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000
FXUS66 KLOX 050338
AFDLOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
838 PM PDT WED MAY 4 2016

.SYNOPSIS...

An slow-moving upper level low pressure system will bring a chance
of showers and a slight chance of thunderstorms to southwestern
California from Thursday through the weekend. Below normal
temperatures can also be expected during the period. High pressure
will then bring mostly clear skies with a warming trend to the area
Monday through the middle of next week.

&&

.UPDATE...

Latest satellite/surface obs indicate mostly clear/partly cloudy
skies as low clouds have dissipated across most areas. Latest
sounding data indicates marine inversion ranging in depth from
3700 feet north of Point Conception to about 1800 feet south of
Point Conception.

In the immediate short term, the main concern will be the
approaching upper low and its impact upon the marine layer. With
the low approaching overnight and strong onshore gradients, will
expect the marine inversion to deepen all areas overnight. So,
will expect stratus to develop late this evening and overnight,
reaching into the coastal slopes. Additionally with such rapid
deepening, some patchy drizzle cannot be ruled out across most
coastal and valley areas late tonight/Thursday morning. Also there
will be the possibility of some light showers developing overnight
over SLO/SBA counties as the low approaches.

Overall, only minor tweaks to the forecast for the immediate
short term this evening, mainly just to adjust cloud wording for
the first period. Otherwise, based on initial 00Z model data, the
current forecast looks on track.

&&

.SHORT TERM...(WED-SAT)

Cloudy skies and a lingering marine incursion have helped to keep
temperatures cool today across the region. Winds have increased as
well ahead of the incoming low pressure system... especially
across Ventura and Los Angeles Counties... but will remain below
advisory criteria for now.

The low center is currently off the Central Coast and will begin
to move more easterly in the next few hours. This will increase
the cloud cover and winds... result in further cooling... and
bring a chance of showers to the entire region beginning on
Thursday. Some light drizzle may come to coastal areas late
tonight.

The low center is projected to move onshore late Thursday across
southeastern California and with it will come a slight chance of
thunderstorms as well. The thunderstorm forecast is a bit tricky
as there looks to be decent instability and more buoyant energy
than usual for the region but moisture is limited in the primary
lift zones and this is projected to be an issue throughout the
event. Higher PWs will be to the south and west of the best
instability and lift and as the low center moves through it is
possible that enough is pulled in where needed for good convective
development. If so then any thunderstorms that move beyond initial
development could strengthen rapidly. If not then a ridgeline
of weak Cb clouds may be the best that can be done. So the chance
is slight... but the potential is strong.

Northern Ventura County has been the focus during the past couple
of days for the best projected instability and CAPE. Thursday and
Friday both look to have good potential and on Friday this
potential expands westward to include much of eastern Santa
Barbara County. The is a slight chance for some development in the
mountains of Los Angeles County on Thursday but the better chance
will come on Friday and Saturday. With the better moisture
availability to the south during that period it may be that the
most activity will be over the marine zones.

.LONG TERM...(SUN-WED)

There is a chance for lingering showers on Sunday... primarily
over the mountains and especially over the Los Angeles County
mountains. The chance for thunderstorms is very low but not zero
and as the low center shifts with time there may be a last shot on
Sunday.

By Monday the low will be moving eastward... the skies clearing...
and temperatures will be warmer. A solid ridge of high pressure
will build off the coast and conditions should be dry and warming
into the next work week. Some overnight low clouds and fog may
return to the coastal areas.

&&

.AVIATION...04/2330Z...

At 2330Z, the marine inversion at KLAX was based at 2500 feet.
The top of the inversion was 3600 feet with a temperature of 14
degrees Celsius.

Overall, low to moderate confidence in 00Z TAF package. Latest
satellite imagery shows low clouds have dissipated rather nicely
this afternoon with only some scattered high clouds overhead.
Stratus should redevelop overnight west of the mountains, but low
confidence in timing of redevelopment. Also with a rapidly
deepening marine inversion, there may be some drizzle Thursday
morning.

KLAX...low confidence in 00Z TAF. High confidence in return of
MVFR ceilings overnight, but low confidence in timing (+/-3 hours
of current 05Z forecast). MVFR ceilings should continue through
Thursday afternoon with some drizzle possible Thursday morning.

KBUR...low confidence in 00Z TAF. High confidence in return of
MVFR ceilings overnight, but low confidence in timing (+/- 3 hours
of current 09Z forecast). MVFR ceilings should continue through
Thursday afternoon with some drizzle possible Thursday morning.

&&

.MARINE...04/800 PM...

For the Outer Waters, good confidence in current forecast. Both
winds and seas are expected to remian below SCA levels through the
weekend.

For the Inner Waters, good confidence in current forecast. Both
winds and seas are expected to remain below SCA levels through the
weekend.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...NONE.

&&

$$

PUBLIC...KJ/RAT
AVIATION...RAT
MARINE...RAT
SYNOPSIS...Sirard

weather.gov/losangeles





000
FXUS66 KLOX 042332
AFDLOX

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
432 PM PDT WED MAY 4 2016

.SYNOPSIS...

The onshore flow will bring overnight clouds...fog and drizzle
into early Thursday. Then a low should arrive by Thursday
afternoon for a chance of showers and thuderstorms into Saturday
night... with showers to linger in the mountains on Sunday. The
temperatures will remain below normal into early next week...then
a warming trend into midweek as a high builds in.

&&

.SHORT TERM...(TDY-SAT)

Cloudy skies and a lingering marine incursion have helped to keep
temperatures cool today across the region. Winds have increased as
well ahead of the incoming low pressure system... especially
across Ventura and Los Angeles Counties... but will remain below
advisory criteria for now.

The low center is currently off the Central Coast and will begin
to move more easterly in the next few hours. This will increase
the cloud cover and winds... result in further cooling... and
bring a chance of showers to the entire region beginning on
Thursday. Some light drizzle may come to coastal areas late
tonight.

The low center is projected to move onshore late Thursday across
southeastern California and with it will come a slight chance of
thunderstorms as well. The thunderstorm forecast is a bit tricky
as there looks to be decent instability and more buoyant energy
than usual for the region but moisture is limited in the primary
lift zones and this is projected to be an issue throughout the
event. Higher PWs will be to the south and west of the best
instability and lift and as the low center moves through it is
possible that enough is pulled in where needed for good convective
development. If so then any thunderstorms that move beyond initial
development could strengthen rapidly. If not then a ridgeline
of weak Cb clouds may be the best that can be done. So the chance
is slight... but the potential is strong.

Northern Ventura County has been the focus during the past couple
of days for the best projected instability and CAPE. Thursday and
Friday both look to have good potential and on Friday this
potential expands westward to include much of eastern Santa
Barbara County. The is a slight chance for some development in the
mountains of Los Angeles County on Thursday but the better chance
will come on Friday and Saturday. With the better moisture
availability to the south during that period it may be that the
most activity will be over the marine zones.


.LONG TERM...(SUN-WED)

There is a chance for lingering showers on Sunday... primarily
over the mountains and especially over the Los Angeles County
mountains. The chance for thunderstorms is very low but not zero
and as the low center shifts with time there may be a last shot on
Sunday.

By Monday the low will be moving eastward... the skies clearing...
and temperatures will be warmer. A solid ridge of high pressure
will build off the coast and conditions should be dry and warming
into the next work week. Some overnight low clouds and fog may
return to the coastal areas.

&&

.AVIATION...04/2330Z...

At 2330Z, the marine inversion at KLAX was based at 2500 feet.
The top of the inversion was 3600 feet with a temperature of 14
degrees Celsius.

Overall, low to moderate confidence in 00Z TAF package. Latest
satellite imagery shows low clouds have dissipated rather nicely
this afternoon with only some scattered high clouds overhead.
Stratus should redevelop overnight west of the mountains, but low
confidence in timing of redevelopment. Also with a rapidly
deepening marine inversion, there may be some drizzle Thursday
morning.

KLAX...low confidence in 00Z TAF. High confidence in return of
MVFR ceilings overnight, but low confidence in timing (+/-3 hours
of current 05Z forecast). MVFR ceilings should continue through
Thursday afternoon with some drizzle possible Thursday morning.

KBUR...low confidence in 00Z TAF. High confidence in return of
MVFR ceilings overnight, but low confidence in timing (+/- 3 hours
of current 09Z forecast). MVFR ceilings should continue through
Thursday afternoon with some drizzle possible Thursday morning.
At 1610Z at KLAX the marine layer was 2800 feet deep. The top of
the inversion was 4300 feet with a temperature of 14 degrees
Celsius.

&&

.MARINE...04/200 PM...

For the Outer Waters, good confidence in current forecast. Winds
and seas are expected to remain below SCA levels through the
weekend. However there is a 30% chance that some SCA level gusts
could develop Friday afternoon/evening across western sections of
the Outer Waters.

For the Inner Waters, good confidence in current forecast. Winds
and seas are expected to remain below SCA levels through the
weekend.


&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...NONE.

&&

$$

PUBLIC...KJ
AVIATION...RAT
MARINE...Sweet
SYNOPSIS...Seto

weather.gov/losangeles





000
FXUS66 KLOX 042105
AFDLOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
205 PM PDT WED MAY 4 2016

.SYNOPSIS...

The onshore flow will bring overnight clouds...fog and drizzle
into early Thursday. Then a low will arrive on Thursday with
a chance of showers and thuderstorms into Saturday night...
with showers to linger in the mountains on Sunday. The
temperatures will remain below normal into early next week...then
a warming trend into midweek as a high builds in.

&&

.SHORT TERM...(TDY-SAT)

Cloudy skies and a lingering marine incursion have helped to keep
temperatures cool today across the region. Winds have increased as
well ahead of the incoming low pressure system... especially
across Ventura and Los Angeles Counties... but will remain below
advisory criteria for now.

The low center is currently off the Central Coast and will begin
to move more easterly in the next few hours. This will increase
the cloud cover and winds... result in further cooling... and
bring a chance of showers to the entire region beginning on
Thursday. Some light drizzle may come to coastal areas late
tonight.

The low center is projected to move onshore late Thursday across
southeastern California and with it will come a slight chance of
thunderstorms as well. The thunderstorm forecast is a bit tricky
as there looks to be decent instability and more buoyant energy
than usual for the region but moisture is limited in the primary
lift zones and this is projected to be an issue throughout the
event. Higher PWs will be to the south and west of the best
instability and lift and as the low center moves through it is
possible that enough is pulled in where needed for good convective
development. If so then any thunderstorms that move beyond initial
development could strengthen rapidly. If not then a ridgeline
of weak Cb clouds may be the best that can be done. So the chance
is slight... but the potential is strong.

Northern Ventura County has been the focus during the past couple
of days for the best projected instability and CAPE. Thursday and
Friday both look to have good potential and on Friday this
potential expands westward to include much of eastern Santa
Barbara County. The is a slight chance for some development in the
mountains of Los Angeles County on Thursday but the better chance
will come on Friday and Saturday. With the better moisture
availability to the south during that period it may be that the
most activity will be over the marine zones.

.LONG TERM...(SUN-TUE)

There is a chance for lingering showers on Sunday... primarily
over the mountains and especially over the Los Angeles County
mountains. The chance for thunderstorms is very low but not zero
and as the low center shifts with time there may be a last shot on
Sunday.

By Monday the low will be moving eastward... the skies clearing...
and temperatures will be warmer. A solid ridge of high pressure
will build off the coast and conditions should be dry and warming
into the next work week. Some overnight low clouds and fog may
return to the coastal areas.

&&

.AVIATION...04/1800z.

At 1610Z at KLAX the marine layer was 2800 feet deep. The top of
the inversion was 4300 feet with a temperature of 14 degrees
Celsius.

Low to moderate confidence in the 18z tafs. Marine clouds are
completely dominant in the coastal and valley sections. The deep
marine layer will deepen further as a trough approaches today with
only partial afternoon clearing expected in a few places near the
coast late this afternoon. Skies are expected to remain cloudy
through thursday morning with mostly MVFR to VFR ceilings. By
thursday morning there will also be a possibility of drizzle or
light showers in some locations.

KLAX...Low to moderate confidence in the 18z TAF. There is a 30
percent chc that MVFR cigs will scour out after 23z.

BUR...Low to moderate confidence in the 18z TAF. There is a 10
percent chc that MVFR cigs will scour out after 23z.

&&

.MARINE...04/200 PM...

For the Outer Waters, good confidence in current forecast. Winds
and seas are expected to remain below SCA levels through the
weekend. However there is a 30% chance that some SCA level gusts
could develop Friday afternoon/evening across western sections of
the Outer Waters.

For the Inner Waters, good confidence in current forecast. Winds
and seas are expected to remain below SCA levels through the
weekend.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...NONE.

&&
$$

PUBLIC...KJ
AVIATION...Sweet
MARINE...Sweet
SYNOPSIS...Seto

weather.gov/losangeles





000
FXUS66 KLOX 042102
AFDLOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
202 PM PDT WED MAY 4 2016

.SYNOPSIS...

The onshore flow will bring overnight clouds...fog and drizzle
into early Thursday. Then a low will arrive Thursday with a chance
of showers and thuderstorms into Saturday night... with showers to
linger in the mountains on Sunday. The temperatures will remain
below normal into early next week...then a warming trend into
midweek as a high builds in.

&&

.SHORT TERM...(TDY-FRI)

Cloudy skies and a lingering marine incursion have helped to keep
temperatures cool today across the region. Winds have increased as
well ahead of the incoming low pressure system... especially
across Ventura and Los Angeles Counties... but will remain below
advisory criteria for now.

The low center is currently off the Central Coast and will begin
to move more easterly in the next few hours. This will increase
the cloud cover and winds... result in further cooling... and
bring a chance of showers to the entire region beginning on
Thursday. Some light drizzle may come to coastal areas late
tonight.

The low center is projected to move onshore late Thursday across
southeastern California and with it will come a slight chance of
thunderstorms as well. The thunderstorm forecast is a bit tricky
as there looks to be decent instability and more buoyant energy
than usual for the region but moisture is limited in the primary
lift zones and this is projected to be an issue throughout the
event. Higher PWs will be to the south and west of the best
instability and lift and as the low center moves through it is
possible that enough is pulled in where needed for good convective
development. If so then any thunderstorms that move beyond initial
development could strengthen rapidly. If not then a ridgeline
of weak Cb clouds may be the best that can be done. So the chance
is slight... but the potential is strong.

Northern Ventura County has been the focus during the past couple
of days for the best projected instability and CAPE. Thursday and
Friday both look to have good potential and on Friday this
potential expands westward to include much of eastern Santa
Barbara County. The is a slight chance for some development in the
mountains of Los Angeles County on Thursday but the better chance
will come on Friday and Saturday. With the better moisture
availability to the south during that period it may be that the
most activity will be over the marine zones.

.LONG TERM...(SAT-TUE)

There is a chance for lingering showers on Sunday... primarily
over the mountains and especially over the Los Angeles County
mountains. The chance for thunderstorms is very low but not zero
and as the low center shifts with time there may be a last shot on
Sunday.

By Monday the low will be moving eastward... the skies clearing...
and temperatures will be warmer. A solid ridge of high pressure
will build off the coast and conditions should be dry and warming
into the next work week. Some overnight low clouds and fog may
return to the coastal areas.

&&

.AVIATION...04/1800z.

At 1610Z at KLAX the marine layer was 2800 feet deep. The top of
the inversion was 4300 feet with a temperature of 14 degrees
Celsius.

Low to moderate confidence in the 18z tafs. Marine clouds are
completely dominant in the coastal and valley sections. The deep
marine layer will deepen further as a trough approaches today with
only partial afternoon clearing expected in a few places near the
coast late this afternoon. Skies are expected to remain cloudy
through thursday morning with mostly MVFR to VFR ceilings. By
thursday morning there will also be a possibility of drizzle or
light showers in some locations.

KLAX...Low to moderate confidence in the 18z TAF. There is a 30
percent chc that MVFR cigs will scour out after 23z.

BUR...Low to moderate confidence in the 18z TAF. There is a 10
percent chc that MVFR cigs will scour out after 23z.

&&

.MARINE...04/200 PM...

For the Outer Waters, good confidence in current forecast. Winds
and seas are expected to remain below SCA levels through the
weekend. However there is a 30% chance that some SCA level gusts
could develop Friday afternoon/evening across western sections of
the Outer Waters.

For the Inner Waters, good confidence in current forecast. Winds
and seas are expected to remain below SCA levels through the
weekend.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...NONE.

&&
$$

PUBLIC...KJ
AVIATION...Sweet
MARINE...Sweet
SYNOPSIS...Seto

weather.gov/losangeles





000
FXUS66 KLOX 041800
AFDLOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
1100 AM PDT WED MAY 4 2016

.SYNOPSIS...

The onshore flow will bring overnight clouds...fog and drizzle
into early Thursday. Then a low should arrive by Thursday
afternoon for a chance of showers and thuderstorms into Saturday
night... with showers to linger in the mountains on Sunday. The
temperatures will remain below normal into early next week...then
a warming trend into midweek as a high builds in.

&&

.UPDATE...

A strong marine incursion topped by increasing incursion of higher
clouds will keep afternoon temperatures cooler today and that is
reflected in the hourly readings. Winds will likely strengthen a
bit but are expected to remain below advisory levels at this time.

The incoming low pressure system and the timing and intensity of
showers and thunderstorms will be the focus of the shift today.
Overall the period of possible precipitation remains Thursday
through Sunday and am not anticipating any significant changes to
the forecast package. There is an increasing possibility of
convective activity on Saturday and that will be a particular
focus for today.

&&

.SHORT TERM...(TDY-FRI)

Southern California`s weather will be dominated by a cut off low
over the next four days. Currently the upper low is just a trof in
the process of cutting off about 400 miles west of Point
Conception...it will be a fully formed cut off later this
afternoon. Today will be a mostly cloudy day as mid and high level
clouds stream over a large marine layer created by increasing
onshore flow and the lift from the trof. There will be some
patchy fog this morning under the marine layer but nothing too
bad. By afternoon the onshore gradients will be over 7mb to KDAG
(or 9mb if you believe the NAM which is not a good idea) This
increase in the onshore push to the east will keep the low clouds
going near the coast. It will also create breezy conditions across
SLO county and the Antelope vly this afternoon. Max temps will
nose drive under the clouds...the falling hgts and the increasing
onshore flow.

The extra lift and the strong onshore flow will likely create a
very deep marine layer and some drizzle over the coasts and vlys
and into the foothills tonight.

The upper low will move within 60 miles of SLO county on Thursday.
hgts will drop to 558 DM and there will be further cooling under
mostly cloudy skies. Small vort maxes will rotate into and out of
the area all day and hit or miss showers will likely develop
throughout the day. Convective parameters look decent across the
interior and there is a slight chc of TSTMs there. Mdl sounding
show good potential for hail as well. Rainfall amounts will be
highly variable and spotty with a tenth of an inch the best bet
and an outside chc of some quarter inch amounts. Snow levels will
fall to about 6500 feet.

The shower threat will persist overngiht but the TSTM threat will
diminish.

On Friday the upper low moves from Point Conception over Srn SBA
county and then over and through VTA and L.A. counties. The
lift...vorticity...and cold pool assoc with low will bring good
convective parameters to VTA and LA county and there will be a
good chance of showers and a slight chc of TSTMs over both
counties. There will be a little more moisture to work with and
can see a little more rainfall over the area...esp over VTA and LA
county. The big question mark will be cloud cover. Right now it
looks like it will be a mostly cloudy day...but if the mid and
upper level clouds are a little less than fcst and it turns into a
partly cloudy day...then watch out. The greater SFC heating during
peak hours in the afternoon will match perfectly with the cold
pool aloft moving over the area and this would allow for a much
bigger convective outbreak.

