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000
FXUS66 KSTO 260518
AFDSTO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
1018 PM PDT Sat Oct 25 2014

.Synopsis...
A few showers...especially at higher elevations through Sunday
morning. Snow levels will above 6500 feet where a couple of
inches of snow are possible. Drier weather expected by Sunday
afternoon. The brief break into Monday will be followed by
potentially more wet weather mid next week and again late week.

&&

.Discussion...
Fairly active late afternoon/evening over Norcal with severe
thunderstorms in the Redding and Anderson areas between 5-6 pm. A
wind gust of 60 mph was reported at Redding airport along with
quarter size hail near Anderson. There was also lots of small hail
reports including accumulations of 1-2 inches around Shingletown.
Shower activity is now generally over the Higher elevations and
foothills...associated with moist up-slope southwest flow. Have
update the forecast to lower valley pops into the isolated to
scattered range. Surface winds have also relaxed significantly and
ended the wind advisory/high wind warning at 9 pm. Snow continues
above 6500 feet and another 1-2 inches will be possible.
Otherwise...forecast is on track.

.Previous Discussion...
After the main frontal passage this morning, scattered showers
with thunderstorms and high winds continue to impact much of
NorCal. Snow levels dropped down to pass levels earlier than
expected so have adjusted the forecast to reflect snow levels
around 6500 ft from this afternoon and into early Sunday. Snow
accumulations up to 10 inches are possible on Mt Lassen and up to
4 inches possible over the higher Sierra passes.

Winds have been very strong in the Northern Sacramento Valley.
Redding and Red Bluff airports were reporting sustained winds of
23-39 mph with gusts up to around 50 mph. We also got a report
near Burney of downed trees due to the gusty winds. Wind
observations in the Southern Sacramento valley (including the Sac
Metro region) did not strengthen as much as previously thought so
have removed that area from the Wind Advisory. Also cancelled part
of the High Wind Warning across the Western Sierra Slopes...south
of Plumas County.

A line of training thunderstorms has been persistent in Western
Shasta County for most of this afternoon and will continue into
the evening. This line crosses Interstate 5 between Redding and
Lakehead so drivers should be extra cautious in this section of I-5.

Thunderstorms will continue to impact portions of the valley
through this evening. We currently have a Significant Weather
Advisory in effect for part of Butte County valid through 4 pm as
small hail, dangerous lightning, gusty winds are possible.

Due to the winds, rain and snow...we continue to emphasize that
motorists should use extra caution while driving. There have been
several reports of vehicle spin-outs and accidents due to weather
conditions.

Winds will weaken by tonight and precipitation will also diminish.
Lingering showers over the mountains could continue bringing snow
and rain/snow through Sunday morning. Expect drier and milder conditions by
Sunday afternoon. High temperatures this weekend will be in the
mid 60s to low 70s in the Valley and mid 30s to low 50s in the
mountains. Monday and Tuesday will be drier and warmer with
ridging dominating. Although there could be a slight chance of
some rain across far Northern CA...generally north of
Marysville...on Tuesday. JBB


.Extended Discussion (Wednesday through Saturday)

Amplifying ridge forecast over the western US during the middle of
next week as another trough deepens over the eastern Pacific. This
will likely keep all but the far northern portion of the forecast
area precipitation-free into Thursday. Forecast confidence
decreases later in the week as significant differences develop
between the models in the handling of the trough as it moves onto
the west coast Halloween and next weekend, though it appears much
of the region will see a chance of precipitation sometime next
Friday or Saturday.

&&

.Aviation...
Scattered showers will continue Overnight. Winds will generally
be less than 10 mph and ceilings above 8000 feet.

&&

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

$$









000
FXUS66 KSTO 260518
AFDSTO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
1018 PM PDT Sat Oct 25 2014

.Synopsis...
A few showers...especially at higher elevations through Sunday
morning. Snow levels will above 6500 feet where a couple of
inches of snow are possible. Drier weather expected by Sunday
afternoon. The brief break into Monday will be followed by
potentially more wet weather mid next week and again late week.

&&

.Discussion...
Fairly active late afternoon/evening over Norcal with severe
thunderstorms in the Redding and Anderson areas between 5-6 pm. A
wind gust of 60 mph was reported at Redding airport along with
quarter size hail near Anderson. There was also lots of small hail
reports including accumulations of 1-2 inches around Shingletown.
Shower activity is now generally over the Higher elevations and
foothills...associated with moist up-slope southwest flow. Have
update the forecast to lower valley pops into the isolated to
scattered range. Surface winds have also relaxed significantly and
ended the wind advisory/high wind warning at 9 pm. Snow continues
above 6500 feet and another 1-2 inches will be possible.
Otherwise...forecast is on track.

.Previous Discussion...
After the main frontal passage this morning, scattered showers
with thunderstorms and high winds continue to impact much of
NorCal. Snow levels dropped down to pass levels earlier than
expected so have adjusted the forecast to reflect snow levels
around 6500 ft from this afternoon and into early Sunday. Snow
accumulations up to 10 inches are possible on Mt Lassen and up to
4 inches possible over the higher Sierra passes.

Winds have been very strong in the Northern Sacramento Valley.
Redding and Red Bluff airports were reporting sustained winds of
23-39 mph with gusts up to around 50 mph. We also got a report
near Burney of downed trees due to the gusty winds. Wind
observations in the Southern Sacramento valley (including the Sac
Metro region) did not strengthen as much as previously thought so
have removed that area from the Wind Advisory. Also cancelled part
of the High Wind Warning across the Western Sierra Slopes...south
of Plumas County.

