Area Forecast Discussion
Issued by NWS Albany, NY
FXUS61 KALY 251429
Area Forecast Discussion
National Weather Service Albany NY
1029 AM EDT Sat Mar 25 2017
Showers will continue through the day as a frontal boundary sags
southward through the region. Some partial clearing is possible
this evening as cooler air filters into the region, but mixed
precipitation is possible Sunday as the frontal boundary lifts
back northward as a warm front. Any snow or ice accumulations
are expected to be light, but untreated surfaces could become
slippery where freezing rain develops. Chances for rain increase
as a wave of low pressure passes to the west of the region
Sunday into Monday. There is some uncertainty as to whether or
not Tuesday remains rainy, but we should finally see some
clearing by Wednesday. However, another approaching low pressure
system could bring more precipitation by the end of the week.
.NEAR TERM /THROUGH TONIGHT/...
As of 1030 AM EDT, Rain/snow showers continue across the
northern half of the forecast area. Some snow was seen on the
webcams in the Adirondacks where temperatures remain at or just
below freezing but not much accumulation is expected. Per
HRRR/RAP13, expect this area of rain/snow showers to continue
developing along the strengthening baroclinic zone and track
across most of the region this morning into the afternoon hours.
Thereafter, isallobaric rises increase north of the Great Lakes
as surface high slides across lower Ontario/Quebec which should
drive the frontal boundary southward during the mid and late
As of 400 AM EDT...Regional radar reveals east-
west oriented bands of precipitation tracking across the
northern 2/3rds of the county warning area (CWA) as a cold front
slowly progresses southward. Impressive baroclinic zone across
Upstate New York this morning as per the RAP/HRRR, this zone
will slip south of I90 toward noon where we will shift our high
chance and likely PoPs from north to south. In addition, as the
colder air slips under the moisture across the north, some of
the precipitation may end with a wintry mixture as H850
temperatures dip below 0C just north of the Capital District.
Then through the afternoon, equally impressive dry air advection
as large surface high north of the Canadian border extends its
influence further south. Could see the sunset along and north of
I90. As far as temperatures are concerned for this afternoon,
very challenging depending on cloud coverage as the NAM MOS is a
few degrees cooler than the MAV. With a northerly flow evolving
we will favor the cooler side of the guidance envelop.
Tonight the frontal zone, more likely the mid-frontal zone as
the surface cold front is expected to be well south of the
region this evening, will keep clouds and the threat for light
showers into portions of the Catskills, mid-Hudson Valley and NW
CT. Otherwise, 1035mb surface high slides across the St
Lawrence Valley further extending its influence across the CWA.
Temperatures tonight under partly cloudy to mostly clear skies
north of the above mentioned areas will likely dip down into the
teens and 20s with some lower 30s for the immediate Capital
District and mid 30s where clouds are more prevalent. As storm
upstream begins to approach the lower Great Lakes overnight,
this will return the cold front as a warm front. Isentropic
analysis is rather diffuse with wind magnitudes on the 290K
surface rather weak. So any precipitation that does occur with
the warm front approaching will likely be light. Again,
depending on those tricky thermal profiles, a period of light
snow, sleet and freezing rain are all possible north of the mid-
Hudson Valley and into the terrain. Due to the aforementioned
light amounts expected, we will continue to highlight in the
.SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...
Sunday into Sunday night, the NCEP model suite and international
guidance differ a bit with respect to timing of the warm frontal
passage and the expected period of tranquil weather late Sunday
into Sunday evening. The operational GFS appears to be the
fastest with the mid level dry slot while the NAM/ECMWF are in
closer agreement with a slower timing which was followed in this
forecast package this morning.
As the warm front lifts northward, a wintry mixture will
overspread the entire region with a transition to mainly light
rain for the region. The challenge remains with boundary layer
temperatures and valley locations where near or sub-freezing
temperatures may linger for a longer period of sleet/freezing
rain. We envision portions of the region will have winter
weather advisories with future updates as confidence that
portions of the terrain may experience some ice accumulation.
However, continued warm advection through the afternoon and late
March sunshine should aid with warming the boundary layer above
freezing by days end to minimize any additional glazing. Highs
Sunday generally into the 30s with some lower 40s for the mid-
Hudson Valley and southern Litchfield County.
Sunday night...A brief lull in the pcpn is possible Sunday
evening, and temps may actually fall below freezing especially
for locations north of the Capital Region/Mohawk Valley. The
low-level flow will be east to northeast with the sfc high still
downstream over New Brunswick. The low-level ageostrophic winds
are hinting at cold air being dammed into place early on again,
especially for the eastern Adirondacks, portions of the Lake
George and northern Saratoga Region and southern VT, as well as
the northern Berkshires. Some freezing rain is possible again
Sunday night into Monday morning. Ice accretions may range from
a few hundredths to a quarter of an inch /though a lot could
change with these amounts depending on temperatures/. Much of
the rest of the region will have a cold rain, as the isentropic
lift increases as the sfc wave and associated H500 upper level
short-wave trough pushes east northeast from the eastern Great
Lakes Region into the St Lawrence River Valley/northern NY
.LONG TERM /MONDAY THROUGH FRIDAY/...
