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Area forecast discussion 
National Weather Service Albany New York
1021 PM EDT Friday Aug 1 2014

Synopsis...
scattered showers and thunderstorms will occur through Tuesday.
Most of the activity will be during the afternoon and evening
hours. The showers and thunderstorms will be mainly the result of
an upper level disturbance across northern Canada which is
associated with a deep trough of low pressure with several spokes
of energy rotating around it. A cold front will swing through on
Tuesday bringing more scattered showers and thunderstorms.

&&

Near term /until 6 am Saturday morning/...
as of 1020 PM EDT...isolated showers and even a rogue thunderstorm
has developed across the western Mohawk Valley. It appears that
this may be tied to a low level moisture gradient...which is
slowly advancing northwest. Also...it is a bit cooler in the
middle/upper levels of the troposphere...leading to some residual
instability for areas north and west of Albany. Will keep slight chance probability of precipitation
across the Mohawk Valley/southern Adirondacks and southern Vermont for
another few hours before ending. Elsewhere...with little forcing
in place...expect mainly rain-free conditions for the bulk of the
overnight hours. Patchy fog is expected to develop...but the areal
extent should be less than this morning due to thickening middle
level clouds preventing temperatures from dropping much.

Speaking of temperatures...the aforementioned cloud cover...along with a
moist boundary layer...and a persistent light south wind...should
prevent temperatures from cooling much below 60 in most areas...with some
portions of the Hudson River valley from Albany south likely
only falling into the middle 60s or even warmer.

Toward daybreak...some forcing associated with an approaching
shortwave from the Middle Atlantic States...and a developing surface wave
along the coast may allow for some light rain or showers to
develop across the middle Hudson Valley and northwest CT. Have kept chance probability of precipitation
in this region...with the best chance most likely occurring after
daybreak.

&&

Short term /6 am Saturday morning through Monday/...
on Saturday...have made some subtle changes to the gridded
database...with some showers or even a period of steady rain
possible across the middle Hudson Valley...northwest CT...and southern
Berkshires through noontime. It appears that the best combination
of forcing...mainly with middle level f-gen...and also moisture may
remain tied closer to the immediate coast. However...some bands of
rain may reach this region through noontime. Thereafter...the main
focus for any showers should shift into the higher terrain mainly
west of the Hudson River...and into the southern Adirondacks...in
association with the slowly approaching middle level trough from the
west. Instability appears a bit less than recent days...so only
isolated thunder is expected...again mainly across the southern
Adirondacks. Any convective elements should be slow moving...and
could produce locally heavy downpours as precipitable water/S approach 1.5
inches. Expect highs on Saturday to be in the 70s to around 80.

For Sat nt and Sunday...additional showers and thunderstorms will
be possible as numerous vorticity maximums rotate across the region around
the base of the upper trough with the upper trough axis expected
to cross the region late Sunday and Sunday night. Even by Monday
there will still be some convection as a secondary trough axis
moves across the region. Mlmucapes will rise as high as 2000 j/kg
across parts of the region Sunday afternoon with precipitable waters up to 1.5
inches. While the forecast area is not outlooked for severe thunderstorms
during this time frame cannot rule out getting a few isolated
storms that approach severe limits. The bigger threat looks to be
Hydro issues as with little flow in the atmosphere the storms will
be relatively slow moving. Lows Saturday night should be in the
middle 50s to lower 60s. Highs on Sunday are expected to be in the
middle 70s to around 80 with lows Sunday night in the middle 50s to middle
60s. Highs on Monday are expected to be in the upper 70s to lower
80s.

&&

Long term /Monday night through Friday/...
much of this time period appears to be transitional...changing from
the relatively stagnant pattern preceding it...as northern stream
energy begins to settle back southeast toward southern Canada and
northern New England. A lead impulse should allow a surface cold front
to settle south and east across the region Tuesday...triggering
scattered showers and thunderstorms. Then...as the main upper level
trough potentially digs further south into southeast Canada and northern
New England...cooling middle levels should support at least isolated to
scattered showers...and perhaps a few thunderstorms...for Wednesday
afternoon...and perhaps again Thursday afternoon...albeit with decreasing
areal coverage. Higher terrain across the southern Adirondacks and
southern Vermont might be favored for this isolated/scattered diurnal
shallow convection for Wed-Thu. High pressure may then build in for
late Thursday into Friday...decreasing the chances for convection.

