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Area forecast discussion 
National Weather Service Albany New York
410 PM EDT Sat Aug 30 2014

Synopsis...
a slow moving cold front will bring a round of showers and
thunderstorms late tonight into Sunday...some possibly with heavy
rainfall. Weak high pressure will build in Labor Day. It will be
very warm humid and mainly rain-free...but an additional
thunderstorm cannot be ruled out. Another cold front is expected
to bring a chance for showers and thunderstorms Tuesday and
Tuesday night.

&&

Near term /until 6 am Sunday morning/...
cloud cover in southern New York is not moving...although the northern
periphery is eroding a little. The coverage of the cloud cover
should not change much through the night...and additional middle and
high clouds will build into the rest of the region from the west.
Some isolated to scattered showers and thunderstorms should
approach western areas around daybreak. Lows tonight in the 60s.

&&

Short term /6 am Sunday morning through Tuesday/...
still some question as to how much cloud cover will be over the
region tomorrow. Southwest boundary layer flow and a loosening
boundary layer thermal gradient should promote some breaks in
cloud cover. There shoudl also be breaks in the leftover
convective debris from convection in the Great Lakes and western
NY/PA. Cloud cover currently upstream in the Ohio Valley and Great
Lakes is scattered to broken. So with the prospects for at least
some intervals of sun...with rapidly warming boundary layer
temperatures...highs solidly in the 80s Sunday...but upper 70s
southern Adirondacks where showers and thunderstorms should affect
earlier in the day.

Upper dynamics...along with a little low level jet segment tracks
through the region Sunday and Sunday night. Deep moisture seen in
the satellite derived sounder imagery of precipitable water...is surging north
from the MS/Tennessee Valley. So...coverage of showers and scattered
thunderstorms should increase to likely in the afternoon in most
areas. Locally heavy rain is possible and will address in
hazardous weather outlook...but no widespread or high impact flood
threat expected.

Weak cold front exits Sunday night with just some lingering
scattered showers and thunderstorms...with the best coverage in
the middle Hudson Valley...Berkshires and northwest CT Sunday evening. Some
question as to how far south the weak low level boundary gets...so
scattered showers and thunderstorms could linger through much of
Monday in the middle Hudson Valley and northwest CT...but just scattered...
with isolated afternoon activity elsewhere. Still...some periods
of sunshine expected Monday...with perhaps more clouds than sun in
the middle Hudson Valley and northwest CT. Highs Monday solidly in the 80s.
There could be a lull in the shower and thunderstorm activity
Monday night with partial clearing...but dew points are not
expected to drop much if any...so lows Monday night in the 60s.

Another cold front approaches Tuesday...with a bit better boundary
layer frontogenesis and thermal gradient tracking toward the
region. Current consensus on timing suggests some sunshine and
daytime heating at least Tuesday morning...with the leading edge
of scattered showers and thunderstorms approaching western areas
midday or early afternoon Tuesday...then affecting the rest of the
region through the afternoon. Highs Tuesday solidly in the 80s.
Thunderstorms Tuesday could be strong based on the potential
instability...thermal gradient forcing and boundary layer winds.

&&

Long term /Tuesday night through Saturday/...
midweek through the end of the work week will feature dry conditions
as high pressure moves over the forecast area behind a cold front.
However...a cold front on Saturday will bring a showery start for
the beginning of the weekend.

Temperatures will average a few degrees above normal...with highs
from around 70 degrees...to the lower and middle 80s Wednesday through
Friday. Saturday will be cooler with highs from the middle 60s to
around 809 degrees.

Nighttime lows will be in the middle 50s to upper 60s range just prior
to the cold front Tuesday night. Wednesday night lows will range
from around 50 degrees in the western Adirondacks...to near 60
degrees down the Hudson Valley. Then readings slowly bounce back...
with lows from mainly the lower and middle 50s in the mountains...to
the lower 60s down the Hudson Valley.

&&

Aviation /20z Saturday through Thursday/...
VFR conditions prevailing across the terminals this
afternoon...however an expansive area of stratus clouds is
noticeably creeping towards the area from PA/New Jersey into the Catskills
of New York...courtesy of low level moisture increasing with a south to
southwest flow. For now...most of the ceilings are in VFR range
although MVFR ceilings have been noted across some higher terrain
areas. Will mention scattered clouds early with ceilings developing later
this afternoon or early evening...from southwest to northeast
across the area. Ceilings expected to lower to MVFR range this
evening...especially later this evening as low level dewpoints
continue to rise. Overnight mainly MVFR conditions expected with
overcast ceilings and some mist. However...there is a chance of some
occasional IFR at kpsf but confidence not great enough to mention
in taf at this time.

Ceilings will only slowly rise on Sunday...but should still generally
remain in MVFR range through 18z Sunday. A cold front will
approach from the west bringing a threat of mainly afternoon
convection. Will mention vcsh in kgfl/kalb taf prior to 18z.

Winds will be southerly around 6-12 knots with some occasional higher
gusts. Wind speeds will decrease to around 3-8 knots after dark.
Winds will generally be south-southwest around 5-10 knots on Sunday.

Outlook...

Sunday night: moderate operational impact. Scattered rain showers...tsra.
Labor day: low operational impact. Isolated rain showers...tsra.
Monday night: low operational impact. Isolated rain showers...tsra.
Tuesday: moderate operational impact. Scattered rain showers...tsra.
Tuesday night: moderate operational impact. Scattered rain showers...tsra.
Wednesday: no operational impact. No sig weather.
Wednesday night: no operational impact. No sig weather.
Thursday: no operational impact. No sig weather.

&&

Fire weather...
late tonight into Sunday a slow moving cold front will bring a
round of showers and thunderstorms...some possibly with heavy
rainfall. Weak high pressure will build in Labor Day. It will be
very warm humid and mainly rain-free...but an additional
thunderstorm cannot be ruled out. Another cold front is
expected to bring a chance for showers and thunderstorms Tuesday
and Tuesday night.

Minimum relative humidity values should be between 65 to 75 percent Sunday ass
coverage of showers and thunderstorms increases. Minimum relative humidity values
Monday should be 55 to 65 percent. Maximum relative humidity values tonight and
tomorrow night are expected to be 80 to 100 percent with some dew
formation.

The surface wind be south to southwest at 15 miles per hour or less tonight
through Sunday night...then become west to southwest Monday.

&&

Hydrology...
showers and thunderstorms will develop late tonight and
especially Sunday into Sunday evening. Average basin rainfalls
look to generally be under an inch so at this point...main stream
rivers will generally see little or no rises.

However...with precipitable water values forecast to increase to 2 inches...any
thunderstorm could contain locally heavy rainfall easily exceeding
an inch. Any training thunderstorms could result localized ponding
of water in areas of poor drainage.

Additional thunderstorms on Labor Day look isolated and generally
not expected to produce additional Hydro problems.

More showers and thunderstorms are possible late Tuesday into
Wednesday as a stronger cold front arrives.



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...NAS
near term...NAS
short term...NAS
long term...elh
aviation...jpv
fire weather...NAS
hydrology...NAS

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