Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

Area forecast discussion 
National Weather Service Albany New York
1006 am EDT Tuesday Apr 28 2015

Synopsis...
an upper level low will move away from the region
today...allowing for a partly sunny sky with seasonable
temperatures and gusty winds. Even milder temperatures are
expected on Wednesday along with plenty of sunshine. More clouds
and a chance for rain showers will return later in the week.

&&

Near term /until 6 PM this evening/...
as of 1000 am EDT...skies have started out mostly sunny to sunny
across much of the region...but clouds are already filling in
across portions of the upper Hudson Valley...southern Vermont and
western Massachusetts. We expect clouds to mix in across most areas later
this morning into the afternoon...as convective temperatures are reached.
Overall cloud depth and upper level dynamics should remain less
than recent days...so have kept out mention of any showers at this
time.

The upper level low that has been impacting the region over the
past several days will finally be losing it/S influence on the
region/S weather...as it slowly drifts eastward today into the
western Atlantic Ocean. Still...our region will continue to be
dominated by northwest flow aloft on the backside of this
system...however...drier air working into the area from Canada
will allow for less clouds than recent days and no precipitation is
expected.

The combination of good daytime mixing and a strong pressure
gradient still in place will allow for gusty winds today...especially
during peak heating in the afternoon hours. North to northwest winds will gust 20
to 30-35 miles per hour...with the strongest gusts over the Catskills. See
our fire weather discussion below for how we anticipate these
winds to impact fire weather conditions.

With more sun than recent days...maximum temperatures look to reach the low
60s for valley areas...with 50s over the high terrain.

&&

Short term /6 PM this evening through Thursday night/...
with the upper level low finally far enough away...weak ridging
aloft and surface high pressure will build into the region for
tonight through Wednesday night. This will continue to allow for dry
weather with seasonable temperatures. Mins tonight and tomorrow night
look to be in the middle 30s to middle 40s. Maximum temperatures on Wednesday look
warmer than recent days due to warmer temperatures aloft and more
sunshine...with highs around 70 in valley areas...and upper 50s to
middle 60s for the high terrain.

A closed off shortwave trough will be moving from the Great Lakes
towards the middle Atlantic region for Thursday into Thursday night.
At the same time....sfc low pressure will be lifting from the Gulf
Coast towards the Carolina coastline. It appears that this upper
level energy will merge into the developing coastal system...but
this should happen too far south to have a major impact on our
weather. As a result...we will see increasing amounts of cloud
cover on Thursday...with most areas mostly cloudy for late Thursday
into Thursday night. Although the bulk of the steady rain will
remain to the south across the middle Atlantic...a shower or two
cannot be ruled out...especially for southern parts of the region from
late Thursday into Thursday night. At this point...any activity
looks fairly light and rather scattered in nature...and most
deterministic guidance as well as the recent runs of the
sref/gefs agree with this scenario as well.

&&

Long term /Friday through Monday/...
NCEP model suite along with international global model consensus
continues to favor the eventual development of the coastal storm off
the middle Atlantic coastline as the southern and northern streams
phase will remain too far south and east to have a direct impact to
our region. The upper trough axis and an inverted surface trough will
keep partly-mostly cloudy skies across the region with the slight
chance to chance probability of precipitation across the entire region during Friday.

As the coastal storm intensifies...subsidence around the western
periphery of this storm increases which will reduce shower potential
and likely additional breaks in the cloud coverage Friday night. As
we look into the first weekend of may...one last piece of energy is
expected to move across the region during Saturday. At this
time...the slightly better potential will be across the terrain
where we will mention a slight chance to chance probability of precipitation. There are
additional subtle hints for another weak disturbance aloft to assist
with touching off diurnally driven showers on Sunday. Yet The
Heights aloft will be increasing so we will withhold the mention of
showers for Sunday at this time.

Monday...the GFS is more aggressive with the approach a cold front
as opposed to the European model (ecmwf) with a large ridge axis along and just east
of the Continental U.S. Coastline. Per wpc guidance...the ridge may linger a
bit more so the potential remains for a rather mild day. A
strengthening south-southwest flow as h850 temperatures climb toward
+10c...lots of 70s for valley locations and maybe a 80f for the middle
Hudson Valley.

Overall...temperatures look to average near to above normal and
precipitation near to slightly below normal.

&&

Aviation /14z Tuesday through Saturday/...
skies have become mostly clear across the region with some few-scattered
VFR stratocu clouds moving through the region. As daytime heating
commences...so will the increase in diurnally driven clouds of which
it should remain in the VFR territory. Toward evening...there could
be a period of scattered-broken cumulus/SC of which it should remain within VFR
category.

Winds will be north/northeast around 7-12 kts early this morning
and increase to 10-15 kts with gusts of 20-25 kts by middle morning
once mixing commences. Those winds will decouple and diminish this
evening as the wind direction backs toward a more west-northwest.

Outlook...

Wednesday night: no operational impact. No sig weather.
Thursday: low operational impact. Slight chance of rain showers.
Thursday night: moderate operational impact. Chance of rain showers.
Friday: low operational impact. Slight chance of rain showers.
Friday night: slight chance of rain showers.
Saturday: no operational impact. No sig weather.

&&

Fire weather...
low relative humidity values and gusty winds expected this afternoon...

As an upper level storm moves away from the region...partial
sunshine is expected this afternoon with seasonable temperatures.
With good daytime mixing expected...relative humidity values will fall to 30 to
40 percent this afternoon along with northwest winds of 10 to 20 miles per hour.
Some gusts of 20 to 30 miles per hour are expected as well. After coordination
with state officials and neighboring offices...no fire weather
headlines are expected due to marginal meteorological conditions
and fuel moisture. However...localized fire weather issues are
possible due to the relatively low relative humidity values and gusty winds.

Relative humidity values should recover back to 80 to 100 percent tonight. Relative humidity
values will once again drop to 30 to 40 percent on Wednesday afternoon across
the entire region...but winds are expected to lighter...generally
northerly at 5 to 10 miles per hour.

Mainly dry weather is expected through the remainder of the
week...although there is a slight to low chance for rain showers
on Thursday into Friday.

&&

Hydrology...
no hydrologic concerns are anticipated at this time over the next
five days.

Dry weather is expected for today and tomorrow...with a
chance for rain showers returning late in the week. With a
coastal storm expected to rain south and east of the region...any
rain showers for Thursday into Friday should be fairly light and
scattered in nature. Dry weather should be in place for the
weekend.

As a result...rivers and streams will generally slowly recede or
hold steady through the week. Nohrsc analysis continues to show a
very limited snowpack in place over the southern Adirondacks and southern
Green Mountains...which will continue to melt away through the
upcoming week. However...the areal coverage of this snow pack is
rather small...so it/S impact on rivers and streams of the region
will be rather minor.

For details on specific area river and lakes...including observed
and forecast river stages and lake elevations...please visit the
advanced hydrologic prediction service /ahps/ graphs on our web-
site.

&&

Aly watches/warnings/advisories...
CT...none.
New York...none.
Massachusetts...none.
Vermont...none.

&&

$$
Synopsis...frugis
near term...kl/frugis
short term...frugis
long term...bgm
aviation...kl/bgm
fire weather...frugis
hydrology...frugis

National Weather Service Glossary of Abbreviations