Shower activity will diminish Friday night.

Saturday could also be an interesting day. In fact it may well be
the most convective day of the next four. The upper low will move
to the UT/NV/AZ border triple point where it will be in perfect
position to advect vort maxes into the interior sections of the
forecast area. There should be much less in the way of clouds so
look for much better sfc heating. This instability could well
interact with the incoming PVA and kick off a very nice convective
outbreak. The coasts and vlys will see much more sunshine than the
previous three days (or the next three days depending on you like
to look at things) and there will be a nice bump up in max temps.



.LONG TERM...(SAT-TUE)


By Sunday the upper low will be far enough away that the only
threat of showers will be confined to the interior sections and
esp the L.A. mtns. There will be noticeable decrease in clouds
and corresponding warm up in temps.

Ridging moves into the area on Monday and intensifies on Tuesday.
Max temps will warm each day and most areas will be above normal
by Tuesday. The high pressure aloft will create a strong enough
marine inversion that some night through morning low clouds will
likely form over the LA coast.

&&

.AVIATION...04/1800z.

At 1610Z at KLAX the marine layer was 2800 feet deep. The top of
the inversion was 4300 feet with a temperature of 14 degrees
Celsius.

Low to moderate confidence in the 18z tafs. Marine clouds are
completely dominant in the coastal and valley sections. The deep
marine layer will deepen further as a trough approaches today with
only partial afternoon clearing expected in a few places near the
coast late this afternoon. Skies are expected to remain cloudy
through thursday morning with mostly MVFR to VFR ceilings. By
thursday morning there will also be a possibility of drizzle or
light showers in some locations.

KLAX...Low to moderate confidence in the 18z TAF. There is a 30
percent chc that MVFR cigs will scour out after 23z.

BUR...Low to moderate confidence in the 18z TAF. There is a 10
percent chc that MVFR cigs will scour out after 23z.

&&

.MARINE...04/0900 aM...

For the Outer Waters, good confidence in current forecast. Winds
and seas are expected to remain below SCA levels through the
weekend. However there is a 30% chance that some SCA level gusts
could develop Friday afternoon/evening across western sections of
the Outer Waters.

For the Inner Waters, good confidence in current forecast. Winds
and seas are expected to remain below SCA levels through the
weekend.


&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...NONE.

&&

$$

PUBLIC...KJ
AVIATION...Sweet
MARINE...Sweet
SYNOPSIS...Seto

weather.gov/losangeles





000
FXUS66 KLOX 041800
AFDLOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
1100 AM PDT WED MAY 4 2016

.SYNOPSIS...

The onshore flow will bring overnight clouds...fog and drizzle
into early Thursday. Then a low should arrive by Thursday
afternoon for a chance of showers and thuderstorms into Saturday
night... with showers to linger in the mountains on Sunday. The
temperatures will remain below normal into early next week...then
a warming trend into midweek as a high builds in.

&&

.UPDATE...

A strong marine incursion topped by increasing incursion of higher
clouds will keep afternoon temperatures cooler today and that is
reflected in the hourly readings. Winds will likely strengthen a
bit but are expected to remain below advisory levels at this time.

The incoming low pressure system and the timing and intensity of
showers and thunderstorms will be the focus of the shift today.
Overall the period of possible precipitation remains Thursday
through Sunday and am not anticipating any significant changes to
the forecast package. There is an increasing possibility of
convective activity on Saturday and that will be a particular
focus for today.

&&

.SHORT TERM...(TDY-FRI)

Southern California`s weather will be dominated by a cut off low
over the next four days. Currently the upper low is just a trof in
the process of cutting off about 400 miles west of Point
Conception...it will be a fully formed cut off later this
afternoon. Today will be a mostly cloudy day as mid and high level
clouds stream over a large marine layer created by increasing
onshore flow and the lift from the trof. There will be some
patchy fog this morning under the marine layer but nothing too
bad. By afternoon the onshore gradients will be over 7mb to KDAG
(or 9mb if you believe the NAM which is not a good idea) This
increase in the onshore push to the east will keep the low clouds
going near the coast. It will also create breezy conditions across
SLO county and the Antelope vly this afternoon. Max temps will
nose drive under the clouds...the falling hgts and the increasing
onshore flow.

The extra lift and the strong onshore flow will likely create a
very deep marine layer and some drizzle over the coasts and vlys
and into the foothills tonight.

The upper low will move within 60 miles of SLO county on Thursday.
hgts will drop to 558 DM and there will be further cooling under
mostly cloudy skies. Small vort maxes will rotate into and out of
the area all day and hit or miss showers will likely develop
throughout the day. Convective parameters look decent across the
interior and there is a slight chc of TSTMs there. Mdl sounding
show good potential for hail as well. Rainfall amounts will be
highly variable and spotty with a tenth of an inch the best bet
and an outside chc of some quarter inch amounts. Snow levels will
fall to about 6500 feet.

The shower threat will persist overngiht but the TSTM threat will
diminish.

On Friday the upper low moves from Point Conception over Srn SBA
county and then over and through VTA and L.A. counties. The
lift...vorticity...and cold pool assoc with low will bring good
convective parameters to VTA and LA county and there will be a
good chance of showers and a slight chc of TSTMs over both
counties. There will be a little more moisture to work with and
can see a little more rainfall over the area...esp over VTA and LA
county. The big question mark will be cloud cover. Right now it
looks like it will be a mostly cloudy day...but if the mid and
upper level clouds are a little less than fcst and it turns into a
partly cloudy day...then watch out. The greater SFC heating during
peak hours in the afternoon will match perfectly with the cold
pool aloft moving over the area and this would allow for a much
bigger convective outbreak.

Shower activity will diminish Friday night.

Saturday could also be an interesting day. In fact it may well be
the most convective day of the next four. The upper low will move
to the UT/NV/AZ border triple point where it will be in perfect
position to advect vort maxes into the interior sections of the
forecast area. There should be much less in the way of clouds so
look for much better sfc heating. This instability could well
interact with the incoming PVA and kick off a very nice convective
outbreak. The coasts and vlys will see much more sunshine than the
previous three days (or the next three days depending on you like
to look at things) and there will be a nice bump up in max temps.



.LONG TERM...(SAT-TUE)


By Sunday the upper low will be far enough away that the only
threat of showers will be confined to the interior sections and
esp the L.A. mtns. There will be noticeable decrease in clouds
and corresponding warm up in temps.

Ridging moves into the area on Monday and intensifies on Tuesday.
Max temps will warm each day and most areas will be above normal
by Tuesday. The high pressure aloft will create a strong enough
marine inversion that some night through morning low clouds will
likely form over the LA coast.

&&

.AVIATION...04/1800z.

At 1610Z at KLAX the marine layer was 2800 feet deep. The top of
the inversion was 4300 feet with a temperature of 14 degrees
Celsius.

Low to moderate confidence in the 18z tafs. Marine clouds are
completely dominant in the coastal and valley sections. The deep
marine layer will deepen further as a trough approaches today with
only partial afternoon clearing expected in a few places near the
coast late this afternoon. Skies are expected to remain cloudy
through thursday morning with mostly MVFR to VFR ceilings. By
thursday morning there will also be a possibility of drizzle or
light showers in some locations.

KLAX...Low to moderate confidence in the 18z TAF. There is a 30
percent chc that MVFR cigs will scour out after 23z.

BUR...Low to moderate confidence in the 18z TAF. There is a 10
percent chc that MVFR cigs will scour out after 23z.

&&

.MARINE...04/0900 aM...

For the Outer Waters, good confidence in current forecast. Winds
and seas are expected to remain below SCA levels through the
weekend. However there is a 30% chance that some SCA level gusts
could develop Friday afternoon/evening across western sections of
the Outer Waters.

For the Inner Waters, good confidence in current forecast. Winds
and seas are expected to remain below SCA levels through the
weekend.


&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...NONE.

&&

$$

PUBLIC...KJ
AVIATION...Sweet
MARINE...Sweet
SYNOPSIS...Seto

weather.gov/losangeles





000
FXUS66 KLOX 041612
AFDLOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
912 AM PDT WED MAY 4 2016

.SYNOPSIS...

The onshore flow will bring overnight clouds...fog and drizzle
into early Thursday. Then a low arrives on Thursday for a chance
of showers and thuderstorms into Saturday night... with showers
to linger in the mountains on Sunday. The temperatures will
remain below normal into early next week...then a warming trend
into midweek as a high builds in.

&&

.UPDATE...

A strong marine incursion topped by increasing incursion of higher
clouds will keep afternoon temperatures cooler today and that is
reflected in the hourly readings. Winds will likely strengthen a
bit but are expected to remain below advisory levels at this time.

The incoming low pressure system and the timing and intensity of
showers and thunderstorms will be the focus of the shift today.
Overall the period of possible precipitation remains Thursday
through Sunday and am not anticipating any significant changes to
the forecast package. There is an increasing possibility of
convective activity on Saturday and that will be a particular
focus for today.

&&

.SHORT TERM...(TDY-FRI)

Southern California`s weather will be dominated by a cut off low
over the next four days. Currently the upper low is just a trof in
the process of cutting off about 400 miles west of Point
Conception...it will be a fully formed cut off later this
afternoon. Today will be a mostly cloudy day as mid and high level
clouds stream over a large marine layer created by increasing
onshore flow and the lift from the trof. There will be some
patchy fog this morning under the marine layer but nothing too
bad. By afternoon the onshore gradients will be over 7mb to KDAG
(or 9mb if you believe the NAM which is not a good idea) This
increase in the onshore push to the east will keep the low clouds
going near the coast. It will also create breezy conditions across
SLO county and the Antelope vly this afternoon. Max temps will
nose drive under the clouds...the falling hgts and the increasing
onshore flow.

The extra lift and the strong onshore flow will likely create a
very deep marine layer and some drizzle over the coasts and vlys
and into the foothills tonight.

The upper low will move within 60 miles of SLO county on Thursday.
hgts will drop to 558 DM and there will be further cooling under
mostly cloudy skies. Small vort maxes will rotate into and out of
the area all day and hit or miss showers will likely develop
throughout the day. Convective parameters look decent across the
interior and there is a slight chc of TSTMs there. Mdl sounding
show good potential for hail as well. Rainfall amounts will be
highly variable and spotty with a tenth of an inch the best bet
and an outside chc of some quarter inch amounts. Snow levels will
fall to about 6500 feet.

The shower threat will persist overngiht but the TSTM threat will
diminish.

On Friday the upper low moves from Point Conception over Srn SBA
county and then over and through VTA and L.A. counties. The
lift...vorticity...and cold pool assoc with low will bring good
convective parameters to VTA and LA county and there will be a
good chance of showers and a slight chc of TSTMs over both
counties. There will be a little more moisture to work with and
can see a little more rainfall over the area...esp over VTA and LA
county. The big question mark will be cloud cover. Right now it
looks like it will be a mostly cloudy day...but if the mid and
upper level clouds are a little less than fcst and it turns into a
partly cloudy day...then watch out. The greater SFC heating during
peak hours in the afternoon will match perfectly with the cold
pool aloft moving over the area and this would allow for a much
bigger convective outbreak.

Shower activity will diminish Friday night.

Saturday could also be an interesting day. In fact it may well be
the most convective day of the next four. The upper low will move
to the UT/NV/AZ border triple point where it will be in perfect
position to advect vort maxes into the interior sections of the
forecast area. There should be much less in the way of clouds so
look for much better sfc heating. This instability could well
interact with the incoming PVA and kick off a very nice convective
outbreak. The coasts and vlys will see much more sunshine than the
previous three days (or the next three days depending on you like
to look at things) and there will be a nice bump up in max temps.

.LONG TERM...(SAT-TUE)

By Sunday the upper low will be far enough away that the only
threat of showers will be confined to the interior sections and
esp the L.A. mtns. There will be noticeable decrease in clouds
and corresponding warm up in temps.

Ridging moves into the area on Monday and intensifies on Tuesday.
Max temps will warm each day and most areas will be above normal
by Tuesday. The high pressure aloft will create a strong enough
marine inversion that some night through morning low clouds will
likely form over the LA coast.

&&

.AVIATION...04/1150

At 1131Z at KLAX the marine layer was 1500 feet deep. The top of
the inversion was 3100 feet with a temperature of 17 degrees
Celsius.

N of Point Conception...Moderate confidence that lifr cigs will
move up two categories to mvfr by 18z. 30% chance to remain in ifr
conds through 18z. 30% that cigs will scatter out after 20z.
Higher confidence for cigs to remain in mvfr category tonight into
Thursday.

S of Point Conception...Moderate confidence that ifr cigs will
become mvfr by 17z. 40% chance that cigs will scour out before
21z. 20 percent chance for cigs to go into vfr for a portion of
the afternoon hours. better chance for Thursday.

KLAX...Fair confidence in 12z TAF. There is a 30 percent chc that
MVFR cigs will scour out after 20z. There is a 20 percent chance
that cigs will get to vfr late this afternoon.

KBUR...good confidence that there will be mvfr cigs...with 30
percent chance for ifr cigs through 16z. 30 percent chance that
mvfr cigs will remain in place all day.

&&

.MARINE...04/0900 aM...

For the Outer Waters, good confidence in current forecast. Winds
and seas are expected to remain below SCA levels through the
weekend. However there is a 30% chance that some SCA level gusts
could develop Friday afternoon/evening across western sections of
the Outer Waters.

For the Inner Waters, good confidence in current forecast. Winds
and seas are expected to remain below SCA levels through the
weekend.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...NONE.

&&
$$

PUBLIC...KJ
AVIATION...CK
MARINE...Sweet
SYNOPSIS...Seto

weather.gov/losangeles





000
FXUS66 KLOX 041149
AFDLOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
449 AM PDT WED MAY 4 2016

.SYNOPSIS...

Night through morning low clouds and fog are expected for the
coast and some coastal valleys tonight through Wednesday, followed
by partial afternoon clearing. A slow moving low pressure system
will bring a chance of showers to the area Thursday through
Sunday, along with cooler conditions. There will be a slight
chance of thunderstorms Thursday and Friday. High pressure early
next week will likely bring a return to near-normal temperatures.

&&

.SHORT TERM...(TDY-FRI)

Southern California`s weather will be dominated by a cut off low
over the next four days. Currently the upper low is just a trof in
the process of cutting off about 400 miles west of Point
Conception...it will be a fully formed cut off later this
afternoon. Today will be a mostly cloudy day as mid and high level
clouds stream over a large marine layer created by increasing
onshore flow and the lift from the trof. There will be some
patchy fog this morning under the marine layer but nothing too
bad. By afternoon the onshore gradients will be over 7mb to KDAG
(or 9mb if you believe the NAM which is not a good idea) This
increase in the onshore push to the east will keep the low clouds
going near the coast. It will also create breezy conditions across
SLO county and the Antelope vly this afternoon. Max temps will
nose drive under the clouds...the falling hgts and the increasing
onshore flow.

The extra lift and the strong onshore flow will likely create a
very deep marine layer and some drizzle over the coasts and vlys
and into the foothills tonight.

The upper low will move within 60 miles of SLO county on Thursday.
hgts will drop to 558 DM and there will be further cooling under
mostly cloudy skies. Small vort maxes will rotate into and out of
the area all day and hit or miss showers will likely develop
throughout the day. Convective parameters look decent across the
interior and there is a slight chc of TSTMs there. Mdl sounding
show good potential for hail as well. Rainfall amounts will be
highly variable and spotty with a tenth of an inch the best bet
and an outside chc of some quarter inch amounts. Snow levels will
fall to about 6500 feet.

The shower threat will persist overngiht but the TSTM threat will
diminish.

On Friday the upper low moves from Point Conception over Srn SBA
county and then over and through VTA and L.A. counties. The
lift...vorticity...and cold pool assoc with low will bring good
convective parameters to VTA and LA county and there will be a
good chance of showers and a slight chc of TSTMs over both
counties. There will be a little more moisture to work with and
can see a little more rainfall over the area...esp over VTA and LA
county. The big question mark will be cloud cover. Right now it
looks like it will be a mostly cloudy day...but if the mid and
upper level clouds are a little less than fcst and it turns into a
partly cloudy day...then watch out. The greater SFC heating during
peak hours in the afternoon will match perfectly with the cold
pool aloft moving over the area and this would allow for a much
bigger convective outbreak.

Shower activity will diminish Friday night.

Saturday could also be an interesting day. In fact it may well be
the most convective day of the next four. The upper low will move
to the UT/NV/AZ border triple point where it will be in perfect
position to advect vort maxes into the interior sections of the
forecast area. There should be much less in the way of clouds so
look for much better sfc heating. This instability could well
interact with the incoming PVA and kick off a very nice convective
outbreak. The coasts and vlys will see much more sunshine than the
previous three days (or the next three days depending on you like
to look at things) and there will be a nice bump up in max temps.

.LONG TERM...(SAT-TUE)

By Sunday the upper low will be far enough away that the only
threat of showers will be confined to the interior sections and
esp the L.A. mtns. There will be noticeable decrease in clouds
and corresponding warm up in temps.

Ridging moves into the area on Monday and intensifies on Tuesday.
Max temps will warm each day and most areas will be above normal
by Tuesday. The high pressure aloft will create a strong enough
marine inversion that some night through morning low clouds will
likely form over the LA coast.

&&

.AVIATION...04/1150

At 1131Z at KLAX the marine layer was 1500 feet deep. The top of
the inversion was 3100 feet with a temperature of 17 degrees
Celsius.

N of Point Conception...Moderate confidence that lifr cigs will
move up two categories to mvfr by 18z. 30% chance to remain in ifr
conds through 18z. 30% that cigs will scatter out after 20z.
Higher confidence for cigs to remain in mvfr category tonight into
Thursday.

S of Point Conception...Moderate confidence that ifr cigs will
become mvfr by 17z. 40% chance that cigs will scour out before
21z. 20 percent chance for cigs to go into vfr for a portion of
the afternoon hours. better chance for Thursday.

KLAX...Fair confidence in 12z TAF. There is a 30 percent chc that
MVFR cigs will scour out after 20z. There is a 20 percent chance
that cigs will get to vfr late this afternoon.

KBUR...good confidence that there will be mvfr cigs...with 30
percent chance for ifr cigs through 16z. 30 percent chance that
mvfr cigs will remain in place all day.

&&

.MARINE...04/145 AM...

For the Outer Waters, good confidence in current forecast. Winds
and seas are expected to remain below SCA levels through the
weekend. However there is a 30% chance that some SCA level gusts
could develop Friday afternoon/evening across western sections of
the Outer Waters.

For the Inner Waters, good confidence in current forecast. Winds
and seas are expected to remain below SCA levels through the
weekend.


&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...NONE.

&&

$$

PUBLIC...Rorke
AVIATION...CK
MARINE...CK
SYNOPSIS...Smith

weather.gov/losangeles





000
FXUS66 KLOX 041006
AFDLOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
306 AM PDT WED MAY 4 2016

.SYNOPSIS...

Night through morning low clouds and fog are expected for the
coast and some coastal valleys tonight through Wednesday, followed
by partial afternoon clearing. A slow moving low pressure system
will bring a chance of showers to the area Thursday through
Sunday, along with cooler conditions. There will be a slight
chance of thunderstorms Thursday and Friday. High pressure early
next week will likely bring a return to near-normal temperatures.