A line of training thunderstorms has been persistent in Western
Shasta County for most of this afternoon and will continue into
the evening. This line crosses Interstate 5 between Redding and
Lakehead so drivers should be extra cautious in this section of I-5.

Thunderstorms will continue to impact portions of the valley
through this evening. We currently have a Significant Weather
Advisory in effect for part of Butte County valid through 4 pm as
small hail, dangerous lightning, gusty winds are possible.

Due to the winds, rain and snow...we continue to emphasize that
motorists should use extra caution while driving. There have been
several reports of vehicle spin-outs and accidents due to weather
conditions.

Winds will weaken by tonight and precipitation will also diminish.
Lingering showers over the mountains could continue bringing snow
and rain/snow through Sunday morning. Expect drier and milder conditions by
Sunday afternoon. High temperatures this weekend will be in the
mid 60s to low 70s in the Valley and mid 30s to low 50s in the
mountains. Monday and Tuesday will be drier and warmer with
ridging dominating. Although there could be a slight chance of
some rain across far Northern CA...generally north of
Marysville...on Tuesday. JBB


.Extended Discussion (Wednesday through Saturday)

Amplifying ridge forecast over the western US during the middle of
next week as another trough deepens over the eastern Pacific. This
will likely keep all but the far northern portion of the forecast
area precipitation-free into Thursday. Forecast confidence
decreases later in the week as significant differences develop
between the models in the handling of the trough as it moves onto
the west coast Halloween and next weekend, though it appears much
of the region will see a chance of precipitation sometime next
Friday or Saturday.

&&

.Aviation...
Scattered showers will continue Overnight. Winds will generally
be less than 10 mph and ceilings above 8000 feet.

&&

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

$$









000
FXUS66 KSTO 252250
AFDSTO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
350 PM PDT Sat Oct 25 2014

.Synopsis...
Storm system will continue to impact NorCal through this evening
with strong winds and precipitation today. Thunderstorms with
heavy rain, accumulating small hail, and maybe even isolated weak
tornadoes are possible. Snow at pass levels through tonight. Drier
weather expected by Sunday afternoon.

&&

After the main frontal passage this morning, scattered showers
with thunderstorms and high winds continue to impact much of
NorCal. Snow levels dropped down to pass levels earlier than
expected so have adjusted the forecast to reflect snow levels
around 6500 ft from this afternoon and into early Sunday. Snow
accumulations up to 10 inches are possible on Mt Lassen and
up to 4 inches possible over the higher Sierra passes.

Winds have been very strong in the Northern Sacramento Valley.
Redding and Red Bluff airports were reporting sustained winds of
23-39 mph with gusts up to around 50 mph. We also got a report
near Burney of downed trees due to the gusty winds. Wind
observations in the Southern Sacramento valley (including the Sac
Metro region) did not strengthen as much as previously thought so
have removed that area from the Wind Advisory. Also cancelled part
of the High Wind Warning across the Western Sierra Slopes...south
of Plumas County.

A line of training thunderstorms has been persistent in Western
Shasta County for most of this afternoon and will continue into
the evening. This line crosses Interstate 5 between Redding and
Lakehead so drivers should be extra cautious in this section of I-5.

Thunderstorms will continue to impact portions of the valley
through this evening. We currently have a Significant Weather
Advisory in effect for part of Butte County valid through 4 pm as
small hail, dangerous lightning, gusty winds are possible.

Due to the winds, rain and snow...we continue to emphasize that
motorists should use extra caution while driving. There have been
several reports of vehicle spin-outs and accidents due to weather
conditions.

Winds will weaken by tonight and precipitation will also diminish.
Lingering showers over the mountains could continue bringing snow
and rain/snow through Sunday morning. Expect drier and milder conditions by
Sunday afternoon. High temperatures this weekend will be in the
mid 60s to low 70s in the Valley and mid 30s to low 50s in the
mountains. Monday and Tuesday will be drier and warmer with
ridging dominating. Although there could be a slight chance of
some rain across far Northern CA...generally north of
Marysville...on Tuesday. JBB


.Extended Discussion (Wednesday through Saturday)

Amplifying ridge forecast over the western US during the middle of
next week as another trough deepens over the eastern Pacific. This
will likely keep all but the far northern portion of the forecast
area precipitation-free into Thursday. Forecast confidence
decreases later in the week as significant differences develop
between the models in the handling of the trough as it moves onto
the west coast Halloween and next weekend, though it appears much
of the region will see a chance of precipitation sometime next
Friday or Saturday.

&&

.Aviation...

Pacific cold front moves across the area today bringing gusty
winds along with areas of MVFR conditions to the valley and
widespread IFR conditions to the mountains. Wind gusts to 45 mph
will be possible til 02Z, especially over the Northern Sacramento
Valley and gusts over 50 mph will be likely over the Northern
Sierra Nevada. Scattered showers will continue through the evening
long with isolated thunderstorms til 03z.

&&

.STO Watches/Warnings/Advisories...
high wind warning until 11 pm pdt this evening burney basin /
eastern shasta county...western plumas county/lassen park.

wind advisory until 11 pm pdt this evening clear lake/southern
lake county...mountains southwestern shasta county to northern
lake county...northeast foothills/sacramento valley...shasta
lake area / northern shasta county.

wind advisory until 8 pm pdt this evening central sacramento
valley...northern sacramento valley.

