Some considerable model differences develop next week with over
200m height differences forecast at 500 mb in the latest
operational runs over NorCal depending on which model you look at.
With ensemble means still favoring a ridge, will continue the dry
and warm/hot forecast for now.


&&

.Aviation...

Mainly VFR conditions next 24 hours with isolated
showers/thunderstorms possible over western Shasta County and
Coastal range beginning this afternoon and spreading SE over
valley and into Sierra by tonight. Local SWerly surface wind gusts
up to 35 to 45 kts possible over higher mountain peaks this
afn/eve and overnight. SWerly gusts up to 20-25 kts through delta
and Sac Valley this afternoon.

&&

.STO Watches/Warnings/Advisories...
None.
&&

$$









000
FXUS66 KSTO 171043
AFDSTO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
343 AM PDT Wed Sep 17 2014

.Synopsis...
Temperatures cooling to below normal Thursday with a chance of
showers and thunderstorms. Warmer and drier weather returns for
the weekend.

&&

.Discussion...
Upper trough axis between 130-140W early this morning. Most of the
region is seeing some mid and high clouds ahead of the trough,
though the far southern portion of the forecast area remains
clear. The marine layer remains quite shallow and onshore
gradients are weak.For the most part, temperatures are a little
warmer than 24 hours ago with the increase in clouds and range
from the 50s in the cooler mountain valleys to the 60s in the
Central Valley.

The trough will continue to approach the region today, however it
looks like precip chances inland will likely hold off until
tonight. We`ll see a mix of clouds and sun today. Temperatures
will likely cool a bit further and winds will increase.

The bigger changes will hold off until later tonight and early
Thursday as the trough nears the coast and a weakening frontal
system moves onshore. Scattered showers can be expected across the
region Thursday along with a chance of thunderstorms in the
afternoon as the cooler air aloft moves overhead. Despite pretty
impressive TPW approaching 1.5 inches, overall QPF is forecast to
be light given the rather weak nature of the system. Some areas
may see a 1/4 inch or so, but most of interior NorCal will likely
see less than a tenth of an inch. The cooler airmass along with
the clouds and showers will result in considerably cooler
temperatures on Thursday.

System forecast to close off and drops south to off the SoCal
coast Friday and Saturday before lifting out to our east across
the Great Basin on Sunday. The eastern fringes of the forecast
area may see some clouds and a slight chance of showers and
thunderstorms, but the remainder of the region will warm up and
dry out.

Some considerable model differences develop next week with over
200m height differences forecast at 500 mb in the latest
operational runs over NorCal depending on which model you look at.
With ensemble means still favoring a ridge, will continue the dry
and warm/hot forecast for now.

&&

.Aviation...
Mainly VFR conditions next 24 hours with isolated showers/
thunderstorms possible over western Shasta County and Coastal
range beginning this afternoon and spreading SE over valley and
into Sierra by tonight. Local SWerly surface wind gusts up to 35
to 45 kts possible over higher mountain peaks this afn/eve and
overnight. SWerly gusts up to 20-25 kts through delta and Sac
Valley this afternoon.

&&

.STO Watches/Warnings/Advisories...None.

&&

$$






000
FXUS66 KSTO 171043
AFDSTO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
343 AM PDT Wed Sep 17 2014

.Synopsis...
Temperatures cooling to below normal Thursday with a chance of
showers and thunderstorms. Warmer and drier weather returns for
the weekend.

&&

.Discussion...
Upper trough axis between 130-140W early this morning. Most of the
region is seeing some mid and high clouds ahead of the trough,
though the far southern portion of the forecast area remains
clear. The marine layer remains quite shallow and onshore
gradients are weak.For the most part, temperatures are a little
warmer than 24 hours ago with the increase in clouds and range
from the 50s in the cooler mountain valleys to the 60s in the
Central Valley.

The trough will continue to approach the region today, however it
looks like precip chances inland will likely hold off until
tonight. We`ll see a mix of clouds and sun today. Temperatures
will likely cool a bit further and winds will increase.

The bigger changes will hold off until later tonight and early
Thursday as the trough nears the coast and a weakening frontal
system moves onshore. Scattered showers can be expected across the
region Thursday along with a chance of thunderstorms in the
afternoon as the cooler air aloft moves overhead. Despite pretty
impressive TPW approaching 1.5 inches, overall QPF is forecast to
be light given the rather weak nature of the system. Some areas
may see a 1/4 inch or so, but most of interior NorCal will likely
see less than a tenth of an inch. The cooler airmass along with
the clouds and showers will result in considerably cooler
temperatures on Thursday.