&&

.SHORT TERM...(TDY-FRI)

Southern California`s weather will be dominated by a cut off low
over the next four days. Currently the upper low is just a trof in
the process of cutting off about 400 miles west of Point
Conception...it will be a fully formed cut off later this
afternoon. Today will be a mostly cloudy day as mid and high level
clouds stream over a large marine layer created by increasing
onshore flow and the lift from the trof. There will be some
patchy fog this morning under the marine layer but nothing too
bad. By afternoon the onshore gradients will be over 7mb to KDAG
(or 9mb if you believe the NAM which is not a good idea) This
increase in the onshore push to the east will keep the low clouds
going near the coast. It will also create breezy conditions across
SLO county and the Antelope vly this afternoon. Max temps will
nose drive under the clouds...the falling hgts and the increasing
onshore flow.

The extra lift and the strong onshore flow will likely create a
very deep marine layer and some drizzle over the coasts and vlys
and into the foothills tonight.

The upper low will move within 60 miles of SLO county on Thursday.
hgts will drop to 558 DM and there will be further cooling under
mostly cloudy skies. Small vort maxes will rotate into and out of
the area all day and hit or miss showers will likely develop
throughout the day. Convective parameters look decent across the
interior and there is a slight chc of TSTMs there. Mdl sounding
show good potential for hail as well. Rainfall amounts will be
highly variable and spotty with a tenth of an inch the best bet
and an outside chc of some quarter inch amounts. Snow levels will
fall to about 6500 feet.

The shower threat will persist overngiht but the TSTM threat will
diminish.

On Friday the upper low moves from Point Conception over Srn SBA
county and then over and through VTA and L.A. counties. The
lift...vorticity...and cold pool assoc with low will bring good
convective parameters to VTA and LA county and there will be a
good chance of showers and a slight chc of TSTMs over both
counties. There will be a little more moisture to work with and
can see a little more rainfall over the area...esp over VTA and LA
county. The big question mark will be cloud cover. Right now it
looks like it will be a mostly cloudy day...but if the mid and
upper level clouds are a little less than fcst and it turns into a
partly cloudy day...then watch out. The greater SFC heating during
peak hours in the afternoon will match perfectly with the cold
pool aloft moving over the area and this would allow for a much
bigger convective outbreak.

Shower activity will diminish Friday night.

Saturday could also be an interesting day. In fact it may well be
the most convective day of the next four. The upper low will move
to the UT/NV/AZ border triple point where it will be in perfect
position to advect vort maxes into the interior sections of the
forecast area. There should be much less in the way of clouds so
look for much better sfc heating. This instability could well
interact with the incoming PVA and kick off a very nice convective
outbreak. The coasts and vlys will see much more sunshine than the
previous three days (or the next three days depending on you like
to look at things) and there will be a nice bump up in max temps.

.LONG TERM...(SAT-TUE)

By Sunday the upper low will be far enough away that the only
threat of showers will be confined to the interior sections and
esp the L.A. mtns. There will be noticeable decrease in clouds
and corresponding warm up in temps.

Ridging moves into the area on Monday and intensifies on Tuesday.
Max temps will warm each day and most areas will be above normal
by Tuesday. The high pressure aloft will create a strong enough
marine inversion that some night through morning low clouds will
likely form over the LA coast.

&&

.AVIATION...

04/0600

At 0545Z at KLAX the marine layer was 1200 feet deep. The top of
the inversion was 3100 feet with a temperature of 20 degrees
Celsius.

Good confidence that stratus will cover all the coasts and vlys by
dawn. Less confidence in exact arrival times of low clouds with up
to two hour errors in timing possible. Good confidence in slower
clearing Wednesday with a 20 percent chc of MVFR cigs remaining
over coastal sites.

KLAX...Fair confidence in TAF. There is a 20 percent chc that cigs
will hold off until 10Z. There is a 20 percent chc that MVFR cigs
will last through the afternoon.

KBUR...good confidence that there will be low clouds over the air
field at dawn. Low confidence on exact overnight arrival time.

&&

.MARINE...

04/145 AM

For the Outer Waters, good confidence in current forecast. Winds
and seas are expected to remain below SCA levels through the
weekend. However there is a 30% chance that some SCA level gusts
could develop Friday afternoon/evening across western sections of
the Outer Waters.

For the Inner Waters, good confidence in current forecast. Winds
and seas are expected to remain below SCA levels through the
weekend.


&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...NONE.

&&

$$

PUBLIC...Rorke
AVIATION...Rorke
MARINE...CK
SYNOPSIS...Smith

weather.gov/losangeles





000
FXUS66 KLOX 040616
AFDLOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
1100 PM PDT TUE MAY 3 2016

...new aviation discussion...

.SYNOPSIS...

Night through morning low clouds and fog are expected for the
coast and some coastal valleys tonight through Wednesday, followed
by partial afternoon clearing. A slow moving low pressure system
will bring a chance of showers to the area Thursday through
Sunday, along with cooler conditions. There will be a slight
chance of thunderstorms Thursday and Friday. High pressure early
next week will likely bring a return to near-normal temperatures.

&&

.UPDATE...

In the immediate short term, main concern will be the marine layer
stratus. Current sounding data indicates marine inversion ranging
from 1000 feet north of Point Conception to about 1200 feet across
the LA basin. Broad swaths of high clouds are obscuring the
stratus on satellite imagery, making it tough to gauge the
current extent of stratus/fog. However with better onshore
gradients tonight and a deeper inversion, do think that stratus
will be rather widespread across the coastal plain and will even
sneak into the lower coastal valleys. Otherwise...no significant
weather issues in the immediate short term.

Overall, current forecast looks on track for the immediate short
term. So, no forecast updates are planned.

&&

.SHORT TERM...(TUE-FRI)

Warm afternoon temperatures across much of the region today.
Slight cooling from the readings yesterday was expected but a
mostly absent marine incursion and weak offshore flow resulted in
higher minimum temperatures and that has been maintained through
the day. If not for a broad swath of high clouds across the region
the temperatures may have been even higher.

Other than adjusting temperatures upward a bit... most in Los
Angeles and Ventura County coastal plains and adjacent valleys...
little was changed in the general forecast package. Temperatures
tomorrow will be moderated by increasing amounts of cloud cover
and should be cooler. Weak offshore flow may continue for another
overnight though so the relative cooling may not be until later
in the day.

The primary weather of note is the incoming low pressure system
that will swing through beginning early Thursday. This system will
bring a shot at showers and thunderstorms to the region. The
best chance of either comes Thursday afternoon/evening and Friday
afternoon/evening in the Ventura and Los Angeles County mountains
and adjacent areas. The Ventura County mountains in particular
look to have good instability and strong positive buoyancy both
Thursday and Friday. However PWs are low on Thursday and marginal
on Friday. A pool of higher PW is expected to be to the south of
the region on Friday and if the low swings through farther north
than currently projected this may lead to a higher thunderstorm
probability. As it now stands... a chance to slight chance of
showers and thunderstorms appropriately represents the likelihood
of either.

.LONG TERM...(SAT-TUE)

A slight chance of showers continues across the region on
Saturday. The instability and CAPE both drop off notably on
Saturday so no thunderstorms are in the forecast but enough
moisture wraps around the low to keep showers lingering into the
mountains through early Sunday.

A moderate ridge begins to build over the region by late Sunday and
conditions return to warm and dry into the next work week.

&&

.AVIATION...

04/0600

At 0545Z at KLAX the marine layer was 1200 feet deep. The top of the
inversion was 3100 feet with a temperature of 20 degrees Celsius.

Good confidence that stratus will cover all the coasts and vlys by
dawn. Less confidence in exact arrival times of low clouds with up
to two hour errors in timing possible. Good confidence in slower
clearing Wednesday with a 20 percent chc of MVFR cigs remaining over
coastal sites.

KLAX...Fair confidence in TAF. There is a 20 percent chc that cigs
will hold off until 10Z. There is a 20 percent chc that MVFR cigs
will last through the afternoon.

KBUR...good confidence that there will be low clouds over the air
field at dawn. Low confidence on exact overnight arrival time.

&&

.MARINE...03/800 PM...

For the Outer Waters, good confidence in current forecast. Winds
and seas are expected to remain below SCA levels through the
weekend. However there is a 30% chance that some SCA level gusts
could develop Friday afternoon/evening across western sections of
the Outer Waters.

For the Inner Waters, good confidence in current forecast. Winds
and seas are expected to remain below SCA levels through the
weekend.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...NONE.

&&

$$

PUBLIC...RAT/KJ
AVIATION...asr
MARINE...RAT
SYNOPSIS...Smith

weather.gov/losangeles





000
FXUS66 KLOX 040616
AFDLOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
1100 PM PDT TUE MAY 3 2016

...new aviation discussion...

.SYNOPSIS...

Night through morning low clouds and fog are expected for the
coast and some coastal valleys tonight through Wednesday, followed
by partial afternoon clearing. A slow moving low pressure system
will bring a chance of showers to the area Thursday through
Sunday, along with cooler conditions. There will be a slight
chance of thunderstorms Thursday and Friday. High pressure early
next week will likely bring a return to near-normal temperatures.

&&

.UPDATE...

In the immediate short term, main concern will be the marine layer
stratus. Current sounding data indicates marine inversion ranging
from 1000 feet north of Point Conception to about 1200 feet across
the LA basin. Broad swaths of high clouds are obscuring the
stratus on satellite imagery, making it tough to gauge the
current extent of stratus/fog. However with better onshore
gradients tonight and a deeper inversion, do think that stratus
will be rather widespread across the coastal plain and will even
sneak into the lower coastal valleys. Otherwise...no significant
weather issues in the immediate short term.

Overall, current forecast looks on track for the immediate short
term. So, no forecast updates are planned.

&&

.SHORT TERM...(TUE-FRI)

Warm afternoon temperatures across much of the region today.
Slight cooling from the readings yesterday was expected but a
mostly absent marine incursion and weak offshore flow resulted in
higher minimum temperatures and that has been maintained through
the day. If not for a broad swath of high clouds across the region
the temperatures may have been even higher.

Other than adjusting temperatures upward a bit... most in Los
Angeles and Ventura County coastal plains and adjacent valleys...
little was changed in the general forecast package. Temperatures
tomorrow will be moderated by increasing amounts of cloud cover
and should be cooler. Weak offshore flow may continue for another
overnight though so the relative cooling may not be until later
in the day.

The primary weather of note is the incoming low pressure system
that will swing through beginning early Thursday. This system will
bring a shot at showers and thunderstorms to the region. The
best chance of either comes Thursday afternoon/evening and Friday
afternoon/evening in the Ventura and Los Angeles County mountains
and adjacent areas. The Ventura County mountains in particular
look to have good instability and strong positive buoyancy both
Thursday and Friday. However PWs are low on Thursday and marginal
on Friday. A pool of higher PW is expected to be to the south of
the region on Friday and if the low swings through farther north
than currently projected this may lead to a higher thunderstorm
probability. As it now stands... a chance to slight chance of
showers and thunderstorms appropriately represents the likelihood
of either.

.LONG TERM...(SAT-TUE)

A slight chance of showers continues across the region on
Saturday. The instability and CAPE both drop off notably on
Saturday so no thunderstorms are in the forecast but enough
moisture wraps around the low to keep showers lingering into the
mountains through early Sunday.

A moderate ridge begins to build over the region by late Sunday and
conditions return to warm and dry into the next work week.

&&

.AVIATION...

04/0600

At 0545Z at KLAX the marine layer was 1200 feet deep. The top of the
inversion was 3100 feet with a temperature of 20 degrees Celsius.

Good confidence that stratus will cover all the coasts and vlys by
dawn. Less confidence in exact arrival times of low clouds with up
to two hour errors in timing possible. Good confidence in slower
clearing Wednesday with a 20 percent chc of MVFR cigs remaining over
coastal sites.

KLAX...Fair confidence in TAF. There is a 20 percent chc that cigs
will hold off until 10Z. There is a 20 percent chc that MVFR cigs
will last through the afternoon.

KBUR...good confidence that there will be low clouds over the air
field at dawn. Low confidence on exact overnight arrival time.

&&

.MARINE...03/800 PM...

For the Outer Waters, good confidence in current forecast. Winds
and seas are expected to remain below SCA levels through the
weekend. However there is a 30% chance that some SCA level gusts
could develop Friday afternoon/evening across western sections of
the Outer Waters.

For the Inner Waters, good confidence in current forecast. Winds
and seas are expected to remain below SCA levels through the
weekend.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...NONE.

&&

$$

PUBLIC...RAT/KJ
AVIATION...asr
MARINE...RAT
SYNOPSIS...Smith

weather.gov/losangeles





000
FXUS66 KLOX 040339
AFDLOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
839 PM PDT TUE MAY 3 2016

.SYNOPSIS...

Night through morning low clouds and fog are expected for the
coast and some coastal valleys tonight through Wednesday, followed
by partial afternoon clearing. A slow moving low pressure system
will bring a chance of showers to the area Thursday through
Sunday, along with cooler conditions. There will be a slight
chance of thunderstorms Thursday and Friday. High pressure early
next week will likely bring a return to near-normal temperatures.

&&

.UPDATE...

In the immediate short term, main concern will be the marine layer
stratus. Current sounding data indicates marine inversion ranging
from 1000 feet north of Point Conception to about 1200 feet across
the LA basin. Broad swaths of high clouds are obscuring the
stratus on satellite imagery, making it tough to gauge the
current extent of stratus/fog. However with better onshore
gradients tonight and a deeper inversion, do think that stratus
will be rather widespread across the coastal plain and will even
sneak into the lower coastal valleys. Otherwise...no significant
weather issues in the immediate short term.

Overall, current forecast looks on track for the immediate short
term. So, no forecast updates are planned.

&&

.SHORT TERM...(TUE-FRI)

Warm afternoon temperatures across much of the region today.
Slight cooling from the readings yesterday was expected but a
mostly absent marine incursion and weak offshore flow resulted in
higher minimum temperatures and that has been maintained through
the day. If not for a broad swath of high clouds across the region
the temperatures may have been even higher.

Other than adjusting temperatures upward a bit... most in Los
Angeles and Ventura County coastal plains and adjacent valleys...
little was changed in the general forecast package. Temperatures
tomorrow will be moderated by increasing amounts of cloud cover
and should be cooler. Weak offshore flow may continue for another
overnight though so the relative cooling may not be until later
in the day.

The primary weather of note is the incoming low pressure system
that will swing through beginning early Thursday. This system will
bring a shot at showers and thunderstorms to the region. The
best chance of either comes Thursday afternoon/evening and Friday
afternoon/evening in the Ventura and Los Angeles County mountains
and adjacent areas. The Ventura County mountains in particular
look to have good instability and strong positive buoyancy both
Thursday and Friday. However PWs are low on Thursday and marginal
on Friday. A pool of higher PW is expected to be to the south of
the region on Friday and if the low swings through farther north
than currently projected this may lead to a higher thunderstorm
probability. As it now stands... a chance to slight chance of
showers and thunderstorms appropriately represents the likelihood
of either.

.LONG TERM...(SAT-TUE)

A slight chance of showers continues across the region on
Saturday. The instability and CAPE both drop off notably on
Saturday so no thunderstorms are in the forecast but enough
moisture wraps around the low to keep showers lingering into the
mountains through early Sunday.

A moderate ridge begins to build over the region by late Sunday and
conditions return to warm and dry into the next work week.

&&

.AVIATION...03/2300Z...

At 2300Z, the marine inversion at KLAX was 700 feet. The top of
the inversion was 2000 feet with a temperature of 23 degrees
Celsius.

Overall, low to moderate confidence in 00Z TAF package. High
clouds are obscuring the location of stratus this afternoon,
making for a low confidence forecast of where/when stratus may
impact airfields. Any stratus/fog that develops overnight will
likely be IFR category or worse.

KLAX...low confidence in 00Z TAF. Moderate confidence in return of
stratus to airfield overnight, but low confidence in timing (+/- 3
hours of current 06Z arrival forecast). With strong onshore
gradients on Wednesday, stratus dissipation may be later than
currently forecast.

KBUR...moderate confidence in 00Z TAF. There is a 50% chance of no
ceiling/vsby restriction overnight.
&&

.MARINE...03/800 PM...

For the Outer Waters, good confidence in current forecast. Winds
and seas are expected to remain below SCA levels through the
weekend. However there is a 30% chance that some SCA level gusts
could develop Friday afternoon/evening across western sections of
the Outer Waters.

For the Inner Waters, good confidence in current forecast. Winds
and seas are expected to remain below SCA levels through the
weekend.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...NONE.

&&

$$

PUBLIC...RAT/KJ
AVIATION...RAT
MARINE...RAT
SYNOPSIS...Smith

weather.gov/losangeles





000
FXUS66 KLOX 032321 AAA
AFDLOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
420 PM PDT TUE MAY 3 2016

.SYNOPSIS...

The overnight marine layer will form early Wednesday. Then
a low should arrive by late Wednesday for a slight chance of
showers and thuderstorms into Saturday night...with showers to
linger in the mountains on Sunday. The temperatures will remain
below normal into early next week then a high will arrive by
Monday with a warming trend into midweek.

&&

.SHORT TERM...(TDY-FRI)

Warm afternoon temperatures across much of the region today.
Slight cooling from the readings yesterday was expected but a
mostly absent marine incursion and weak offshore flow resulted in
higher minimum temperatures and that has been maintained through
the day. If not for a broad swath of high clouds across the region
the temperatures may have been even higher.

Other than adjusting temperatures upward a bit... most in Los
Angeles and Ventura County coastal plains and adjacent valleys...
little was changed in the general forecast package. Temperatures
tomorrow will be moderated by increasing amounts of cloud cover
and should be cooler. Weak offshore flow may continue for another
overnight though so the relative cooling may not be until later
in the day.

The primary weather of note is the incoming low pressure system
that will swing through beginning early Thursday. This system will
bring a shot at showers and thunderstorms to the region. The
best chance of either comes Thursday afternoon/evening and Friday
afternoon/evening in the Ventura and Los Angeles County mountains
and adjacent areas. The Ventura County mountains in particular
look to have good instability and strong positive buoyancy both
Thursday and Friday. However PWs are low on Thursday and marginal
on Friday. A pool of higher PW is expected to be to the south of
the region on Friday and if the low swings through farther north
than currently projected this may lead to a higher thunderstorm
probability. As it now stands... a chance to slight chance of
showers and thunderstorms appropriately represents the likelihood
of either.

.LONG TERM...(SAT-MON)

A slight chance of showers continues across the region on
Saturday. The instability and CAPE both drop off notably on
Saturday so no thunderstorms are in the forecast but enough
moisture wraps around the low to keep showers lingering into the
mountains through early Sunday.

A moderate ridge begins to build over the region by late Sunday and
conditions return to warm and dry into the next work week.

&&

.AVIATION...03/2320Z...

At 2300Z, the marine inversion at KLAX was 700 feet. The top of the
inversion was 2000 feet with a temperature of 23 degrees Celsius.

Overall, low to moderate confidence in 00Z TAF package. High clouds
are obscuring the location of stratus this afternoon, making for a
low confidence forecast of where/when stratus may impact airfields.
Any stratus/fog that develops overnight will likely be IFR category
or worse.

KLAX...low confidence in 00Z TAF. Moderate confidence in return of
stratus to airfield overnight, but low confidence in timing (+/- 3
hours of current 06Z arrival forecast). With strong onshore
gradients on Wednesday, stratus dissipation may be later than
currently forecast.

KBUR...moderate confidence in 00Z TAF. There is a 50% chance of no
ceiling/vsby restriction overnight.

&&

.MARINE...03/200 pM...

High confidence for coastal waters remaining below SCA levels
through Friday morning. There is a 40% chance for SCA level winds
from Friday afternoon to late Friday night across the very western
portion of zone PZZ670 from Point Piedras Blancas to Point Sal.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...NONE.

