Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Albany New York
428 PM EDT Tuesday Apr 28 2015
a weak ridge of high pressure in the middle levels of the atmosphere
will result in lots of sunshine and mild temperatures on Wednesday.
More clouds and a chance for rain showers will return later in the
week as another upper level low pressure system affects the region.
Near term /until 6 am Wednesday morning/...
as of 415 PM EDT...satellite pics show that clouds appear to have
already reached their diurnal peak across the region and have
begun to slowly decrease. The decrease in clouds will continue
into this evening...with clear to mainly clear skies expected most
of the night. Lows will be in the middle 3os to middle 40s.
Short term /6 am Wednesday morning through Thursday night/...
with the upper level low finally far enough away...weak ridging
aloft and surface high pressure will build into the region Wednesday
and Wednesday night. This will produce dry weather...plenty of
sunshine and above normal highs on Wednesday. Highs Wednesday will
be in the 60s to lower 70s. Lows Wednesday night in the upper 30s
to middle 40s.
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. Highs Thursday
will be in the upper 50s and 60s. Lows Thursday night in the upper
30s to middle 40s.
Long term /Friday through Tuesday/...
Friday through Sunday...latest 28/12z model trends are continuing to
trend further south some unsettled weather by an upper level low
pressure system as we head into the first half of the weekend.
Global models do differ in intensity of low pressure ranging from a
coastal low pressure well south of Long Island to an open upper
level wave producing low amounts of quantitative precipitation forecast. Probability of precipitation will be low and
isolated showers well south of the immediate capital region will
dissipate to tranquil weather conditions for the entire region as we
go from Saturday night through Sunday. Winds will shift from a
northerly wind Friday and Saturday to a more westerly wind as we go
into Sunday. This will allow temperatures to rebound nicely where
temperatures may be above average as we go into Sunday...especially
for valley locations.
Sunday night through Tuesday...as we go into early next
week...latest 12z data indicated a small amplitude upper level ridge
of high pressure will move into the region during the day on Monday
ahead of an approaching cold front moving across the Great Lakes
region. The exact timing of the cold front is not in agreement
between the models and probabilistic data. Although not mentioned in
the current forecast...a thunderstorm or two may be possible Tuesday
afternoon as the cold front will move through the region. We will
update the forecast as we get closer to this event date. With
numerical data showing a good southwesterly flow advecting h925
temperatures between 17c to 20c...high temperatures to start the week on
Monday and Tuesday will be well above average with high
temperatures ranging from the upper 60s in the high terrain to middle
and even a few upper 70s in valley locations...especially the middle
Aviation /20z Tuesday through Sunday/...
generally VFR conditions are expected over the next 24 hours...with
only some patchy clouds with bases of 4500-6000 feet above ground level expected at
Winds will be mainly from the north to northeast this afternoon at
speeds of 8-12 knots...with occasional gusts of 20-25 kts. Winds will
back slightly after sunset into the northwest...and decrease to 5-10 knots.
Shortly after sunrise on Wednesday...expect mainly west to northwest winds at
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.
Saturday night: no operational impact. No sig weather.
Sunday: no operational impact. No sig weather.
Relative humidity values will recover to between 80 and 100 percent
tonight...then drop to between 30 and 40 percent Wednesday
afternoon across the entire region...but winds are expected to
lighter...generally from the north 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.
no hydrologic concerns are anticipated at this time over the next
Dry weather is expected through Wednesday...with a chance of light
rain showers returning late in the week as a coastal storm passes
out to sea well to the south of the region. Any rain showers Thursday
into Friday will be fairly light and scattered in nature. Dry
weather will return 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-