&&

$$









000
FXUS66 KSTO 251608
AFDSTO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
908 AM PDT Sat Oct 25 2014

.Synopsis...
Cold front will bring strong winds and precipitation today.
Thunderstorms expected with heavy rain, accumulating small hail, and maybe
even isolated weak tornadoes. Snow levels will come down to below
Sierra passes tonight. A brief break late Sunday into Monday will
be followed by potentially more wet weather mid next week and
again late week.

&&

At 8 am, the main band of precipitation with the cold front was
oriented SW to NE in a line including Oakland, Vacaville, Chico,
Shingletown, and Newell. Winds continue to be fairly gusty in
parts of NorCal, especially over the Sierra crest and in the
Sacramento Valley from Chico northward. The Redding & Red Bluff
airports have already had peak gusts over 40 mph this morning.
Some Sierra ridge-top peak gusts have been over 70 mph. Winds will
continue to be breezy to gusty for much of NorCal today. No
changes anticipated to this morning`s forecast package as emphasis
remains on the wet and windy weather along with thunderstorms -
some of which may become severe with weak tornadoes possible.  JBB

.Previous Discussion...Southerly winds have dramatically increased this
morning. We have added wind advisories to the Coastal Range and
lower foothills of Plumas and Shasta counties, to go with the wind
advisory already in place over the Sacramento Valley and western
Delta. We have also issued a High Wind Warning for the higher
Sierra into tonight. As the front approaches and passes later this
morning and afternoon, winds will continue to increase to 15 to 30
mph with gusts 40 to 50 mph in the Valley and 50 to 90 mph over
higher terrain. This could cause some trees and even some power
poles to come down, potential causing some localized power
outages. Remember that leaves are still on the trees, so these
stronger winds can potentially produce more damage to trees. Winds
should be decreasing this evening.

Shasta county mountains could see up to 2 inches of precipitation
by Sunday morning with good orographics with the southerly winds.
Snow levels will be around 8000 ft this morning and drop down to
around 5300 to 6500 ft on Sunday morning. Snow accumulations up to
10 inches are possible on Mt Lassen and up to 4 inches possible
over the higher Sierra passes. Consequently, motorists should be
prepared for possible winter driving conditions in the mountains
this weekend. Good instability and shear this afternoon behind the
cold front will bring a threat of thunderstorms and possibly weak
tornadoes, especially within the northern and central Sacramento
Valley. Precipitation will taper off on Sunday with showers mainly
lingering over the Shasta County and down the Sierra. High
temperatures this weekend will be in the mid 60s to low 70s in the
Valley and mid 30s to low 50s in the mountains. Monday and Tuesday
will be drier and warmer with ridging dominating, expect for a
slight chance of rain over western Shasta county by Tuesday
afternoon.  JClapp


.Extended Discussion (Wednesday through Saturday)

Amplifying ridge forecast over the western US during the middle of
next week as another trough deepens over the eastern Pacific. This
will likely keep all but the far northern portion of the forecast
area precipitation-free into Thursday. Forecast confidence
decreases later in the week as significant differences develop
between the models in the handling of the trough as it moves onto
the west coast Halloween and next weekend, though it appears much
of the region will see a chance of precipitation sometime next
Friday or Saturday.

&&

.Aviation...

Pacific cold front moves across the area today bringing rain and
increasing winds along with areas of MVFR conditions to the valley
and widespread IFR conditions to the mountains. Wind gusts to 45
mph will be possible after 12Z, especially over the northern
Sacramento Valley and gusts over 50 mph will be likely over the
northern Sierra Nevada. Scattered showers along with isolated
thunderstorms will be likely behind the front this afternoon into
this evening.

&&

.STO Watches/Warnings/Advisories...
high wind warning until 11 pm pdt this evening burney basin /
eastern shasta county...west slope northern sierra nevada...
western plumas county/lassen park.

wind advisory until 11 pm pdt this evening clear lake/southern
lake county...mountains southwestern shasta county to northern
lake county...northeast foothills/sacramento valley...shasta
lake area / northern shasta county.

wind advisory until 8 pm pdt this evening carquinez strait and
delta...central sacramento valley...northern sacramento valley...
southern sacramento valley.

&&

$$









000
FXUS66 KSTO 251231
AFDSTO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
531 AM PDT Sat Oct 25 2014

.Synopsis...
Strong winds and precipitation moves in today with a frontal
system. Thunderstorms today with heavy rain, accumulating small
hail, and maybe even isolated tornadoes. Snow levels will come
down to below Sierra passes tonight. A brief break late Sunday
into Monday will be followed by potentially more wet weather mid
next week and again late week.

&&

A frontal rain band is reaching the Coastal Range as of 500am with
the cold front near the coast. The front is moving about 20 mph
and rain should begin over Redding and Red Bluff between 530 and
600am. Southerly winds have dramatically increased this morning.
We have added wind advisories to the Coastal Range and lower
foothills of Plumas and Shasta counties, to go with the wind
advisory already in place over the Sacramento Valley and western
Delta. We have also issued a High Wind Warning for the higher
Sierra into tonight. As the front approaches and passes later this
morning and afternoon, winds will continue to increase to 15 to 30
mph with gusts 40 to 50 mph in the Valley and 50 to 90 mph over
higher terrain. This could cause some trees and even some power
poles to come down, potential causing some localized power
outages. Remember that leaves are still on the trees, so these
stronger winds can potentially produce more damage to trees. Winds
should be decreasing this evening.

