Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Albany New York
1007 am EDT sun may 3 2015
high pressure will continue to build off the middle Atlantic coast
through Monday...providing partly to mostly sunny conditions and
above normal temperatures. A cold front approaching from the eastern
Great Lakes region and Saint Lawrence valley Monday night into
Tuesday will bring scattered showers to the region.
Near term /until 6 PM this evening/...
as of 1000 am...have only made some minor adjustments to the
hourly sky cover and hourly temperatures grids to account for current
conditions. Have also made some adjustments to the maximum temperatures for
this afternoon. High temperatures for some of the higher terrain areas
appeared to be too high.
some patches of middle and high clouds still tracking through the
region and will probably be the case through the day. Still...even
with some periods of clouds...most areas are expected to be mostly
sunny... except some areas of high terrain could be partly sunny.
There should be enough sunshine to boost temperatures to the middle
to upper 70s in many areas...cooler in higher terrain. There could
be a sprinkle or isolated shower in higher terrain during the
afternoon...but quite isolated and not measurable...so not
carrying any showers in the forecast.
Short term /6 PM this evening through Tuesday night/...
gradually increasing warm advection tonight through Tuesday
night...with west to southwest boundary layer flow increasing
ahead of a cold front dropping down from the north. Highs
Monday...with some intervals of middle and high clouds...should be
solidly in the lower 80s...some middle 80s southern areas and around
80 northern areas. The west to southwest boundary layer flow could
aid in downsloping and better mixing...again supporting highs in
the 80s many areas Monday. Monday night...with the increasing
cloud cover and low level moisture could be rather balmy...with
lows in the middle to upper 50s in many areas.
The cold front that is approaching Monday night into Tuesday looks
to be quite displaced from any upper dynamics...and low level
jet forcing looks to be weak. The timing of the front is expected
late Monday night into Tuesday morning for most of the forecast
area...except the middle Hudson Valley to southern Berkshires and
northwest Connecticut. Because of the overnight timing and the
relatively weak dynamics and low level forcing...and lack of
instability...along with some potential downsloping...keeping
just scattered showers building south through the night...even
though some sources of guidance are suggesting more coverage than
As the cold front continues to build south through the day
Tuesday...the middle Hudson Valley and northwestern Connecticut may
see a period of slightly better instability ahead of the boundary
layer thermal and moisture gradient. Wording scattered showers and
and adding thunderstorms for those areas Tuesday afternoon.
There are suggestions in guidance that most of the cloud cover
could be confined to whatever showers and thunderstorms develop
and outside of the showers...there could be periods of sun
Tuesday. The cooling boundary layer temperatures and the thermal
gradient may support a bit more cloud cover...but still...most
areas north of the middle Hudson Valley and northwestern Connecticut
could see some breaks and some periods of sun Tuesday afternoon.
Winds are expected to be rather weak...so with the limited mixing
potential and the gradual cooling behind the cold front...highs
Tuesday in the 70s most areas...some upper 60s to around 70 in
The cooling is expected to be limited enough so that there are no
issues with frost or freezes expected Tuesday night into Wednesday
morning...with lows in the 40s to lower 50s...around 40 northern
Long term /Wednesday through Saturday/...
the early part of the period Wednesday into Thursday will feature
warm temperatures and dry conditions with surface high pressure in
control. The ridge axis aloft is forecast to remain to our
west...which will result in downstream subsidence providing plenty
of sunshine and maximum temperatures around 10 degrees above normal. Low level
moisture will still be lacking...so overnight mins may only be
slightly below normal.
Chances for precipitation will then gradually increase from Friday
into next weekend...as the upper level ridge first moves overhead
Friday then is forecast to flatten out with a surface frontal
boundary slowly approaching from the Great Lakes and southeast
Canada. This front will be the focus for the best chance of
measurable rainfall in quite some time. Since the GFS/European model (ecmwf) indicate
the front will still be north and west of the region on Friday will
only mention slight chance probability of precipitation...increasing to chance range by
Saturday as the front potentially gets closer. Will include mention
of thunder on Saturday as well...as models indicating instability
developing along with increasing low level moisture.
If the upper ridge does not end up breaking down as quickly as the
models are indicating at this time...dry weather could linger into
Temperatures should continue to be solidly above normal with the
mean ridge in the eastern Continental U.S.. slowly advecting low level moisture
will result in milder overnight lows compared to previous days as
Aviation /14z Sunday through Thursday/...
VFR conditions are expected to prevail at the kgfl/kalb/kpou/kpsf
taf sites through the 24 hour taf period ending at 12z Monday. A
ridge of high pressure will build in from the west across our
region today. Daytime heating will result in few-scattered cumulus in VFR
range developing again by late morning...dissipating after sunset.
Light and variable winds will become westerly around 5-7
kts...except at kgfl where southerly winds will prevail. Winds will
once again become light and variable after dark.
Monday night-tuesday: moderate operational impact. Scattered rain showers.
Tuesday night: low operational impact. Isolated rain showers.
Wednesday-Thursday night: no operational impact. No sig weather.
Friday: low operational impact. Slight chance of rain showers.
relative humidity values will lower to 20 to 30 percent today and Monday...
winds gusts may occasionally reach 25 miles per hour Monday afternoon...
Dry weather will hold through Monday with high pressure mainly in
control. It has been more than a week since our region has
received significant rainfall. No locations have reached a quarter
of an inch of rain in the past 5 days.
Relative humidity values should be in the 80-100 percent range tonight with some
dew formation. Relative humidity values Monday night are expected to be in the 60
to 90 percent range. The relative humidity values will lower to 20 to 30 percent
this afternoon and Monday afternoon.
The winds will be generally light from the southwest to northwest
at 15 miles per hour or less today. South to southwest winds at 15 miles per hour or
less are expected tonight. The winds will increase from the south
to southwest Monday at 1o to 20 miles per hour with some gusts to 25 to 30
miles per hour. The south to southwest winds should diminish Monday night to
15 miles per hour or less.
Coordination with fire weather users may be needed for Monday...
due to the expected low relative humidities and potentially gusty
The next chance for any rainfall is Monday night into Tuesday as
a cold front works through our region.
no hydrologic issues are anticipated over the next five days
It looks mainly dry through Monday which will allow rivers and
streams to lower further...especially from Albany southward as
vegetation is beginning to bloom. A few showers may reach the
Adirondacks Monday afternoon with light precipitation.
The next chance of showers will be Monday night into Tuesday with
a slow moving cold front. Most areas should see around a tenth of
an inch of rain. Some parts of the middle Hudson Valley and
northwestern Connecticut could see locally up to a quarter inch
of rain if scattered thunderstorms develop Tuesday.
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 web site.