As for temperatures...Tuesday should be warm and humid ahead of the incoming
surface front...with maximum temperatures reaching at least the Lower/Middle 80s in
valleys...and 75-80 across higher terrain. Even warmer maximum temperatures
could occur should there be sufficient sunshine before any
convection...or any convective debris clouds develop. Maximum temperatures
should gradually cool down for Wed-Fri...initially in the upper 70s
to lower 80s in valleys...and Lower/Middle 70s for higher elevations on
Wednesday...cooling to 75-80 in valleys...and middle 60s to around 70 for
higher elevations by Friday...although even cooler maximum temperatures could
occur. Min temperatures should initially be rather warm...mainly in the 60s
for Monday nt/Tuesday am...then trending down into the 50s for valley
areas...and 45-50 for higher elevations by Wednesday-Friday am...with even
cooler mins possible.

&&

Aviation /02z Saturday through Wednesday/...
an upper level trough will slowly approach from the west
Saturday...as a low pressure system develops along a stalled
frontal boundary across the Atlantic coastline and rides
northeast.

For tonight...high and middle level clouds will be thickening for
kalb/kpsf and kpou...while increasing a bit slower at kgfl. A
period of radiational cooling may promote ground fog formation at
kgfl after 04z/Sat...with occasional IFR visibilities/ceilings possible
through 12z/Sat. Elsewhere...moderate to heavy rainfall occurred
this afternoon at kpou...providing for a very moist boundary
layer. However...temperatures are expected to only cool slightly
overnight due to the expected thickening cloud cover.
So...prospects for fog are not as high as might be expected for
kpou...although some low ceilings could develop after 08z/Sat. At
kpsf...some fog and/or low clouds may also develop after 07z/Sat.
At this time...it appears that kalb should remain VFR overnight.

Any low clouds/fog should burn off by 13z-14z/Sat. However...the low
pressure system to our southeast may bring a period of steady rain
to kpou and kpsf between roughly 13z-17z/Sat...possibly producing
MVFR to IFR vsbys/cigs. Otherwise...the bulk of any showers
associated with the slowly approaching upper level trough should
remain mainly west of the taf sites Saturday. However...will
include vcsh for the afternoon hours...in case some of these
expand or drift further east.

Outlook...

Saturday night: moderate operational impact. Chance of rain showers...tsra.
Sunday: moderate operational impact. Chance of rain showers...tsra.
Sunday night: moderate operational impact. Chance of rain showers...tsra.
Monday: moderate operational impact. Chance of rain showers...tsra.
Monday night: low operational impact. Slight chance of rain showers.
Tuesday: moderate operational impact. Scattered rain showers...tsra.
Tuesday night: low operational impact. Isolated rain showers...tsra.
Wednesday: moderate operational impact. Scattered rain showers...tsra.

&&

Fire weather...
scattered showers and thunderstorms will occur through Tuesday.
Most of the activity will be during the afternoon and evening
hours. The showers and thunderstorms will be mainly the result of
an upper level disturbance across northern Canada which is
associated with a deep trough of low pressure with several spokes
of energy rotating around it. A cold front will swing through on
Tuesday bringing more scattered showers and thunderstorms.

&&

Hydrology...
isolated to scattered rain showers or thunderstorms are possible
today...mainly this afternoon and evening...across southern parts
of the area. Any showers or thunderstorms will be slow moving and
are capable of causing some hydrologic concerns. The main concern
will be for urban and poor drainage flooding.

Over the weekend more humid conditions will be gradually
returning and lasting into early next week. There will be a
continued threat for showers and thunderstorms...locally heavy
downpours could occur...and minor flooding of poor drainage and
urban areas will be possible if thunderstorms repeatedly pass over
the same locations... especially on the weekend into Monday.

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...11
near term...kl/11
short term...kl/11
long term...kl
aviation...kl/wasula
fire weather...11
hydrology...11

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