Shasta county mountains could see up to 2 inches of precipitation
by Sunday morning with good orographics with the southerly winds.
Snow levels will be around 8000 ft this morning and drop down to
around 5300 to 6500 ft on Sunday morning. Snow accumulations up to
10 inches are possible on Mt Lassen and up to 4 inches possible
over the higher Sierra passes. Consequently, motorists should be
prepared for possible winter driving conditions in the mountains
this weekend. Good instability and shear this afternoon behind the
cold front will bring a threat of thunderstorms and possibly weak
tornadoes, especially within the northern and central Sacramento
Valley. Precipitation will taper off on Sunday with showers mainly
lingering over the Shasta County and down the Sierra. High
temperatures this weekend will be in the mid 60s to low 70s in the
Valley and mid 30s to low 50s in the mountains. Monday and Tuesday
will be drier and warmer with ridging dominating, expect for a
slight chance of rain over western Shasta county by Tuesday
afternoon.  JClapp


.Extended Discussion (Wednesday through Saturday)
Amplifying ridge forecast over the western US during the middle
of next week as another trough deepens over the eastern Pacific.
This will likely keep all but the far northern portion of the
forecast area precipitation-free into Thursday. Forecast
confidence decreases later in the week as significant differences
develop between the models in the handling of the trough as it
moves onto the west coast Halloween and next weekend. Though, it
appears much of the region will see a chance of precipitation
sometime next Friday or Saturday.

&&

.Aviation...
Pacific cold front moves across the area today bringing rain and
increasing winds along with areas of MVFR conditions to the valley
and widespread IFR conditions to the mountains. Wind gusts to 45
mph will be developing after 12Z, especially over the northern
Sacramento Valley and gusts over 50 mph will be likely over the
northern Sierra Nevada. Scattered showers along with isolated to
scattered thunderstorms will be likely behind the front this
afternoon into this evening.

&&

.STO Watches/Warnings/Advisories...
High Wind Warning until 11 pm PDT this evening Burney Basin /
eastern Shasta county...west slope Northern Sierra Nevada...
western Plumas county/Lassen Park.

Wind Advisory until 11 pm PDT this evening Clear Lake/southern
Lake county...mountains southwestern Shasta county to northern
Lake county...northeast foothills/Sacramento Valley...Shasta
Lake area / northern Shasta county.

Wind Advisory until 8 pm PDT this evening Carquinez Strait and
Delta...Sacramento Valley.

&&

$$

JClapp







000
FXUS66 KSTO 250520
AFDSTO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
1020 PM PDT Fri Oct 24 2014

.Synopsis...
Wet and windy weather moves in later tonight into Saturday as an
upper level trough and associated front move into the area.
Thunderstorms with heavy rain, accumulating small hail and gusty
winds and maybe even a weak tornado are possible on Saturday. Snow
levels will lower below Sierra passes Saturday night. Decreasing
winds are expected Saturday evening and precipitation will taper off
Sunday. A brief break Monday will be followed by a chance of rain
over areas north of Sacramento Tuesday and Wednesday. This
precipitation threat will drop southward bringing rain or mountain
snow over much of NORCAL for the end of the next week.

&&

.Discussion...

Occluded front looking very ominous offshore with definite/sharp
backedge of front and area of enhanced clouds indicating band of
convective precip along the front which is along 127W. WAA clouds
precede the front and will be overspreading interior Norcal
overnite...but precip associated with the front not forecast to move
into the coastal range until around 12z (5 am). Frontal precip moves
into the Siernev late morning and afternoon with break in the valley
until upper air dynamics and colder/unstable move into the area
later in the afternoon and evening.

925 mbs winds indicate 40-45 kts Sly winds developing in the valley
by and after 12z with MFR-SAC gradient at least topping 12 mbs. This
is sufficient for wind advsry and AWW for KRDD as Sly gusts top out
at 40+ MPH as front moves across the area and for a few hours behind
the front. Strongly sheared environment expected to lead to isolated
to scattered CBs late morning and afternoon.

Locally heavy showers expected with deep convection as PW over +2
standard deviations Sat morning and at least one standard deviation
behind the front Sat afternoon. QPFS will vary widely due to the
convection but the Shasta/Siernev mtns with strong upslope flow
should have significant QPF.    JHM


.Previous Discussion...

Upper level trough offshore of the West Coast will move into
Northern California tonight into Saturday bringing a change to wet
and windy weather. Increasing clouds and precipitation moving into
the Coastal range and Shasta County around midnight and spread
southeast across interior northern California Saturday. Southerly
winds will increase late tonight into Saturday as the cold front and
trough move inland. This will bring breezy and gust winds with
southerly winds 15 to 30 mph with gusts to around 40 mph in the
Valley...strongest in the Nrn Sacramento Valley and up to 70 mph
over the ridges. Holiday decorations should be secured with the gusty
winds and high profile vehicles should use caution. Winds should be
decreasing Saturday evening. Shasta County mountains could see up to
2 inches of precipitation by Sunday morning with good orographics
with the southerly winds. Snow levels will be around 8000 ft
Saturday morning and drop down to around 5000 to 6000 ft on Sunday
morning. Snow accumulations up to 10 inches are possible on Mt
Lassen and up to 4 inches possible over the higher Sierra passes.
Motorists should be prepared for possible winter driving conditions
in the mountains this weekend. Good instability and shear on
Saturday will bring a threat of thunderstorms and possibly weak
tornadoes. Precipitation will taper off on Sunday with showers
mainly lingering over the Shasta County and down the Sierra. High
temperatures this weekend will be in the mid 60s to low 70s in the
Valley and mid 30s to low 50s in the mountains. Monday will be a
drier and warmer day with ridge building into the area as trough
shifts east.