System forecast to close off and drops south to off the SoCal
coast Friday and Saturday before lifting out to our east across
the Great Basin on Sunday. The eastern fringes of the forecast
area may see some clouds and a slight chance of showers and
thunderstorms, but the remainder of the region will warm up and
dry out.

Some considerable model differences develop next week with over
200m height differences forecast at 500 mb in the latest
operational runs over NorCal depending on which model you look at.
With ensemble means still favoring a ridge, will continue the dry
and warm/hot forecast for now.

&&

.Aviation...
Mainly VFR conditions next 24 hours with isolated showers/
thunderstorms possible over western Shasta County and Coastal
range beginning this afternoon and spreading SE over valley and
into Sierra by tonight. Local SWerly surface wind gusts up to 35
to 45 kts possible over higher mountain peaks this afn/eve and
overnight. SWerly gusts up to 20-25 kts through delta and Sac
Valley this afternoon.

&&

.STO Watches/Warnings/Advisories...None.

&&

$$





000
FXUS66 KSTO 170414
AFDSTO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
914 PM PDT Tue Sep 16 2014

.Synopsis...
Temperatures cooling to below normal later this week with a chance
of showers and thunderstorms returning to the region later
Wednesday into Thursday.

&&

.Discussion...
Temperatures are cooler this evening over the northern areas to
slightly warmer for the Sacramento region this evening. Winds in
the delta are lighter this evening but are expected to pick up
slightly late tonight then some more during the day on Wednesday. In
the mountains the winds have settled down and are shifting
downslope. Smoke from the Kings wildfire will be moving toward the
foothills overnight again...mainly from El Dorado county
northward into Nevada County.

Low pressure area off the coast will spread some clouds over the
region in advance of the system. Winds will become breezy through
the delta and breezy from the south to southwest in the mountains
and valley on Wednesday...Windy over the crest. Humidities will
remain low during the daytime and combined with the winds, low RH
and dry fuels conditions will continue to cause poor conditions
for fighting the wildfires at times.

The low will move onto the coast late Wednesday to bring a chance
of showers to the coastal range. The low will then move over the
interior on Thursday and winds will be decreasing while humidities
should be increasing. Chances of showers will develop over the
remainder of the interior Wednesday night and Thursday.
Unfortunately the models are not indicating any precipitation over
the Kings wildfire area again this evening. Temperatures will
continue to cool each day through Thursday. Instability looks the
greatest Thursday afternoon over the Southern Sacramento valley.
Isolated thunderstorms look possible as the system moves through
with scattered showers.

The center of the low will move along the central coast for
Friday. Instability looks greatest over the sierra Nevada
mountains at this time. This might bring a better opportunity for
showers and thunderstorms to move over the kings wildfire for the
afternoon and evening hours. Winds will be shifting northerly and
temperatures in the valley will be rebounding closer to seasonal
normals.

&&

.Extended Discussion (Saturday through Tuesday)

Latest 12z ECMWF-HiRes showing a more progressive solution,
similar to the Oper GFS with handling of omega pattern over the
Western U.S. Models continue to slowly fill trapped upper low over
SoCal Saturday then progress it downstream along with upper
ridging early next week as EPAC upper ridging amplifies and build
into NorCal. This will result in dry weather with temperatures
around 5 to 10 degrees above normal. Highs expected mostly in the
90s for the Central Valley with 70s to around 90 for the mountains
and foothills.

PCH

&&

.Aviation...

Incrsg SWly flow alf as Pac stm apchs the W Cst. VFR conds ovr
Intr NorCal nxt 24 hrs with isold shwr/tstm poss ovr Wrn
Shasta/Cstl rng Wed aftn. Conds dtrtg Wed ngt into Thu. Lcl SWly
sfc wnd gsts to 25 kts poss ovr hyr mtn trrn this aftn into eve and
in the Delta tngt.

&&

.STO Watches/Warnings/Advisories...
None.
&&

$$








000
FXUS66 KSTO 162219
AFDSTO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
319 PM PDT Tue Sep 16 2014

.Synopsis...
Temperatures cooling to below normal later this week with a chance
of showers and thunderstorms returning to the region later
Wednesday into Thursday.

&&

.Discussion...
Upper level ridging is shifting eastward bringing noticeable
cooler temperatures over the region. Current temperatures over the
forecast area are anywhere from 2 to 10 degrees cooler than
yesterday. Breezy southwest winds have picked up in the Sierra,
now gusting to 24 mph at Blue Canyon. The southwest winds are also
pushing the smoke from the King Fire northeast into Nevada.

