Area Forecast Discussion
Issued by NWS Albany, NY

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FXUS61 KALY 270522

Area Forecast Discussion
National Weather Service Albany NY
122 AM EDT Thu Oct 27 2016

High pressure will build in from southern Quebec
tonight with partly cloudy and cold conditions.  Clouds will thicken
and lower ahead of a warm front tomorrow ahead of low pressure
approaching from the lower Great Lakes Region.  This storm system
will bring predominately a mix of snow and rain to the region with
the highest snow totals over the mountains north and west of the
Capital Region.  The complex system will move east of the region
Thursday night into Friday with brisk and cool conditions with
isolated to scattered rain and snow showers mainly over the


High clouds are spreading across the region and will thicken
through the night. Winds are easing and the rate of the
temperatures dropping through the night will depend on how quickly
the clouds thicken and lower overnight. There are light north winds
and temperatures in northern areas are in the upper 20s and lower
30s, so even with cloud cover, cooler temperatures should build
south through the night. Just some minor adjustments to sky cover
and temperatures through tonight. The previous AFD has more
details and is below...

Low temperatures should be in the 20s. The high clouds should
increase through the night. The clouds will continue to thicken
and lower based on the short-range guidance. The air mass will be
very dry ahead of the system with sfc dewpts in the teens to mid

The trend with the majority of the guidance has the leading edge
of the warm advection pcpn just west of the forecast area prior to
10Z/6 am THU. However...there are some signals it will be close
just after sunrise for some wet bulb cooling for snowfall towards
12Z/THU based on the ECMWF/NAM12/GFS over the eastern
Catskills/Schoharie Valley/western Mohawk Valley. Lows tonight
were blended and shaded towards the warmer METMOS with teens and
lower 20s over the southern Adirondacks...Lake George Region...and
southern VT...and eastern Catskills...and mid to upper 20s over
the majority of the rest of the forecast area.


Winter Weather Advisory remains in effect for 8 am Thursday-
Thursday evening across the southwest Adirondacks and elevations
above 1500 feet in the eastern Catskills of western Ulster and
Western Greene Counties and northern Warren County...

Tomorrow...the trend continues warm for the main onset of pcpn
associated with the strong isentropic lift on the 295K sfcs of the
GFS and NAM to be 11Z-14Z /7-10 am/ west of the Capital
District...Berkshires and NW CT...and from these locations north
and east 14Z-17Z /10 am - 1 pm/. This timeframe could change if
the wet bulb cooling and saturation of the cooling occurs quicker.
The isentropic lift is very strong and BUFKIT model soundings do show
strong upward vertical motion with the initial surge of pcpn.

Most locations should begin as snow and the 925 hPa and sfc wet
bulb temps start out cold or subfreezing. The 12Z GFS does warm
the column quicker than the NAM this cycle. We believe most
locations could receive a coating to less than a an inch of
snowfall in the valley locations...and then the temps should
quickly warm. must be stressed that if the pcpn
remains heavy that the column could stay cool for a couple of
inches of snowfall in some of the valley areas. The NAM hinted as
this possibility for portions of the Capital Region. The GFS has
an inch or less. We leaned closer to the GFS and WPC guidance in
the valley areas for generally an inch or less of
snowfall...except for the Schoharie Valley/Western Mohawk Valley
where 1-3" are possible. Special Weather Statements maybe needed
for the morning commute into the lunchtime hour.

The higher terrain is a different story as the strong QG lift
coupled with the wet bulb cooling could allow for several inches
of snow in the late morning into the afternoon north and west of
the Hudson River Valley into the eastern Catskills...and the
Adirondack Park. 2 to 6 inches of wet snowfall is possible with
snow ratios of 7-10:1. Some isolated higher amounts are possible.
Warm air will be trying to come in aloft as the south to southeast
low-level jet increase to 45-50+ kts. As the previous fcst
mentioned...elevations greater than 1500 FT in the Catskills and
foothills of the Adirondacks have a chance at 2 to 6 inches of
snow. A more solid 3 to 6 inches of 4 to 8 inches maybe possible
in the southern Adirondacks. The guidance from WPC is a tad lower
this cycle and we are close to it and will leave the headlines up.