At the start of the extended period, an upper level shortwave trough
will be moving from the eastern Great Lakes on Monday morning
towards northern New England for Monday night. Along with this upper
level feature will be a weak surface wave of low pressure that
tracks across the area from west to east. All 00z operational
guidance (GFS, GGEM and ECMWF) along with all 00z GEFS members
suggest that a period of steady rainfall occurs across the area for
Monday morning into at least the early afternoon hours. Will go
with categorical POPs across the majority of the area for Monday. A
few spots across western New England and in the central Adirondacks
may start out on early Monday morning with temps just at or below
freezing, so a brief period of freezing rain is possible for a few
hours in some sheltered mountain valleys, allowing for a light
accretion of ice. Otherwise, southerly flow (both at the surface and
aloft) will allow temps to warm up on Monday, with highs reaching
into the 40s. Some rain or drizzle may linger into Monday night,
although many spots may see a break at some point. Temps will fall
into the 30s with persistent cloudy and damp conditions in place.
The forecast is a little more uncertain for Tuesday, as the GFS
suggest yet another wave of low pressure moves across the area as a
cold front heads towards the area. Meanwhile, the other models are
a little more quiet for during the day Tuesday, but do have some
additional showers associated with the cold front for late Tuesday
into Tuesday night. As colder air works into the area, some rain
showers may change to snow showers over the high terrain of the
Adirondacks or southern Greens for Tuesday night, but any
accumulation will be fairly limited, as QPF should be fairly
minimal. Despite plenty of clouds, temperatures look to reach into
the upper 40s to mid 50s ahead of the cold front on Tuesday, but
will fall into the 30s for Tuesday night.
Mainly quiet weather is expected for Wednesday, although the
departing upper level trough could still allow for a few additional
rain or snow showers over the high terrain. Otherwise, clouds will
finally break for some sunshine on Wednesday with temperatures once
again reaching in the mid 40s to mid 50s.
With surface high pressure located near the area, it will continue
to be dry for Wednesday night into Thursday with a partly to mostly
clear sky. Lows will be in the upper 20s to mid 30s on Wed night and
highs on Thursday will reach the 40s to low 50s.
Another storm system will be possible for Friday into Saturday,
although the models are all over the place regarding the track and
timing of this system. For now, will go with chc pops for rain or
snow depending on diurnally-driven sfc temps, with temps close
to seasonal normals.
.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
A period of MVFR/IFR conditions with increasing coverage of
precipitation this morning, mainly in the form of rain,
overspread KGFL, KALB, KPSF. It will take several hours longer
for KPOU to experience MVFR conditions with the rainfall
arriving later this afternoon. Winds are generally light and
variable with a tendency to become from the north-northeast
through the day with frontal passages.
A period of VFR conditions for KGFL, KALB with MVFR conditions
at KALB and MVFR/IFR for KPOU through this evening. Then frontal
boundary lifts northward overnight as expectations for wintry
mixture and lower flight categories to be realized.
Sunday Night: High Operational Impact. Likely RA.
Monday: High Operational Impact. Definite RA.
Monday Night: Moderate Operational Impact. Chance of RA.
Tuesday: Moderate Operational Impact. Chance of RA.
Tuesday Night: Moderate Operational Impact. Chance of SHRA.
Wednesday: No Operational Impact. NO SIG WX.
Wednesday Night: No Operational Impact. NO SIG WX.
Thursday: No Operational Impact. NO SIG WX.
The snow pack remains in place across much of eastern New York
and western New England. The weather pattern will remain
unsettled this weekend into early next week with occasional
rain and wintry mixed precipitation. A warm front will move
southward as a cold front today with high pressure trying to
build in late, but the boundary and a wave of low pressure
brings additional rounds of precipitation Sunday into early next
An unsettled weather pattern will impact the hydro service area
the next several days.
There is a potential for several rounds of precipitation into
early next week. Initially, the precipitation will be light with
a frontal boundary moving southward through today as high
pressure builds in from eastern Canada. Most of the
precipitation will fall in the form of light rain and snow
initially with total QPF a few hundredths to a few tenths of an
Tonight into Sunday, the front will lift back northward from PA
and the Mid Atlantic Region bringing a mixture of snow, sleet,
freezing rain, and rain to the region. The front stalls over
central NY into eastern PA and Long Island for mix precipitation
to occur again Sunday night into early Monday. A wave of low
pressure approaches from the eastern Great Lakes Region with the
warm front moving through finally with periods of rainfall. The
rainfall looks the heaviest late Sunday night into Monday.
Temperatures look to be warm enough during the afternoon hours
each day that most of the precipitation should fall in the form
of rain before changing over to a wintry mix at night on the
weekend into early next week. While there is still some
uncertainty with precipitation types and amounts, there is the
potential for between three quarters of an inch of rain to up
to an inch and a half tonight through Monday.
The latest MMEFS forecast indicates a few locations going into
action stage by early next week, but confidence is not high for
potential of any flooding at this time.
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