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Area forecast discussion 
National Weather Service Albany New York
122 am EDT Wednesday Jul 23 2014

Synopsis...
hazy...very warm and humid conditions are forecast through
Wednesday. A cold front will bring showers and thunderstorms to the
area Wednesday afternoon and evening. Behind the cold front...cooler
and less humid air is expected for Thursday and Friday.

&&

Near term /until 6 am this morning/...
muggy night continues with lows generally 65 to 70 degrees. Skies are
mostly clear across the region. Clouds are not expected to
increase until near sunrise ahead of an approaching cold front.
Will have some patchy fog in those areas prone to the development
fog with high dew points and light to calm winds.

&&

Short term /6 am this morning through Thursday night/...
the Storm Prediction Center /spc/ continues to highlight an area
of slight risk for severe weather from the capital region and
locations to the north and east. Forecast instability parameters
are rather high and consistent with a severe weather episode for
the region. Sbcapes climb at or above 2k j/kg...precipitable waters up to 2
inches...bulk shears of 30-40kts and the timing of this front
coincides with the maximum daytime heating for the region. The main
threat from these thunderstorms will be from damaging wind gusts and
cloud to ground lightning strikes. Some large hail also possible if
the SBCAPE becomes high enough. With the likely probability of precipitation ahead of the
front have added enhanced wording for heavy rainfall and gusty
winds.

High temperatures on Wednesday will be in the 80 to 90 degree
range most areas...but in the middle and upper 70s over the
Adirondack zones where the cold front will pass early enough to
prevent temperatures from rising that much.

The cold front is generally forecast to be progressive by most of
the models and should continue to slowly move southeast during
Wednesday night and early Thursday. Convective threat should
diminish rather quickly with frontal passage and do not mention thunderstorms after
midnight since the entire region will be behind the front. Probability of precipitation are
forecast to decrease slowly during the night. By 12z Thursday probability of precipitation
are forecast to be between 20 and 40 percent across the southeast
half of the forecast area...and elsewhere. The probability of precipitation over the
southeast will continue to decrease and become dry in all areas by
Thursday afternoon. Lows Wednesday night will be in the 60s across the
southeast...and 50s northwest. Highs Thursday generally between 70
and 80.

Mainly clear...cool and dry Thursday night as a large Canadian high
pressure system builds into the region. Lows will be in the 40s to
middle 50s.

&&

Long term /Friday through Tuesday/...
weather turns unsettled as we head into the later part of the
weekend into next week.

Model guidance is in agreement that the longwave pattern will have
changed with an amplified ridge in the west and a deepening trough
in the east by the time we head into the weekend. However...there
are model difference in regards to the position of frontal boundaries
and weak surface lows as we head through the weekend. At this
time...indications are that Friday and even Saturday should be
dry with chances for storms returning on Sunday as waves of low
pressure move eastward boundary which lifts northward into the middle
Atlantic region.

As we head into next week a stronger system is expected to develop
as the closed low from the Pacific northwest overrides the ridge and
enters the trough deepening it over the eastern United States and
drawing the closed upper low near hudson's Bay. The associated
surface low pressure system will approach and move across the
region Monday and Tuesday with better chances for storms.

Overall have favored guidance for the weather prediction center
for the placement and movement of features and to offer forecast
consistency.

In general temperatures should be seasonably warm with increasingly
humidity as we head into next week.

&&

Aviation /06z Wednesday through Sunday/...
muggy night continues. Cumulus clouds have dissipated with loss of
heating. Skies are mostly clear across the region. Cloud cover is
not expected to increase until late ahead of an approaching cold
front. Have continued with the development of fog for kgfl with high
dew points in the 60s and surface winds lightening up overnight.
Looking at IFR conditions developing at kgfl.

Showers and thunderstorm will occur across the area as a cold
front approaches and interacts with the very warm and humid air mass
in place across the region. There are now indications that the front
will slow down as a wave of low pressure moves northeast along it.
Have used prob30 groups to address the timing of the
convection...for the afternoon into the evening.

Precipitable water values are expected to increase to near 2 inches...so
any storm will capable of very heavy downpours. Forecast instability
parameters are rather high so some storms may become strong to severe
during the afternoon and evening hours.

South winds weakening tonight. Start off with a south-southwest wind
of 5 to 10 knots Wednesday shifting more to the west and then
northwest in the wake of the cold front during the evening hours.

Outlook...
Wednesday night: moderate operational impact.Likely rain showers...tsra.
Thursday-Sat: no operational impact. No sig weather.
Sat night: low operational impact. Slight chance of rain showers.
Sun: moderate operational impact. Chance of rain showers...tsra.

&&

Fire weather...
mainly dry weather is expected through early Wednesday.

Relative humidity values will be elevated through Wednesday with minimum values
generally at or above the 40-50 percentile range and overnight
lows generally at or above 90 percent.

By Wednesday...shower and thunderstorm activity will increase as a
cold front begins to impact the region...which will interact with a
hot and humid air mass.

The surface wind will be south to southwest tonight at 5 to 10
miles per hour...then becoming southwest to west on Wednesday at 5 to 15 miles per hour
with some gusts to 20 miles per hour.

&&

Hydrology...
showers and thunderstorm will occur across the area as a cold
front approaches and interacts with the very warm and humid air
mass in place across the region. Precipitable water values are
expected to increase to near 2 inches...so any storm will capable
of very heavy downpours which could cause flooding of low lying
and poor drainage areas. Have added enhanced wording for the heavy
rainfall to the forecast for Wednesday afternoon and evening and
have this mentioned in our hazardous weather outlook.

With the passage of the cold front...a cooler and less humid air
will be ushered in. Expected some lingering showers into Thursday
morning as the front will be slow to move off to the east. Then
looking at dry weather into the weekend. The weather will turn
unsettled as we head into the second half of the weekend and into
next week.

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...gjm
near term...iaa/gjm/bgm
short term...gjm
long term...iaa
aviation...iaa/11
fire weather...iaa/bgm
hydrology...iaa/bgm



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