Extensive collaboration was done with WFO BTV about potential
headlines for the southern Greens. The pcpn arrives later and the
column warms some after 2 to 4 inches with perhaps some locally
higher amounts in the afternoon into the early evening. If
confidence increases for higher amounts such as 3 to 6 inches or
more...than an advisory maybe needed for elevations greater than
2000 ft in the southern Greens. Many of the hill
towns/Berkshires/Litchfield could see a slushy inch or two before
a changeover to rain. There maybe some ice pellets around...but
this looks like a classic rain to snow situation.

The transition to rain should continue in most areas by the mid to
late the upper trough starts to turn negative...and
sfc low moves into the western NY and Lake Ontario corridor. Some
short-wave energy shifts to Long Island and southern New England
Coast for secondary cyclone development towards nightfall. Highs
temps during the day will likely get into the lower to mid 40s in
the CT...and Hudson well as NW CT...and much of the
Taconics..and west of the southern Green Mtns with the strong
southeasterly sfc wind gusts could get to 20-30 mph
there. Expect mainly mid and upper 30s over the mtns and western
Mohawk Valley.

Thu night...The secondary low pressure forms over southern New the H500 upper low closes off. The pcpn may
transition back over to snow over the mountains for an additional
inch or two. The showalter values get close to 0C near NW CT and
the mid Hudson a rumble of thunder is possible as this
secondary development occurs. The period of rain for most the
region will taper to showers after midnight. The secondary low
moves over Cape Cod towards daybreak. The advisories were kept up
to midnight for the mountains. If significant additional snow is
expected, then they may have to be extended later in time. Our
current forecast only calls for a coating to an inch or slightly
more for the southern Greens in VT. Temps should not fall off too
much lows with mainly in the mid and upper 30s in most locations
with a few lower 40s across the mid Hudson Valley and NW CT. The
southern Greens and southern Adirondacks may have lows in the
lower 30s.

Friday...The sfc low moves east to northeast into the Gulf of
Maine. Some lingering upper deformation zone sct rain or snow
showers will linger through the morning especially north and east
of the Capital Region...and then a transition to west to northwest
upslope activity is briefly expected for the western
Adirondacks...southern Greens and Berkshires. Some light snow
accums may be possible. It will be brisk /west to northwest winds
of 10 to 20 mph with gusts 30 to 35 mph/ and cool as H850 temps
fall to 0 to -3C. Highs will generally be in the mid 40s to spotty
50F readings in the valley areas...and mid 40s to lower 40s over
the mountains.

Friday night into Saturday...some weak ridging builds in briefly
Friday the next system in the fast upper level flow
arrives for Saturday. This low pressure system may pass north of
the region with the cold front bringing scattered showers on
Saturday. Maybe a few snow showers over the southern Dacks Sat
morning. Lows Fri night will be chilly still in the 30s with a
few upper 20s in the southern Dacks...and highs rebound ahead of
the system in the upper 40s to 50s.


A pattern of quick-moving systems will dominate...with the first
system moving through at the provide the best chance for
precipitation during the period.  This will consist mainly of rain
showers...which could eventually mix with snow in the Adirondacks
and Greens.  Just some lingering sprinkles on Sunday associated with
predominantly broken cloudiness.

The start of the work week will be mostly sunny and dry...but clouds
will increase ahead of the next system.  The system looks to be
moisture-starved...and little or no precipitation is expected by
the time the cold front moves through Tuesday night.

Daytime high temperatures Sunday and Monday will range from around
40 degrees in the high peaks of the Adirondacks to the mid or upper
50s in the Mid-Hudson Valley.  Tuesday will be somewhat milder...
with highs ranging from around 50 degrees in the high peaks of the the upper 50s in the valleys.  Wednesday will be milder
down the Hudson Valley...with highs there mostly in the lower to mid
60s.  Meanwhile...the Adirondacks will be cooling behind the
front...with highs there mostly in the upper 40s.

