Area Forecast Discussion
Issued by NWS Albany, NY

Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
FXUS61 KALY 212014

Area Forecast Discussion
National Weather Service Albany NY
414 PM EDT Tue Aug 21 2018

A low pressure system moving into the eastern Great Lakes
Region and its warm front will bring showers and isolated
thunderstorms tonight. A cold front moves through Wednesday
morning into early afternoon with additional scattered showers
and thunderstorms, which should taper off by late afternoon as
it becomes breezy and less humid. High pressure builds in from
the west Wednesday night into Thursday with fair weather and
comfortable humidity levels heading into the weekend.


As of 410 PM EDT, a band of rain showers was moving across the
western/central Mohawk Valley and southwest Adirondacks, with
some sprinkles extending as far east as the eastern Mohawk
Valley/Saratoga region. These showers/sprinkles will continue
advancing northeast through sunset, with more frequent showers
farther west across the southwest Adirondacks, and lighter
showers/sprinkles extending into the Lake George region/SE
Adirondacks. Elsewhere, clouds will continue to increase
through sunset, with a few sprinkles possible from the SE
Catskills into the Capital Region, and southern VT. Mainly dry
conditions should continue through sunset across MA and NW CT
extending into the mid Hudson Valley.

Several bands of showers are expected to move northeast between
sunset and midnight, with the most persistent showers remaining
across the Mohawk Valley/SW Adirondack region, and less
coverage farther south and east.

After midnight, the bands of convection currently across PA are
expected to expand/track northeast. Chances for showers will
therefore increase for areas south and east of the Capital
Region at that time, and with some weak elevated instability, a
few rumbles of thunder will be possible. As PWAT`s increase to
near 2 inches, any deeper convective elements may contain
briefly heavy rain. Fortunately, it appears that forward
movement of convection should be quick enough to prevent more
significant hydrologic issues. Additional bands of
showers/embedded thunderstorms will also continue from Albany
and points N/W into the Mohawk Valley/Adirondacks and southern
VT/western MA.

It will be quite breezy tonight, as the core of a 40-50 KT low
level jet translates northeast through west/central NYS into the
St Lawrence Valley. Some wind gusts of 30-40 mph could occur
across portions of the southwest Adirondacks, and 25-35 mph
within the immediate Capital Region and other north/south
oriented valleys.

Lows mainly in the 60s, although some areas where wind persists
may only drop to around 70.


Wednesday, the system`s cold front should cross through the
region between roughly 12Z-16Z/Wed. It appears that the best
moisture and forcing may outrun the surface front, limiting the
potential for convection along the front. However, still can not
rule out some low topped convection, especially should any
breaks in the clouds occur before the front passes. Should this
occur, the combination of surface based CAPE of 400-800 J/kg
and deep layer shear of 25-35 KT could promote stronger
thunderstorms with gusty winds. This potential appears greatest
(although low overall) across southern VT, western MA and
perhaps northern Litchfield County, CT, with some possibility as
far N/W as the Taconics in NY. After the front passes, there
should be a significant decrease in showers with some sun
possibly breaking out, especially in valley areas. With the main
cold pool/upper trough aloft still approaching from the west,
additional isolated to scattered showers may develop, especially
across portions of the Adirondacks/Mohawk Valley. An isolated
thunderstorm could even occur, as sfc based instability
increases somewhat with the mid level cooling occurring. It will
be breezy in the afternoon, with temps mainly in the 60s for
higher elevations, and mid 70s/lower 80s in valley areas.

Wednesday Night-Friday, the aforementioned upper level trough
will move across the region late Wednesday night into Thursday.
Moisture will remain limited, although some lake moisture could
promote isolated showers across western areas Wednesday night.
Have indicated dry conditions for Thursday, but if the upper
level trough slows at all, isolated showers may develop with
diurnal heating. Dry conditions are expected for Thursday
night-Friday. It will be cool and much less humid through the
period, with daytime highs mainly in the 70s for valleys, and
60s across higher terrain, and overnight lows mainly in the 50s,
except for 40s across higher terrain, especially across the
southwest Adirondacks.


