Area Forecast Discussion
Issued by NWS Albany, NY
FXUS61 KALY 271048
Area Forecast Discussion
National Weather Service Albany NY
648 AM EDT Thu Oct 27 2016
A storm system will impact the region today through Friday with a
wintry mixture of snow and rain. Some accumulating snow is
expected across the higher terrain. As this storm intensifies over
eastern New England on Friday, snow and rain showers will linger
with a gusty northwest wind. A period of tranquil weather is
expected Friday night before the next storm system set to impact
the region this weekend with mainly rain.
.NEAR TERM /THROUGH TONIGHT/...
As of 640 AM...Not much change to the forecast as the leading edge
of the snow was near the Catskills. HRRR/HRRR-X remains consistent
with precipitation evolving across the region later this morning.
Thermal profiles are a little cooler than the 00Z guidance so could
be a little more snow at the onset.
Winter Weather Advisory has been expanded to include portions of
the Mohawk Valley and Schoharie Valley.
Regional radar and surface observations reveal the leading edge of
snow was progressing across the Southern Tier of NY this early
Thursday morning. However, the leading edge of the snow was
evaporating due to high dewpoint depressions across eastern NY.
HRRR/HRRR-X also supports this idea as we will delay the onset of
the precipitation a couple of hours from the previous excellent
forecast. As the morning progresses, the surface low between KTOL
and KCLE will approach. Rather impressive isentropic lift unfolds
across the region as low level jet magnitudes increase to around
50kts. Thermal profiles ahead of this lift are quite challenging.
Due to the aforementioned high dewpoint depressions, wet-bulb
processes will be the main element as the onset of the upstream
precipitation should fall in the form of snow. However, as that
low level jet increases and becomes more southeasterly,
downsloping component should moderate temperatures for the
Taconics, Mid Hudson Valley, Berkshires and western portions of
Bennington County to limit too much accumulation. Hence, no
headlines for these areas at this time. This may change once
precipitation is underway. Otherwise, with the burst of the
precipitation, accumulations will vary with up to an inch for
Hudson Valley locations and points east with perhaps up to 8
inches for portions of the Adirondacks.
Warm advection will eventually become quite dominant that by
afternoon into early evening, snow mixing with rain and some sleet
should transition to mainly rain. Exception would be portions of
the Adirondacks where forecast wet bulb zero heights remain a bit
low for the wintry mixture to continue. Meanwhile, surface low
will begin to reform near NJ and begin to intensify over eastern
New England overnight. This will allow for cold advection to wrap
back into eastern NY for another transition back to snow/snow-
showers with additional light accumulations. Furthermore,
northwesterly winds will be on the increase overnight.
Highs today may not occur until this evening when the max warm
advection is over the region. Mainly 30s for the terrain to lower
40s into the Hudson River Valley, Taconics, NW CT, portions of the
Berkshires and lower elevations of southern Vermont.
.SHORT TERM /FRIDAY/...
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 favored west to
northwest upslope activity is briefly expected for the western
Adirondacks...southern Greens and Berkshires. Some light snow
accums may be possible with up too an additional inch. 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 -4C. Highs will
generally be in the mid 40s to upper 40s in the valley
areas...and mid to upr 30s across the mountains.
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
A fast moving/zonal flow will occur during much of the long term
portion of the forecast, with gradual height rises heights expected
across eastern CONUS by Tue-Wed.
One fast moving impulse should track from the Northern Plains into
northern New England Saturday. A surge of warm advection ahead of
this system could bring some showers to the region late Friday night
or early Saturday morning, especially for western areas. In fact,
some models suggest weak elevated instability, with showalter
indices dipping below zero across the eastern Catskills. Will keep
out mention of thunder at this time, but can not completely rule out
a few rumbles of thunder across some areas of the eastern
Catskills/mid Hudson Valley. Showery conditions may shift northward
for a time Saturday afternoon, before the system`s cold front brings
additional showers for Saturday night and Sunday.
Some lingering showers could occur Sunday evening, otherwise a
period of fair weather is expected for Monday-Wednesday, with
seasonable temperatures Monday trending to above normal for Tuesday-
Wednesday. There will be another system tracking north/west of the
region late Tuesday-Tuesday night, which could brush the Adirondacks
with some showers.
Temperatures Saturday-Sunday will be dependent on how much, if any
sunshine can break through. At this time, expect 50s for most valley
areas, and 40s across higher elevations, although warmer max temps
could occur if sunshine breaks through, especially Saturday
afternoon. Overnight lows will range from the mid 30s to lower 40s.
Monday should be seasonably cool, with highs mainly in the mid 40s
to lower 50s, and overnight lows in the 30s, with some 20s across
higher terrain. A warming trend is expected for Tuesday-Wednesday,
with above normal temperatures expected. Highs should reach the 50s
for most valley areas, and 40s across higher terrain. Some southern
valley areas could even reach into the 60s. Overnight lows Tuesday
night/Wednesday morning will mainly be in the 40s.
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
Low pressure will track from the southern Great Lakes region
into northern New England today into tonight. A warm front
associated with this low will approach from the southwest late
today, with an occluded front approaching overnight.
Some light snow is expected to develop between roughly 13Z-
16Z/Thu from southwest to northeast. 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. Rain should taper to showers or drizzle
Light north to northeast winds at less than 5 KT through mid
morning will become more east to southeast, and increase to 5-10
KT by mid/late morning, and should continue into this
afternoon/evening. Winds may become somewhat gusty just as the
snow begins, with some gusts possibly up to 20-25 KT, esp at KALB.
Winds are expected to shift into the north to northwest between
roughly 07Z-10Z/Fri as the occluded front passes.
Low level wind shear will be possible tonight, 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. The best chance for low level wind shear
will likely be between roughly 23Z/Thu-05Z/Fri.
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.
A complex system will move east of the region today into tonight
with a period of snow and rain. As this storm tracks east of the
New England coast Friday, brisk and cool conditions with isolated
to scattered rain and snow showers mainly over the mountains.
Widespread precipitation is expected through tonight with snow
mixing with rain will be over much of the area... with snow
mixing in across the Adirondack region...and perhaps the southern
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 until midnight EDT tonight for NYZ032-