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fxus61 kaly 252028 
afdaly

Area forecast discussion
National Weather Service Albany New York
428 PM EDT Tue Apr 25 2017

Synopsis...
low pressure that is over eastern North Carolina today, will slowly
move northeast up the Atlantic Seaboard, passing over Cape Cod on
Thursday. This will bring a persistent cool and damp easterly flow
into our area into Thursday. By Friday, a milder westerly flow is
expected along with a chance of showers and thunderstorms.

&&

Near term /through Wednesday/...
as of 300 PM EDT, cool and moist easterly flow continues across
the region to the north of a nearly vertically stacked cut-off
coastal low pressure system centered over eastern North
Carolina. Temperatures are only in the upper 40s to mid 50s with
overcast skies.

The next batch of widespread rain will quickly move northward late
this afternoon into evening hours, as the cut-off low and its
associated moisture feed drift northward. Rainfall intensity will
also be moderate to briefly heavy at times this evening into the
overnight due to the deeper moisture from the Atlantic Ocean, as
pwats are forecast to increase to +2 to +3 stdev. Southeast flow
will continue to result in gusty winds of 25 to 35 mph in favored
areas east of Albany into this evening.

Widespread rainfall will continue through much of the night as the
cut-off low meanders close to the Delmarva by sunrise Wednesday.
Total rainfall will range from around 0.25 inches across the
northwest part of the area to just over an inch across
Dutchess/Litchfield counties. The rainfall is not expected to cause
any Hydro issues.

Steady rain will taper off from SW to NE around or shortly after
sunrise Wednesday. The deep moisture feed will shift towards coastal
New England, with scattered showers associated with the broad
cyclonic flow mainly through Wednesday morning. Coverage of showers
will decrease considerably during the afternoon, as the flow aloft
starts to become more anticyclonic. Despite the decrease in showers,
clouds are expected to linger due to residual low level moisture
trapped beneath an inversion. So will side on the cooler side of
guidance with highs in the mid 50s to mid 60s.

&&

Short term /Wednesday night through Friday night/...
Wednesday night, the coastal low continues its slow movement
northeast, getting close to Cape Cod by Thursday morning. A
cool, moist southeast to easterly flow continues into the Albany
forecast area through the night. Clouds and occasional light
rain or drizzle is expected with the highest rainfall totals
expected across the southern Green Mountains of Vermont, the
Berkshires and the Litchfield Hills. Amounts will be light
generally a tenth of an inch or less. Lows in the 40s and 50s.

Thursday, the surface low has weakened considerably with an
upper level low east of New England. A surface low will track
northward across the western Great Lakes and into southern
Canada. The pressure gradient between high pressure off the East
Coast and this low is forecast to lead to a low-level southeast
flow. Model low-level relative humidity fields show that at least the eastern
half of our area will remain mostly cloudy even though mid
level temperatures show our area solidly in the warm sector.
Have sided toward cooler guidance eastern areas with expected
slower clearing and light surface flow with an easterly
component. With 850 mb temps approach +15c, warming potential is
best over the western part of the forecast area where some
downsloping will aid clearing. Highs 70s to near 80 west and 60s
across southern Green Mountains, Berkshires and Litchfield
Hills.

Thursday night, the weakening cold front with the
aforementioned surface low approaches our area. Convergence
along the front appears weak, and main short wave looks to be
west of our area. Showalter index GOES negative ahead of front
so thunder is possible. Rainfall coverage will be scattered
given overall weak forcing for ascent. Mainly chance pops. Lows
in the 50s.

Friday, the cold front will cross the area in the morning. A
chance of showers and thunder during the morning. Clearing is
expected during the afternoon with a westerly flow developing
across the area. This will allow temperatures to rise into the
70s valleys with some 60s higher terrain.

&&

Long term /Saturday through Tuesday/...
a mild but rather unsettled weather is expected during the long term
period from Saturday through Tuesday.

A stationary front will be across the region on Saturday with a
chance of showers for much of the day. Highs will range from the mid
60s northwest to the upper 70s to around 80 southeast. Showers
should taper off Saturday night with lows in the upper 30s to mid
50s.

On Sunday the frontal boundary will stall just to the south of our
region with a slightly cooler day expected with highs in the upper
50s to lower 70s with a chance of showers and a slight chance of
thunderstorms. The chance for showers will linger Sunday night with
lows in the mid 40s to mid 50s.

Monday looks to be the most unsettled day of the long term period
with showers likely and a chance of thunderstorms as a couple of
frontal boundaries impact the region with low pressure back across
the Great Lakes. Highs will be in the mid 60s to mid 70s. There will
still be lingering showers Monday night with lows in the mid 40s to
mid 50s.

Tuesday looks to be the best day of the long term period with
increasing sunshine as high pressure builds in behind the departing
cold front with highs in the mid 50s to upper 60s.

&&

Aviation /20z Tuesday through Sunday/...
a coastal low pressure system along the North Carolina coast
will gradually move up the coast through the taf period reaching
the Delmarva tonight. The first batch of widespread rain has
ended across the terminals, with just scattered showers through
the next few hours. Then, another larger round of steadier and
more intense rainfall is expected from late this afternoon or
early evening into the overnight hours, due to deeper Atlantic
moisture feed associated with the northward moving coastal
storm.

Conditions will initially be VFR or MVFR this afternoon, then
deteriorating to IFR once the next round of steadier rainfall
moves in. Rainfall expected to be moderate in intensity, which
should allow for vsby/cig reduction to IFR range. Rain will
taper to scattered showers Wednesday morning, with conditions
only slowly improving to MVFR through 18z Wednesday.

Winds will be east or northeast around 6-12 kt through the
period ending 18z Wednesday.

Outlook...

Wednesday night and thursday: no operational impact. No sig weather.
Thursday night: moderate operational impact. Chance of rain showers...tsra.
Friday: moderate operational impact. Chance of rain showers...tsra.
Friday night: moderate operational impact. Chance of rain showers.
Saturday and Saturday night: moderate operational impact. Chance
of rain showers.
Sunday: moderate operational impact. Chance of rain showers...tsra.

&&

Fire weather...
low pressure that is over eastern North Carolina today, will slowly
move northeast up the Atlantic Seaboard, passing over Cape Cod on
Thursday. This will bring a persistent cool and damp easterly flow
into our area into Thursday. By Friday, a milder westerly flow is
expected along with a chance of showers and thunderstorms.

Max relative humidity values tonight increase to 90-100 percent. On Wednesday, relative humidity
will only fall into the 60 to 80 percent range with light
winds. Wednesday night rh values will once again increase to
90-100 percent.

Winds will generally be light and from the northeast.

&&

Hydrology...
additional rainfall forecast through 8 PM Wednesday ranges from
around a half an inch to three quarters of an inch. Some minor
river rises are possible.

Some light rain or drizzle is possible Wednesday night and
Thursday. Isolated to scattered showers and thunderstorms are
possible on Friday which could bring some locally heavy
rainfall, but river flooding is not expected 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
website.

&&

Aly watches/warnings/advisories...
CT...none.
New York...none.
Massachusetts...none.
Vermont...none.

&&

$$
Synopsis...sand
near term...jpv
short term...sand

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