.Extended Discussion (Tuesday through Friday)

Flat high pressure over the southwest U.S will keep at least the
southern half of the forecast area dry Tuesday. The northern
portions of the forecast area will see a continued threat of light
rain. Daytime high temperatures under mainly cloudy skies are
expected to come in a few to several degrees below normal. Another
cool low pressure system dropping out of the Gulf of Alaska will
bring precipitation chances southward Wednesday through Friday.
Significant model differences exist in the Wednesday-Friday time
frame. The European model is much deeper and brings deeper
moisture into Norcal versus the drier GFS. Have opted for a blend
of solutions but forecast confidence not high during this time
frame.

&&

.Aviation...

Pacific cold front moves across the area on Sat bringing chances of
rain and increasing winds. Wind gusts to 45 mph will be possible
after 12z especially over the northern valley.


&&

.STO Watches/Warnings/Advisories...
wind advisory from 5 am to 8 pm pdt saturday central sacramento
valley...northern sacramento valley...southern sacramento valley.

&&

$$











000
FXUS66 KSTO 242254
AFDSTO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
354 PM PDT Fri Oct 24 2014

.Synopsis...
Wet and windy weather moves in later tonight into Saturday as an
upper level trough and associated front move into the area.
Thunderstorms with heavy rain, accumulating small hail and gusty
winds and maybe even a weak tornado are possible on Saturday.
Snow levels will come down to below Sierra passes Saturday night.
Decreasing winds are expected Saturday evening and precipitation
will taper off Sunday. A brief break Monday will be followed by a
chance of rain over areas north of Sacramento Tuesday and
Wednesday. This precipitation threat will drop southward bringing rain or
mountain snow over much of NORCAL for the end of the next week.

&&

Upper level trough offshore of the West Coast will move into
Northern California tonight into Saturday bringing a change to wet
and windy weather. Increasing clouds and precipitation moving into the
Coastal range and Shasta County around midnight and spread
southeast across interior northern California Saturday. Southerly
winds will increase late tonight into Saturday as the cold front
and trough move inland. This will bring breezy and gust winds with
southerly winds 15 to 30 mph with gusts to around 40 mph in the
Valley...strongest in the Sacramento Valley and up to 70 mph over the
ridges. Holiday decorations should be secured with the gusty
winds and high profile vehicles should use caution. Winds should
be decreasing Saturday evening. Shasta County mountains could see
up to 2 inches of precipitation by Sunday morning with good
orographics with the southerly winds. Snow levels will be around
8000 ft Saturday morning and drop down to around 5000 to 6000 ft
on Sunday morning. Snow accumulations up to 10 inches are possible
on Mt Lassen and up to 4 inches possible over the higher Sierra
passes. Motorists should be prepared for possible winter driving
conditions in the mountains this weekend. Good instability and
shear on Saturday will bring a threat of thunderstorms and
possibly weak tornadoes. Precipitation will taper off on Sunday
with showers mainly lingering over the Shasta County and down the
Sierra. High temperatures this weekend will be in the mid 60s to
low 70s in the Valley and mid 30s to low 50s in the mountains.
Monday will be a drier and warmer day with ridge building into
the area as trough shifts east.


.Extended Discussion (Tuesday through Friday)

Flat high pressure over the southwest U.S will keep at least the
southern half of the forecast area dry Tuesday. The northern
portions of the forecast area will see a continued threat of light
rain. Daytime high temperatures under mainly cloudy skies are
expected to come in a few to several degrees below normal. Another
cool low pressure system dropping out of the Gulf of Alaska will
bring precipitation chances southward Wednesday through Friday.
Significant model differences exist in the Wednesday-Friday time
frame. The European model is much deeper and brings deeper
moisture into Norcal versus the drier GFS. Have opted for a blend
of solutions but forecast confidence not high during this time
frame.

&&

.Aviation...

High thin clouds with winds from the south between 10-15 mph in
the afternoon. A system spreads in late tonight and Saturday bringing
chances of rain and increasing winds. Wind gusts to 45 mph will be
possible after 12z especially over the northern valley.


&&

.STO Watches/Warnings/Advisories...
wind advisory from 5 am to 8 pm pdt saturday central sacramento
valley...northern sacramento valley...southern sacramento valley.

&&

$$









000
FXUS66 KSTO 241709
AFDSTO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
1009 AM PDT Fri Oct 24 2014

.Synopsis...
Warmer conditions today as a ridge of high pressure builds
over the western U.S. A weather system will bring rain, mountain
snow and windy conditions Saturday with showers Sunday. A brief
break Monday will be followed by a chance of rain over areas north
of Sacramento Tuesday and Wednesday. This precip threat will drop
southward bringing rain or mountain snow over much of NORCAL for
the end of the next week.