&&
$$

PUBLIC...KJ
AVIATION...RAT
MARINE...Sweet
SYNOPSIS...Seto

weather.gov/losangeles





000
FXUS66 KLOX 032321 AAA
AFDLOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
420 PM PDT TUE MAY 3 2016

.SYNOPSIS...

The overnight marine layer will form early Wednesday. Then
a low should arrive by late Wednesday for a slight chance of
showers and thuderstorms into Saturday night...with showers to
linger in the mountains on Sunday. The temperatures will remain
below normal into early next week then a high will arrive by
Monday with a warming trend into midweek.

&&

.SHORT TERM...(TDY-FRI)

Warm afternoon temperatures across much of the region today.
Slight cooling from the readings yesterday was expected but a
mostly absent marine incursion and weak offshore flow resulted in
higher minimum temperatures and that has been maintained through
the day. If not for a broad swath of high clouds across the region
the temperatures may have been even higher.

Other than adjusting temperatures upward a bit... most in Los
Angeles and Ventura County coastal plains and adjacent valleys...
little was changed in the general forecast package. Temperatures
tomorrow will be moderated by increasing amounts of cloud cover
and should be cooler. Weak offshore flow may continue for another
overnight though so the relative cooling may not be until later
in the day.

The primary weather of note is the incoming low pressure system
that will swing through beginning early Thursday. This system will
bring a shot at showers and thunderstorms to the region. The
best chance of either comes Thursday afternoon/evening and Friday
afternoon/evening in the Ventura and Los Angeles County mountains
and adjacent areas. The Ventura County mountains in particular
look to have good instability and strong positive buoyancy both
Thursday and Friday. However PWs are low on Thursday and marginal
on Friday. A pool of higher PW is expected to be to the south of
the region on Friday and if the low swings through farther north
than currently projected this may lead to a higher thunderstorm
probability. As it now stands... a chance to slight chance of
showers and thunderstorms appropriately represents the likelihood
of either.

.LONG TERM...(SAT-MON)

A slight chance of showers continues across the region on
Saturday. The instability and CAPE both drop off notably on
Saturday so no thunderstorms are in the forecast but enough
moisture wraps around the low to keep showers lingering into the
mountains through early Sunday.

A moderate ridge begins to build over the region by late Sunday and
conditions return to warm and dry into the next work week.

&&

.AVIATION...03/2320Z...

At 2300Z, the marine inversion at KLAX was 700 feet. The top of the
inversion was 2000 feet with a temperature of 23 degrees Celsius.

Overall, low to moderate confidence in 00Z TAF package. High clouds
are obscuring the location of stratus this afternoon, making for a
low confidence forecast of where/when stratus may impact airfields.
Any stratus/fog that develops overnight will likely be IFR category
or worse.

KLAX...low confidence in 00Z TAF. Moderate confidence in return of
stratus to airfield overnight, but low confidence in timing (+/- 3
hours of current 06Z arrival forecast). With strong onshore
gradients on Wednesday, stratus dissipation may be later than
currently forecast.

KBUR...moderate confidence in 00Z TAF. There is a 50% chance of no
ceiling/vsby restriction overnight.

&&

.MARINE...03/200 pM...

High confidence for coastal waters remaining below SCA levels
through Friday morning. There is a 40% chance for SCA level winds
from Friday afternoon to late Friday night across the very western
portion of zone PZZ670 from Point Piedras Blancas to Point Sal.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...NONE.

&&
$$

PUBLIC...KJ
AVIATION...RAT
MARINE...Sweet
SYNOPSIS...Seto

weather.gov/losangeles





000
FXUS66 KLOX 032108
AFDLOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
208 PM PDT TUE MAY 3 2016

.SYNOPSIS...

The overnight marine layer will form early Wednesday. Then
a low should arrive by late Wednesday for a slight chance of
showers and thuderstorms into Saturday night...with showers to
linger in the mountains on Sunday. The temperatures will remain
below normal into early next week then a high will arrive by
Monday with a warming trend into midweek.

&&

.SHORT TERM...(TDY-FRI)

Warm afternoon temperatures across much of the region today.
Slight cooling from the readings yesterday was expected but a
mostly absent marine incursion and weak offshore flow resulted in
higher minimum temperatures and that has been maintained through
the day. If not for a broad swath of high clouds across the region
the temperatures may have been even higher.

Other than adjusting temperatures upward a bit... most in Los
Angeles and Ventura County coastal plains and adjacent valleys...
little was changed in the general forecast package. Temperatures
tomorrow will be moderated by increasing amounts of cloud cover
and should be cooler. Weak offshore flow may continue for another
overnight though so the relative cooling may not be until later
in the day.

The primary weather of note is the incoming low pressure system
that will swing through beginning early Thursday. This system will
bring a shot at showers and thunderstorms to the region. The
best chance of either comes Thursday afternoon/evening and Friday
afternoon/evening in the Ventura and Los Angeles County mountains
and adjacent areas. The Ventura County mountains in particular
look to have good instability and strong positive buoyancy both
Thursday and Friday. However PWs are low on Thursday and marginal
on Friday. A pool of higher PW is expected to be to the south of
the region on Friday and if the low swings through farther north
than currently projected this may lead to a higher thunderstorm
probability. As it now stands... a chance to slight chance of
showers and thunderstorms appropriately represents the likelihood
of either.

.LONG TERM...(SAT-MON)

A slight chance of showers continues across the region on
Saturday. The instability and CAPE both drop off notably on
Saturday so no thunderstorms are in the forecast but enough
moisture wraps around the low to keep showers lingering into the
mountains through early Sunday.

A moderate ridge begins to build over the region by late Sunday and
conditions return to warm and dry into the next work week.

&&

.AVIATION...03/1800Z.

At 1720Z, the marine layer depth at KLAX was around 800 feet. The
top of the inversion was 3100 feet with a temperature of 19.6
degrees Celsius.

Low confidence in the 18z tafs. The main question mark continues
to be the marine clouds. Although the marine cloud coverage was
smaller than expected this morning...the marine layer depth was
about 800 feet this morning which was close to expectations.
Increasing onshore flow in the next 24 hours along with a
deepening marine layer will allow more marine cloud coverage
tonight and wednesday...possibly extending into some of the
valleys.

KLAX...Low to moderate confidence in 18Z TAF. MVFR conditions are
expected overnight. There is a 30 percent chance of ifr
conditions.

KBUR...Low confidence in 18Z TAF. There is a 40 percent chance of
VFR conditions through the TAF period.

&&

.MARINE...03/200 pM...

High confidence for coastal waters remaining below SCA levels
through Friday morning. There is a 40% chance for SCA level winds
from Friday afternoon to late Friday night across the very western
portion of zone PZZ670 from Point Piedras Blancas to Point Sal.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...NONE.

&&
$$

PUBLIC...KJ
AVIATION...Sweet
MARINE...Sweet
SYNOPSIS...Seto

weather.gov/losangeles





000
FXUS66 KLOX 031848
AFDLOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
1148 AM PDT TUE MAY 3 2016

.SYNOPSIS...

the overnight marine layer will persist into early Wednesday. Then
a low should arrive by late Wednesday for a slight chance of
showers and thuderstorms into Saturday night...with showers to
linger in the mountains on Sunday. The temperatures will remain
below normal into early next week. Then a high will arrive by
Monday with a warming trend into midweek.

&&

.UPDATE...

*** mid morning discussion update ***

Temperatures are up this morning across the region.  With the
little to no marine incursion this morning and slightly offshore
flow... temperatures will likely be at least a few degrees higher
than currently forecast in many locations.  Otherwise the current
forecast package looks to be generally on target.  Will be
checking on the timing of the incoming showers later in the week
and the timing and extent of possible thunderstorms but expect any
changes to be tweaks as opposed to wholesale changes.

&&

.SHORT TERM...(TDY-THU)

*** early morning discussion ***

The marine layer is about a 1000 feet deep at the moment. But sfc
gradients are just barely onshore and there is no eddy to speak of
and as a result there are hardly any low clouds. It looks like
this mornings low clouds will be confined to the immediate central
coast and the long beach area. Otherwise skies will be sunny in
the morning and partly cloudy in the afternoon as some high level
cloud advect in ahead of an upper level trof. The sunshine and the
reduced onshore flow will allow all areas to warm a few degrees
from Mondays values.

A wise old long retired forecaster here once said of the marine
layer stratus "just forecast persistence and then you`ll only be
wrong once" Will foolishly go against this advice and once again
forecast a fairly robust marine layer stratus deck tonight on the
basis of the approaching upper level trof which will provide
enough low level lift to create the clouds. The onshore flow is
not really what it should be so may well be another stratus free
start to the day.

On Wednesday the trof cuts off into a closed low and approaches
the coast. clouds and onshore gradients will increase through the
day and hgts will fall. Look for max temps to fall 4 to 8 degrees
from todays readings.

The upper low moves from a point about 60 NM west of KSFO early
Thursday morning to a point 60 miles SW of Point Conception late
Thursday evening and then to the Needles area by afternoon
Friday. There is not much moisture to work with and am not
expecting too much rainfall maybe a quarter inch and more like a
tenth of an inch from hit or miss showers that will occur over the
two day period. The big question mark will be afternoon cloud
cover. If afternoon skies are partly cloudy the high sun angle sfc
heating below the cool upper air aloft will form a very good
convective environment. If skies are more on the overcast side of
things there will be much less in the way of shower activity. The
best chance of TSTMs on Thursday will be over the interior with
some vorticity moving overhead. On Friday the area will switch
over to all of LA and VTA counties as the cold pool aloft moves
directly overhead for maximum instability. snow levels will fall
to about 6000 feet and there could be some local accumulations at
the highest elevations.


.LONG TERM...(FRI-MON)


Scattered shower activity will persist Saturday across the
interior and especially the mtns as the upper low moves into SE
NV and spins several vort lobes into the area from the NE. In fact
if skies are fairly clear there could be quite a bit of afternoon
mtn convection.

The upper low will then pull so far to the east that it will no
longer affect Srn CA and a ridge will begin to nose in from the W.
This will kick off a clearing and warming trend.



&&

.AVIATION...03/1800Z.

At 1720Z, the marine layer depth at KLAX was around 800 feet. The
top of the inversion was 3100 feet with a temperature of 19.6
degrees Celsius.

Low confidence in the 18z tafs. The main question mark continues
to be the marine clouds. Although the marine cloud coverage was
smaller than expected this morning...the marine layer depth was
about 800 feet this morning which was close to expectations.
Increasing onshore flow in the next 24 hours along with a
deepening marine layer will allow more marine cloud coverage
tonight and wednesday...possibly extending into some of the
valleys.

KLAX...Low to moderate confidence in 18Z TAF. MVFR conditions are
expected overnight. There is a 30 percent chance of ifr
conditions.

KBUR...Low confidence in 18Z TAF. There is a 40 percent chance of
VFR conditions through the TAF period.

&&

.MARINE...03/900 AM...

High confidence for coastal waters remaining below SCA levels
through Friday morning. There is a 40% chance for SCA level winds
from Friday afternoon to late Friday night across the very western
portion of zone PZZ670 from Point Piedras Blancas to Point Sal.



&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...NONE.

&&

$$

PUBLIC...KJ
AVIATION...Sweet
MARINE...Sweet
SYNOPSIS...Seto

weather.gov/losangeles





000
FXUS66 KLOX 031848
AFDLOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
1148 AM PDT TUE MAY 3 2016

.SYNOPSIS...

the overnight marine layer will persist into early Wednesday. Then
a low should arrive by late Wednesday for a slight chance of
showers and thuderstorms into Saturday night...with showers to
linger in the mountains on Sunday. The temperatures will remain
below normal into early next week. Then a high will arrive by
Monday with a warming trend into midweek.

&&

.UPDATE...

*** mid morning discussion update ***

Temperatures are up this morning across the region.  With the
little to no marine incursion this morning and slightly offshore
flow... temperatures will likely be at least a few degrees higher
than currently forecast in many locations.  Otherwise the current
forecast package looks to be generally on target.  Will be
checking on the timing of the incoming showers later in the week
and the timing and extent of possible thunderstorms but expect any
changes to be tweaks as opposed to wholesale changes.

&&

.SHORT TERM...(TDY-THU)

*** early morning discussion ***

The marine layer is about a 1000 feet deep at the moment. But sfc
gradients are just barely onshore and there is no eddy to speak of
and as a result there are hardly any low clouds. It looks like
this mornings low clouds will be confined to the immediate central
coast and the long beach area. Otherwise skies will be sunny in
the morning and partly cloudy in the afternoon as some high level
cloud advect in ahead of an upper level trof. The sunshine and the
reduced onshore flow will allow all areas to warm a few degrees
from Mondays values.

A wise old long retired forecaster here once said of the marine
layer stratus "just forecast persistence and then you`ll only be
wrong once" Will foolishly go against this advice and once again
forecast a fairly robust marine layer stratus deck tonight on the
basis of the approaching upper level trof which will provide
enough low level lift to create the clouds. The onshore flow is
not really what it should be so may well be another stratus free
start to the day.

On Wednesday the trof cuts off into a closed low and approaches
the coast. clouds and onshore gradients will increase through the
day and hgts will fall. Look for max temps to fall 4 to 8 degrees
from todays readings.

The upper low moves from a point about 60 NM west of KSFO early
Thursday morning to a point 60 miles SW of Point Conception late
Thursday evening and then to the Needles area by afternoon
Friday. There is not much moisture to work with and am not
expecting too much rainfall maybe a quarter inch and more like a
tenth of an inch from hit or miss showers that will occur over the
two day period. The big question mark will be afternoon cloud
cover. If afternoon skies are partly cloudy the high sun angle sfc
heating below the cool upper air aloft will form a very good
convective environment. If skies are more on the overcast side of
things there will be much less in the way of shower activity. The
best chance of TSTMs on Thursday will be over the interior with
some vorticity moving overhead. On Friday the area will switch
over to all of LA and VTA counties as the cold pool aloft moves
directly overhead for maximum instability. snow levels will fall
to about 6000 feet and there could be some local accumulations at
the highest elevations.


.LONG TERM...(FRI-MON)


Scattered shower activity will persist Saturday across the
interior and especially the mtns as the upper low moves into SE
NV and spins several vort lobes into the area from the NE. In fact
if skies are fairly clear there could be quite a bit of afternoon
mtn convection.

The upper low will then pull so far to the east that it will no
longer affect Srn CA and a ridge will begin to nose in from the W.
This will kick off a clearing and warming trend.



&&

.AVIATION...03/1800Z.

At 1720Z, the marine layer depth at KLAX was around 800 feet. The
top of the inversion was 3100 feet with a temperature of 19.6
degrees Celsius.

Low confidence in the 18z tafs. The main question mark continues
to be the marine clouds. Although the marine cloud coverage was
smaller than expected this morning...the marine layer depth was
about 800 feet this morning which was close to expectations.
Increasing onshore flow in the next 24 hours along with a
deepening marine layer will allow more marine cloud coverage
tonight and wednesday...possibly extending into some of the
valleys.

KLAX...Low to moderate confidence in 18Z TAF. MVFR conditions are
expected overnight. There is a 30 percent chance of ifr
conditions.

KBUR...Low confidence in 18Z TAF. There is a 40 percent chance of
VFR conditions through the TAF period.

&&

.MARINE...03/900 AM...

High confidence for coastal waters remaining below SCA levels
through Friday morning. There is a 40% chance for SCA level winds
from Friday afternoon to late Friday night across the very western
portion of zone PZZ670 from Point Piedras Blancas to Point Sal.



&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...NONE.

&&

$$

PUBLIC...KJ
AVIATION...Sweet
MARINE...Sweet
SYNOPSIS...Seto

weather.gov/losangeles





000
FXUS66 KLOX 031617
AFDLOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
917 AM PDT TUE MAY 3 2016

.SYNOPSIS...

the overnight marine layer will persist into early Wednesday. Then
a low should arrive by late Wednesday for a slight chance of
showers and thuderstorms into Saturday night...with showers to
linger in the mountains on Sunday. The temperatures will remain
below normal into early next week. Then a high will arrive by
Monday with a warming trend into midweek.

&&

.UPDATE...

*** mid morning discussion update ***

Temperatures are up this morning across the region.  With the
little to no marine incursion this morning and slightly offshore
flow... temperatures will likely be at least a few degrees higher
than currently forecast in many locations.  Otherwise the current
forecast package looks to be generally on target.  Will be
checking on the timing of the incoming showers later in the week
and the timing and extent of possible thunderstorms but expect any
changes to be tweaks as opposed to wholesale changes.

&&

.SHORT TERM...(TDY-THU)

*** early morning discussion ***

The marine layer is about a 1000 feet deep at the moment. But sfc
gradients are just barely onshore and there is no eddy to speak of
and as a result there are hardly any low clouds. It looks like
this mornings low clouds will be confined to the immediate central
coast and the long beach area. Otherwise skies will be sunny in
the morning and partly cloudy in the afternoon as some high level
cloud advect in ahead of an upper level trof. The sunshine and the
reduced onshore flow will allow all areas to warm a few degrees
from Mondays values.

A wise old long retired forecaster here once said of the marine
layer stratus "just forecast persistence and then you`ll only be
wrong once" Will foolishly go against this advice and once again
forecast a fairly robust marine layer stratus deck tonight on the
basis of the approaching upper level trof which will provide
enough low level lift to create the clouds. The onshore flow is
not really what it should be so may well be another stratus free
start to the day.

On Wednesday the trof cuts off into a closed low and approaches
the coast. clouds and onshore gradients will increase through the
day and hgts will fall. Look for max temps to fall 4 to 8 degrees
from todays readings.

The upper low moves from a point about 60 NM west of KSFO early
Thursday morning to a point 60 miles SW of Point Conception late
Thursday evening and then to the Needles area by afternoon
Friday. There is not much moisture to work with and am not
expecting too much rainfall maybe a quarter inch and more like a
tenth of an inch from hit or miss showers that will occur over the
two day period. The big question mark will be afternoon cloud
cover. If afternoon skies are partly cloudy the high sun angle sfc
heating below the cool upper air aloft will form a very good
convective environment. If skies are more on the overcast side of
things there will be much less in the way of shower activity. The
best chance of TSTMs on Thursday will be over the interior with
some vorticity moving overhead. On Friday the area will switch
over to all of LA and VTA counties as the cold pool aloft moves
directly overhead for maximum instability. snow levels will fall
to about 6000 feet and there could be some local accumulations at
the highest elevations.


.LONG TERM...(FRI-MON)


Scattered shower activity will persist Saturday across the
interior and especially the mtns as the upper low moves into SE
NV and spins several vort lobes into the area from the NE. In fact
if skies are fairly clear there could be quite a bit of afternoon
mtn convection.

The upper low will then pull so far to the east that it will no
longer affect Srn CA and a ridge will begin to nose in from the W.
This will kick off a clearing and warming trend.



&&

.AVIATION...03/1035Z...

At 1020Z, the marine inversion at KLAX was around 1400 feet. The
top of the inversion was 2300 feet with a temperature of 19 degrees
Celsius.

N of Point Conception...
Moderate confidence with 12z tafs. 30% percent chance that cigs
will scour out +/1 2 hours from tafs. low confidence for mvfr
cigs. good confidence that cigs will return back and be a bit
deeper with a better chance of ifr/low mvfr cigs.

S of Point Conception...Low to moderate confidence with areal
coverage and timing of stratus. 30 percent chance for ifr cigs for
klax and 30 percent chance that ifr cigs will not develop at klgb
this morning. Higher confidence for ifr/mvfr cigs across most
coastal sites later tonight. +/- 2 hours from current tafs.

