Scientific Forecaster Discussion
fxus61 kaly 192014
Area forecast discussion
National Weather Service Albany New York
307 PM EST Tue Nov 19 2019
the storm system that brought a wet snow to much of the area
this morning has moved off to the northeast and will continue
moving away from the area tonight. Upper level low pressure will
move across the area late tonight, triggering a little light
precipitation mainly for areas east of the Hudson River valley
late tonight and Wednesday morning. Spotty freezing drizzle will
be possible, especially in the mountains of Vermont and western
Massachusetts. Improving weather is expected on Thursday, then
a cold front will bring breezy weather on Friday, along with a
chance of showers.
Near term /until 6 PM Wednesday/...
surface and upper level low pressure will be moving northeast
across the Canadian Maritimes this evening, while a weak ridge
of high pressure builds in from the west. This pattern will
result in a light north- northwesterly flow and lots of low-
level moisture left-over across the area tonight as there will
be little to no dry air advection behind this system. A mid-to-
upper level trough will deepen as it moves east across the mid-
Atlantic states later tonight, and this will help to energize
another area of low pressure well east of the mid- atantic later
tonight. North- northeasterly flow around the northwest fringe
of this storm will increase later tonight and will result in
weak isentropic lift and warm air advection developing over New
England and eastern New York toward morning Wednesday. This will
likely result in some light precipitation, especially for areas
east of the Hudson River including The Greens and Berkshires
early on wedensday. Forecast moisture and temperature profiles
early Wednesday indicate that the moist layer will be mainly
confined to lower-levels where temperatures will be above -10 c,
indicating unfavorable conditions for snow growth and the
potential for some freezing drizzle. At this time we believe
that the freezing drizzle will not be widespread enough to
warrant a headline as it will be rather spotty and will also be
mixed with some light snow in areas where the lift is a little
deeper and stronger. Based on all of this, we have gone with
high chance pops for a some light snow showers and patches of
freezing drizzle mainly east of the Hudson River and especially
in the Green Mountains Wednesday morning. Otherwise, a mostly
cloudy, cool day is expected Wednesday, with highs mainly in the
30s to lower 40s.
Short term /6 PM Wednesday through Friday/...
Thursday will feature dry weather and probably some sunshine as
high pressure moves east across the mid-Atlantic region.
Temperatures will be near to slightly below normal, but
certainly warmer than recently, as highs range from the upper
30s in the Adirondacks to the mid 40s over the Mid- Hudson
The next weather system to affect our area will be a cold front
approaching rapidly from the northwest on Friday. Clouds will
increase from the west Thursday evening, and a little light
precipitation may reach our western counties overnight, with a
light wintry mix possible over the southwestern Adirondacks and
central Mohawk Valley. Friday will likely be the warmest day of
the week, especially over the Mid-Hudson valley as we will be
located briefly within the warm sector of a potent storm systems
tracking northeast from the Great Lakes toward Quebec. Highs on
Friday could reach the 50s in the Hudson Valley with 40s
elsewhere. The storm moving toward Quebec will drag a fast
moving cold front across the area later Friday, probably
accompanied by a few rain showers and gusty southwest winds
shifting to northwest with the passage of the front.
Long term /Friday night through Tuesday/...
as the surface low continues to pull away, high pressure will build
in from the west during Friday night and Saturday. A few lingering
snow showers are possible Friday evening, especially in the
Adirondacks, where low and mid-level moisture will be greatest.
Highs on Saturday will be in the 30s to lower 40s under a partly
Models have come into better agreement regarding the track of a
storm system for Saturday night and Sunday. There will be two pieces
of energy that will determine the actual track of this system. The
first is a fast-moving upper-level shortwave projected to move
across Ontario and Quebec. The second is another upper-level
shortwave that is expected to move across the Tennessee Valley
toward the mid-Atlantic coast. The 12 UTC model suite generally
fails to phase these two shortwaves together, leading to a surface
low tracking from the Tennessee Valley to the mid-Atlantic coast.
Should this occur, a period of snow is expected across much of the
viewing area; however, temperatures in some locations could be warm
enough for rain or a wintry mix. Have trended toward this solution
for this update with the highest pops across the lower Hudson
Valley, closer to the projected track of the surface low.
There is still the chance these two shortwaves can phase in future
runs which could lead to a storm track farther inland (possibly west
of the appalachians), which would lead to a completely different
The remainder of the long term period will be under the control of
high pressure and weak ridging at 500 hpa. This will allow for
mainly dry weather with a partly to mostly clear sky for both Monday
and Tuesday. Temperatures should be fairly close to seasonal
normals, with valley highs in the mid to upper 40s and overnight
lows in the 40s. The next chance for widespread precipitation will
be ahead of a cold frontal boundary for sometime during the middle
portion of the week.
Aviation /20z Tuesday through Sunday/...
precipitation is finally lifting out of the forecast area early
this afternoon but expect low ceilings to remain in place. The
remainder of the afternoon will remain dry but there will be a
chance for some rain/snow showers overnight into Wednesday
morning as the upper level trough axis moves across the area.
Winds will generally be light at speeds of 5kts or less through the
Wednesday night: no operational impact. No sig weather.
Thursday: no operational impact. No sig weather.
Thursday night: moderate operational impact. Chance of rain showers...shsn.
Friday: moderate operational impact. Chance of rain showers.
Friday night: low operational impact. Slight chance of rain showers.
Saturday: low operational impact. No sig weather.
Saturday night: moderate operational impact. Chance of rain...sn.
Sunday: low operational impact. No sig weather.
mainly cloudy and cool conditions will continue tonight into
Wednesday with a few light snow showers or freezing drizzle possible.
Brighter and slightly warmer conditions are expected for
Thursday, then a cold front will bring the next chance of
showers on Friday.
precipitation amounts will be less than a tenth of an inch
through the rest of the week. River levels will be steady or
slowly falling through the period.
For details on specific area rivers and lakes, including latest
observed and forecast river stages and lake elevations, please
visit the advanced hydrologic prediction service /ahps/ graphs
on our website.