Forecast Discussions mentioning any of "ACARS" "MDCRS" "AIRCRAFT" "TAMDAR" "AMDAR" "WVSS" received at GSD on 11/09/19

Area Forecast Discussion

National Weather Service Burlington VT

 924 PM EST Fri Nov 8 2019

.SYNOPSIS...
Snow showers will continue through the early evening hours with
decent instability present across the North Country. Gusty winds
will also be observed through the remainder of the afternoon and
early evening hours. Temperatures tonight will drop quickly as
skies clear a little and winds diminish. This should yield lows
in the lower teens to lower 20s, which is about 15 degrees below
normal. Below normal temperatures are expected to continue
through the weekend with Sunday being the warmest day with
temperatures in the 40s across the region. Saturday and the
first half of Sunday will remain dry but snow chances increase
heading into Sunday afternoon. The next big storm looks like it
could impact the North Country Monday afternoon and Tuesday and
bring decent snow accumulations to the region.

&&

.NEAR TERM /THROUGH SATURDAY NIGHT/...
As of 922 PM EST Friday...Clouds continue to linger in the
favorable upslope regions of the northern Dacks into
central/northern VT. Expect areal coverage to decrease with a
window of mostly clear skies later tonight into early Saturday,
before more clouds develop. The idea of lows ranging from the
lower teens slk/nek to l/m 20s cpv/slv looks good. Just tweaked
sky cover grids and updated to ingest latest hourly trends.

Previous discuss below:
The axis of the convective snow showers has shifted to the east
this afternoon with the band of heaviest snowfall now extending
across eastern Chittenden County, eastern Addison Country and
Washington County. Additional snow showers are moving into
northern Vermont from Canada as we remain in an unstable
environment characterized by 200-500 J/kg of CAPE. It`ll be
interesting to see how some of the showers moving across Lake
Champlain over the next few hours behave as there is a localized
maximum of 1000 J/kg of CAPE due to the warmer lake
temperatures. Thermal profiles continue to shower near super
adiabatic lapse rates over the lake which will help aid in the
development of a few lake enhanced showers through the afternoon
hours. The majority of the lingering snow showers this
afternoon will likley be across northern Vermont and portions of
central Vermont with the best accumulations likely above 2000
ft where we could see another 1-3 inches of snowfall. Otherwise
a dusting to another inch of snowfall will be possible in the
band of stronger showers moving across central Vermont. Winds
will continue in to increase through early evening as our mixing
depth aloft continues to deepen and we mix to about 10,000 feet
until about 6 or 7 PM. An ACARS sounding from a plane leaving
KBTV showed the 30 knots at 750 mb which further verifies we
should continue to see some stronger gusts until the surface
decouples after sunset.

Tonight is going to be the coldest night across the North Country so
far this fall. Satellite imagery continues to show drier air
advecting into the North Country which will allow for a good bit of
the clouds currently overhead dissipating. While it won`t be
entirely clear tonight, good radiational cooling coupled with
weakening winds will set us up for lows in the lower teens to lower
20s. Winds do begin to back to the west/southwest toward dawn which
may limit the total effects of radiational cooling as we begin to
enter a weak warm air regime but nevertheless the overnight lows
will range from 12-15 degrees below normal.

Saturday is shaping up to be a pretty nice day, albeit a bit on the
chilly side like today. High pressure will move across the region
throughout the day which will help keep winds relatively light while
allowing temperatures to warm into the lower to mid 30s. Clouds
cover is a little tricky on Saturday as we begin to see some
moisture move into the region during the afternoon hours which will
likely bring in some partly to mostly cloudy conditions by sunset.
With continued southerly flow Saturday night, temperatures won`t
fall nearly as far as they will Friday night with lows only dropping
into the upper teens to around 30 degrees.

&&

.SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...
As of 250 PM EST Friday...No big changes noted in the 12Z NWP
guidance for the latter half of the weekend which highlights a
dynamically weak but thermally strong cold front passage late Sunday
through Sunday night. The best forcing along the boundary will be
across west/northwestern zones before it falls apart moving across
the region, and as such the highest chances for precipitation will
across northern New York and along the VT/Canada border during the
afternoon and evening hours. Ptype looks to be mainly rain as
southerly low level flow strengthens between the front and exiting
high pressure with gusts 20-30 mph ushering in a return of more
seasonal to above normal temperatures in the low/mid 40s during the
day, but overnight might end as a mix of rain and snow showers with
little to no snow accumulations likely. Behind the frontal passage
Sunday night lows will drop back into the teens and 20s.