KLAX...low to moderate confidence in 12Z TAF. 30 percent chance
for ifr cigs to develop between 12z-16z this morning. Higher
confidence for ifr/mvfr cigs and vsbys later this evening. +/- 2
hours from 12z taf time.

KBUR...high confidence in 12Z TAF for VFR conditions are
anticipated through the TAF period. There is a 30% chance of IFR
conditions 09Z-17Z Wed.

&&

.MARINE...03/900 AM...

High confidence for coastal waters remaining below SCA levels
through Friday morning. There is a 40% chance for SCA level winds
from Friday afternoon to late Friday night across the very western
portion of zone PZZ670 from Point Piedras Blancas to Point Sal.



&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...NONE.

&&

$$

PUBLIC...KJ
AVIATION...Sweet
MARINE...Sweet
SYNOPSIS...Seto

weather.gov/losangeles





000
FXUS66 KLOX 031617
AFDLOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
917 AM PDT TUE MAY 3 2016

.SYNOPSIS...

the overnight marine layer will persist into early Wednesday. Then
a low should arrive by late Wednesday for a slight chance of
showers and thuderstorms into Saturday night...with showers to
linger in the mountains on Sunday. The temperatures will remain
below normal into early next week. Then a high will arrive by
Monday with a warming trend into midweek.

&&

.UPDATE...

*** mid morning discussion update ***

Temperatures are up this morning across the region.  With the
little to no marine incursion this morning and slightly offshore
flow... temperatures will likely be at least a few degrees higher
than currently forecast in many locations.  Otherwise the current
forecast package looks to be generally on target.  Will be
checking on the timing of the incoming showers later in the week
and the timing and extent of possible thunderstorms but expect any
changes to be tweaks as opposed to wholesale changes.

&&

.SHORT TERM...(TDY-THU)

*** early morning discussion ***

The marine layer is about a 1000 feet deep at the moment. But sfc
gradients are just barely onshore and there is no eddy to speak of
and as a result there are hardly any low clouds. It looks like
this mornings low clouds will be confined to the immediate central
coast and the long beach area. Otherwise skies will be sunny in
the morning and partly cloudy in the afternoon as some high level
cloud advect in ahead of an upper level trof. The sunshine and the
reduced onshore flow will allow all areas to warm a few degrees
from Mondays values.

A wise old long retired forecaster here once said of the marine
layer stratus "just forecast persistence and then you`ll only be
wrong once" Will foolishly go against this advice and once again
forecast a fairly robust marine layer stratus deck tonight on the
basis of the approaching upper level trof which will provide
enough low level lift to create the clouds. The onshore flow is
not really what it should be so may well be another stratus free
start to the day.

On Wednesday the trof cuts off into a closed low and approaches
the coast. clouds and onshore gradients will increase through the
day and hgts will fall. Look for max temps to fall 4 to 8 degrees
from todays readings.

The upper low moves from a point about 60 NM west of KSFO early
Thursday morning to a point 60 miles SW of Point Conception late
Thursday evening and then to the Needles area by afternoon
Friday. There is not much moisture to work with and am not
expecting too much rainfall maybe a quarter inch and more like a
tenth of an inch from hit or miss showers that will occur over the
two day period. The big question mark will be afternoon cloud
cover. If afternoon skies are partly cloudy the high sun angle sfc
heating below the cool upper air aloft will form a very good
convective environment. If skies are more on the overcast side of
things there will be much less in the way of shower activity. The
best chance of TSTMs on Thursday will be over the interior with
some vorticity moving overhead. On Friday the area will switch
over to all of LA and VTA counties as the cold pool aloft moves
directly overhead for maximum instability. snow levels will fall
to about 6000 feet and there could be some local accumulations at
the highest elevations.


.LONG TERM...(FRI-MON)


Scattered shower activity will persist Saturday across the
interior and especially the mtns as the upper low moves into SE
NV and spins several vort lobes into the area from the NE. In fact
if skies are fairly clear there could be quite a bit of afternoon
mtn convection.

The upper low will then pull so far to the east that it will no
longer affect Srn CA and a ridge will begin to nose in from the W.
This will kick off a clearing and warming trend.



&&

.AVIATION...03/1035Z...

At 1020Z, the marine inversion at KLAX was around 1400 feet. The
top of the inversion was 2300 feet with a temperature of 19 degrees
Celsius.

N of Point Conception...
Moderate confidence with 12z tafs. 30% percent chance that cigs
will scour out +/1 2 hours from tafs. low confidence for mvfr
cigs. good confidence that cigs will return back and be a bit
deeper with a better chance of ifr/low mvfr cigs.

S of Point Conception...Low to moderate confidence with areal
coverage and timing of stratus. 30 percent chance for ifr cigs for
klax and 30 percent chance that ifr cigs will not develop at klgb
this morning. Higher confidence for ifr/mvfr cigs across most
coastal sites later tonight. +/- 2 hours from current tafs.

KLAX...low to moderate confidence in 12Z TAF. 30 percent chance
for ifr cigs to develop between 12z-16z this morning. Higher
confidence for ifr/mvfr cigs and vsbys later this evening. +/- 2
hours from 12z taf time.

KBUR...high confidence in 12Z TAF for VFR conditions are
anticipated through the TAF period. There is a 30% chance of IFR
conditions 09Z-17Z Wed.

&&

.MARINE...03/900 AM...

High confidence for coastal waters remaining below SCA levels
through Friday morning. There is a 40% chance for SCA level winds
from Friday afternoon to late Friday night across the very western
portion of zone PZZ670 from Point Piedras Blancas to Point Sal.



&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...NONE.

&&

$$

PUBLIC...KJ
AVIATION...Sweet
MARINE...Sweet
SYNOPSIS...Seto

weather.gov/losangeles





000
FXUS66 KLOX 031609
AFDLOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
909 AM PDT TUE MAY 3 2016

.SYNOPSIS...

The overnight marine layer will persist into early Wednesday. Then
a low should arrive by late Wednesday for a slight chance of
showers and thuderstorms into Saturday night...with showers to
linger in the mountains on Sunday. The temperatures will remain
below normal into early next week then a high will arrive by
Monday with a warming trend into midweek.

&&

.UPDATE...

Temperatures are up this morning across the region.  With the
little to no marine incursion this morning and slightly offshore
flow... temperatures will likely be at least a few degrees higher
than currently forecast in many locations.  Otherwise the current
forecast package looks to be generally on target.  Will be
checking on the timing of the incoming showers later in the week
and the timing and extent of possible thunderstorms but expect any
changes to be tweaks as opposed to wholesale changes.

&&

.SHORT TERM...(TDY-THU)

The marine layer is about a 1000 feet deep at the moment. But sfc
gradients are just barely onshore and there is no eddy to speak of
and as a result there are hardly any low clouds. It looks like
this mornings low clouds will be confined to the immediate central
coast and the long beach area. Otherwise skies will be sunny in
the morning and partly cloudy in the afternoon as some high level
cloud advect in ahead of an upper level trof. The sunshine and the
reduced onshore flow will allow all areas to warm a few degrees
from Mondays values.

A wise old long retired forecaster here once said of the marine
layer stratus "just forecast persistence and then you`ll only be
wrong once" Will foolishly go against this advice and once again
forecast a fairly robust marine layer stratus deck tonight on the
basis of the approaching upper level trof which will provide
enough low level lift to create the clouds. The onshore flow is
not really what it should be so may well be another stratus free
start to the day.

On Wednesday the trof cuts off into a closed low and approaches
the coast. clouds and onshore gradients will increase through the
day and hgts will fall. Look for max temps to fall 4 to 8 degrees
from todays readings.

The upper low moves from a point about 60 NM west of KSFO early
Thursday morning to a point 60 miles SW of Point Conception late
Thursday evening and then to the Needles area by afternoon
Friday. There is not much moisture to work with and am not
expecting too much rainfall maybe a quarter inch and more like a
tenth of an inch from hit or miss showers that will occur over the
two day period. The big question mark will be afternoon cloud
cover. If afternoon skies are partly cloudy the high sun angle sfc
heating below the cool upper air aloft will form a very good
convective environment. If skies are more on the overcast side of
things there will be much less in the way of shower activity. The
best chance of TSTMs on Thursday will be over the interior with
some vorticity moving overhead. On Friday the area will switch
over to all of LA and VTA counties as the cold pool aloft moves
directly overhead for maximum instability. snow levels will fall
to about 6000 feet and there could be some local accumulations at
the highest elevations.

.LONG TERM...(FRI-MON)

Scattered shower activity will persist Saturday across the
interior and especially the mtns as the upper low moves into SE
NV and spins several vort lobes into the area from the NE. In fact
if skies are fairly clear there could be quite a bit of afternoon
mtn convection.

The upper low will then pull so far to the east that it will no
longer affect Srn CA and a ridge will begin to nose in from the W.
This will kick off a clearing and warming trend.

&&

.AVIATION...03/1035Z...

At 1020Z, the marine inversion at KLAX was around 1400 feet. The
top of the inversion was 2300 feet with a temperature of 19 degrees
Celsius.

N of Point Conception...
Moderate confidence with 12z tafs. 30% percent chance that cigs
will scour out +/1 2 hours from tafs. low confidence for mvfr
cigs. good confidence that cigs will return back and be a bit
deeper with a better chance of ifr/low mvfr cigs.

S of Point Conception...Low to moderate confidence with areal
coverage and timing of stratus. 30 percent chance for ifr cigs for
klax and 30 percent chance that ifr cigs will not develop at klgb
this morning. Higher confidence for ifr/mvfr cigs across most
coastal sites later tonight. +/- 2 hours from current tafs.

KLAX...low to moderate confidence in 12Z TAF. 30 percent chance
for ifr cigs to develop between 12z-16z this morning. Higher
confidence for ifr/mvfr cigs and vsbys later this evening. +/- 2
hours from 12z taf time.

KBUR...high confidence in 12Z TAF for VFR conditions are
anticipated through the TAF period. There is a 30% chance of IFR
conditions 09Z-17Z Wed.

&&

.MARINE...03/200 AM...

High confidence for coastal waters remaining below SCA levels
through Friday morning. There is a 60% chance for SCA level winds
from Friday afternoon to late Friday night across the very
western portion of zone PZZ670 from Point Piedras Blancas to Point
Sal.

There is a 60% chance of patchy dense fog off the Orange County
Coast this morning...with less chance to 40% off the Los Angeles
County Coast.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...NONE.

&&
$$

PUBLIC...Rorke/KJ
AVIATION...CK
MARINE...CK
SYNOPSIS...Seto

weather.gov/losangeles





000
FXUS66 KLOX 031609
AFDLOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
909 AM PDT TUE MAY 3 2016

.SYNOPSIS...

The overnight marine layer will persist into early Wednesday. Then
a low should arrive by late Wednesday for a slight chance of
showers and thuderstorms into Saturday night...with showers to
linger in the mountains on Sunday. The temperatures will remain
below normal into early next week then a high will arrive by
Monday with a warming trend into midweek.

&&

.UPDATE...

Temperatures are up this morning across the region.  With the
little to no marine incursion this morning and slightly offshore
flow... temperatures will likely be at least a few degrees higher
than currently forecast in many locations.  Otherwise the current
forecast package looks to be generally on target.  Will be
checking on the timing of the incoming showers later in the week
and the timing and extent of possible thunderstorms but expect any
changes to be tweaks as opposed to wholesale changes.

&&

.SHORT TERM...(TDY-THU)

The marine layer is about a 1000 feet deep at the moment. But sfc
gradients are just barely onshore and there is no eddy to speak of
and as a result there are hardly any low clouds. It looks like
this mornings low clouds will be confined to the immediate central
coast and the long beach area. Otherwise skies will be sunny in
the morning and partly cloudy in the afternoon as some high level
cloud advect in ahead of an upper level trof. The sunshine and the
reduced onshore flow will allow all areas to warm a few degrees
from Mondays values.

A wise old long retired forecaster here once said of the marine
layer stratus "just forecast persistence and then you`ll only be
wrong once" Will foolishly go against this advice and once again
forecast a fairly robust marine layer stratus deck tonight on the
basis of the approaching upper level trof which will provide
enough low level lift to create the clouds. The onshore flow is
not really what it should be so may well be another stratus free
start to the day.

On Wednesday the trof cuts off into a closed low and approaches
the coast. clouds and onshore gradients will increase through the
day and hgts will fall. Look for max temps to fall 4 to 8 degrees
from todays readings.

The upper low moves from a point about 60 NM west of KSFO early
Thursday morning to a point 60 miles SW of Point Conception late
Thursday evening and then to the Needles area by afternoon
Friday. There is not much moisture to work with and am not
expecting too much rainfall maybe a quarter inch and more like a
tenth of an inch from hit or miss showers that will occur over the
two day period. The big question mark will be afternoon cloud
cover. If afternoon skies are partly cloudy the high sun angle sfc
heating below the cool upper air aloft will form a very good
convective environment. If skies are more on the overcast side of
things there will be much less in the way of shower activity. The
best chance of TSTMs on Thursday will be over the interior with
some vorticity moving overhead. On Friday the area will switch
over to all of LA and VTA counties as the cold pool aloft moves
directly overhead for maximum instability. snow levels will fall
to about 6000 feet and there could be some local accumulations at
the highest elevations.

.LONG TERM...(FRI-MON)

Scattered shower activity will persist Saturday across the
interior and especially the mtns as the upper low moves into SE
NV and spins several vort lobes into the area from the NE. In fact
if skies are fairly clear there could be quite a bit of afternoon
mtn convection.

The upper low will then pull so far to the east that it will no
longer affect Srn CA and a ridge will begin to nose in from the W.
This will kick off a clearing and warming trend.

&&

.AVIATION...03/1035Z...

At 1020Z, the marine inversion at KLAX was around 1400 feet. The
top of the inversion was 2300 feet with a temperature of 19 degrees
Celsius.

N of Point Conception...
Moderate confidence with 12z tafs. 30% percent chance that cigs
will scour out +/1 2 hours from tafs. low confidence for mvfr
cigs. good confidence that cigs will return back and be a bit
deeper with a better chance of ifr/low mvfr cigs.

S of Point Conception...Low to moderate confidence with areal
coverage and timing of stratus. 30 percent chance for ifr cigs for
klax and 30 percent chance that ifr cigs will not develop at klgb
this morning. Higher confidence for ifr/mvfr cigs across most
coastal sites later tonight. +/- 2 hours from current tafs.

KLAX...low to moderate confidence in 12Z TAF. 30 percent chance
for ifr cigs to develop between 12z-16z this morning. Higher
confidence for ifr/mvfr cigs and vsbys later this evening. +/- 2
hours from 12z taf time.

KBUR...high confidence in 12Z TAF for VFR conditions are
anticipated through the TAF period. There is a 30% chance of IFR
conditions 09Z-17Z Wed.

&&

.MARINE...03/200 AM...

High confidence for coastal waters remaining below SCA levels
through Friday morning. There is a 60% chance for SCA level winds
from Friday afternoon to late Friday night across the very
western portion of zone PZZ670 from Point Piedras Blancas to Point
Sal.

There is a 60% chance of patchy dense fog off the Orange County
Coast this morning...with less chance to 40% off the Los Angeles
County Coast.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...NONE.

&&
$$

PUBLIC...Rorke/KJ
AVIATION...CK
MARINE...CK
SYNOPSIS...Seto

weather.gov/losangeles





000
FXUS66 KLOX 031035
AFDLOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
335 AM PDT TUE MAY 3 2016

.SYNOPSIS...

Night through morning low clouds and fog are expected for many
areas west of the mountains through Wednesday, followed by
partial afternoon clearing. A slow moving low pressure system
will bring a chance of showers and thunderstorms Thursday through
Sunday, along with cooler conditions. Temperatures will likely
return to near normal early next week as high pressure returns.

&&

.SHORT TERM...(TDY-THU)

The marine layer is about a 1000 feet deep at the moment. But sfc
gradients are just barely onshore and there is no eddy to speak
of and as a result there are hardly any low clouds. It looks like
this mornings low clouds will be confined to the immediate central
coast and the long beach area. Otherwise skies will be sunny in
the morning and partly cloudy in the afternoon as some high level
cloud advect in ahead of an upper level trof. The sunshine and the
reduced onshore flow will allow all areas to warm a few degrees
from Mondays values.

A wise old long retired forecaster here once said of the marine
layer stratus "just forecast persistence and then you`ll only be
wrong once" Will foolishly go against this advice and once again
forecast a fairly robust marine layer stratus deck tonight on the
basis of the approaching upper level trof which will provide
enough low level lift to create the clouds. The onshore flow is
not really what it should be so may well be another stratus free
start to the day.

On Wednesday the trof cuts off into a closed low and approaches
the coast. clouds and onshore gradients will increase through the
day and hgts will fall. Look for max temps to fall 4 to 8 degrees
from todays readings.

The upper low moves from a point about 60 NM west of KSFO early
Thursday morning to a point 60 miles SW of Point Conception late
Thursday evening and then to the Needles area by afternoon
Friday. There is not much moisture to work with and am not
expecting too much rainfall maybe a quarter inch and more like a
tenth of an inch from hit or miss showers that will occur over the
two day period. The big question mark will be afternoon cloud
cover. If afternoon skies are partly cloudy the high sun angle sfc
heating below the cool upper air aloft will form a very good
convective environment. If skies are more on the overcast side of
things there will be much less in the way of shower activity. The
best chance of TSTMs on Thursday will be over the interior with
some vorticity moving overhead. On Friday the area will switch
over to all of LA and VTA counties as the cold pool aloft moves
directly overhead for maximum instability. snow levels will fall
to about 6000 feet and there could be some local accumulations at
the highest elevations.

.LONG TERM...(FRI-MON)

Scattered shower activity will persist Saturday across the
interior and especially the mtns as the upper low moves into SE
NV and spins several vort lobes into the area from the NE. In fact
if skies are fairly clear there could be quite a bit of afternoon
mtn convection.

The upper low will then pull so far to the east that it will no
longer affect Srn CA and a ridge will begin to nose in from the W.
This will kick off a clearing and warming trend.

&&

.AVIATION...03/1035Z...

At 1020Z, the marine inversion at KLAX was around 1400 feet. The
top of the inversion was 2300 feet with a temperature of 19 degrees
Celsius.

N of Point Conception...
Moderate confidence with 12z tafs. 30% percent chance that cigs
will scour out +/1 2 hours from tafs. low confidence for mvfr
cigs. good confidence that cigs will return back and be a bit
deeper with a better chance of ifr/low mvfr cigs.

S of Point Conception...Low to moderate confidence with areal
coverage and timing of stratus. 30 percent chance for ifr cigs for
klax and 30 percent chance that ifr cigs will not develop at klgb
this morning. Higher confidence for ifr/mvfr cigs across most
coastal sites later tonight. +/- 2 hours from current tafs.

KLAX...low to moderate confidence in 12Z TAF. 30 percent chance
for ifr cigs to develop between 12z-16z this morning. Higher
confidence for ifr/mvfr cigs and vsbys later this evening. +/- 2
hours from 12z taf time.

KBUR...high confidence in 12Z TAF for VFR conditions are
anticipated through the TAF period. There is a 30% chance of IFR
conditions 09Z-17Z Wed.

&&

.MARINE...03/200 AM...

High confidence for coastal waters remaining below SCA levels
through Friday morning. There is a 60% chance for SCA level winds
from Friday afternoon to late Friday night across the very
western portion of zone PZZ670 from Point Piedras Blancas to Point
Sal.

There is a 60% chance of patchy dense fog off the Orange County
Coast this morning...with less chance to 40% off the Los Angeles
County Coast.


&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...NONE.