&&
Upper level trough in the Eastern Pacific with a weak ridge over
Northern California today. Areas of fog developed around Chico and
south to east of Modesto this morning. Fog became dense in some
locations this morning including Sacramento and Marysville so
dense fog advisory is out until 10 am as Visibilities are gradually
improving this morning. Temperatures this afternoon will be warmer
than yesterday with mostly sunny skies and a little warmer
airmass. Although temperatures will be similar to yesterday around
Sacramento  to Stockton with fog and low clouds this morning.

The trough approaches the coast tonight increasing the clouds and
spreading a threat of precipitation into the Coastal range and
Shasta County around midnight and spread southeast across interior
northern California Saturday. Southerly winds will increase late
tonight into Saturday as the cold front and trough move inland.
This will bring breezy and gust winds with gusts to around 40 mph
in the Valley and up to 60 mph in the mountains so holiday
decorations should be secured. Precipitation amounts are expected
to be around an inch in the mountains except Shasta County
mountains will see more due to good orographics. About a quarter
to half an inch in the Northern Sacramento Valley to less than a
tenth of inch in the northern San Joaquin Valley is expected. Some
instability Saturday afternoon and evening for threat of
thunderstorms. Winds should decrease Saturday evening and
precipitation decreasing Sunday morning. Snow levels will start
between 8000 and 9000 ft and drop to around 6000 to 7000 feet by
Sunday morning. Several inches of snow are possible around Mount
Lassen but only around a couple inches expected around the Sierra
passes. Precipitation will taper off on Sunday with showers mainly
lingering over the Shasta County and down the Sierra. Monday will
be a drier and warmer day with ridge building into the area as
trough shifts east.


.Extended Discussion (Tuesday through Friday)

Flat high pressure over the southwest U.S will keep at least the
southern half of the forecast area dry Tuesday and Wednesday. The
northern portions of the forecast area will see a continued threat
of light rain. Daytime high temperatures under mainly cloudy skies
are expected to come in a few to several degrees below normal.
Another cool low pressure system dropping out of the Gulf of
Alaska will bring precipitation chances southward on Thursday and
Friday. Models still not showing real good consistency during this
7 to 8 day time frame however both run to run and model to model so
forecast confidence not high during this time frame.

&&

.Aviation...

Lingering rainfall this morning is associated with a frontal
boundary currently located along the northern coastal range and
northern mountains. This is shifting north, with dry conditions to
the south. Areas of dense fog around KCIC to KSCK this morning
including Sacramento. Visibilities should increase aft 17z with
VFR/MVFR conditions expected this afternoon. High thin clouds
with winds from the south between 10-15 mph in the afternoon. A
system spreads in late tonight bringing chances of rain and
increasing winds.


&&

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

$$









000
FXUS66 KSTO 241146
AFDSTO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
446 AM PDT Fri Oct 24 2014

.Synopsis...
Dry and warmer conditions today as a ridge of high pressure builds
over the western U.S. A weather system will bring rain, mountain
snow and windy conditions Saturday with showers Sunday. A brief
break Monday will be followed by a chance of rain over areas north
of Sacramento Tuesday and Wednesday. This precip threat will drop
southward bringing rain or mountain snow over much of NORCAL for
the end of the next week.

&&

The high pressure ridge over the southwest U.S has continued to
build northward in response to a low pressure trough digging into
the eastern Pacific. Radar has shown the rain line over Shasta
county pushing northward overnight and at this time, only the far
northern most CWA is seeing any shower activity. This activity is
likely to clear by later today with mainly fair skies expected
over the entire CWA by afternoon. Clearer skies and a warmer
airmass will result in higher daytime temperatures today with many
locations hitting highs a little above normal. The offshore trough
will move coastward over night with the associated frontal system
moving onshore by morning. The main frontal passage impacts will
be during the afternoon on Saturday. Light to moderate amounts of
precipitation are expected with this system with perhaps the main
impact being a period of fairly strong winds. 9 or 10 mb surface
gradients are predicted between MFR and SAC between about 18z
Saturday and 00z Sunday with good upper level support from the
upper trough. Would expect the central and northern Sacramento
valley to hit wind advisory criteria during this time. Shear in
the central SAC valley is quite high and stability proggs showing
enough instability over the northern half of the CWA for a threat
of thunderstorms as well. Instability is somewhat weak however so
at this time would not expect to see much in the way of
significant thunderstorm activity. Main front passes east of the
CWA by Saturday evening and surface gradients drop off quickly.
Upper trough passes through Saturday night and early Sunday for a
continued threat of showers on Sunday mainly over the mountains.
Snow levels are expected to remain quite high especially during
the main precip event, not dropping until after frontal passage
Saturday. Therefore not expecting much snow at the higher
elevations with only an inch or two at pass levels. High pressure
ridging slides temporarily over over west coast on Monday for a
brief clearing and warming trend.
This weekend, the main weather system will move inland and bring
widespread rain and some breezy to locally windy conditions to
the region. Saturday looks to be the day with the most activity.
Winds, widespread showers and potential for afternoon/evening
isolated thunderstorms. At this time, the winds look like they`ll
be a nuisance for outdoor events and may blow holiday decorations
around. However, the slower progression of this system may result
in slightly higher winds. We will continue to monitor later runs
and see if any wind headlines are necessary. Also, the snow levels
are expected to lower to around 7000 feet Saturday night, so there
could be some light accumulations over the higher passes. Showers
will linger on Sunday, but should see decreasing showers from
south to north through the day. Precipitation amounts this weekend
should be a couple tenths in the San Joaquin Valley to up to half
an inch in the northern Sacramento Valley. The mountains could see
1-1.5 inches of liquid.

