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fxus61 kaly 170950 
afdaly

Area forecast discussion
National Weather Service Albany New York
550 am EDT Tue Jul 17 2018

Synopsis...
showers and thunderstorms, some containing very heavy rainfall
and gusty winds, will move across the region in advance of a
cold front. A cooler and much less humid airmass will follow in
the wake of the front, along with fair weather, for Wednesday
through Friday.

&&

Near term /until 6 PM this evening/...
Flash Flood Watch issued for southern VT, western Massachusetts and northwest CT
from noon until 8 PM today...

As of 550 am EDT, showers with a few embedded thunderstorms
continue across the southeast Adirondacks, upper Hudson Valley
and northern portions of the capital region, including the
Saratoga area. Elsewhere, it remains partly to mostly cloudy
and very humid, with temperatures mainly in the lower/mid 70s.

Several clusters of showers/thunderstorms across central New York state
should continue tracking east/northeast through the morning
commute. This will bring heavy rainfall to the Mohawk Valley,
northern Schoharie County, and at least the northern portions of
the capital region, occasionally into the immediate capital
region. Heavy downpours will be likely through 9 am in these
areas, along with occasional lightning strikes.

Farther south and east should remain mainly dry through mid
morning, with some breaks of sun possible.

The showers/thunderstorms should intensify during the mid to
late morning hours, with a band developing from the southeast
Adirondacks into the eastern Mohawk Valley, and should continue
tracking east/southeast through early to mid afternoon. In
addition to locally heavy downpours, as mid level winds
strengthen with the approach of the upper level trough from the
west, 0-6 km bulk shear will increase to 25-35 kt, and therefore
some thunderstorms may produce strong/gusty winds, with a few
damaging wind gusts possible within any more organized bowing
segments that develop. The Storm Prediction Center (spc) has
placed most areas from the Hudson River valley and eastern
Catskills eastward through western New England within a slight
risk for severe thunderstorms due to this potential of damaging
wind gusts, with a marginal risk extending north and west into
most of the southern Adirondacks and central Mohawk Valley.

With pwat's around 2 inches, thunderstorms will have the
potential to produce rainfall rates of 1-2 inches/hour, if not
greater. As storms move toward western New England, they may
tend to become slightly slower and/or backbuild slightly, thus
have included western New England within a Flash Flood Watch
from noon through 8 PM.

There could be a second, broken line or band of
showers/thunderstorms later this afternoon/evening associated
with the actual cold front, which may not pass areas south and
east of Albany until later this evening, perhaps between 9-11
PM.

It will be warm and humid, with highs reaching the upper 70s to
lower 80s, except for mid/upper 80s across portions of the Mid
Hudson valley and possibly lower elevations in Litchfield County
CT. Some Max temps may actually occur later this afternoon after
the showers/storms move away and some breaks of sun occur. This
will be most likely across portions of the Adirondacks, Mohawk
Valley and upper Hudson Valley.

&&

Short term /6 PM this evening through Thursday night/...
tonight, the main cold front will still be sagging south and
east through southern VT, western MA, the Mid Hudson valley and
northwest CT, and should pass south and east of these locations by
midnight. Until then, can not rule out isolated to scattered
showers/thunderstorms, although with deeper moisture shunting
east of the region, the threat for very heavy rainfall rates
should decrease. A secondary cold front looks to track southward
across the region toward or after daybreak, and could allow for
an isolated shower/sprinkle across the southern Adirondacks.
Otherwise, becoming less humid overnight, with lows by daybreak
ranging from the mid 50s to lower 60s, except possibly cooler
across portions of the southwest Adirondacks.

Wednesday-Thursday, much less humid conditions will build into
the region along with high pressure. Daytime highs mainly
ranging from the mid 70s to lower 80s, warmest within valley
areas. Some higher elevations may barely reach 70 both days.
Wednesday night will be very cool, with lows mainly in the 50s,
except for 40s across higher terrain areas. In fact, it could
drop to around 40 for some areas of northern Herkimer and
Hamilton counties.