&&

$$

PUBLIC...Rorke
AVIATION...CK
MARINE...CK
SYNOPSIS...Sukup

weather.gov/losangeles





000
FXUS66 KLOX 030509
AFDLOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
1009 PM PDT MON MAY 2 2016

.SYNOPSIS...

Night through morning low clouds and fog are expected for many
areas west of the mountains through Wednesday, followed by
partial afternoon clearing. A slow moving low pressure system
will bring a chance of showers and thunderstorms Thursday through
Sunday, along with cooler conditions. Temperatures will likely
return to near normal early next week as high pressure returns.

&&

.UPDATE...

Latest sounding data (VBG and AMDAR) indicates marine inversion
ranging from 1200 feet deep north of Point Conception to about
800 feet south of Point Conception. With weaker onshore gradients,
slightly increasing 500 MB heights and no forecasted eddy, do not
expect much deepening of the marine inversion overnight. So,
will expect stratus/fog to become rather widespread across the
Central Coast and Santa Ynez Valley. For areas south of Point
Conception, will expect stratus to develop across the coastal
plain, but should be rather limited in the coastal valleys (due to
no expected deepening of the marine inversion). Otherwise, some
high level clouds will drift in overnight.

Earlier, an update was issued to scale back stratus/fog coverage
across the coastal valleys of Ventura and Los Angeles counties.
Otherwise, current forecast looks to be in good shape in the
immediate short term.

&&

.SHORT TERM...(Tonight-THU)

Forecast area generally under weak high pressure aloft for the
next couple of days. A remnant of the last trough to move through
the area has left enough cold air aloft to induce some cumulus
over the mountains and extending into the Antelope Valley.
Showers developed over the eastern San Gabriels by late morning
but they have recently decreased due to warming aloft and weak
height rises. The overnight stratus has cleared out over coastal
areas of Los Angeles County and for the most part north to Point
Conception. However, stratus has held on over the immediate
central coast due to a slightly stronger onshore pressure gradient
versus southern coastal areas. Expect a similar stratus pattern
tonight as pressure gradients and marine layer depth change little
from last night.

Heights and thickness values continue to increase tomorrow to
bring another few degrees of warming nearly all areas. High clouds
will move across the area in advance of the next trough. Some mid
level clouds may sneak in by early evening. These shouldn`t deter
the warming trend. Another round of overnight coastal stratus for
Tuesday night. But with an increase in onshore flow and resultant
increase in the marine layer depth expect it to penetrate further
inland compared to last night and tonight.

By Wednesday 12z the upper trough axis is about 500 miles west of
LAX with fairly good agreement among models. Upper level
southwest flow increases as it gets closer along with general
cooling through the column. High temperatures on Wednesday will be
around 5 to 10 degrees cooler than Tuesday`s highs. By late in the
day Wednesday the upper trough is close enough to possibly produce
some showers over northern San Luis Obispo County extending westward
offshore.

By late in the day Thursday the upper level trough becomes a well
defined closed low, the center of which by 00Z Friday is around or
just west of Point Conception.  Mid level temperatures of -23C
near the core of the low will produce a marginally unstable
conditions. The NAM indicates lifted indices around -3.5C over
the Ventura County Mountains and CAPE values around 600 J/kg.
These numbers justify the the possibility of thunderstorms mainly
over the mountains for late Thursday into Thursday night. The GFS
swings a pocket of unstable air across southern sections Thursday
afternoon. This along with the favored dynamics south of the low
center would put the best chance of thunder over the San Gabriel
Mountains. At lower elevations, expect isolated to scattered
showers on Thursday but at this time do not expect any thunder
these areas. Moisture is lacking a bit at the onset of the
system`s arrival on Thursday. The precipitation will be highly hit
and miss on Thursday. Some areas may not receive any measurable
precipitation at all. Of course temperatures continue to cool on
Thursday when highs will be as much as 10-15 degrees below normal.

.LONG TERM...(FRI-MON)

Models generally agree in putting the center of the upper closed low
by Friday morning somewhere just south of Los Angeles, the ECMWF a
little further southwest compared to the GFS. Friday represents
the best chance of thunder lower elevations mainly south of Point
Conception. Increasing moisture that models show wrapping around
the low`s center could be a factor in chances for thunder on
Friday. The GFS places the upper low`s center around the Calif-
Ariz border south of Vegas by 00Z Saturday which keeps the
stronger dynamics well east of the forecast area. Again,
difficult this far out to identify any areas that have better
chances of precipitation over others. Friday will be the coolest
day of the 7-day forecast.

By around midday Saturday models put the upper low`s center over
western Utah with moist and cool northernly flow behind it
sweeping across southern California. Both the GFS and ECMWF
indicate a weak vort lobe rotating around its back side but any
precipitation from this at this time looks to stay well offshore.
Despite the low`s position well to the north and east there`s just
enough weak instability and moisture around to keep at least a
slight chance of showers on Saturday. Some slight warming expected
on Saturday despite the cloudiness although high temps still quite
a bit below normal.

Total QPF from this system between Thursday and late Saturday
should stay below a quarter most areas, less than a tenth more
likely. The one exception would be higher amounts under any
thunderstorms that develop. Overall this will not be a big rain
maker. Snow-wise, minimum snow levels with this system could be
as low as around 5700 to 6000 feet on Friday night.

The low continues to lift out through the intermountain west on
Sunday. Some additional warming is expected along with clearer
skies. High temperatures inch a few degrees higher on Sunday but
still not enough to get back to normal. Have backed off on
precipitation chances on Sunday as the low is just too far
removed. Additional warming for Monday when upper level high
pressure builds in earnest to help get high temps around or just
below normal.

&&

.AVIATION...03/0507Z...

At 0507Z, the marine inversion at KLAX was based at 800 feet. The
top of the inversion was 1800 feet with a temperature of 21
degrees Celsius.

Overall, moderate confidence in 06Z TAF package. Moderate
confidence in stratus/fog returning to coastal TAF sites this
evening and overnight, but low confidence in timing. There is a
10% chance of stratus reaching into the coastal valley TAF sites
overnight.

KLAX...moderate confidence in 06Z TAF. Moderate confidence in
stratus returning overnight, but low confidence in timing (could
develop 2-4 hours earlier than current 12Z forecast).

KBUR...high confidence in 06Z TAF as VFR conditions are
anticipated through the TAF period. There is a 10% chance of IFR
conditions 09Z-17Z.

&&

.MARINE...02/830 PM...

For the Outer Waters, moderate to high confidence in current
forecast. High confidence in winds and seas remaining below SCA
levels through Tuesday night. From Wednesday through Friday, winds
will increase and there is a chance of SCA level winds developing
(especially in the afternoon and evening hours).

For the Inner Waters, high confidence in current forecast. High
confidence that winds and seas will remain below SCA levels
through Friday (although there is a 20% chance of SCA level gusts
Thursday and Friday afternoon across the waters north of Point Sal
as well as western sections of the southern Inner Waters).

Given the limited depth of the marine inversion, there could be
some patchy dense fog across the coastal waters late tonight and
Tuesday morning.


&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...NONE.

&&

$$

PUBLIC...RAT/MJ
AVIATION...RAT
MARINE...RAT
SYNOPSIS...Sukup

weather.gov/losangeles





000
FXUS66 KLOX 030509
AFDLOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
1009 PM PDT MON MAY 2 2016

.SYNOPSIS...

Night through morning low clouds and fog are expected for many
areas west of the mountains through Wednesday, followed by
partial afternoon clearing. A slow moving low pressure system
will bring a chance of showers and thunderstorms Thursday through
Sunday, along with cooler conditions. Temperatures will likely
return to near normal early next week as high pressure returns.

&&

.UPDATE...

Latest sounding data (VBG and AMDAR) indicates marine inversion
ranging from 1200 feet deep north of Point Conception to about
800 feet south of Point Conception. With weaker onshore gradients,
slightly increasing 500 MB heights and no forecasted eddy, do not
expect much deepening of the marine inversion overnight. So,
will expect stratus/fog to become rather widespread across the
Central Coast and Santa Ynez Valley. For areas south of Point
Conception, will expect stratus to develop across the coastal
plain, but should be rather limited in the coastal valleys (due to
no expected deepening of the marine inversion). Otherwise, some
high level clouds will drift in overnight.

Earlier, an update was issued to scale back stratus/fog coverage
across the coastal valleys of Ventura and Los Angeles counties.
Otherwise, current forecast looks to be in good shape in the
immediate short term.

&&

.SHORT TERM...(Tonight-THU)

Forecast area generally under weak high pressure aloft for the
next couple of days. A remnant of the last trough to move through
the area has left enough cold air aloft to induce some cumulus
over the mountains and extending into the Antelope Valley.
Showers developed over the eastern San Gabriels by late morning
but they have recently decreased due to warming aloft and weak
height rises. The overnight stratus has cleared out over coastal
areas of Los Angeles County and for the most part north to Point
Conception. However, stratus has held on over the immediate
central coast due to a slightly stronger onshore pressure gradient
versus southern coastal areas. Expect a similar stratus pattern
tonight as pressure gradients and marine layer depth change little
from last night.

Heights and thickness values continue to increase tomorrow to
bring another few degrees of warming nearly all areas. High clouds
will move across the area in advance of the next trough. Some mid
level clouds may sneak in by early evening. These shouldn`t deter
the warming trend. Another round of overnight coastal stratus for
Tuesday night. But with an increase in onshore flow and resultant
increase in the marine layer depth expect it to penetrate further
inland compared to last night and tonight.

By Wednesday 12z the upper trough axis is about 500 miles west of
LAX with fairly good agreement among models. Upper level
southwest flow increases as it gets closer along with general
cooling through the column. High temperatures on Wednesday will be
around 5 to 10 degrees cooler than Tuesday`s highs. By late in the
day Wednesday the upper trough is close enough to possibly produce
some showers over northern San Luis Obispo County extending westward
offshore.

By late in the day Thursday the upper level trough becomes a well
defined closed low, the center of which by 00Z Friday is around or
just west of Point Conception.  Mid level temperatures of -23C
near the core of the low will produce a marginally unstable
conditions. The NAM indicates lifted indices around -3.5C over
the Ventura County Mountains and CAPE values around 600 J/kg.
These numbers justify the the possibility of thunderstorms mainly
over the mountains for late Thursday into Thursday night. The GFS
swings a pocket of unstable air across southern sections Thursday
afternoon. This along with the favored dynamics south of the low
center would put the best chance of thunder over the San Gabriel
Mountains. At lower elevations, expect isolated to scattered
showers on Thursday but at this time do not expect any thunder
these areas. Moisture is lacking a bit at the onset of the
system`s arrival on Thursday. The precipitation will be highly hit
and miss on Thursday. Some areas may not receive any measurable
precipitation at all. Of course temperatures continue to cool on
Thursday when highs will be as much as 10-15 degrees below normal.

.LONG TERM...(FRI-MON)

Models generally agree in putting the center of the upper closed low
by Friday morning somewhere just south of Los Angeles, the ECMWF a
little further southwest compared to the GFS. Friday represents
the best chance of thunder lower elevations mainly south of Point
Conception. Increasing moisture that models show wrapping around
the low`s center could be a factor in chances for thunder on
Friday. The GFS places the upper low`s center around the Calif-
Ariz border south of Vegas by 00Z Saturday which keeps the
stronger dynamics well east of the forecast area. Again,
difficult this far out to identify any areas that have better
chances of precipitation over others. Friday will be the coolest
day of the 7-day forecast.

By around midday Saturday models put the upper low`s center over
western Utah with moist and cool northernly flow behind it
sweeping across southern California. Both the GFS and ECMWF
indicate a weak vort lobe rotating around its back side but any
precipitation from this at this time looks to stay well offshore.
Despite the low`s position well to the north and east there`s just
enough weak instability and moisture around to keep at least a
slight chance of showers on Saturday. Some slight warming expected
on Saturday despite the cloudiness although high temps still quite
a bit below normal.

Total QPF from this system between Thursday and late Saturday
should stay below a quarter most areas, less than a tenth more
likely. The one exception would be higher amounts under any
thunderstorms that develop. Overall this will not be a big rain
maker. Snow-wise, minimum snow levels with this system could be
as low as around 5700 to 6000 feet on Friday night.

The low continues to lift out through the intermountain west on
Sunday. Some additional warming is expected along with clearer
skies. High temperatures inch a few degrees higher on Sunday but
still not enough to get back to normal. Have backed off on
precipitation chances on Sunday as the low is just too far
removed. Additional warming for Monday when upper level high
pressure builds in earnest to help get high temps around or just
below normal.

&&

.AVIATION...03/0507Z...

At 0507Z, the marine inversion at KLAX was based at 800 feet. The
top of the inversion was 1800 feet with a temperature of 21
degrees Celsius.

Overall, moderate confidence in 06Z TAF package. Moderate
confidence in stratus/fog returning to coastal TAF sites this
evening and overnight, but low confidence in timing. There is a
10% chance of stratus reaching into the coastal valley TAF sites
overnight.

KLAX...moderate confidence in 06Z TAF. Moderate confidence in
stratus returning overnight, but low confidence in timing (could
develop 2-4 hours earlier than current 12Z forecast).

KBUR...high confidence in 06Z TAF as VFR conditions are
anticipated through the TAF period. There is a 10% chance of IFR
conditions 09Z-17Z.

&&

.MARINE...02/830 PM...

For the Outer Waters, moderate to high confidence in current
forecast. High confidence in winds and seas remaining below SCA
levels through Tuesday night. From Wednesday through Friday, winds
will increase and there is a chance of SCA level winds developing
(especially in the afternoon and evening hours).

For the Inner Waters, high confidence in current forecast. High
confidence that winds and seas will remain below SCA levels
through Friday (although there is a 20% chance of SCA level gusts
Thursday and Friday afternoon across the waters north of Point Sal
as well as western sections of the southern Inner Waters).

Given the limited depth of the marine inversion, there could be
some patchy dense fog across the coastal waters late tonight and
Tuesday morning.


&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...NONE.

&&

$$

PUBLIC...RAT/MJ
AVIATION...RAT
MARINE...RAT
SYNOPSIS...Sukup

weather.gov/losangeles





000
FXUS66 KLOX 030330
AFDLOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
830 PM PDT MON MAY 2 2016

.SYNOPSIS...

Night through morning low clouds and fog are expected for many
areas west of the mountains through Wednesday, followed by
partial afternoon clearing. A slow moving low pressure system
will bring a chance of showers and thunderstorms Thursday through
Sunday, along with cooler conditions. Temperatures will likely
return to near normal early next week as high pressure returns.

&&

.UPDATE...

Latest sounding data (VBG and AMDAR) indicates marine inversion
ranging from 1200 feet deep north of Point Conception to about
800 feet south of Point Conception. With weaker onshore gradients,
slightly increasing 500 MB heights and no forecasted eddy, do not
expect much deepening of the marine inversion overnight. So,
will expect stratus/fog to become rather widespread across the
Central Coast and Santa Ynez Valley. For areas south of Point
Conception, will expect stratus to develop across the coastal
plain, but should be rather limited in the coastal valleys (due to
no expected deepening of the marine inversion). Otherwise, some
high level clouds will drift in overnight.

Earlier, an update was issued to scale back stratus/fog coverage
across the coastal valleys of Ventura and Los Angeles counties.
Otherwise, current forecast looks to be in good shape in the
immediate short term.

&&

.SHORT TERM...(MON-THU)

Forecast area generally under weak high pressure aloft for the
next couple of days. A remnant of the last trough to move through
the area has left enough cold air aloft to induce some cumulus
over the mountains and extending into the Antelope Valley.
Showers developed over the eastern San Gabriels by late morning
but they have recently decreased due to warming aloft and weak
height rises. The overnight stratus has cleared out over coastal
areas of Los Angeles County and for the most part north to Point
Conception. However, stratus has held on over the immediate
central coast due to a slightly stronger onshore pressure gradient
versus southern coastal areas. Expect a similar stratus pattern
tonight as pressure gradients and marine layer depth change little
from last night.

Heights and thickness values continue to increase tomorrow to
bring another few degrees of warming nearly all areas. High clouds
will move across the area in advance of the next trough. Some mid
level clouds may sneak in by early evening. These shouldn`t deter
the warming trend. Another round of overnight coastal stratus for
Tuesday night. But with an increase in onshore flow and resultant
increase in the marine layer depth expect it to penetrate further
inland compared to last night and tonight.

By Wednesday 12z the upper trough axis is about 500 miles west of
LAX with fairly good agreement among models. Upper level
southwest flow increases as it gets closer along with general
cooling through the column. High temperatures on Wednesday will be
around 5 to 10 degrees cooler than Tuesday`s highs. By late in the
day Wednesday the upper trough is close enough to possibly produce
some showers over northern San Luis Obispo County extending westward
offshore.

By late in the day Thursday the upper level trough becomes a well
defined closed low, the center of which by 00Z Friday is around or
just west of Point Conception.  Mid level temperatures of -23C
near the core of the low will produce a marginally unstable
conditions. The NAM indicates lifted indices around -3.5C over
the Ventura County Mountains and CAPE values around 600 J/kg.
These numbers justify the the possibility of thunderstorms mainly
over the mountains for late Thursday into Thursday night. The GFS
swings a pocket of unstable air across southern sections Thursday
afternoon. This along with the favored dynamics south of the low
center would put the best chance of thunder over the San Gabriel
Mountains. At lower elevations, expect isolated to scattered
showers on Thursday but at this time do not expect any thunder
these areas. Moisture is lacking a bit at the onset of the
system`s arrival on Thursday. The precipitation will be highly hit
and miss on Thursday. Some areas may not receive any measurable
precipitation at all. Of course temperatures continue to cool on
Thursday when highs will be as much as 10-15 degrees below normal.

.LONG TERM...(FRI-MON)

Models generally agree in putting the center of the upper closed low
by Friday morning somewhere just south of Los Angeles, the ECMWF a
little further southwest compared to the GFS. Friday represents
the best chance of thunder lower elevations mainly south of Point
Conception. Increasing moisture that models show wrapping around
the low`s center could be a factor in chances for thunder on
Friday. The GFS places the upper low`s center around the Calif-
Ariz border south of Vegas by 00Z Saturday which keeps the
stronger dynamics well east of the forecast area. Again,
difficult this far out to identify any areas that have better
chances of precipitation over others. Friday will be the coolest
day of the 7-day forecast.

By around midday Saturday models put the upper low`s center over
western Utah with moist and cool northernly flow behind it
sweeping across southern California. Both the GFS and ECMWF
indicate a weak vort lobe rotating around its back side but any
precipitation from this at this time looks to stay well offshore.
Despite the low`s position well to the north and east there`s just
enough weak instability and moisture around to keep at least a
slight chance of showers on Saturday. Some slight warming expected
on Saturday despite the cloudiness although high temps still quite
a bit below normal.

Total QPF from this system between Thursday and late Saturday
should stay below a quarter most areas, less than a tenth more
likely. The one exception would be higher amounts under any
thunderstorms that develop. Overall this will not be a big rain
maker. Snow-wise, minimum snow levels with this system could be
as low as around 5700 to 6000 feet on Friday night.

The low continues to lift out through the intermountain west on
Sunday. Some additional warming is expected along with clearer
skies. High temperatures inch a few degrees higher on Sunday but
still not enough to get back to normal. Have backed off on
precipitation chances on Sunday as the low is just too far
removed. Additional warming for Monday when upper level high
pressure builds in earnest to help get high temps around or just
below normal.

&&

.AVIATION...02/2245Z...

At 2245Z...the marine inversion at KLAX was based at 800 feet.
The top of the inversion was 1900 feet with a temperature of
20 degrees Celsius.

