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Area forecast discussion 
National Weather Service Albany New York
216 PM EDT Monday Jul 28 2014

Synopsis...
low pressure over the southern tier of New York...will move
northeast to near northern Maine by Tuesday morning. This weather
system will bring clouds and showers to the Albany forecast area
today. A weak ridge of high pressure will bring mainly fair and
cool weather on Tuesday. On Wednesday...mostly fair and cool
weather is expected...but an upper level impulse may cause a few
afternoon showers or thunderstorms.

&&

Near term /until 6 PM this evening/...
..included Severe Thunderstorm Watch...Valid until 8 PM...

Upper impulse pivoting east now early this afternoon...and two
distinct areas of vorticity seen in radar imagery...one between
rme/gtb and the other near bgm. Convection developing and
increasing in coverage along the leading edge of the deeper
cloudiness in central/northern New York. Breaks in the clouds in
southern and eastern New York and western New England has allowed
temperatures to warm a little more than current forecast...so some
temperature adjustments through this afternoon. Adjusting rain
chances based on radar trends and including wording for gusty
winds...small hail and heavy rain.

Upper impulses like this one can enhance chances for severe
thunderstorms and localized flooding...so will suggest areas of
Urban and Small Stream flooding in some areas...with isolated
flash flooding not out of the question...but no Flash Flood Watch
at this time. Antecedent rainfall heaviest in western Massachusetts/Vermont and
northern Taconics of New York...where precipitation amounts should be
less than in the Schoharie valley...western Mohawk Valley and
eastern Catskills.

Interesting 12z soundings across the region with obvious cooling
aloft between kbuf and kalb...so again...chances for severe are
present but should be isolated...along and just south of the
leading edge of the upper comma head and vorticity centers seen on
radar.

&&

Short term /6 PM this evening through Wednesday night/...
with the passage of the system's cold front...the threat for
thunderstorms will come to an end. Will have lingering threat of
showers through the evening as the low is drawn northward as the
short wave becomes absorbed by the large cut off low centered near
hudson's Bay Canada. .

With the passage of the system cooler air will be drawn into the
region on northwest flow. Into middle week the region will be under a
longwave trough with pieces of energy spinning about the large
closed low over southern Canada...which will be hard to time. While
at the surface high pressure builds in. Guidance is in agreement that
the region should be between short waves Tuesday so expecting a dry
day. Have probability of precipitation in forecast for Wednesday mainly to the west of the
Hudson River valley.

Temperatures will average below normal for late July by 5 to 10
degrees.

&&

Long term /Thursday through Sunday/...
the weather will continue to be somewhat unsettled during the
extended period.

A large cut off upper level low will remain situated just to our
northwest over southern Canada to start the long term period.
Although this upper level low will be weakening...it will remain
close enough to the area to allow for cyclonic flow showers and
thunderstorms for Thursday and Friday...especially during the diurnally
favored afternoon and evening hours. Daytime temperatures will be close to
normal...with highs in the upper 70s to low 80s for valley
areas...and mins generally in the 50s to low 60s.

Although the upper level low will finally start to lift out to the
northeast...another impulse diving out of the south central Canada
will move towards the Great Lakes and northeast for the weekend.
This will strengthen the mean longwave trough over the eastern
portion of the Continental U.S....while a strong ridge remains in place across
the western US. The result will be a continued threat for scattered
showers and thunderstorms over the weekend. Again...the highest
coverage/best chance will be during peak daytime heating. Temperatures
will continue to run similar to the past few days...with highs right
around 80 and lows in the upper 50s to low 60s for valley areas.

&&

Aviation /18z Monday through Saturday/...
changeable flying conditions can be expected at all terminals over
the next 6-10 hours thanks to a strong storm system moving across the
area.

Thunderstorms have developed over central New York...the
Catskills...and the middle Hudson Valley. These storms are moving
towards the northeast at 20-30 miles per hour. We have included thunder at
all the terminals for this afternoon. There is the potential for
MVFR with any showers/thundershowers that hit a terminal site.

A cold front should clear the area between 00z and 02z this
evening. Behind this front...westerly winds will transport cooler
and less humid air into the region. This will end the threat for
precipitation...with surface winds increasing to around 10-15 kts with a
few higher gusts for this evening. Some lingering clouds will
continue into the first half of tonight...but flying conditions
should be VFR for all sites. By late tonight...clouds should
scatter out and winds will start to diminish so localized fog is
a threat at the taf sites.

Outlook...
Tuesday night-Wed: no operational impact. No sig weather.
Wednesday night: low operational impact. Slight chance of rain showers...tsra.
Thu: moderate operational impact. Chance of rain showers...tsra.
Thursday night: no operational impact. No sig weather.
Fri: moderate operational impact. Chance of rain showers...tsra.
Friday night: low operational impact. Slight chance of rain showers...tsra.
Sat: moderate operational impact. Chance of rain showers...tsra.

&&

Fire weather...
showers are likely much of the day with scattered thunderstorms as a
a low pressure system over New York state continues to move eastward.
The system will move off to our northeast tonight allowing cooler
air to filter into the region. High pressure will build in at the
surface as we head through middle week...however aloft disturbances
will pass over the region.

&&

Hydrology...
showers are likely much of the day with scattered thunderstorms as a
a low pressure system over New York state continues to move eastward.
Heavy rainfall will occur with some storms as the atmosphere is
very moist with dew points in the 60s. Have continued with
enhanced wording in forecast for heavy rainfall.

The highest rainfall total are expected mainly north of I-90 with
around an inch of additional rainfall today. Locally heavy rainfall
may result in some flooding of low lying and poor drainage areas.
Areas which have already received a round of heavy rainfall will
be the most vulnerable.

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...snd/NAS
near term...snd/NAS
short term...iaa
long term...frugis
aviation...sand
fire weather...iaa
hydrology...iaa

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