Approaching Pacific trough will spread precipitation into the
Coastal Range by Wednesday afternoon, along with breezy southwest
winds. Afternoon heating and elevated instability look sufficient
for afternoon and evening thunderstorms in that area, especially
if enough heating from the sun occurs through breaks in clouds. A
vort max tracking through northern California late in the day will
provide some lift. More stable conditions expected overnight, with
general showers spreading across the Valley Wednesday night into
early Thursday as the main trough moves inland.

Rain showers and seasonably cool temperatures expected for
Thursday. Increasing instability is expected by Thursday
afternoon, with a slight chance of thunderstorms across the area.
Rain amounts overall should be light, except locally with
thunderstorms. By evening, precipitation should be mainly
lingering convection over the mountains.

Friday is expected to be dry with temperatures rebounding to near
normal levels, which is upper 80s to mid 90s. EK

&&

.Extended Discussion (Saturday through Tuesday)

Latest 12z ECMWF-HiRes showing a more progressive solution,
similar to the Oper GFS with handling of omega pattern over the
Western U.S. Models continue to slowly fill trapped upper low over
SoCal Saturday then progress it downstream along with upper
ridging early next week as EPAC upper ridging amplifies and build
into NorCal. This will result in dry weather with temperatures
around 5 to 10 degrees above normal. Highs expected mostly in the
90s for the Central Valley with 70s to around 90 for the mountains
and foothills.

PCH

&&

.Aviation...

Incrsg SWly flow alf as Pac stm apchs the W Cst. VFR conds ovr
Intr NorCal nxt 24 hrs with isold shwr/tstm poss ovr Wrn
Shasta/Cstl rng Wed aftn. Conds dtrtg Wed ngt into Thu. Lcl SWly
sfc wnd gsts to 25 kts poss ovr hyr mtn trrn this aftn into eve and
in the Delta tngt.

&&

.STO Watches/Warnings/Advisories...
None.
&&

$$








000
FXUS66 KSTO 162219
AFDSTO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
319 PM PDT Tue Sep 16 2014

.Synopsis...
Temperatures cooling to below normal later this week with a chance
of showers and thunderstorms returning to the region later
Wednesday into Thursday.

&&

.Discussion...
Upper level ridging is shifting eastward bringing noticeable
cooler temperatures over the region. Current temperatures over the
forecast area are anywhere from 2 to 10 degrees cooler than
yesterday. Breezy southwest winds have picked up in the Sierra,
now gusting to 24 mph at Blue Canyon. The southwest winds are also
pushing the smoke from the King Fire northeast into Nevada.

Approaching Pacific trough will spread precipitation into the
Coastal Range by Wednesday afternoon, along with breezy southwest
winds. Afternoon heating and elevated instability look sufficient
for afternoon and evening thunderstorms in that area, especially
if enough heating from the sun occurs through breaks in clouds. A
vort max tracking through northern California late in the day will
provide some lift. More stable conditions expected overnight, with
general showers spreading across the Valley Wednesday night into
early Thursday as the main trough moves inland.

Rain showers and seasonably cool temperatures expected for
Thursday. Increasing instability is expected by Thursday
afternoon, with a slight chance of thunderstorms across the area.
Rain amounts overall should be light, except locally with
thunderstorms. By evening, precipitation should be mainly
lingering convection over the mountains.

Friday is expected to be dry with temperatures rebounding to near
normal levels, which is upper 80s to mid 90s. EK

&&

.Extended Discussion (Saturday through Tuesday)

Latest 12z ECMWF-HiRes showing a more progressive solution,
similar to the Oper GFS with handling of omega pattern over the
Western U.S. Models continue to slowly fill trapped upper low over
SoCal Saturday then progress it downstream along with upper
ridging early next week as EPAC upper ridging amplifies and build
into NorCal. This will result in dry weather with temperatures
around 5 to 10 degrees above normal. Highs expected mostly in the
90s for the Central Valley with 70s to around 90 for the mountains
and foothills.

PCH

&&

.Aviation...

Incrsg SWly flow alf as Pac stm apchs the W Cst. VFR conds ovr
Intr NorCal nxt 24 hrs with isold shwr/tstm poss ovr Wrn
Shasta/Cstl rng Wed aftn. Conds dtrtg Wed ngt into Thu. Lcl SWly
sfc wnd gsts to 25 kts poss ovr hyr mtn trrn this aftn into eve and
in the Delta tngt.