Overall, moderate confidence in 00Z TAF package. High confidence
in stratus/fog returning to coastal TAF sites this evening and
overnight, but low confidence in timing. There is a 20% chance of
stratus reaching into the coastal valley TAF sites overnight.

KLAX...moderate confidence in 00Z TAF. High confidence in stratus
returning overnight (with IFR conditions likely), but low
confidence in timing (+/- 3 hours of current 09Z forecast).

KBUR...high confidence in 00Z TAF as VFR conditions are
anticipated through the TAF period. There is a 20% chance of IFR
conditions 09Z-17Z.

&&

.MARINE...02/830 PM...

For the Outer Waters, moderate to high confidence in current
forecast. High confidence in winds and seas remaining below SCA
levels through Tuesday night. From Wednesday through Friday, winds
will increase and there is a chance of SCA level winds developing
(especially in the afternoon and evening hours).

For the Inner Waters, high confidence in current forecast. High
confidence that winds and seas will remain below SCA levels
through Friday (although there is a 20% chance of SCA level gusts
Thursday and Friday afternoon across the waters north of Point Sal
as well as western sections of the southern Inner Waters).

Given the limited depth of the marine inversion, there could be
some patchy dense fog across the coastal waters late tonight and
Tuesday morning.


&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...NONE.

&&

$$

PUBLIC...RAT/MJ
AVIATION...RAT
MARINE...RAT
SYNOPSIS...Sukup

weather.gov/losangeles





000
FXUS66 KLOX 022246
AFDLOX

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
346 PM PDT MON MAY 2 2016

.SYNOPSIS...

There will be night through morning patchy low clouds and fog
through Wednesday. A slow moving low pressure system will bring a
chance of showers and thunderstorms along with cooler conditions
to the area Thursday through Sunday.

&&

.SHORT TERM...(TDY-THU)

Forecast area generally under weak high pressure aloft for the
next couple of days. A remnant of the last trough to move through
the area has left enough cold air aloft to induce some cumulus
over the mountains and extending into the Antelope Valley.
Showers developed over the eastern San Gabriels by late morning
but they have recently decreased due to warming aloft and weak
height rises. The overnight stratus has cleared out over coastal
areas of Los Angeles County and for the most part north to Point
Conception. However, stratus has held on over the immediate
central coast due to a slightly stronger onshore pressure gradient
versus southern coastal areas. Expect a similar stratus pattern
tonight as pressure gradients and marine layer depth change little
from last night.

Heights and thickness values continue to increase tomorrow to
bring another few degrees of warming nearly all areas. High clouds
will move across the area in advance of the next trough. Some mid
level clouds may sneak in by early evening. These shouldn`t deter
the warming trend. Another round of overnight coastal stratus for
Tuesday night. But with an increase in onshore flow and resultant
increase in the marine layer depth expect it to penetrate further
inland compared to last night and tonight.

By Wednesday 12z the upper trough axis is about 500 miles west of
LAX with fairly good agreement among models. Upper level
southwest flow increases as it gets closer along with general
cooling through the column. High temperatures on Wednesday will be
around 5 to 10 degrees cooler than Tuesday`s highs. By late in the
day Wednesday the upper trough is close enough to possibly produce
some showers over northern San Luis Obispo County extending westward
offshore.

By late in the day Thursday the upper level trough becomes a well
defined closed low, the center of which by 00Z Friday is around or
just west of Point Conception.  Mid level temperatures of -23C
near the core of the low will produce a marginally unstable
conditions. The NAM indicates lifted indices around -3.5C over
the Ventura County Mountains and CAPE values around 600 J/kg.
These numbers justify the the possibility of thunderstorms mainly
over the mountains for late Thursday into Thursday night. The GFS
swings a pocket of unstable air across southern sections Thursday
afternoon. This along with the favored dynamics south of the low
center would put the best chance of thunder over the San Gabriel
Mountains. At lower elevations, expect isolated to scattered
showers on Thursday but at this time do not expect any thunder
these areas. Moisture is lacking a bit at the onset of the
system`s arrival on Thursday. The precipitation will be highly hit
and miss on Thursday. Some areas may not receive any measurable
precipitation at all. Of course temperatures continue to cool on
Thursday when highs will be as much as 10-15 degrees below normal.

.LONG TERM...(FRI-MON)

Models generally agree in putting the center of the upper closed low
by Friday morning somewhere just south of Los Angeles, the ECMWF a
little further southwest compared to the GFS. Friday represents
the best chance of thunder lower elevations mainly south of Point
Conception. Increasing moisture that models show wrapping around
the low`s center could be a factor in chances for thunder on
Friday. The GFS places the upper low`s center around the Calif-
Ariz border south of Vegas by 00Z Saturday which keeps the
stronger dynamics well east of the forecast area. Again,
difficult this far out to identify any areas that have better
chances of precipitation over others. Friday will be the coolest
day of the 7-day forecast.

By around midday Saturday models put the upper low`s center over
western Utah with moist and cool northernly flow behind it
sweeping across southern California. Both the GFS and ECMWF
indicate a weak vort lobe rotating around its back side but any
precipitation from this at this time looks to stay well offshore.
Despite the low`s position well to the north and east there`s just
enough weak instability and moisture around to keep at least a
slight chance of showers on Saturday. Some slight warming expected
on Saturday despite the cloudiness although high temps still quite
a bit below normal.

Total QPF from this system between Thursday and late Saturday
should stay below a quarter most areas, less than a tenth more
likely. The one exception would be higher amounts under any
thunderstorms that develop. Overall this will not be a big rain
maker. Snow-wise, minimum snow levels with this system could be
as low as around 5700 to 6000 feet on Friday night.

The low continues to lift out through the intermountain west on
Sunday. Some additional warming is expected along with clearer
skies. High temperatures inch a few degrees higher on Sunday but
still not enough to get back to normal. Have backed off on
precipitation chances on Sunday as the low is just too far
removed. Additional warming for Monday when upper level high
pressure builds in earnest to help get high temps around or just
below normal.

&&

.AVIATION...02/2245Z...

At 2245Z...the marine inversion at KLAX was based at 800 feet.
The top of the inversion was 1900 feet with a temperature of
20 degrees Celsius.

Overall, moderate confidence in 00Z TAF package. High confidence
in stratus/fog returning to coastal TAF sites this evening and
overnight, but low confidence in timing. There is a 20% chance of
stratus reaching into the coastal valley TAF sites overnight.

KLAX...moderate confidence in 00Z TAF. High confidence in stratus
returning overnight (with IFR conditions likely), but low
confidence in timing (+/- 3 hours of current 09Z forecast).

KBUR...high confidence in 00Z TAF as VFR conditions are
anticipated through the TAF period. There is a 20% chance of IFR
conditions 09Z-17Z.

&&

.MARINE...02/200 pM.

High confidence that SCA conditions will not affect the waters
through at least Tuesday afternoon. There will be a minimally
better chance of SCA conds Wednesday. Advisory level winds are
possible across the outer waters by Thursday.


&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Beach Hazards Statement in effect through Tuesday afternoon
      For zones 40-41-87. (See LAXCFWLOX).
PZ...NONE.

&&

$$

PUBLIC...Jackson
AVIATION...RAT
MARINE...Sweet
SYNOPSIS...KJ

weather.gov/losangeles





000
FXUS66 KLOX 022119
AFDLOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
219 PM PDT MON MAY 2 2016

.SYNOPSIS...

There will be night through morning patchy low clouds and fog
through Wednesday. A slow moving low pressure system will bring a
chance of showers and thunderstorms along with cooler conditions
to the area Thursday through mainly Saturday. A warming trend is in
store for Sunday and Monday.

&&

.SHORT TERM...(TDY-THU)

Forecast area generally under weak high pressure aloft for the
next couple of days. A remnant of the last trough to move through
the area has left enough cold air aloft to induce some cumulus
over the mountains and extending into the Antelope Valley.
Showers developed over the eastern San Gabriels by late morning
but they have recently decreased due to warming aloft and weak
height rises. The overnight stratus has cleared out over coastal
areas of Los Angeles County and for the most part north to Point
Conception. However, stratus has held on over the immediate
central coast due to a slightly stronger onshore pressure gradient
versus southern coastal areas. Expect a similar stratus pattern
tonight as pressure gradients and marine layer depth change little
from last night.

Heights and thickness values continue to increase tomorrow to
bring another few degrees of warming nearly all areas. High clouds
will move across the area in advance of the next trough. Some mid
level clouds may sneak in by early evening. These shouldn`t deter
the warming trend. Another round of overnight coastal stratus for
Tuesday night. But with an increase in onshore flow and resultant
increase in the marine layer depth expect it to penetrate further
inland compared to last night and tonight.

By Wednesday 12z the upper trough axis is about 500 miles west of
LAX with fairly good agreement among models. Upper level
southwest flow increases as it gets closer along with general
cooling through the column. High temperatures on Wednesday will be
around 5 to 10 degrees cooler than Tuesday`s highs. By late in the
day Wednesday the upper trough is close enough to possibly produce
some showers over northern San Luis Obispo County extending westward
offshore.

By late in the day Thursday the upper level trough becomes a well
defined closed low, the center of which by 00Z Friday is around or
just west of Point Conception.  Mid level temperatures of -23C
near the core of the low will produce a marginally unstable
conditions. The NAM indicates lifted indices around -3.5C over
the Ventura County Mountains and CAPE values around 600 J/kg.
These numbers justify the the possibility of thunderstorms mainly
over the mountains for late Thursday into Thursday night. The GFS
swings a pocket of unstable air across southern sections Thursday
afternoon. This along with the favored dynamics south of the low
center would put the best chance of thunder over the San Gabriel
Mountains. At lower elevations, expect isolated to scattered
showers on Thursday but at this time do not expect any thunder
these areas. Moisture is lacking a bit at the onset of the
system`s arrival on Thursday. The precipitation will be highly hit
and miss on Thursday. Some areas may not receive any measurable
precipitation at all. Of course temperatures continue to cool on
Thursday when highs will be as much as 10-15 degrees below normal.

.LONG TERM...(FRI-MON)


Models generally agree in putting the center of the upper closed low
by Friday morning somewhere just south of Los Angeles, the ECMWF a
little further southwest compared to the GFS. Friday represents
the best chance of thunder lower elevations mainly south of Point
Conception. Increasing moisture that models show wrapping around
the low`s center could be a factor in chances for thunder on
Friday. The GFS places the upper low`s center around the Calif-
Ariz border south of Vegas by 00Z Saturday which keeps the
stronger dynamics well east of the forecast area. Again,
difficult this far out to identify any areas that have better
chances of precipitation over others. Friday will be the coolest
day of the 7-day forecast.

By around midday Saturday models put the upper low`s center over
western Utah with moist and cool northernly flow behind it
sweeping across southern California. Both the GFS and ECMWF
indicate a weak vort lobe rotating around its back side but any
precipitation from this at this time looks to stay well offshore.
Despite the low`s position well to the north and east there`s just
enough weak instability and moisture around to keep at least a
slight chance of showers on Saturday. Some slight warming expected
on Saturday despite the cloudiness although high temps still quite
a bit below normal.

Total QPF from this system between Thursday and late Saturday
should stay below a quarter most areas, less than a tenth more
likely. The one exception would be higher amounts under any
thunderstorms that develop. Overall this will not be a big rain
maker. Snow-wise, minimum snow levels with this system could be
as low as around 5700 to 6000 feet on Friday night.

The low continues to lift out through the intermountain west on
Sunday. Some additional warming is expected along with clearer
skies. High temperatures inch a few degrees higher on Sunday but
still not enough to get back to normal. Have backed off on
precipitation chances on Sunday as the low is just too far
removed. Additional warming for Monday when upper level high
pressure builds in earnest to help get high temps around or just
below normal.

&&

.AVIATION...02/1800Z.

AT 1741Z, the marine layer depth at KLAX was around 1000 feet.
The top of the inversion was around 2700 feet with a temperature
of 18 degrees Celsius.

good confidence in the 18z tafs. slow clearing is expected in
some areas...mainly from the ventura coast northward today. some
weak ridging is expected in the next 24 hours...so the depth of
the marine layer may drop slightly by tuesday morning...although
the nam12 model shows very little change in marine layer coverage.
the main change in the 18z taf package was to remove any mention
of marine clouds in the LA county valleys...in agreement with the
nam12 model.

KLAX...good confidence in the 18Z TAF. there is a 30 percent
chance of ceilings moving in 2 hours later than forecast.

KBUR..fair confidence in the 18Z TAF. there is a 30 percent chance
of marine clouds with ifr conditions late tonight and tuesday
morning.

&&

.MARINE...02/200 pM.

High confidence that SCA conditions will not affect the waters
through at least Tuesday afternoon. There will be a minimally
better chance of SCA conds Wednesday. Advisory level winds are
possible across the outer waters by Thursday.


&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...NONE.

&&

$$

PUBLIC...Jackson
AVIATION...Sweet
MARINE...Sweet
SYNOPSIS...KJ

weather.gov/losangeles





000
FXUS66 KLOX 022119
AFDLOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
219 PM PDT MON MAY 2 2016

.SYNOPSIS...

There will be night through morning patchy low clouds and fog
through Wednesday. A slow moving low pressure system will bring a
chance of showers and thunderstorms along with cooler conditions
to the area Thursday through mainly Saturday. A warming trend is in
store for Sunday and Monday.

&&

.SHORT TERM...(TDY-THU)

Forecast area generally under weak high pressure aloft for the
next couple of days. A remnant of the last trough to move through
the area has left enough cold air aloft to induce some cumulus
over the mountains and extending into the Antelope Valley.
Showers developed over the eastern San Gabriels by late morning
but they have recently decreased due to warming aloft and weak
height rises. The overnight stratus has cleared out over coastal
areas of Los Angeles County and for the most part north to Point
Conception. However, stratus has held on over the immediate
central coast due to a slightly stronger onshore pressure gradient
versus southern coastal areas. Expect a similar stratus pattern
tonight as pressure gradients and marine layer depth change little
from last night.

Heights and thickness values continue to increase tomorrow to
bring another few degrees of warming nearly all areas. High clouds
will move across the area in advance of the next trough. Some mid
level clouds may sneak in by early evening. These shouldn`t deter
the warming trend. Another round of overnight coastal stratus for
Tuesday night. But with an increase in onshore flow and resultant
increase in the marine layer depth expect it to penetrate further
inland compared to last night and tonight.

By Wednesday 12z the upper trough axis is about 500 miles west of
LAX with fairly good agreement among models. Upper level
southwest flow increases as it gets closer along with general
cooling through the column. High temperatures on Wednesday will be
around 5 to 10 degrees cooler than Tuesday`s highs. By late in the
day Wednesday the upper trough is close enough to possibly produce
some showers over northern San Luis Obispo County extending westward
offshore.

By late in the day Thursday the upper level trough becomes a well
defined closed low, the center of which by 00Z Friday is around or
just west of Point Conception.  Mid level temperatures of -23C
near the core of the low will produce a marginally unstable
conditions. The NAM indicates lifted indices around -3.5C over
the Ventura County Mountains and CAPE values around 600 J/kg.
These numbers justify the the possibility of thunderstorms mainly
over the mountains for late Thursday into Thursday night. The GFS
swings a pocket of unstable air across southern sections Thursday
afternoon. This along with the favored dynamics south of the low
center would put the best chance of thunder over the San Gabriel
Mountains. At lower elevations, expect isolated to scattered
showers on Thursday but at this time do not expect any thunder
these areas. Moisture is lacking a bit at the onset of the
system`s arrival on Thursday. The precipitation will be highly hit
and miss on Thursday. Some areas may not receive any measurable
precipitation at all. Of course temperatures continue to cool on
Thursday when highs will be as much as 10-15 degrees below normal.

.LONG TERM...(FRI-MON)


Models generally agree in putting the center of the upper closed low
by Friday morning somewhere just south of Los Angeles, the ECMWF a
little further southwest compared to the GFS. Friday represents
the best chance of thunder lower elevations mainly south of Point
Conception. Increasing moisture that models show wrapping around
the low`s center could be a factor in chances for thunder on
Friday. The GFS places the upper low`s center around the Calif-
Ariz border south of Vegas by 00Z Saturday which keeps the
stronger dynamics well east of the forecast area. Again,
difficult this far out to identify any areas that have better
chances of precipitation over others. Friday will be the coolest
day of the 7-day forecast.

By around midday Saturday models put the upper low`s center over
western Utah with moist and cool northernly flow behind it
sweeping across southern California. Both the GFS and ECMWF
indicate a weak vort lobe rotating around its back side but any
precipitation from this at this time looks to stay well offshore.
Despite the low`s position well to the north and east there`s just
enough weak instability and moisture around to keep at least a
slight chance of showers on Saturday. Some slight warming expected
on Saturday despite the cloudiness although high temps still quite
a bit below normal.

Total QPF from this system between Thursday and late Saturday
should stay below a quarter most areas, less than a tenth more
likely. The one exception would be higher amounts under any
thunderstorms that develop. Overall this will not be a big rain
maker. Snow-wise, minimum snow levels with this system could be
as low as around 5700 to 6000 feet on Friday night.

The low continues to lift out through the intermountain west on
Sunday. Some additional warming is expected along with clearer
skies. High temperatures inch a few degrees higher on Sunday but
still not enough to get back to normal. Have backed off on
precipitation chances on Sunday as the low is just too far
removed. Additional warming for Monday when upper level high
pressure builds in earnest to help get high temps around or just
below normal.

&&

.AVIATION...02/1800Z.

AT 1741Z, the marine layer depth at KLAX was around 1000 feet.
The top of the inversion was around 2700 feet with a temperature
of 18 degrees Celsius.

good confidence in the 18z tafs. slow clearing is expected in
some areas...mainly from the ventura coast northward today. some
weak ridging is expected in the next 24 hours...so the depth of
the marine layer may drop slightly by tuesday morning...although
the nam12 model shows very little change in marine layer coverage.
the main change in the 18z taf package was to remove any mention
of marine clouds in the LA county valleys...in agreement with the
nam12 model.

KLAX...good confidence in the 18Z TAF. there is a 30 percent
chance of ceilings moving in 2 hours later than forecast.

KBUR..fair confidence in the 18Z TAF. there is a 30 percent chance
of marine clouds with ifr conditions late tonight and tuesday
morning.

&&

.MARINE...02/200 pM.

High confidence that SCA conditions will not affect the waters
through at least Tuesday afternoon. There will be a minimally
better chance of SCA conds Wednesday. Advisory level winds are
possible across the outer waters by Thursday.


&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...NONE.

&&

$$

PUBLIC...Jackson
AVIATION...Sweet
MARINE...Sweet
SYNOPSIS...KJ

weather.gov/losangeles





000
FXUS66 KLOX 021834
AFDLOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
1134 AM PDT MON MAY 2 2016

.SYNOPSIS...

There will be night through morning patchy low clouds and fog
through Wednesday. A slow moving low pressure system will bring a
chance of showers and thunderstorms along with cooler conditions
to the area Thursday through Sunday.

&&

.SHORT TERM...(TDY-WED)

Low clouds along the coast are clearing out to the beaches most
areas as expected, clearing out fastest over Los Angeles County
but holding on along the Santa Barbara south coast northward along
the central coast. Onshore gradients are a little weaker this
morning south of Point Conception while slightly stronger north.
Expect plenty of clear skies today all areas of Ventura and Los
Angeles County but would not be surprised to see cloud cover
continue along the immediate central coast. Visible satellite
imagery showing some cumulus buildup over the eastern San Gabriels
due to some remnant cold air aloft lagging behind the last system.
These may produce a few sprinkles to weak showers that area but
nothing significant. Expect a return of overnight low clouds
coastal areas tonight, and with a similar coverage as last night
due to fairly similar surface pressure gradients and marine layer
depth.

