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Area forecast discussion 
National Weather Service Albany New York
409 PM EST sun Mar 1 2015

Synopsis...
a low pressure system approaching from the Great Lakes and Ohio
Valley is expected to bring a light to moderate snowfall to our
region through tonight. High pressure will build back in late
Monday into early Tuesday...before another storm system approaches
from the west. This system is expected to bring more unsettled
weather late Tuesday into Wednesday...including the potential for
a wintry mix of precipitation.

&&

Near term /until 6 am Monday morning/...
Winter Weather Advisory remains in place across Herkimer
County...the Mohawk and Schoharie valleys...eastern
Catskills...middle Hudson Valley...Taconics...Litchfield Hills...
Berkshires and southern Green Mountains until 700 am Monday.

As of 400 PM EST...light snow was becoming more widespread across
the region with a few bursts of moderate snowfall occurring. For
this update have lowered snow amounts slightly across the northernhalf
of the forecast area and pretty much left the snow amounts in tact across
southern areas. Two areas of low pressure are responsible for
producing the snowfall with one area of low pressure north of Lake
Ontario and a second area of low pressure in the Ohio Valley with
warm front extending east across the middle Atlantic region. Weak
isentropic lift across the area late this afternoon through this
evening should enhance the snowfall some. Generally expecting 1
to 3 inches north and 3 to 6 inches south. Will leave the Winter
Weather Advisory in tact as is for now. The heaviest snow will
fall across southern portions of Ulster and Dutchess counties in
New York...and southern Berkshire and Litchfield counties in western New
England. Will continue to use a 13 to 1 snow to liquid
ratio...although this could vary across the area. The steady snow
should end a few hours before sunrise Monday. Lows tonight are
expected to be in the upper teens to middle 20s.

&&

Short term /6 am Monday morning through Tuesday/...
on Monday low pressure will intensify as it tracks NE into the
Canadian Maritimes...while high pressure builds east into the Ohio
Valley during the day Monday. The pressure gradient between the
high and low will result in gusty northwest winds across our area.
Wind gusts as high as 40 miles per hour are expected. There will also be some
upslope snow showers across the southern adiriondacks and southern
Green Mountains with light accumulations generally under an inch
expected. Highs on Monday are expected to be in the upper 20s to
upper 30s with the highest readings in the middle Hudson Valley and
Litchfield Hills.

Any snow shower activity will have ended by Monday evening as high
pressure builds into our region and the flow becomes anticyclonic.
This will allow for yet another very cold night with wind speeds
decreasing and mainly clear skies with a deep snowpack in place.
Lows are expected to be in the 5 below to 10 above zero range.

For Tuesday the ridge of high pressure will high pressure will
quickly shift east of the region. A stregthening storm system is
expected to track from the middle Mississippi Valley northeastward toward
the Ohio Valley. Snow will break out across the region from west
to east during the afternoon with the best chance for accumulating
snows by 6 PM across the western half of the forecast area. At this point
will call for half an inch to an inch accumulation. Highs on
Tuesday will be in the middle 20s to around 30.

&&

Long term /Tuesday night through Sunday/...
Tuesday night through Wednesday night...latest 01/12z model and
numerical data continue to show a surface low pressure tracking from
a domain ranging from the eastern Great Lakes westward into lower
Michigan. High confidence at this time shows that precipitation will
start as snow across the entire region as lower to middle level weak
warm air advection will be established out ahead of the middle level strip vorticity
with maximum enhancing precipitation downstream and along a
progressing surface cold front. Stronger warm air advection will be present moving
into the region shortly after 00z Wednesday where a transition from
snow to a wintry mix of sleet and freezing rain will occur across
the region from south to north as the 925-850 hpa wind field will
shift to more southwesterly. As we go past 12z Wednesday...most
areas will support plain rain at times with snow in the high terrain
of the Adirondacks. However...as most of the area still have several
inches to a few feet of snow cover still on the ground...surface
temperatures will still support icy conditions as a cold rain will fall
from the late morning hours into the afternoon hours as rain will
make contact with a frozen surface and a surface with several feet
of frost depth. As we head toward Wednesday night... a cold front
associated with the low pressure system to the northwest of the
region will make its way through the entire region as we approach
00z where precipitation type will end as snow showers for the entire
region as moderate cold air advection returns to the region behind the cold front.
Temperatures during this time period will not follow diurnal trends. Low
temperatures Tuesday night will only drop a few degrees. High temperatures on
Wednesday which follows more American global guidance with 850 hpa
and 925 hpa temperatures between 0c and 4c will support high temperatures
briefly ranging from the middle 30s in the adks to low and middle 40s for
valley locations. Temperatures Wednesday night will range from the upper single
digits to middle and upper teens behind the cold frontal passage.