&&

.STO Watches/Warnings/Advisories...
None.
&&

$$









000
FXUS66 KSTO 161949 CCA
AFDSTO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
956 AM PDT Tue Sep 16 2014

.Synopsis...
Temperatures cooling to below normal later this week with a chance
of showers and thunderstorms returning to the region later
Wednesday into Thursday.

&&

.Discussion...
A noticeably cooler start to the day today with temperatures 3 to
9 degrees cooler than this time yesterday. The upper level ridge
which has been bringing unseasonable warmth to the area is giving
way as a cool Pacific trough approaches. Today will be dry and
sunny, with some high thin clouds spreading in from the west later
today and tonight. Highs this afternoon look on track to be 4-5
degrees lower than yesterday, though this will still be a little
above normal levels. Some breezy southwest winds will pick up
again this afternoon, especially in the mountains.

Smoky/hazy conditions continue from the King Fire in portions of
the Sierra and the foothills. Visible satellite shows smoke in a
v-shape, with some smoke that spread down the American River
Canyon with easterly winds now being pushed to the northeast with
southwesterly winds. Breezy southwest winds this afternoon may
further enhance the spread of the fire.

Approaching trough will spread precipitation into the Coastal
Range by Wednesday afternoon. Elevated convection parameters with
the 12z NAM are looking more favorable. May need to add the potential
for a few thunderstorms there late afternoon and early evening.
More significant precipitation spreads in by Thursday. Lift and
atmospheric moisture are adequate for potential rainfall over the
area, but most areas should see fairly light amounts.

Forecast looks on track for today, no updates necessary. EK

&&

.Extended Discussion (Saturday through Tuesday)

Medium range models continue to have difficulty with handling
trapped upper low. 12z ECMWF-HiRes has come more inline with the
Oper GFS in keeping the low farther south and building stronger
ridging over the weekend into Monday. So will follow these
solutions for now with understanding progs do poorly with trapped
lows. Thus expect dry weather Friday through Monday for Interior
NorCal with above normal temperatures. Highs expected mostly in
the 90s for the Central Valley with 70s to around 90 for the
mountains and foothills.
PCH

&&

.Aviation...

General VFR conditions over interior Northern California through
early Wednesday with an upper level trough in the the Eastern
Pacific approaching the California coast. Smoke from King Fire near
Pollock Pines will locally reduce visibility over portions of the
Sierra. Local SW surface wind gusts to 30 kts over the higher Sierra.


&&

.STO Watches/Warnings/Advisories...
None.
&&

$$










000
FXUS66 KSTO 161656
AFDSTO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
956 AM PDT Tue Sep 16 2014

.Synopsis...
Temperatures cooling to below normal later this week with a chance
of showers and thunderstorms returning to the region later
Wednesday into Thursday.

&&

.Discussion...
A noticeably cooler start to the day today with temperatures 3 to
9 degrees cooler than this time yesterday. The upper level ridge
which has been bringing unseasonable warmth to the area is giving
way as a cool Pacific ridge approaches. Today will be dry and
sunny, with some high thin clouds spreading in from the west later
today and tonight. Highs this afternoon look on track to be 4-5
degrees lower than yesterday, though this will still be a little
above normal levels. Some breezy southwest winds will pick up
again this afternoon, especially in the mountains.

Smoky/hazy conditions continue from the King Fire in portions of
the Sierra and the foothills. Visible satellite shows smoke in a
v-shape, with some smoke that spread down the American River
Canyon with easterly winds now being pushed to the northeast with
southwesterly winds. Breezy southwest winds this afternoon may
further enhance the spread of the fire.

Approaching trough will spread precipitation into the Coastal
Range by Wednesday afternoon. Elevated convection parameters with
the 12z NAM are looking more favorable. May need to add the potential
for a few thunderstorms there late afternoon and early evening.
More significant precipitation spreads in by Thursday. Lift and
atmospheric moisture are adequate for potential rainfall over the
area, but most areas should see fairly light amounts.

Forecast looks on track for today, no updates necessary. EK

&&

.Extended Discussion (Saturday through Tuesday)

Medium range models continue to have difficulty with handling
trapped upper low. 12z ECMWF-HiRes has come more inline with the
Oper GFS in keeping the low farther south and building stronger
ridging over the weekend into Monday. So will follow these
solutions for now with understanding progs do poorly with trapped
lows. Thus expect dry weather Friday through Monday for Interior
NorCal with above normal temperatures. Highs expected mostly in
the 90s for the Central Valley with 70s to around 90 for the
mountains and foothills.
PCH

&&

.Aviation...

General VFR conditions over interior Northern California through
early Wednesday with an upper level trough in the the Eastern
Pacific approaching the California coast. Smoke from King Fire
near Pollock Pines will locally reduce visibility over portions of the
Sierra. Local SW surface wind gusts to 30 kts over the higher Sierra.