As heights rise today and tomorrow we should see some warmup most
areas. Temperatures over much of Los Angeles County are a few
degrees ahead of schedule this morning while areas north of Point
Conception are 5 to as much as 10 degrees cooler than yesterday at
this time due to a slightly stonger onshore push and more cloud
cover. The current temperature change pattern should hold true for
this afternoon`s high temps. Continued height rises will warm
things a few more degrees tomorrow when the weak ridge axis passes
by, and despite an increase in cloud cover ahead of the next
trough to move through the area for the second half of the week.

The trough to move through the area for the second half of the
week will start by cooling temperatures on Wednesday. Expect high
temperatures to cool down by 5 to 10 degrees from Tuesday`s highs most
areas, and under increasingly cloudy skies.



.LONG TERM...(THU-SUN)


GFS/EC agree that a cutoff low pressure system will slowly drift over
the forecast area Thursday and Friday, then slowly move east over
the weekend. There will be a chance for hit and miss showers in
most places Thursday through Saturday (with the highest probability
from Thursday afternoon through Friday evening). The cold core
upper low (with 500 mb temperatures of -24 degrees Celsius) will
move across Southwest California sometime between Thursday
afternoon through Friday. The cold air aloft combined with early
May sunshine will be create enough instability to warrant a
slight chance of thunderstorms(especially over interior sections).
Right now it does not look like this system will have that much
moisture to work with and do not expect large rainfall amounts
with it. This system is cold enough that snow levels will likely
dip to between 5000 and 6000 feet.



&&

.AVIATION...02/1800Z.

AT 1741Z, the marine layer depth at KLAX was around 1000 feet.
The top of the inversion was around 2700 feet with a temperature
of 18 degrees Celsius.

good confidence in the 18z tafs. slow clearing is expected in
some areas...mainly from the ventura coast northward today. some
weak ridging is expected in the next 24 hours...so the depth of
the marine layer may drop slightly by tuesday morning...although
the nam12 model shows very little change in marine layer coverage.
the main change in the 18z taf package was to remove any mention
of marine clouds in the LA county valleys...in agreement with the
nam12 model.

KLAX...good confidence in the 18Z TAF. there is a 30 percent
chance of ceilings moving in 2 hours later than forecast.

KBUR..fair confidence in the 18Z TAF. there is a 30 percent chance
of marine clouds with ifr conditions late tonight and tuesday
morning.

&&

.MARINE...02/900 AM.

High confidence that SCA conditions will not affect the waters
through at least Tuesday afternoon. there will be a better chance
of SCA conds Wednesday. Advisory level winds are possible across
the outer waters by Wednesday night.


&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...NONE.

&&

$$

PUBLIC...Jackson
AVIATION...Sweet
MARINE...Sweet
SYNOPSIS...KJ

weather.gov/losangeles





000
FXUS66 KLOX 021656
AFDLOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
956 AM PDT MON MAY 2 2016

.SYNOPSIS...

There will be night through morning patchy low clouds and fog
through Wednesday. A slow moving low pressure system will bring a
chance of showers and thunderstorms along with cooler conditions
to the area Thursday through Sunday.

&&

.SHORT TERM...(TDY-WED)

Low clouds along the coast are clearing out to the beaches most
areas as expected, clearing out fastest over Los Angeles County
but holding on along the Santa Barbara south coast northward along
the central coast. Onshore gradients are a little weaker this
morning south of Point Conception while slightly stronger north.
Expect plenty of clear skies today all areas of Ventura and Los
Angeles County but would not be surprised to see cloud cover
continue along the immediate central coast. Visible satellite
imagery showing some cumulus buildup over the eastern San Gabriels
due to some remnant cold air aloft lagging behind the last system.
These may produce a few sprinkles to weak showers that area but
nothing significant. Expect a return of overnight low clouds
coastal areas tonight, and with a similar coverage as last night
due to fairly similar surface pressure gradients and marine layer
depth.

As heights rise today and tomorrow we should see some warmup most
areas. Temperatures over much of Los Angeles County are a few
degrees ahead of schedule this morning while areas north of Point
Conception are 5 to as much as 10 degrees cooler than yesterday at
this time due to a slightly stronger onshore push and more cloud
cover. The current temperature change pattern should hold true for
this afternoon`s high temps. Continued height rises will warm
things a few more degrees tomorrow when the weak ridge axis passes
by, and despite an increase in cloud cover ahead of the next
trough to move through the area for the second half of the week.

The trough to move through the area for the second half of the
week will start by cooling temperatures on Wednesday. Expect high
temperatures to cool down by 5 to 10 degrees from Tuesday`s highs most
areas, and under increasingly cloudy skies.

*** From previous discussion ***

.LONG TERM...(THU-SUN)


GFS/EC agree that a cutoff low pressure system will slowly drift over
the forecast area Thursday and Friday, then slowly move east over
the weekend. There will be a chance for hit and miss showers in
most places Thursday through Saturday (with the highest probability
from Thursday afternoon through Friday evening). The cold core
upper low (with 500 mb temperatures of -24 degrees Celsius) will
move across Southwest California sometime between Thursday
afternoon through Friday. The cold air aloft combined with early
May sunshine will be create enough instability to warrant a
slight chance of thunderstorms(especially over interior sections).
Right now it does not look like this system will have that much
moisture to work with and do not expect large rainfall amounts
with it. This system is cold enough that snow levels will likely
dip to between 5000 and 6000 feet.



&&

.AVIATION...02/1145Z.

AT 11Z, the marine layer depth at KLAX was around 1800 feet.
The top of the inversion was around 3000 feet with a temperature
of 15 degrees Celsius.

Widespread stratus on the Central Coast and in the Santa Ynez
Valley early this morning, with IFR to LIFR conds. Expect IFR to
LIFR conds to push into the Salinas Valley. South of Pt
Conception, stratus with IFR conds was affecting the south
coast of Sba County and the Vtu County coast, with IFR to LIFR
conds beginning to spread into the Vtu County valleys. Stratus
across Los Angeles county has been confined to southern sections,
but was beginning to spread northward, and will likely affect all
coastal sections of L.A. county by daybreak. Cigs were higher
here, with mostly MVFR conditions. Expect rather slow clearing,
especially in coastal sections of Vtu and southern Sba Counties,
where clearing may not take place until early afternoon.
Widespread stratus is expected in all coastal and valley areas
tonight, with IFR conds north of Pt Conception and MVFR conds
south.

KLAX...Moderate confidence in the 12Z TAF. There is a 20 to 30
percent chance that cigs will not scatter out until at 21Z. There
is a 30 percent chance that cigs will not arrive tonight until
after 09Z.

KBUR..Moderate confidence in the 12Z TAF. There is a 20 to 30
percent chance of low MVFR or high IFR cigs between 13Z and 17Z
this morning. There is a 20 percent chance that cigs will not
arrive tonight until after 12Z.

&&

.MARINE...02/900 AM.

High confidence that SCA conditions will not affect the waters
through at least Tuesday afternoon. there will be a better chance
of SCA conds Wednesday. Advisory level winds are possible across
the outer waters by Wednesday night.


&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Beach Hazards Statement in effect until 10 AM PDT this
      morning For zones 34-35-40-41-87. (See LAXCFWLOX).
PZ...NONE.

&&

$$

PUBLIC...Jackson/Rorke
AVIATION...DB
MARINE...DB
SYNOPSIS...KJ

weather.gov/losangeles





000
FXUS66 KLOX 021656
AFDLOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
956 AM PDT MON MAY 2 2016

.SYNOPSIS...

There will be night through morning patchy low clouds and fog
through Wednesday. A slow moving low pressure system will bring a
chance of showers and thunderstorms along with cooler conditions
to the area Thursday through Sunday.

&&

.SHORT TERM...(TDY-WED)

Low clouds along the coast are clearing out to the beaches most
areas as expected, clearing out fastest over Los Angeles County
but holding on along the Santa Barbara south coast northward along
the central coast. Onshore gradients are a little weaker this
morning south of Point Conception while slightly stronger north.
Expect plenty of clear skies today all areas of Ventura and Los
Angeles County but would not be surprised to see cloud cover
continue along the immediate central coast. Visible satellite
imagery showing some cumulus buildup over the eastern San Gabriels
due to some remnant cold air aloft lagging behind the last system.
These may produce a few sprinkles to weak showers that area but
nothing significant. Expect a return of overnight low clouds
coastal areas tonight, and with a similar coverage as last night
due to fairly similar surface pressure gradients and marine layer
depth.

As heights rise today and tomorrow we should see some warmup most
areas. Temperatures over much of Los Angeles County are a few
degrees ahead of schedule this morning while areas north of Point
Conception are 5 to as much as 10 degrees cooler than yesterday at
this time due to a slightly stronger onshore push and more cloud
cover. The current temperature change pattern should hold true for
this afternoon`s high temps. Continued height rises will warm
things a few more degrees tomorrow when the weak ridge axis passes
by, and despite an increase in cloud cover ahead of the next
trough to move through the area for the second half of the week.

The trough to move through the area for the second half of the
week will start by cooling temperatures on Wednesday. Expect high
temperatures to cool down by 5 to 10 degrees from Tuesday`s highs most
areas, and under increasingly cloudy skies.

*** From previous discussion ***

.LONG TERM...(THU-SUN)


GFS/EC agree that a cutoff low pressure system will slowly drift over
the forecast area Thursday and Friday, then slowly move east over
the weekend. There will be a chance for hit and miss showers in
most places Thursday through Saturday (with the highest probability
from Thursday afternoon through Friday evening). The cold core
upper low (with 500 mb temperatures of -24 degrees Celsius) will
move across Southwest California sometime between Thursday
afternoon through Friday. The cold air aloft combined with early
May sunshine will be create enough instability to warrant a
slight chance of thunderstorms(especially over interior sections).
Right now it does not look like this system will have that much
moisture to work with and do not expect large rainfall amounts
with it. This system is cold enough that snow levels will likely
dip to between 5000 and 6000 feet.



&&

.AVIATION...02/1145Z.

AT 11Z, the marine layer depth at KLAX was around 1800 feet.
The top of the inversion was around 3000 feet with a temperature
of 15 degrees Celsius.

Widespread stratus on the Central Coast and in the Santa Ynez
Valley early this morning, with IFR to LIFR conds. Expect IFR to
LIFR conds to push into the Salinas Valley. South of Pt
Conception, stratus with IFR conds was affecting the south
coast of Sba County and the Vtu County coast, with IFR to LIFR
conds beginning to spread into the Vtu County valleys. Stratus
across Los Angeles county has been confined to southern sections,
but was beginning to spread northward, and will likely affect all
coastal sections of L.A. county by daybreak. Cigs were higher
here, with mostly MVFR conditions. Expect rather slow clearing,
especially in coastal sections of Vtu and southern Sba Counties,
where clearing may not take place until early afternoon.
Widespread stratus is expected in all coastal and valley areas
tonight, with IFR conds north of Pt Conception and MVFR conds
south.

KLAX...Moderate confidence in the 12Z TAF. There is a 20 to 30
percent chance that cigs will not scatter out until at 21Z. There
is a 30 percent chance that cigs will not arrive tonight until
after 09Z.

KBUR..Moderate confidence in the 12Z TAF. There is a 20 to 30
percent chance of low MVFR or high IFR cigs between 13Z and 17Z
this morning. There is a 20 percent chance that cigs will not
arrive tonight until after 12Z.

&&

.MARINE...02/900 AM.

High confidence that SCA conditions will not affect the waters
through at least Tuesday afternoon. there will be a better chance
of SCA conds Wednesday. Advisory level winds are possible across
the outer waters by Wednesday night.


&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Beach Hazards Statement in effect until 10 AM PDT this
      morning For zones 34-35-40-41-87. (See LAXCFWLOX).
PZ...NONE.

&&

$$

PUBLIC...Jackson/Rorke
AVIATION...DB
MARINE...DB
SYNOPSIS...KJ

weather.gov/losangeles





000
FXUS66 KLOX 021156
AFDLOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
456 AM PDT MON MAY 2 2016

.SYNOPSIS...

There will be night through morning low clouds and fog today and
Wednesday with slightly above normal temperatures in the morning. A
slow moving low pressure system will bring a chance of showers
and thunderstorms along with cooler conditions to the area
Thursday through the weekend.

&&

.SHORT TERM...(TDY-WED)

Low clouds are a little better organized this morning. The
gradients are about 3 MB onshore push both to the north and the
east and the marine layer inversion has strengthened both of which
are helping the marine layer stratus along. By dawn most of the
coasts and the vly will be covered with stratus. There will be
good clearing by the afternoon as there is no eddy and the onshore
push is not that strong. The barest of ridges pops up today and
this will allow for a little warming esp across the interior.
There is just enough residual moisture over the mtns to allow for
some afternoon cu but not enough lift or instability to form
showers.

Since the marine layer is already fairly well established the
stratus deck will reform a little quicker overnight. It will still
burn off pretty quickly. Skies will turn partly cloudy in the
afternoon as mid and esp high level clouds stream in the sw flow
ahead of an approaching trof. MDLs indicating quite a bit of
warming but with the ridge moving off and the increase of clouds
there will be...at best...only a degree or two of warming.

The trof will be right along the West Coast on Wednesday morning
and the lift associated with it will drive marine layer stratus
over the csts and vlys and onto the coastal slopes. Mid and high
level clouds will increase through the day. Onshore flow will
increase through the day as well. All of these trend will conspire
to cause a sharp drop in temperatures. Max temps will drop 5 to 10
degrees and will be 3 to 6 degrees below normal.

.LONG TERM...(THU-SUN)


GFS/EC agree that a cutoff low pressure system will slowly drift over
the forecast area Thursday and Friday, then slowly move east over
the weekend. There will be a chance for hit and miss showers in
most places Thursday through Saturday (with the highest probability
from Thursday afternoon through Friday evening). The cold core
upper low (with 500 mb temperatures of -24 degrees Celsius) will
move across Southwest California sometime between Thursday
afternoon through Friday. The cold air aloft combined with early
May sunshine will be create enough instability to warrant a
slight chance of thunderstorms(especially over interior sections).
Right now it does not look like this system will have that much
moisture to work with and do not expect large rainfall amounts
with it. This system is cold enough that snow levels will likely
dip to between 5000 and 6000 feet.

&&

.AVIATION...02/1145Z.

AT 11Z, the marine layer depth at KLAX was around 1800 feet.
The top of the inversion was around 3000 feet with a temperature
of 15 degrees Celsius.

Widespread stratus on the Central Coast and in the Santa Ynez
Valley early this morning, with IFR to LIFR conds. Expect IFR to
LIFR conds to push into the Salinas Valley. South of Pt
Conception, stratus with IFR conds was affecting the south
coast of Sba County and the Vtu County coast, with IFR to LIFR
conds beginning to spread into the Vtu County valleys. Stratus
across Los Angeles county has been confined to southern sections,
but was beginning to spread northward, and will likely affect all
coastal sections of L.A. county by daybreak. Cigs were higher
here, with mostly MVFR conditions. Expect rather slow clearing,
especially in coastal sections of Vtu and southern Sba Counties,
where clearing may not take place until early afternoon.
Widespread stratus is expected in all coastal and valley areas
tonight, with IFR conds north of Pt Conception and MVFR conds
south.

KLAX...Moderate confidence in the 12Z TAF. There is a 20 to 30
percent chance that cigs will not scatter out until at 21Z. There
is a 30 percent chance that cigs will not arrive tonight until
after 09Z.

KBUR..Moderate confidence in the 12Z TAF. There is a 20 to 30
percent chance of low MVFR or high IFR cigs between 13Z and 17Z
this morning. There is a 20 percent chance that cigs will not
arrive tonight until after 12Z.

&&

.MARINE...02/330 AM.

High confidence that SCA conditions will not affect the waters
through at least Tuesday afternoon. There is a chance that a
Small Craft Advisory may be needed across the outer waters
Tuesday night, with a better chance of SCA conds Wednesday.
Advisory level winds are likely across the outer waters by
Wednesday night.


&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Beach Hazards Statement in effect until 10 AM PDT this
      morning For zones 34-35-40-41-87. (See LAXCFWLOX).
PZ...NONE.

&&

$$

PUBLIC...Rorke
AVIATION...DB
MARINE...DB
SYNOPSIS...Smith

weather.gov/losangeles





000
FXUS66 KLOX 021044
AFDLOX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LOS ANGELES/OXNARD CA
344 AM PDT MON MAY 2 2016

.SYNOPSIS...

There will be night through morning low clouds and fog today and
Wednesday with slightly above normal temperatures in the morning. A
slow moving low pressure system will bring a chance of showers
and thunderstorms along with cooler conditions to the area
Thursday through the weekend.

&&

.SHORT TERM...(TDY-WED)

Low clouds are a little better organized this morning. The
gradients are about 3 MB onshore push both to the north and the
east and the marine layer inversion has strengthened both of which
are helping the marine layer stratus along. By dawn most of the
coasts and the vly will be covered with stratus. There will be
good clearing by the afternoon as there is no eddy and the onshore
push is not that strong. The barest of ridges pops up today and
this will allow for a little warming esp across the interior.
There is just enough residual moisture over the mtns to allow for
some afternoon cu but not enough lift or instability to form
showers.

Since the marine layer is already fairly well established the
stratus deck will reform a little quicker overnight. It will still
burn off pretty quickly. Skies will turn partly cloudy in the
afternoon as mid and esp high level clouds stream in the sw flow
ahead of an approaching trof. MDLs indicating quite a bit of
warming but with the ridge moving off and the increase of clouds
there will be...at best...only a degree or two of warming.

The trof will be right along the West Coast on Wednesday morning
and the lift associated with it will drive marine layer stratus
over the csts and vlys and onto the coastal slopes. Mid and high
level clouds will increase through the day. Onshore flow will
increase through the day as well. All of these trend will conspire
to cause a sharp drop in temperatures. Max temps will drop 5 to 10
degrees and will be 3 to 6 degrees below normal.

.LONG TERM...(THU-SUN)

GFS/EC agree that a cutoff low pressure system will slowly drift over
the forecast area Thursday and Friday, then slowly move east over
the weekend. There will be a chance for hit and miss showers in
most places Thursday through Saturday (with the highest probability
from Thursday afternoon through Friday evening). The cold core
upper low (with 500 mb temperatures of -24 degrees Celsius) will
move across Southwest California sometime between Thursday
afternoon through Friday. The cold air aloft combined with early
May sunshine will be create enough instability to warrant a
slight chance of thunderstorms(especially over interior sections).
Right now it does not look like this system will have that much
moisture to work with and do not expect large rainfall amounts
with it. This system is cold enough that snow levels will likely
dip to between 5000 and 6000 feet.

&&

.AVIATION...

02/1130Z

AT 11Z, the marine layer depth was around 1100 feet at KLAX. The
top of the inversion was around 3800 feet with a temperature of 15
degrees Celsius.



KLAX...

KBUR...


&&

.MARINE...

01/900 PM

High confidence in light winds and diminishing seas through at
least Tuesday afternoon. There is a chance that a Small Craft
Advisory may be needed on Tuesday evening. Advisory level winds
will likely develop on Wednesday.


&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Beach Hazards Statement in effect until 10 AM PDT this
      morning For zones 34-35-40-41-87. (See LAXCFWLOX).
PZ...NONE.

&&

$$

PUBLIC...Rorke
AVIATION...DB
MARINE...DB
SYNOPSIS...Smith

weather.gov/losangeles





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