Scientific Forecaster Discussion
fxus61 kaly 250223
Area forecast discussion
National Weather Service Albany New York
923 PM EST Fri Nov 24 2017
although temperatures won't be quite as chilly as the
past few nights, it will be another dry night tonight. With a milder
air mass in place, an approaching frontal boundary will allow for a
few passing rain showers tomorrow. Behind the front, colder
temperatures will return for Sunday, with some lake effect snow
showers in western parts of the area.
Near term /until 6 am Saturday morning/...
as of 915 PM EST...temperatures varied greatly this evening as
they were dependent upon whether or not the wind was still
occurring. Across the region temperatures varied from the upper
20s to lower 30s where no wind was occurring to the mid 40s
where a breeze was still occurring.
A storm system was located well upstream of the region, with an
area of low pressure just south of James Bay and a trailing
cold front moving through the Great Lakes region.
Although this storm system will be quickly heading eastward, it
will continue to remain dry through our region overnight. Temps
will be tricky overnight, as skies should remain fairly clear
through much of the overnight hours. However, in areas where a
light southerly wind remains, temps will only fall into the mid
to upper 30s, while more sheltered areas will see lows in the
mid 20s to low 30s. Some spots may reach their lows around
midnight, with temps holding steady or slightly rising for later
in the overnight hours.
Short term /6 am Saturday morning through Sunday night/...
although the surface low will be lifting well north of the
region as it travels across James Bay and northern Quebec, the
storm's trailing cold front will provide some surface
convergence and lift to allow for some scattered rain showers.
Temps, both aloft and at the surface, will warm up enough to
keep any precip as liquid rain for the entire are, but limited
moisture will keep any showers rather spotty and fairly light.
Many areas may wind up staying dry, with highs in the 40s to low
50s for most locations.
The front should cross by the afternoon hours, allowing surface
winds to switch to the west and strong cold air advection to
take place. With 850 hpa temps crashing behind the front to -5
to -10 degrees c by Saturday night, some lake-effect snow
showers will develop off Lake Ontario for Sat night. The
activity looks rather transitory, as the shifting winds and
conditional instability will allow for disorganized multi-bands
that will shift from the western Adirondacks and western Mohawk
Valley towards Schoharie County and the eastern Catskills. In
addition, boundary layer temps will be cooling, so initially,
precip may fall as rain showers before transitioning over to
snow showers, especially for valley areas. Up to an inch of
snowfall is possible, mainly for grassy and high terrain areas.
Some upslope snow showers are possible for the high terrain of
the southern greens, Berkshires and Taconics as well thanks to
the strong westerly flow. A light coating is possible for these
areas as well. Elsewhere, skies will be partly to mostly
cloudy, with breezy conditions and lows falling into the mid 20s
to mid 30s.
Some additional snow showers are possible on Sunday morning, as
the activity shifts back northward towards the western
Adirondacks, but it looks be weakening and diminishing, as
surface high pressure builds in and inversion levels fall.
Despite some sun returning, it looks to a blustery and chilly
day on Sunday thanks to the cold temps aloft. Highs look to
reach the upper 20s to upper 30s for most areas, although some
downsloping may allow parts of the Mid-Hudson valley to reach
into the low 40s. Gusty northwest winds may reach 20-30 mph,
especially for areas that channel the flow.
For Sunday night, it will be another seasonably chilly night
with lows in the 20s. Another fast moving shortwave will move
from the northern Great Lakes towards northern New England.
Although this will be another moisture-starved system, a few
snow showers and flurries are possible across the Adirondacks
and Mohawk Valley, especially in areas that area enhanced thanks
to some lake moisture being picked up. Further south and east,
there may be a few passing flurries, but little to no
accumulating snowfall is expected due to the limited moisture
and fast movement of this system.
Long term /Monday through Friday/...
the long term period will feature a progressive upper tropospheric
pattern with multiple pieces of energy, followed with brief high
pressure, progressing through eastern New York/western New England. Global
guidance suggests a positive pv anomaly and surface low pressure
just north of the U.S. Boarder toward the end of the week.
Monday and Tuesday...snow showers will linger in the Adirondacks and
points north of the capital region Monday morning before high
pressure builds into the region from the mid Atlantic states for
Monday afternoon through Tuesday. Highs Monday will be seasonable in
the 30s with the southern Hudson Valley creeping into the low 40s.
Lows will be primarily in the 20s Monday night with highs rebounding
nicely into the upper 40s on Tuesday.
Wednesday through Friday...a clipper-type disturbance traversing
over regions north of the capital region will bring a quick shot of
rain/snow showers early Wednesday before high pressure builds in
through early Thursday keeping conditions dry. Good upper dynamics,
surface low pressure, and a large precipitation field will build in
from the west late Thursday through Friday. Precipitation type will
depend on the exact track of the low and is uncertain at this time.
Temperatures look to be slightly above average for this time period
with highs in the 40s/low 50s and lows in the upper 20s/low 30s.
Aviation /02z Saturday through Wednesday/...
high pressure will continue to slide south and east of our region
through tonight. There will be some intervals of mid and high clouds
Saturday morning with the approach of a cold front. Conditions
are expected to remain VFR except for a low probability of
showers at kgfl and kpsf late in the taf period. Persistent
light south winds should prevent much fog from forming late
The winds will will be generally south to southwest at 10 kts
or less through the taf period. There is the potential for some
low level wind shear at kpsf late tonight into Saturday morning
as a cold front approaches the region.
Saturday night: low operational impact. Slight chance of rain showers...shsn.
Sunday: low operational impact. Breezy no sig weather.
Sunday night: low operational impact. Slight chance of shsn.
Monday: no operational impact. No sig weather.
Monday night: no operational impact. No sig weather.
Tuesday: no operational impact. No sig weather.
Tuesday night: no operational impact. No sig weather.
Wednesday: no operational impact. No sig weather.
after a dry night tonight, a passing cold front will allow for
a few scattered rain showers on Saturday. Southerly winds of 5
to 15 mph will become southwest for Saturday and eventually
shift to the west for Saturday evening and Saturday night behind
the frontal boundary. Northwest winds will be gusty for Sunday,
with some gusts up to 30 mph possible. Relative humidity values will be as low
at 50 to 60 percent on Saturday and 45 to 65 percent on Sunday.
no hydrologic issues are anticipated through early next week.
After dry weather tonight, a cold front may bring some light
rain showers to the area on Saturday. Any rain showers will be
fairly spotty and total quantitative precipitation forecast will only be a few hundredths on an
inch. Behind this front, some lake-effect snow showers will
occur for western areas for Saturday evening into Saturday night
and Sunday morning, but amounts look fairly light.
Some additional light snow showers are possible for Sunday
evening into Sunday night across the Adirondacks as another
fast-moving shortwave allows some light lake-enhanced
precipitation. Behind this feature, more dry weather is
expected for early next week.
As a result, river levels will either hold steady or slightly
fall through early next week. Temperatures will be fairly
seasonable through the weekend, but may start to trend above
normal towards the middle of next week.
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 website.