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Area forecast discussion 
National Weather Service Albany New York
730 am EDT sun Aug 31 2014

Synopsis...
disturbances moving along a slow moving cold front will pretty much
insure most if not all of the area will receive some showers today.
Thunderstorms are also possible, containing heavy rainfall. In
addition...any thunderstorm to the south of the capital region could
contain gusty winds. It will turn more humid today. Labor Day still
looks mainly rainfree...warm but humid. Nevertheless...a stray
thunderstorm cannot be ruled out.

&&

Near term /until 6 PM this evening/...
as of 645 am EDT...isolated to scattered showers were working into
areas just to the north and west of the capital region and it won't
be long until they will be right in the capital region (probably
another hour or two). So far...no cloud to ground lightning strikes
in our region...which makes sense since the airmass was only
marginally unstable.

Low clouds have now were scattered across the region. Albany briefly
had them...but they were not being reported at of this hour.

Showers will continue to expand south and eastward...and by
midday...most areas from Albany north and westward should receive at
least one shower...maybe a thunderstorm as the atmosphere becomes
more unstable.

A slow moving cold front still to the northwest of New York...will attempt
to combine with a disturbance moving up through the Ohio Valley to
bring the unsettled weather. The best forcing with this feature (the
exit region of a rather impressive upper level jet) looks to slide
just to the south of the region but will be close enough when
combined with an increasingly low level jet and the the exit region
of an upper level jet entrance region...to produce the showers and
storms. Also...there is long fetched trough that was pulling very
moist air from the Gulf of Mexico northward into our region.

While it should be a mostly cloudy day...enough breaks of
sunshine...combined with dewpoints approaching 70 degrees will allow
for a rather unstable atmosphere south and east of Albany...where up
to 1500 j/kg or better could be present by afternoon. Despite meager
middle level lapse rates of only about 5... 0-6 km bulk shear
will increase to about 35kts. This increase in bulk shear along with
instability could be just enough to produce robust discrete
thunderstorm cells capable of producing strong to damaging wind
gusts. One or two storms could produce large hail if they become
tall enough and an extremely remote chance (less than 5 percent) of
producing a brief isolated tornado during the afternoon.

The Storm Prediction Center has our region just south and east of
the capital region in slight risk of severe thunderstorms
today...again with the main risk damaging winds (15 percent)...large
hail (5%) and tornadoes (2%). We will mention thunderstorm with
gusty winds for now in our grids in this specific area.

Precipitable waters look to ramp up to over two inches this afternoon and evening.
Therefore we will continue to mention possible heavy rainfall
everywhere this afternoon and evening.

With the clouds showers and thunderstorms...temperatures will be
held down a bit today...but are still expected to reach close to
80...except lower 80s in the middle Hudson Valley and lower Litchfield
County...and middle 70s well to the northwest of Albany.

A south wind will average 5-15 miles per hour today.

&&

Short term /6 PM this evening through Tuesday night/...
the aforementioned disturbance will move to our northeast tonight.
However...the frontal system will still be in our area...likely
stalling in our southern areas. There are some indicators that
another weaker short wave will ride along the front later
tonight...bringing perhaps another round of showers and
thunderstorms to mainly our southern areas. For now...just have the
highest probability of precipitation to our south. Even areas from Albany northward could
see an additional shower or thunderstorm as well.

It will be quite muggy tonight...something we have not seen much of
during the month of August.

Monday...Labor Day...is also the first day of meteorological fall.
It will definitely not feel like fall tomorrow...as weak high
pressure builds in but the air behind this cold front will not be
cooler at all. In fact...with some sunshine expected...especially
from Albany northward...temperatures will climb well into the 80s.
Combine that with dewpoints well into the 60s...and it will feel
quite warm. While the cold front should be pretty much gone...there
might still be enough of convergence area (along with outflow
boundaries from previous storms) along with instability to produce
an isolated afternoon shower or thunderstorm Albany northward...with
a slightly better chance across the higher terrain surrounding the
capital region and areas south. Still...most of the day should be
rainfree.

The threat of thunderstorms should diminish Tuesday night with the
high pressure still nearby.

By Tuesday however...another cold front will be approaching which
will increase the threat of thunderstorms once more by afternoon. It
will be quite warm ahead of this front. With potentially high
instability and an increasing wind field through the column...some
of these storms could potentially get strong to locally severe. More
about this possibility will follow in the area forecast discussions
to come.