&&

.STO Watches/Warnings/Advisories...
None.
&&

$$









000
FXUS66 KSTO 161656
AFDSTO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
956 AM PDT Tue Sep 16 2014

.Synopsis...
Temperatures cooling to below normal later this week with a chance
of showers and thunderstorms returning to the region later
Wednesday into Thursday.

&&

.Discussion...
A noticeably cooler start to the day today with temperatures 3 to
9 degrees cooler than this time yesterday. The upper level ridge
which has been bringing unseasonable warmth to the area is giving
way as a cool Pacific ridge approaches. Today will be dry and
sunny, with some high thin clouds spreading in from the west later
today and tonight. Highs this afternoon look on track to be 4-5
degrees lower than yesterday, though this will still be a little
above normal levels. Some breezy southwest winds will pick up
again this afternoon, especially in the mountains.

Smoky/hazy conditions continue from the King Fire in portions of
the Sierra and the foothills. Visible satellite shows smoke in a
v-shape, with some smoke that spread down the American River
Canyon with easterly winds now being pushed to the northeast with
southwesterly winds. Breezy southwest winds this afternoon may
further enhance the spread of the fire.

Approaching trough will spread precipitation into the Coastal
Range by Wednesday afternoon. Elevated convection parameters with
the 12z NAM are looking more favorable. May need to add the potential
for a few thunderstorms there late afternoon and early evening.
More significant precipitation spreads in by Thursday. Lift and
atmospheric moisture are adequate for potential rainfall over the
area, but most areas should see fairly light amounts.

Forecast looks on track for today, no updates necessary. EK

&&

.Extended Discussion (Saturday through Tuesday)

Medium range models continue to have difficulty with handling
trapped upper low. 12z ECMWF-HiRes has come more inline with the
Oper GFS in keeping the low farther south and building stronger
ridging over the weekend into Monday. So will follow these
solutions for now with understanding progs do poorly with trapped
lows. Thus expect dry weather Friday through Monday for Interior
NorCal with above normal temperatures. Highs expected mostly in
the 90s for the Central Valley with 70s to around 90 for the
mountains and foothills.
PCH

&&

.Aviation...

General VFR conditions over interior Northern California through
early Wednesday with an upper level trough in the the Eastern
Pacific approaching the California coast. Smoke from King Fire
near Pollock Pines will locally reduce visibility over portions of the
Sierra. Local SW surface wind gusts to 30 kts over the higher Sierra.


&&

.STO Watches/Warnings/Advisories...
None.
&&

$$








000
FXUS66 KSTO 161130
AFDSTO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
430 AM PDT Tue Sep 16 2014

.Synopsis...
Temperatures cooling to below normal later this week with a chance
of showers and thunderstorms returning to the region later
Wednesday into Thursday.

&&

.Discussion...
Clear skies across interior NorCal early this morning under dry
southwest flow aloft ahead of deepening upstream trough west of
130W. Temperatures are mostly cooler compared to 24 hours ago and
range from the upper 40s in the colder mountain valleys to the mid
50s to mid 60s in the Central Valley.

Temperatures will be down by about 5 degrees across the region
today compared to Monday. The strong upper ridge will continue to
shift slowly eastward allowing minor synoptic cooling. While
onshore gradients have weakened compared to 24 hours ago and the
marine layer has been disrupted, some Delta influence will
continue into the southern Sacramento Valley today.

The cool down will accelerate Wednesday as the upper trough and
frontal system approach and onshore flow increases. Appears there
will be enough moisture with this system (TPW around 1.5 inches)
that despite relatively weak forcing, many areas will see
potential for showers. Looks like the best timing for any
precipitation will be later Wednesday into early Thursday as the
front moves inland, and then again later Thursday as deep
convection increases as the upper trough moves overhead. Overall
QPF will be light with most areas likely lucky to see a tenth of
an inch of rain.

Still looks like a good bet that the region will see warmer and
drier conditions return for the weekend as the trough forms a
closed low that drifts south to off the SoCal coast. Still a lot
of model uncertainty by early next week as the GFS, GEM and EC
differ in the timing and evolution of how the low moves off to the
east, but appears main impacts would be south of our area.

&&

.Aviation...
VFR conditions over interior Northern California through early
Wednesday with an upper level trough in the the Eastern Pacific
approaching the California coast. Local SW surface wind gusts to
30 kts over mountains and in the Delta.

&&

.STO Watches/Warnings/Advisories...None.

&&

$$





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