&&

Long term /Friday through Monday/...
dry weather is expected Friday through Saturday as a large ridge of
high pressure moves east off the New England coast on Friday and out
to sea on Saturday. Highs on Friday will be in the upper 70s to
upper 80s with lows Friday night in the upper 50s to mid 60s. Highs
on Saturday will be in the mid 70s to mid 80s.

Unsettled weather is expected over the second half of the weekend,
however there are some differences on the timing of the onset of the
precipitation with the European model (ecmwf) being slower than the GFS. The European model (ecmwf)
would keep Saturday night dry while the GFS brings rain in during
the second half of Saturday night. For now will include slight
chance to chance pops on Saturday night as a low pressure system
moves into the eastern Great Lakes region with a warm front in the
middle Atlantic region. Lows Saturday night will be in the upper 50s
to mid 60s. Once the precipitation arrives on Sunday it will be here
for awhile lasting well into next week as upper low closes off over
the Ohio Valley. Highs on Sunday will be in the upper 60s to lower
80s, but could be cooler if rainfall arrives sooner in the day. Lows
Sunday night will be in the 60s with highs on Monday in the mid 70s
to mid 80s.

&&

Aviation /10z Tuesday through Saturday/...
a shortwave trough and associated surface cold front are heading
towards the region. Latest mosaic radar imagery shows bands of
showers and embedded thunderstorms extending towards the region from
western and central New York. Brief reductions to MVFR/IFR
conditions (mainly due to visibility) are possible at kgfl/kalb as
these showers/T-storms move across the northern half of the area for
the late night early morning hours. Kpou may be far enough
south/east to see any impact from these showers, but will
include a tempo for kpsf in case it brushes there or if other
showers develop along outflow boundaries from this activity.
Otherwise, it will remain VFR with a bkn high clouds in place
and a light south to southeast flow for the rest of the
overnight hours.

During the day on Tuesday, the storm's cold front will allow for one
or two bands of convection that will move across the area from west
to east. These showers and thunderstorms will impact the region
mainly during the afternoon hours (perhaps lingering into the
early evening at kpou). Within any shower or T-storm, visibility
may be reduced to IFR levels, with MVFR cigs. There is also the
possibility of gusty westerly winds within any thunderstorm as
well. Outside of showers or T-storms, it looks VFR with bkn cigs
around 4-6 kft and southerly winds will be around 5-10 kts
throughout the day.

Behind the front, winds will switch to the W-NW for Tuesday evening
into Tuesday night. Clouds should clear out for most areas,
although kpou may see some lingering mid level clouds through the
evening hours.

Outlook...

Wednesday night: no operational impact. No sig weather.
Thursday: no operational impact. No sig weather.
Thursday night: no operational impact. No sig weather.
Friday: no operational impact. No sig weather.
Friday night: no operational impact. No sig weather.
Saturday: no operational impact. No sig weather.

&&

Fire weather...
showers and thunderstorms, some containing very heavy rainfall
and gusty winds, will move across the region in advance of a
cold front. A cooler and much less humid airmass will follow in
the wake of the front, along with fair weather, for Wednesday
through Friday.

&&

Hydrology...
numerous showers and thunderstorms are expected today as a cold
front approaches and moves across the region. Storms will be
capable of very heavy downpours which may lead to some urban low
lying and poor drainage flooding. Rainfall rates may reach 1 to
2 inches per hour, if not more. This will increase the threat
for mainly urban/poor drainage flash flooding, especially across
western New England, where storms may tend to move slower and/or
backbuild slightly. A Flash Flood Watch was issued for western
New England, where this potential is slightly greater.

Basin-average rainfall amounts of up to around an inch are
expected, which should be enough to cause some rises on area
rivers.

Mainly dry weather is then expected for Wednesday through
Friday. Showers and thunderstorms may return for next weekend
as a low pressure system approaches.

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...Flash Flood Watch from noon EDT today through this evening for
ctz001-013.
New York...none.
Massachusetts...Flash Flood Watch from noon EDT today through this evening for
maz001-025.
Vermont...Flash Flood Watch from noon EDT today through this evening for
vtz013>015.

&&

$$
Synopsis...iaa/kl
near term...kl

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