Thursday through Sunday...the first half of Thursday will continue
to have some low probability of precipitation as the frontal system will be very slow to
move out of the region as upper level winds behind the front will be
rather weak. Otherwise most of Thursday through Sunday will remain
tranquil. Some numerical guidance does show a weak upper level
trough moving across the New York/Canada border during the day on Saturday
which may provide some isolated snow showers for our far northern
areas. Otherwise temperatures will also continue to be well below
normal for early March. As we go through the rest of the extended
period...a surface high pressure in the Ohio Valley will shift to
the east going into the weekend where a west southwest wind may
moderate temperatures closer to average as we go into the weekend.

&&

Aviation /21z Sunday through Friday/...
an upper level disturbance and a frontal boundary will focus
periods of light snow this afternoon into tonight. A cold front
will move across the region by tomorrow morning. High pressure
will ridge back in Monday night.

Conditions will vary from low VFR at kgfl...to MVFR/IFR at
kalb/kpsf/kpou in the light snow this afternoon. The ceilings are
mainly MVFR...but visibilities are fluctuating between MVFR/IFR levels.
The light snow will get into kgfl between 18z-21z/sun. Some very
brief bursts of moderate snow may get into kpou/kpsf. The main surface
low will be well south of the region. The inverted surface trough and
a frontal boundary will focus most of the snowfall.

The snow will taper off from northwest to southeast between 04z-07z/Mon. The
conditions will gradually improve from IFR/MVFR levels to VFR
levels by 11z-13z/Mon. Kpsf will have a chance to continue high MVFR
ceilings. The winds will increase from the west to northwest at 10-15 kts by
daybreak tomorrow.

S to southeast winds of 5-12 kts will prevail this afternoon...and then
become light and variable direction early this evening. The winds
will initially shift to SW to west at 10 kts or less after
midnight...11z-14z/Mon the winds will increase to 10-15 kts from
the west/northwest with some gusts in the 20-25 knots range at kalb/kpsf.

Outlook...

Mon: low operational impact. Slight chance snow mainly in the morning.
Monday night: no operational impact. No sig weather.
Tue: moderate operational impact. Chance snow in the afternoon.
Tuesday nt-Wed: moderate operational impact. Snow/mixed precipitation to rain.
Thu: low operational impact. Isolated-scattered snow showers.
Fri: no operational impact. No sig weather.

&&

Hydrology...
no widespread Hydro problems are expected through the next 5 days. A
light to moderate snowfall is expected through tonight. This snow
will have no immediate impact on area waterways. Dry weather is
expected again from late Monday through Tuesday morning.
However...another storm system will impact the region late Tuesday
into Wednesday...with the possibility of snow...mixed
precipitation and/or rain.

Temperatures will remain below freezing through tonight.
Temperatures may briefly rise above freezing during the day on
Monday for some areas south of Albany...before another cold air mass
settles in for Monday night into Tuesday. With the continued cold
conditions in place...ice will continue to strengthen and thicken on
area rivers...streams...creeks...lakes...and ponds.

A brief warmup may occur on Wednesday...but the short timing and
magnitude of the warmth will likely not be enough to cause any Hydro
concerns. Another cold air mass will build in late Wednesday into
Thursday...with temperatures falling back below freezing.

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.

&&

Climate...
February 2015 will go down as one of the coldest months on record
across the region.

At Albany...February 2015 was the 2nd coldest February on record
with an average temperature of 12.7 degrees f. This also marked
the 4th coldest single month on record and the coldest month since
January 1994. Temperature records at Albany date back to 1820.
Here is a list of the all time coldest months at albany:

1) 9.7 degrees f January 1970
2) 11.8 degrees f January 1857
3) 12.1 degrees f February 1934
t4) 12.7 degrees f February 2015
t4) 12.7 degrees f January 1994

At Glens Falls...February 2015 was the coldest February on record
with an average temperature of 7.3 degrees f. This also marked
the 4th coldest single month on record and the coldest month since
January 1994. Temperature records at Glens Falls date back to
1945. Here is a list of the all time coldest months at glens
falls:

1) 4.9 degrees f January 1970
2) 6.5 degrees f January 1982
3) 7.1 degrees f January 1994
4) 7.3 degrees f February 2015

At Poughkeepsie...February 2015 was the coldest February on record
with an average temperature of 15.6 degrees f. This also marked
the 2nd coldest single month on record. Temperature records at
Poughkeepsie date back to 1949...although data is missing from
January 1993 to July 2000.

&&

Aly watches/warnings/advisories...
CT...Winter Weather Advisory until 7 am EST Monday for ctz001-013.
New York...Winter Weather Advisory until 7 am EST Monday for nyz032-
038>040-047-048-051-054-058>061-063>066-082.
Massachusetts...Winter Weather Advisory until 7 am EST Monday for maz001-025.
Vermont...Winter Weather Advisory until 7 am EST Monday for vtz013-014.

&&

$$
Synopsis...11/jpv
near term...11
short term...11
long term...lfm
aviation...wasula
hydrology...11/jpv
climate...

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