Monday will once again see a drying trend as a weak ridge builds
in behind the exiting system with temperatures rebounding to near
seasonal.



.Extended Discussion (Tuesday through Friday)

Flat high pressure over the southwest U.S will keep at least the
southern half of the forecast area dry Tuesday and Wednesday. The
northern portions of the forecast area will see a continued threat
of light rain. Daytime high temperatures under mainly cloudy skies
are expected to come in a few to several degrees below normal.
Another cool low pressure system dropping out of the Gulf of
Alaska will bring precipitation chances southward on Thursday and
Friday. Models still not showing real good consistency during this
7 to 8 day time frame however both run to run and model to model so
forecast confidence not high during this time frame.

&&

.Aviation...

Lingering rainfall this morning is associated with a frontal
boundary currently located along the northern coastal range and
northern mountains. This is shifting north, with dry conditions to
the south. VFR conditions for the Valley today except for lcl
MVFR/IFR possible in patchy BR/FG for the northern and central
Sacramento Valley through 16z this morning. High thin clouds with
winds from the south between 10-15 mph in the afternoon. A system
spreads in tonight late tonight bringing chances of rain and
increasing winds. EK


&&

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

$$









000
FXUS66 KSTO 240512
AFDSTO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
1010 PM PDT Thu Oct 23 2014

.Synopsis...
A stalled cold front will keep a chance of light rain over  the
northern mountains overnight. Dry and warming conditions on Friday
as a ridge of high pressure builds overhead. Stronger weather system
will move into northern California through the weekend bringing
rain...cooler temperatures and gusty winds.

&&

.Discussion...
Digging Ern Pac trof along 140W is beginning to amplify the
downstream ridge over the SWrn CONUS. The nearly stationary cold
front across the NWrn portion of the CWA is beginning to lift NNWwd
and should be mainly affecting the coastal range and Wrn portions of
Tehama/Shasta counties overnite before lifting NW of our CWA by late
Fri morning.

Much warmer temps expected over the Nrn third to half of our CWA on
Fri as the rain and thick cloud cover will yield to sunshine. Maxes
should be near or slightly above normal over our CWA...and some 10
to 17 degrees warmer over the Nrn half of the CWA and 2 to 5 degrees
over the Srn portion of the area which had filtered sunshine on
Thu.     JHM


.Previous Discussion...

This weekend, the main weather system will move inland and bring
widespread rain and some breezy to locally windy conditions to
the region. Saturday looks to be the day with the most activity.
Winds, widespread showers and potential for afternoon/evening
isolated thunderstorms. At this time, the winds look like they`ll
be a nuisance for outdoor events and may blow holiday decorations
around. However, the slower progression of this system may result
in slightly higher winds. We will continue to monitor later runs
and see if any wind headlines are necessary. Also, the snow levels
are expected to lower to around 7000 feet Saturday night, so there
could be some light accumulations over the higher passes. Showers
will linger on Sunday, but should see decreasing showers from
south to north through the day. Precipitation amounts this weekend
should be a couple tenths in the San Joaquin Valley to up to half
an inch in the northern Sacramento Valley. The mountains could see
1-1.5 inches of liquid.

.Extended Discussion (Monday through Thursday)

Monday will once again see a drying trend as a weak ridge builds
in behind the exiting system with temperatures rebounding to near
seasonal.

Tuesday through the end of the week, a series of weather systems
will flatten the ridge as they move through the Pacific Northwest.
These waves will result in an increase of clouds and cooler
temperatures with a chance of precipitation across the northern
mountains on Tuesday and Tuesday night. Beyond Tuesday night, the
models really begin to diverge so confidence in the Wednesday and
Thursday forecast is low. GFS rebuilds a fairly strong ridge over
the west coast Wednesday and Thursday, while the ECMWF and GEM
dig the next upper trough into the eastern Pacific. Therefore,
kept a slight chance of showers in the mountains and near seasonal
temperatures. We will continue to monitor the models and adjust
the forecast as needed.

&&

.Aviation...

Area of light rain has lifted NWwd mainly along and N of a line from
Yolla Bolly-RDD-Lassen Park...and is forecast to remain nearly
stationary or possibly lift a little father NWwd overnight. MVFR
conditions with isolated IFR over mtns or valleys possible overnite.
VFR SKC conditions from MYV Swd. Friday will see just high thin
clouds with winds from the south between 10-15 mph in the afternoon.


&&

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

$$











000
FXUS66 KSTO 232245
AFDSTO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
345 PM PDT Thu Oct 23 2014

.Synopsis...
A stalled cold front will keep showers over the northern
Sacramento valley this evening. Dry and warming conditions on
Friday as a ridge of high pressure builds overhead. Saturday the
main weather system will swing into northern California and bring
more rain and cooler temperatures to the region through the
weekend. Dry weather will start the work week, but more weather
systems will move into the Pacific northwest Tuesday with Northern
California seeing clouds and some light precipitation through mid week.

&&
A stalled cold front is resulting in a decent band of rain across
northern Sacramento valley, from Chico north, and adjacent
mountains. This front will shift north and west this evening,
shunting the showers out of the region by day break, as the main weather
system digs off the West Coast. Friday will be under high pressure
with plenty of sunshine and temperatures rebounding back to
normal.

