Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Albany New York
415 PM EDT Sat Aug 29 2015
high pressure will be over New York and New England
through most of the weekend with tranquil weather. A weak warm front
will spread some clouds in tonight into early Sunday and perhaps
trigger a stray shower or thunderstorm by Sunday afternoon.
Then...the humidity and heat will increase as we head into next week.
Near term /until 6 am Sunday morning/...
as of 415 PM EDT...another nice day around the region
although not as clear as previous days. There were some cumulus and cirrus.
However...based on satellite pictures and approximate trajectories...
thinking there was actually some smoke aloft from the massive Forest fires
across the northwest.
It will be interesting to see if this smoke has any bearing on
high/low temperatures on the days to come...but either way...its
effect will be minimal at best.
Otherwise...it will be dry through eveningwith any showers...
the result of a very weak short wave well to the north of Canadian/US border...
remaining mostly north of the region.
Temperatures will top out 75-80 Highlands...80-85 valleys (warmest in the
middle Hudson valley). Dewpoints have crept up a little compared to yesterday...
but generally were in the upper 50s...still on the comfortable side.
A few light showers might brush northern Herkimer County. (It should be noted
the latest hrrr actually indicated some showers working down the Mohawk Valley
later this evening). However...at this time...we are not buying this solution
since high pressure and subsidence remained overhead.
We do think there will be a generally increase in clouds this evening and
especially overnight...ahead of an advancing warm front. If this is the case...
overnight temperatures will be milder than last night...that is actually
how we sketched it out in our forecast package. Most areas will range from
the middle 50s to lower 60s tonight.
A south wind around 10 miles per hour...will become light and variable tonight.
Due to more clouds than perhaps previous anticipated we backed off a little
on our thinking of fog for tonight. For now...we confide it to the most
prevalent valleys and just call it patchy fog.
Short term /6 am Sunday morning through Monday night/...
high pressure will continue to "rule the roost" for at least the next several
days to come. Initially stronger at the surface...it will ultimately
strengthen aloft as well as offshore through early in the week.
A southerly flow of ultimately more humid air will overspread the
region. The leading edge of this more humid air...a warm front...
will advance to our region early Sunday and tend to wash out. Still...
this will leave some residual (mostly high clouds behind). Sunday could
start out rather cloudy with perhaps a sprinkle or two (not in the grids
at this time).
We think some sunshine will increase during Sunday afternoon but again
any smoke aloft could have a bearing on Hugh temperatures. Either way...
it will feel more humid by afternoon with dewpoints getting up into the
lower end of the 60s...except even higher across our southern zones.
With some sunshine anticipated we leaned with the warm mav
guidance giving US high temperatures lower to middle 80s in the valleys...75-80
While conditions will not be ideal for convection on Sunday afternoon...
there will be some instability...especially south of I-90
where sbcapes could reach 500 j/kg. Also there will be some
sort of boundary (dissipating warm front) to act as a focus for
convection. The above along with increasing low level moisture was
enough justification to re-introduce a 20 pop for showers/thunder on
Sunday afternoon. Middle level lapses rate look to remain meager at only
around 5.5 c/km) and the wind field weak so
no severe thunderstorms (or even strong for that matter) expected.
Sunday night should be clear to partly cloudy with lows from the middle 50s to the middle
60s...warmest in the capital region. Since there look to be less clouds and
little or no wind...fog might be a better bet. For now though we just kept pathcy fog
in the climatologically favored regions.
Monday looks very warm with a good deal of sunshine...scattered midday
and afternoon cumulus. H850 temperatures will be around +16c translating highs
into the 80s (upper 80s capital region southward in the valleys).
A light wind will become west to southwest 5-10 miles per hour.
Dry Monday night with lows generally in the 60s. The sky will average partly cloudy
with perhaps some valley fog (not in the grids at this time).
Long term /Tuesday through Saturday/...
a large upper level ridge will dominate the weather through most of
the extended period...allowing for above normal temperatures and
mainly dry weather.
The upper level ridge axis will be centered right through the
northeast for Tuesday into Wednesday. 850 hpa around 16-19 degrees c
will allow for daytime temperatures well into the 80s...with some low 90s
even possible for the Hudson Valley region. Overnight low will
mainly be in the 60s. Along with the warm temperatures...it will be
fairly muggy with dewpoints into the 60s. Dry weather should be in
place...although cannot rule out an afternoon shower for the
Adirondacks for Wednesday afternoon.
An upper level disturbance will slide across the top of the ridge
across eastern Canada for Thursday into Friday. This feature will
probably be too far away from our area to have a major impact...but
it could push a backdoor surface boundary close enough to the area from
the north or northeast to allow a stray shower or thunderstorm to
develop in the afternoon or evening hours. Otherwise...dry and very warm
weather will continue...with highs well into the 80s each day...and
overnight lows mainly in the 60s.
Warm temperatures will continue for the weekend as well...with temperatures
continuing well above normal. Will continue to forecast Valley High
temperatures in the middle to upper 80s for Sat with the upper level ridge
still in place over much of the central and eastern US...with no
precipitation expected to occur.
Aviation /20z Saturday through Thursday/...
ridging will remain across the region...however the center
of the high will gradually shift offshore into Sunday. In the
meantime...a short wave trough over the Great Lakes region
will move eastward and dampen out as it passes over eastern
Looking at VFR conditions...the exception will be at kpsf where
some fog is expected to form overnight and may lower to IFR for
a period late at night. Otherwise...much of diurnal cumulus should
dissipate this evening with high level cirrus clouds continuing
to stream overhead. Middle level clouds area are expected to move
in overnight. A ceiling of around 5k is expected for Sunday morning.
Light south to southwest winds will diminish becoming calm
overnight with a southwest to west flow developing Sunday.
However the flow should be more southerly at kgfl.
Sun night-Wednesday night: patchy fog late at night/early in the am.
Thu: low operational impact. Isolated rain showers...thunderstorms and rain
no significant rainfall expected through this week as a large high
pressure area...not only at the surface...but aloft...dominants
In fact...nothing more than a stray shower or thunderstorm
is expected with the best chances of that Sunday afternoon
and again Friday. Even this would be the exception than the rule.
Expect normal diurnal trends regarding the relative humidity...with full or nearly
full recovery expected each overnight. Daytime relative humidity values will be moderate
generally in the 40-60 percent range.
The wind each day will light and variable...mainly under 10 miles per hour.
no hydrologic issues are anticipated over the next five days.
No widespread rainfall is forecast to fall for at least the next
five days as a ridge of high pressure builds in.
River levels will continue to run at or below normal levels for
August...and if anything...might drop a little more.
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