FXUS61 KALY 110905
Area Forecast Discussion
National Weather Service Albany NY
405 AM EST Mon Dec 11 2017
As lake effect dissipates today, we await our next winter
weather event. Snow will overspread most of the region overnight
Monday and continue through Tuesday. Some warmer air may allow
for snow to mix with rain from Albany and points southward
through the Hudson River Valley. Brisk and colder weather is
expected for the middle of the week in the wake of this storm.
.NEAR TERM /UNTIL NOON TODAY/...
As of 345 AM EST...Winter Weather Advisory for lake effect snow
remains in effect til about sunrise for northern Herkimer and
western Hamilton counties.
Lake effect plume off Ontario is finally showing signs of
dissipating as combinations of departing upper trough, lowering
inversion heights, and low level trajectories becoming more
northerly. Otherwise, some flurries across the terrain will also
dissipate as cloud break for sunshine for a tranquil start to
the work and school week. As partial snow cover and low sun
angle, we will favor a blended approach of the guidance at this
.SHORT TERM /NOON TODAY THROUGH 6 PM TUESDAY/...
...Winter Storm Watch continues for the Dacks, Lake George
Saratoga Region into southern Vermont...
...Winter Weather Advisory has been issued for the Berkshires...
Breaks of sunshine will become filtered with additional higher
and mid level clouds later in the afternoon into the evening
hours. H2O vapor loop shows rather impressive and compact wave
crossing across the Dakotas into Minnesota. This Alberta Clipper
will initiate surface cyclogenesis across the lower Great Lakes
and result with impressive isentropic lift across the northeast
corridor overnight into Tuesday. As stated in the previous AFD,
snow is expected across the entire region Tuesday morning as
surface low deepens to around 990mb Tuesday afternoon.
Difference this run is the attempt for some warmer air to advect
into the mid levels from Albany and points southward through
the Hudson River Valley for some rain/snow mixture. While this
will cut down on overall accumulations, any slight deviations to
the thermal profiles will influence the snow accumulations. Per
extensive collaboration with neighboring offices and WPC
guidance, we will continue with the winter storm watch for those
areas already highlighted, and issue a winter weather advisory
for the Berks. Additional expansion of the advisory is expected
later today. Overnight lows in the 20s and highs Tuesday climb
into the 30s for most of the region with near 30F for the Dacks.
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
An active and wintry pattern will continue into next work week
as a longwave trough persists over the eastern CONUS. While we
will be monitoring numerous shortwaves rotating into the
Northeast which will present a number of snow threats, model
agreement remains poor on exact timing, placement and intensity
of each shortwave. However, we have higher confidence in a
period of below normal temperatures impacting eastern NY/western
New England Wednesday - Friday.
Tuesday night, the surface low and associated snowfall will be
lifting into New England as cold air quickly filters into the
region. A dry slot, evident in the model RH fields, will nose
northward across eastern New York/western New England behind the
surface low. This will help cut off the snowfall during the
overnight period, with some snow showers lingering in the
During the day on Wednesday, the closed upper low will pass through
the area, with some light snow showers possible. On the back side of
this system, cold air flowing over the relatively warm lakes could
lead to continued lake effect snow, especially in the Adirondacks
and Mohawk Valley. Northwest flow will also lead to cold air
advection and the start of cold temperatures in our region. H850
isotherms fall to -15C to -20C throughout the day with little to no
rise in afternoon temperatures. Blustery winds will also set in
during the day with gusts of 30-40 mph possible, especially in the
high terrain locations. These below normal temperatures, along with
northwest flow, will lead to temperatures dropping towards 0 degrees
in the Adirondacks to teens elsewhere Wednesday night. Wind chills
overnight could fall into the negative teens in the Adirondacks
overnight so we'll be keeping a close eye if any wind chill advisory
headlines will be needed.
High pressure tries to nose in from Canada during the day Thursday
and the change in flow regime plus subsidence should suppress the
lake effect snow bands. Outside of lake effect snow chances,
locations should stay dry.
Chilly temperatures remain in placement Thursday - Friday with high
temperatures likely only rising into the upper teens to upper 20s
and lows in the teens/single digits which is about 10 - 15 degrees
below normal for mid-December. Our next shortwave exits the Great
Lakes and heads into our area bringing the next threat for snow
Friday - Saturday. While some moisture is associated with this
disturbance, poor model agreement remains on placement, timing and
intensity giving us a low confidence forecast on snow potential.
Rising heights are possible in the wake of this upper disturbance
leading to the flow regime shifting to W or even SW with
temperatures rebounding closer to normal heading into the weekend.
However, additional shortwaves are expected to traverse the
Northeast late in the weekend into early next week which will once
again bring additional threats for snow.
.AVIATION /09Z MONDAY THROUGH FRIDAY/...
VFR conditions are expected the remainder of the overnight and
into the day on Monday. With an upper level trough overhead and
lake-effect snow upstream of the area, there will continue to
bkn-ovc cigs around 4-9 kft, esp for KGFL/KALB. Otherwise,
light and variable winds or s-sw winds of around 5 kts is
expected through the overnight hours with no precipitation
Daylight hours on Monday, there will be sct-bkn cigs around 4-6
kft with no precip through the day. Westerly winds will be
around 10 kts. Some mid level clouds may increase towards
evening as the next storm system approaches from the west.
Chance of snow appears to be after this TAF forecast cycle.
Monday Night: High Operational Impact. Definite SN.
Tuesday: High Operational Impact. Definite SN.
Tuesday Night: Low Operational Impact. Slight Chance of SHSN.
Wednesday: Moderate Operational Impact. Breezy Chance of SHSN.
Wednesday Night: No Operational Impact. NO SIG WX.
Thursday: No Operational Impact. NO SIG WX.
Thursday Night: Low Operational Impact. Slight Chance of SHSN.
Friday: Moderate Operational Impact. Chance of SHSN.
No hydrologic problems are expected through the week ahead.
Cold weather with periods of snow and snow showers are forecast.
Ice will form and thicken on area lakes and rivers and some
river gauges may start to show erroneous readings due to ice by
the end of the 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.
NY...Winter Storm Watch from late tonight through late Tuesday
night for NYZ032-033-038-039-041>043-050-082>084.
Winter Weather Advisory until 7 AM EST this morning for NYZ032-
MA...Winter Weather Advisory from 1 AM Tuesday to 1 AM EST
Wednesday for MAZ001-025.
VT...Winter Storm Watch from late tonight through late Tuesday
night for VTZ013>015.