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
As of 250 PM EST Friday...Love the snow? Well this long term forecast
is for you, as models are coming into much better agreement compared
to yesterday in regard to the potential for a significant snowfall
across the North Country Monday night through Tuesday. Latest
GFS/ECMWF/GEM are all in fairly close agreement with the strength
and track of low pressure developing over the central Appalachians
Monday afternoon and tracking along a stalled frontal boundary
draped across the mid- Atlantic to southeast New England states. Some
minor differences from west to east of the track does complicate the
low level thermal profiles where the GFS and ECMWF show a warm nose
between 925-850mb nudging into southern Vermont Monday night, but
ensembles are slightly cooler. This would support a brief period of
mixed precip across our southern zones, while elsewhere the
soundings support all snow through the event. While early,
indications are for the potential for 6-10" of snow in the lower
elevations when it`s all said and done Tuesday evening. High summits
could make out with a foot or more with upslope lingering into
Tuesday night as well.

Hate the cold? The rest of the long term forecast is not for you,
because behind the snow cold high pressure builds into the region
with strong low/mid level northerly flow ushering in the coldest air
of the season yet with 925/850mb temps in the teens below zero
through Thursday. This supports highs Wednesday only in the 20s with
Tues/Wed night lows in the single digits to teens above zero. Some
reprieve comes though Thursday into Friday as the high shifts east
and southerly winds return. Temps look to warm back to normal with
highs Thu/Fri in the 30s.

&&

.AVIATION /03Z SATURDAY THROUGH WEDNESDAY/...
Through 00z Sunday...Light snow occasionally producing MVFR
conditions may persist for a few more hours at Saranac Lake and
Montpelier before ending. Otherwise, VFR conditions will
prevail during the next 24 hours. Clouds will gradually thin out
overnight across the entire region as the influence of high
pressure to our south takes hold. Some southerly return flow at
the surface will lead to some veering winds but speeds should
reach only up to around 10 knots Saturday afternoon. During
that time, a general increase in high cloud cover is expected
with more coverage over northern New York as moisture is
gradually funneled into the North Country.

Outlook...

Saturday Night: VFR. NO SIG WX.
Sunday: Mainly VFR, with local MVFR possible. Chance SHRA, Chance
SHSN.
Sunday Night: Mainly VFR, with local MVFR possible. Slight chance
SHRA, Slight chance SHSN.
Veterans Day: Mainly VFR, with local MVFR possible. Chance SHSN,
Chance SN.
Monday Night: Mainly MVFR and IFR, with local VFR possible.
Definite SN.
Tuesday: Mainly MVFR, with local IFR possible. Definite SN,
Likely SHSN.
Tuesday Night: Mainly VFR, with areas MVFR possible. Chance SHSN.
Wednesday: Mainly VFR, with areas MVFR possible. Slight chance
SHSN.

&&

.BTV WATCHES/WARNINGS/ADVISORIES...
VT...None.
NY...None.

&&

$$
SYNOPSIS...Clay
NEAR TERM...Clay/Taber
SHORT TERM...Lahiff
LONG TERM...Lahiff
AVIATION...Kutikoff/Taber



Area Forecast Discussion

National Weather Service Los Angeles/Oxnard CA

 751 PM PST Fri Nov 8 2019

.SYNOPSIS...08/816 AM.

It will be rather warm through early next week, with above normal
temperatures. A cooling trend is expected by the end of next week,
with temperatures dropping to slightly below normal. Conditions
will remain dry with light offshore winds in the mountains.

&&

.SHORT TERM (FRI-MON)...08/749 PM.

***UPDATE***

Slightly stronger offshore flow today helped to warm up most
coast and coastal valleys 4-10 degrees today from yesterday. The
offshore gradient between LAX-DAG was around -2MB stronger this
afternoon compared to yesterday afternoon. Highs across most
valleys were in the mid 80s to low 90s. As is typical with
offshore flow, there was significant warming across coast and
valleys and a few degrees of cooling today across the Antelope
Valley and interior locations of SBA/SLO Counties.

The latest GOES-W Fog Product Imagery indicted mostly clear skies
across the forecast area with the exception of some patchy low
clouds moving in across the Santa Barbara Central Coast,
including Lompoc. Latest 4 PM sounding at Vandenberg AFB was
showing the marine layer around 900 ft deep. Therefore chances of
dense fog for the Central Coast might not be as high as
originally thought and will adjust accordingly. Otherwise, no
changes expected to the short term forecast.