Saturday night lows will be mostly in the mid 30s to lower 40s
range...and will be several degrees colder the following night...
with many mainly high peak locations getting below freezing.  Then
temperatures moderate once more...with most locations Tuesday night
bottoming out in the lower and mid 40s.


Low pressure will track from the southern Great Lakes region
into northern New England Thursday into Thursday night. A warm
front associated with this low will approach from the southwest
late Thursday, with an occluded front approaching Thursday night.

High clouds spreading across the region tonight, ahead of the
system that will be affecting our region Thursday. Clouds lower
and thicken around daybreak Thursday to around 5000 feet AGL and
some light snow is expected by mid to late morning, starting
between roughly 13Z-16Z/Thu. MVFR/IFR conditions will develop with
the snow. Snow is forecast to change to rain/sleet first at KPOU
by late morning, then plain rain by early afternoon.

Trends in data and in sources of guidance are not completely
consistent, with some suggestion that snow could change to just a
mix of rain and snow with some sleet at KALB, KGFL and KPSF after
about 19Z-20Z, if the snow starts early enough and intensity of
precipitation is as much as the guidance suggests. Indicating a
slight leaning toward a colder forecast because of these factors.
Ceilings and visibilities could be borderline MVFR/IFR through
Thursday afternoon if the transition to a mix or rain is more

Eventually, all rain is expected after around 22Z/Thu, and may be
moderate in intensity at times through at least 06Z/Fri. MVFR/IFR
conditions will prevail.

Light north to northeast winds at less than 5 KT through daybreak
will become more east to southeast, and increase to 5-10 KT by
mid/late morning, and should continue into Thursday
afternoon/evening. Winds may become somewhat gusty just as the
snow begins, with some gusts possibly up to 20-25 KT, esp at KALB.

Low level wind shear will be possible Thursday night, as southeast
to south winds increase to 30-40 KT around 2000 FT AGL, while
surface winds remain east to southeast at only 5-10 KT. For now,
no mention in TAFs, but likely will need to include mention with
subsequent issuances.


Thursday Night: High Operational Impact. Definite SHRA...RA.
Friday: Low Operational Impact. Breezy NO SIG WX.
Friday Night: No Operational Impact. NO SIG WX.
Saturday: Moderate Operational Impact. Chance of SHRA.
Saturday Night: Moderate Operational Impact. Chance of SHRA.
Sunday:  Slight Chance of SHRA.
Sunday Night: No Operational Impact. NO SIG WX.
Monday: No Operational Impact. NO SIG WX.


High pressure will build in from southern Quebec
tonight with partly cloudy and cold conditions.  Clouds will thicken
and lower ahead of a warm front tomorrow ahead of low pressure
approaching from the lower Great Lakes Region.  This storm system
will bring predominately a mix of snow and rain to the region with
the highest snow totals over the mountains north and west of the
Capital Region.  The complex system will move east of the region
Thursday night into Friday with brisk and cool conditions with
isolated to scattered rain and snow showers mainly over the


Widespread precipitation is expected tomorrow into tomorrow night.
With a cold start to the morning tomorrow...areas west of the
Hudson Valley and the higher elevations could see a period of snow
before going over to or mixing with rain.

Locations in Hudson River Valley east could have a brief period
of rain and snow before changing to rain in the late morning into
the afternoon. The mountains of southern VT could have a few
inches of snow before changing to rain.

By the late afternoon/night...rain will be over much of the
area... with snow mixing in across the Adirondack region...and
perhaps the southern Greens again.

Precipitation totals will generally be from three quarters of an
inch to around an inch and a quarter through daybreak Friday.

Another system will bring light rainfall amounts Saturday into
Saturday night of generally a quarter of an inch or less.

For details on specific area rivers and lakes, including observed
and forecast river stages and lake elevations, please visit the
Advanced Hydrologic Prediction Service /AHPS/ graphs on our


NY...Winter Weather Advisory from 8 AM this morning to midnight EDT
     tonight for NYZ032-033-042-058-063-082.


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