Highs on Tuesday will be well into the 80s once more...possibly
touching 90 in some of the hot spots to the south of the capital
region. Dewpoints will continue to elevated in the 60s.

Tuesday night the cold front will pass through and a slightly drier
cooler air will be ushered in. There will still be the chance of a
thunderstorm during the evening hours however. Lows will range from
the middle 50s across the northwestern areas...to middle 60s Albany
southward.

&&

Long term /Wednesday through Saturday/...
high pressure will bring dry weather Wednesday through Friday. The
high pressure system will not be of Canadian origin so expect temperatures
to average above normal Wednesday through Friday... especially on
Friday when the high shifts offshore and a south to southwesterly
flow develops. Under mainly clear conditions...highs Wednesday will
be in the 70s to lower 80s. Lows Wednesday night in the 50s. Highs
Thursday in the middle 70s to lower 80s. Lows Thursday night in the middle
50s to lower 60s. Highs Friday will be in the upper 70s to middle 80s
and clouds will be slowly increasing during the day.

Friday night and Saturday a cold front will approach from the Great
Lakes...it will move across the region late Saturday. Have forecast
chance probability of precipitation for both Friday night and Saturday. Lows Friday night
will be in the upper 50s to middle 60s. Highs Saturday 70 to 80.

&&

Aviation /12z Sunday through Thursday/...
as a frontal boundary and associated upper level trough cross the
region today and early tonight...expect a 5 to 8 hour period of
widespread showers and possibly a thunderstorm at the
kalb/kpou/kgfl/kpsf taf sites. In addition to the showers...low
level moisture was producing areas of MVFR/VFR stratus this morning
across the region. As a result...expect VFR/MVFR conditions early
today...especially at kgfl/kpou/kpsf...then deteriorating to mainly
MVFR conditions this afternoon and early early evening as the
widespread band of showers moves through. Showers will become
scattered later this evening...but mainly MVFR conditions will still
prevail for most of the night as low level moisture produces MVFR
fog and stratus for most of the night. Well after midnight have
forecast the fog and stratus to reach IFR levels at kgfl.

Winds will become south or southwest at 7 to 10 kts today and this
evening...then 5 kts or less from the south or southwest after 02z
Sunday night.

Outlook...

Labor day: low operational impact. Isolated rain showers...tsra.
Monday night: low operational impact. Isolated rain showers...tsra.
Tuesday: moderate operational impact. Scattered rain showers...tsra.
Tuesday night: moderate operational impact. Scattered rain showers...tsra.
Wednesday: no operational impact. No sig weather.
Wednesday night: no operational impact. No sig weather.
Thursday: no operational impact. No sig weather.

&&

Fire weather...
much of our region has not seen measurable rainfall in the past
week. That will change today through the evening as most areas see
showers and thunderstorms likely bringing around a quarter inch of
rainfall...and in some cases...locally up to an inch or better. It
will remain humid today with relative humidity values only dropping to about the
60-70 percent range.

A stray shower or thunderstorm is possible overnight and Labor
Day...mainly south of the capital region. Most other areas should
remain rainfree. However relative humidity values will be nearly 100 percent
overnight...only dropping to 50-60 percent range Monday
afternoon.

Another cold could bring another round of showers and thunderstorms
on Tuesday afternoon. Relative humidity values will remain elevated.

Drier weather including lower afternoon relative humidity values should take hold
Wednesday through Friday.



The surface wind be mainly south today and tonight 5-15
miles per hour...becoming south to southwest 5-10 miles per hour on Monday.

&&

Hydrology...
showers and thunderstorms will develop Sunday and continue into this
evening. Average basin rainfalls look to generally be around half an
inch or so at this point...main stream rivers will likely not see
any significant rises.

However...with precipitable water values forecast to increase to over 2
inches...any thunderstorm could contain locally heavy rainfall
easily exceeding an inch. Any training thunderstorms could result
localized ponding of water in areas of poor drainage.

Additional thunderstorms on Labor Day look isolated and generally
not expected to produce additional Hydro problems.

More showers and thunderstorms are possible late Tuesday into
Wednesday as a stronger cold front arrives.



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...hwjiv
near term...hwjiv
short term...hwjiv
long term...gjm
aviation...gjm/jpv
fire weather...hwjiv
hydrology...hwjiv

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