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Area forecast discussion 
National Weather Service Albany New York
547 am EDT Monday Oct 20 2014

Synopsis...
high pressure will slide offshore today. A complex weather
disturbance will organize in the Great Lakes today...and intensify
as it shifts to the middle Atlantic coast by Wednesday. Clouds will
increase today...with a long period of unsettled weather and
intermittent rain from tonight through Thursday night or Friday.

&&

Near term /through today/...
as of 545 am EDT...satellite pics indicated partly cloudy skies. Surface
observation show temperatures outside of the freeze warning area generally in the
20s to around 30. In the freeze warning area temperatures were in the low
30s.

Today will be the last dry period for a long time as surface high
pressure moves off the coast. This will result in partly sunny to
mostly cloudy conditions across the region as middle/hi clouds spread
out ahead of a strong upper level trough moving through the Great
Lakes. Highs today will be in the upper 40s and 50s.

&&

Short term /tonight through Wednesday /...
a strong upper level trough will deepen as it moves through the Great
Lakes today and tonight...then develop into a cutoff upper low over
the central Appalachians by Tuesday afternoon and evening. On Wednesday the
upper low will move off the middle Atlantic coast as surface low
pressure develops off the New Jersey coast. This will bring a long
period of wet weather to the region...possibly through Thursday
night or Friday.

Probability of precipitation are forecast to slowly increase tonight to likely levels over
western areas...but will remain in the chance levels over eastern
areas. On Tuesday the probability of precipitation will rise to likely levels in all areas
and remain that way through Wednesday. Generally an inch or less of
rain is expected through Wednesday...which should cause to Hydro
problems.

Lows tonight will be in the middle 30s to middle 40s. Highs Tuesday
generally in the 50s and lower 60s. Lows Tuesday night in the upper
30s and 40s. Highs Wednesday in the upper 40s and 50s.

&&

Short term /Wednesday night through Sunday/...
our region will still be under the influence of a cut-off low
pressure system...likely centered somewhere just south of Long
Island and southern New England through Wednesday night. Fairly good
agreement with models in terms of large-scale feature
placement...but there is still considerable spread regarding quantitative precipitation forecast
which is typical when dealing with cut-off lows. 00z gefs indicating
anomalously strong easterly flow of -3 to -4 stdev with our region
downstream of strongest anomalies. This signal is usually indicative
of heavy rainfall...although it is too early to pinpoint exact
amounts or locations that will receive the heaviest rainfall.

While Thursday will still be rather gloomy with the center of the
upper low only slowly meandering eastward towards Cape Cod and a
moist northeast flow persisting...the strongest wind anomalies
should start to lift north of the region...so rainfall amounts may
be less prolific by Thursday. Will continue to mention likely probability of precipitation.
While it will be cool and damp...temperatures aloft do not look cold
enough for snow even in the mountains for now.

The cut-off low should start to finally pull away and out to sea on
Friday...however we will still be influenced by a sprawling upper
level trough. As the flow turns more northwesterly...will confine
higher probability of precipitation to favored upslope areas north and west of the capital
district. Improving conditions are then expected during the weekend
along with a warming trend...as some sunshine is expected to finally
return after an expected overcast work week. Cannot rule out a few
upslope showers over the western Adirondacks on Saturday...but
otherwise dry weather is anticipated with high pressure building in
on Sunday.

&&

Aviation /06z Monday through Thursday/...
VFR conditions expected to prevail through the 24 hour taf period
ending 06z Tuesday. Patchy stratocu deck in 3500-5000 feet above ground level range
will eventually dissipate by dawn...although middle/high level clouds
will increase during the day ahead of an upper level trough
approaching from the Great Lakes.

Winds will be light and variable becoming southerly around 5-8 kts
by noon today.

Outlook...
Monday night to tuesday: moderate operational impact. Chance of
rain showers.
Tuesday night through thursday: high operational impact. Likely rain.
Thursday night to Friday moderate operational impact. Chance of rain showers.

&&

Fire weather...
today will be a dry day with a light wind becoming southerly around
10 miles per hour during the afternoon. Relative humidity values will drop to between 35 and
50 percent.

A vertically stacked upper level low pressure system will begin to
impact our weather tonight through at least Thursday night with
periods of rain...tapering to scattered showers by Friday. All areas
are expected to receive well over a quarter inch of rainfall during
this period.

Drier weather should return by the weekend.

&&

Hydrology...
no hydrologic issues expected into Tuesday. The weather is
expected to turn unsettled and wet by the middle of the week...as an
upper level low cuts off near the region. Intermittent rainfall is
expected from Tuesday into Friday.

In the periods of rainfall...some moderate to heavy bursts may
occur. The potential exists for one to three inches of rainfall
over portions of the Hydro service area depending on this systems
evolution...and track. This rainfall would occur over the period
of a few days...so no widespread flooding is anticipated 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...freeze warning from 2 am to 9 am EDT Monday for ctz013.
New York...freeze warning from 2 am to 9 am EDT Monday for nyz049-050-052-
053-059-060-064-065.
Massachusetts...none.
Vermont...none.

&&

$$
Synopsis...gjm
near term...gjm
short term...gjm
long term...jpv
aviation...jpv
fire weather...gjm
hydrology...gjm

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