Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Albany New York
139 PM EDT Friday Sep 19 2014
large Canadian high pressure will build across the northeast
corridor today. As this high slides off the New England coast...the
return southerly flow will increase this weekend and assist with
temperatures climbing above normal. A cold front will approach on
Sunday associated with a period of wet weather. This will signify
a return back to cooler temperatures for early next week.
Near term /through tonight/...
the forecast is on track. Stratus clouds eroded and have sunny
skies across forecast area thanks ridging over the region. Despite all
this sunshine temperatures will be below normal with 50s for the
higher terrain and lower 60s for valley locations. Only some minor
The surface high...1032mb..over the region will shift eastward
shifting offshore tonight. Its influence will keep our weather
quiet tonight under a mostly clear sky through at least the
evening and early nighttime period. Overnight some moisture seen
in the middle level relative humidity fields will increase with some stratus
redevelopment possible. Overnight lows will be a bit milder than
those observed this morning with mainly 40s expected.
Short term /Saturday through Sunday night/...
surface low pressure tracking along and just north of the
U.S./Canadian border along with middle level support per the water
vapor loop analysis this morning will begin to spread its
influence through the weekend. Meanwhile the surface high will
slide further offshore which will tighten the surface pressure
gradient. The result should be an increase in southerly wind
magnitudes...along with an increase in middle level moisture. NCEP
model suite is rather persistent with high relative humidity values between
h925-h850 layer. Furthermore...these models go further to show
some light quantitative precipitation forecast. A close examination of the bufr profiles suggest
this would be in the form of drizzle and/or very light rain
showers on Saturday. For now...we will keep probability of precipitation below the
thresholds on mentioning precipitation but later shifts will evaluate
this potential along with evolving upstream trends.
The best chance for wet weather arrives on Sunday with the cold
front. Per coordination from surrounding offices...we will
continue to expand the likely probability of precipitation for showers across the majority
of the region. The upper trough is forecast to sharpen up too
which will assist with cloud cover and overall shower coverage.
The one small entity to this forecast is the potential development
of a low across the southeast Continental U.S.. the National Hurricane Center
outlook is also monitoring this evolving area with latest
available guidance keeping this entity far enough offshore to
limit its impact to the region.
The cold front passes well east Sunday evening with cold advection
expected. This will assist with Lake Ontario contributions to
increase where we will keep chance-scattered probability of precipitation for the dacks and western
Mohawk Valley for rain showers. Also models differ with respect to
track and intensity of a short wave moving through the trough axis
with the NAM quite strong with this feature.
Temperatures will be rather mild this weekend with values at or
above climatology. A return back to at or below normal
temperatures are expected Sunday night.
Long term /Monday through Thursday/...
behind a surface cold front...an upper level shortwave trough will be
moving across the region on Monday. Although most of the moisture
will already be gone due to the passage of the cold front...there
may be a lingering shower or two...especially during the morning
hours...over the high terrain areas. With cool temperatures aloft due to
the passing of the upper level trough...temperatures will be below normal.
Highs will only be in the middle 50s to middle 60s across the
region...with a brisk westerly wind. Clouds should gradually break
for increasing amounts of sun throughout the day.
Another shortwave diving through the main upper level trough will
move across southern Canada for Monday night into Tuesday. Although
the bulk of the upper level dynamics will remain north of the
region...it may be close enough for an isolated shower across far
northern areas between Monday night and Tuesday. Otherwise...it will be
dry with a partly cloudy sky for the remainder of the area. Mins Monday
night will be in the middle 30s to middle 40s...and highs on Tuesday will
be in the upper 50s to upper 60s.
Through the remainder of the week...dry weather is expected...as a
large sprawling area of high pressure moves from the Great Lakes
towards the northeast. In addition to an extended period of dry
weather and mostly clear skies...this will allow for temperatures to slowly
warm through the week. Valley highs will generally be in the middle to
upper 60s...and overnight lows will be in the 40s...with some upper
30s across the outlying and high terrain areas.
Aviation /17z Friday through Tuesday/...
VFR conditions with mainly clear skies will persist into the this
evening with high pressure remaining in control. However...after
midnight low stratus clouds in MVFR range will likely advect
northward into the region as a return southerly flow develops around
high pressure shifting eastward off the New England coast. The
expected increasing clouds should preclude radiational fog
formation. However...if the clouds increase later than expected
there is a chance of some fog forming at kgfl/kpsf. Will only
mention VFR visibility at these sites for now...with higher confidence in
stratus clouds moving in before fog can develop. Ceilings should tend to
become broken by late Saturday morning or early afternoon...and
rising to VFR levels.
Winds through tonight will be light and variable...then shifting to
the south and increasing to around 10-15 knots on Saturday...with gusts
up to 25 knots possible at kalb.
Saturday night: no operational impact. No sig weather.
Sunday: high operational impact. Likely rain showers.
Sunday night: moderate operational impact. Chance of rain showers.
Monday through wednesday: no operational impact. No sig weather.
high pressure approaches from southeast Canada today. The center
of the high will settle across New England...with a return
southerly flow developing as this high moves off the New England
coast on Saturday. Increasing southerly flow will allow
temperatures to warm back to normal or above. Above normal
temperatures are then expected for Saturday night into
Sunday...ahead of a cold front approaching from the Great Lakes.
Relative humidity values will drop to minimum values of between
25 and 40 percent this afternoon. Maximum relative humidity values tonight are
expected to be around 90 to 100 percent.
Winds tonight will be northerly around 5 miles per hour or less that will
gradually shift from northeast to southeast at 5 to 10 miles per hour. Winds
tonight are expected to be south-southeast around 5 to 10 miles per hour.
no Hydro problems are anticipated through at least the next 5 days.
High pressure will influence our weather through Saturday with dry
conditions. The next chance of showers will be on Sunday...as a cold
front pushes through the area. Generally one quarter to one half
inch of rainfall are expected on Sunday...which will have little
to no impact on main Stem river levels.
Thereafter...it seems a rather prolonged period of dry weather is
expected for next week.
Dry conditions will return for Monday of next week.
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.