Some offshore winds are expected to develop across the San Lucia
Mtns reaching portions of the Central Coast after midnight and could
cause some of the marine layer stratus to scour out before sunrise
across the Central Coast. Weak offshore flow will most likely
prevent any low clouds from developing across coastal areas S of
Point Conception overnight. Latest AMDAR Sounding around LAX
indicated the marine layer depth was near the surface with a
relatively strong inversion up to 800 ft which would also support
the lack of clouds. However, if low clouds do develop, patchy
dense fog is likely near the immediate coast. For now will keep
the mention of low clouds out of the forecast for LA/VTU Coastal
areas as well as the SBA South Coast.

For Saturday, not much change to the forecast. Expecting weak
offshore flow in the morning across the wind prone mountain and
valley passes of LA/VTU Counties similar to today. Continued
offshore flow is expected through SLO/SBA Counties with coastal
areas warming into the mid 70s to upper 80s.

Winds become onshore Sunday, but not as strong as previously
expected. Therefore will adjust temperatures up a few degrees
across coasts and valleys from current forecast to reflect this.

***From Previous Discussion***

Sunday will be cooler with gradients turning onshore. Similar
Monday with possibly some marine layer clouds returning, though
gradients start flipping back around to offshore as surface
pressures increase across the Great Basin.

.LONG TERM (TUE-FRI)...08/244 PM.

The ridge moves in and over CA Tue and early Wed and there will
be a little more (but not much more) offshore flow. Just enough to
keep the stratus away and bring some warming Tuesday. Later
Wednesday a little trof moves in and lower hgts and brings onshore
trends to the state. This will lower temps some.

Weak trofing persists Thursday and the weak offshore flow switches
to weak onshore. There will be 3 to 6 degrees of cooling across
the board and for the first time in a while there will be blo
normal temps.

Still a lot of uncertainty for the end of next week into the
weekend as models are struggling with the handling of the trough
and whether it will evolve into a cutoff low.

&&

.AVIATION...09/0017Z.

At 2338Z, A near surface based inversion was in place. The top of
the inversion was around 900 feet with a temperature of 27
degrees Celsius.

Generally hi confidence in the 00Z TAFs across all TAF sites
except moderate confidence for Central Coast TAFs including
KSMX/kSBP. There will likely be low clouds with VLIFR to IFR
conditions at KSMX between about 03Z and 12Z tonight, with some
uncertainties in the timing of these conditions. There is a 40%
chance for VLIFR to IFR CIGs at KSBP late tonight and early Sat.
Otherwise, VFR conditions are expected at the airfields thru Sat
morning.

KLAX...Hi confidence in the 00Z TAF with VFR conditions expected
through Sat afternoon. There is a 20% chance for VLIFR/IFR Cigs
between 11z-15z

KBUR...Hi confidence in the 00Z TAF with CAVU conditions expected
through Sat.

&&

.MARINE...08/1204 PM.

For the Outer Waters, moderate to high confidence in current
forecast. Through Saturday, winds and seas will largely remain
below Small Craft Advisory (SCA) levels except for a 30% chance of
SCA level gusts at times especially for the southern waters. For
Saturday night, there is a 60-70% chance of SCA level northwest
winds, and again Sunday night for the northern zone (PZZ670).
Otherwise, for Sunday through Wednesday, winds and seas should
remain below SCA levels.

For the Inner Waters north of Point Sal, moderate to high
confidence in current forecast. Through Saturday morning, high
confidence in winds and seas remaining below SCA levels. For
Saturday afternoon through Sunday, there is a 30%-40% chance of
SCA level northwest winds each afternoon and evening. For Sunday
night through Wednesday, winds and seas should remain below SCA
levels.

For the Inner Waters south of Point Conception, high confidence in
current forecast. Through Wednesday, winds and seas are expected
to remain below SCA levels. However, there is a 20% chance of SCA
level northeast winds late tonight and Saturday morning near
shore from Point Mugu to Malibu.

&&

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

&&

.HAZARD POTENTIAL OUTLOOK (MON-FRI).

Elevated to briefly critical fire weather conditions possible
next Tuesday and Wednesday due to light to moderate offshore flow.

&&

$$

PUBLIC...Phillips/CK/MW
AVIATION...Kaplan
MARINE...Sirard
SYNOPSIS...Sweet

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