At upper levels, a ridge will build into the southeastern CONUS
allowing for several disturbances to ride along the top of the ridge
and into the northeast. To start the period, an upper level
shortwave/low pressure system will skirt by to our north, with S-SW
flow resulting in warmer temperatures and gradually increasing
humidity levels. Saturday looks to be the nicer of the two days for
the weekend, as some unsettled weather may arrive on Sunday. The
ridge aloft is expected to flatten out by Sunday, as additional
short wave energy moves in from the Great Lakes. Still, it is
unclear how much instability/forcing will be present, so will only
mention slight to low chance pops with the better chances west of
the Hudson Valley.

Additional short wave energy may move through on Monday as well as
the upper level ridge strengthens across the Tennessee Valley. This
set up would result in more unsettled weather early next week with
multiple chances for showers and thunderstorms and continued above
normal temperatures. In fact, we may even see temperatures take a
late-season run at the 90 degree mark Monday and Tuesday, especially
for the mid-Hudson Valley region.


VFR conditions will prevail through this afternoon. A frontal
system in central and western NY is producing rain with the
leading edge into central NY. Showers will track into eastern NY
and western New England through this evening and increase in
coverage. Indicating MVFR ceilings and visibilities this
Avignon through tonight with the potential for some IFR
conditions between 08Z-13Z, when the best coverage and potential
for an isolated thunderstorm is possible. Not including thunder
in the TAFs but it may need to be included if thunderstorms
develop overnight.

Conditions gradually improve through Wednesday morning with VFR
conditions by midday at KGFL, KALB and KPOU. VFR conditions may
be delayed at KPSF until after 18Z. There are some indications
of some lingering isolated to scattered showers after the cold
front tracks through. Including VCSH through much of Wednesday
morning depending on how much some isolated to scattered showers
do linger.

Variable to south and southeast winds around 10 kt this
afternoon, possibly gusting near 20 Kt at KALB and KPSF. South
to southeast winds around 10 Kt tonight, shifting to southwest
at 10 to 15 Kt Wednesday morning and west toward midday.


Wednesday Night: No Operational Impact. NO SIG WX.
Thursday: No Operational Impact. NO SIG WX.
Thursday Night: No Operational Impact. NO SIG WX.
Friday: No Operational Impact. NO SIG WX.
Friday Night: No Operational Impact. NO SIG WX.
Saturday: No Operational Impact. NO SIG WX.
Saturday Night: No Operational Impact. NO SIG WX.
Sunday: Low Operational Impact. Slight Chance of SHRA...TSRA.


A low pressure system moving into the eastern Great Lakes
Region and its warm front will bring showers and isolated
thunderstorms tonight. A cold front moves through Wednesday
morning into early afternoon with additional scattered showers
and thunderstorms, which should taper off by late afternoon as
it becomes breezy and less humid. High pressure builds in from
the west Wednesday night into Thursday with fair weather and
comfortable humidity levels heading into the weekend.

The RH values will recover to around 100 percent tonight. The
min RH values will be 50 to 75 percent Wednesday afternoon.

It will remain breezy overnight with south to southwest winds
of 10 to 20 mph, with some gusts of 25 to 35 mph possible,
especially across the southwest Adirondacks and within the
Capital Region of NY. Winds will shift to the west to northwest
at 10 to 20 mph by Wednesday afternoon with gusts in the 25 to
35 mph range.

A widespread wetting rain is likely tonight through Wednesday


Showers will increase tonight into early Wednesday ahead of a
strong low pressure system and its warm and cold fronts, with
isolated to scattered thunderstorms possible Wednesday morning
into the early afternoon. Total QPF ranges from a few tenths of
an inch to an inch from the system, with greatest amounts
expected across portions of the southwest Adirondacks and
western Mohawk Valley region.

Some minor within-bank river rises are possible, but no
widespread problems are currently anticipated. Locally heavy
downpours could also lead to ponding of water in poor
drainage/urban areas.

Dry weather returns Wednesday night into the Saturday, as river
flows recede again.

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.




HYDROLOGY...KL/Wasula is the U.S. government's official web portal to all federal, state and local government web resources and services.