This weekend, the main weather system will move inland and bring
widespread rain and some breezy to locally windy conditions to
the region. Saturday looks to be the day with the most activity.
Winds, widespread showers and potential for afternoon/evening
isolated thunderstorms. At this time, the winds look like they`ll
be a nuisance for outdoor events and may blow holiday decorations
around. However, the slower progression of this system may result
in slightly higher winds. We will continue to monitor later runs
and see if any wind headlines are necessary. Also, the snow levels
are expected to lower to around 7000 feet Saturday night, so there
could be some light accumulations over the higher passes. Showers
will linger on Sunday, but should see decreasing showers from
south to north through the day. Precipitation amounts this weekend
should be a couple tenths in the San Joaquin Valley to up to half
an inch in the northern Sacramento Valley. The mountains could see
1-1.5 inches of liquid.

.Extended Discussion (Monday through Thursday)

Monday will once again see a drying trend as a weak ridge builds
in behind the exiting system with temperatures rebounding to near
seasonal.

Tuesday through the end of the week, a series of weather systems
will flatten the ridge as they move through the Pacific Northwest.
These waves will result in an increase of clouds and cooler
temperatures with a chance of precipitation across the northern
mountains on Tuesday and Tuesday night. Beyond Tuesday night, the
models really begin to diverge so confidence in the Wednesday and
Thursday forecast is low. GFS rebuilds a fairly strong ridge over
the west coast Wednesday and Thursday, while the ECMWF and GEM
dig the next upper trough into the eastern Pacific. Therefore,
kept a slight chance of showers in the mountains and near seasonal
temperatures. We will continue to monitor the models and adjust
the forecast as needed.

&&

.Aviation...

A stalled cold front over northern Sacramento valley is producing a
persistent band of rain from Chico north to the Oregon border.
This rain is resulting in MVFR conditions with isolated IFR in
stronger cells. The rain will shift north and west between 02-08z
and remain along the coastal range and locations west overnight.
Ceilings will lift and shift west overnight as drier air moves
into the region. Friday will see just high thin clouds with winds
from the south between 10-15 mph in the afternoon.


&&

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

$$









000
FXUS66 KSTO 231158
AFDSTO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
458 AM PDT Thu Oct 23 2014

.Synopsis...
A weak Pacific cold front will drag slowly across NORCAL bringing
light precipitation north of about I-80 today and tonight. A brief
break Friday will be followed by another frontal passage on
Saturday with thunderstorms possible north of the Sacramento
area. Drying and warming most areas early next week then another
frontal system moving in around Tuesday. Weather model confidence
decreases by mid week but more light precip possible next Wednesday
and Thursday mainly north of Sacramento.

&&

A weak Pacific cold front dragging across the northwest corner of
the state is bringing light precipitation from about Chico
northward. The precipitation is forecast to continue moving very
slowly to the southeast with light precipitation reaching
southward to about the Sacramento area by 00z this afternoon.
Cloud cover and a slightly cooler airmass will bring slightly
cooler temperatures today. High pressure is forecast to rebound
northward over the western U.S on Friday limiting any
precipitation to the far northwest corner of the state. Clearing
skies and a warming airmass under the ridge will bring daytime
highs to near or a little above normal Friday. A Pacific low
pressure system approaching the coast will bring a threat of
precipitation inland Friday night with a chance of rain and high
elevation snow across the entire forecast area by Saturday
afternoon and evening. Precipitable water proggs show a moderate
amount of moisture associated with this system with moderate
dynamics but it will take mountain orograhics to squeeze out more
than light precipitation. 500 mb winds associated with the main
frontal passage early Saturday are progged to top 60 mph so
ridgetops may see some fairly gusty winds. Stability proggs show
enough instability behind the cold front for a threat of
thunderstorms Saturday afternoon and evening across the northern
CWA. As the upper trough passes through the Pacific Northwest
Saturday night and Sunday, winds will decrease and precipitation
will shift to the northeast. Daytime highs over the weekend will
remain well below normal under the cool airmass behind the front.

.Extended Discussion (Monday through Thursday)

Monday looks like a dry day with models rebuilding a ridge over
the eastern Pacific and west coast. Daytime highs may push back up
to near normal. A shortwave trough moving through the Paciiic
Northwest will flatten the west coast ridge on Tuesday bringing
clouds and cooler temperatures with a chance of precipitaton
across the northern mountains. After Tuesday...models really begin
to diverge so confidense in the day 6 plus forecast not real high.
GFS rebuilds a fairly strong ridge over the west coast Wednesday
and Thursday and has been doing so over the last couple of runs.
ECMWF and GEM dig the next upper trough into the eastern Pacific
Wednesday and Thursday bringing cooler temperatures and a
continued threat of precipitation especially across the northern
portions of the forecast area. Have leaned towards the more stable
ECMWF and GEM for now but will continue to watch model
developments in this time frame.

&&

.Aviation...

Cold front moving on shore today with increasing rain spreading
into the northern Sacramento Valley, peaking around 15z-21z. This
will bring some lcl visibilities reduced to MVFR levels, IFR in
the mountains. Local precipitation will stay mainly north of I80 today,
and will decrease in intensity by 00z. Mid level cloud cover will
increase over the rest of the area. Winds around 10 kt or less
expected today for TAF sites. EK

&&

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

$$









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