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Area forecast discussion 
National Weather Service Albany New York
408 am EDT Thursday Sep 18 2014

Synopsis...
a cold front will move across eastern New York and western New
England late tonight into tomorrow with only isolated to widely
scattered showers and a reinforcing shot of cool air. High pressure
will ridge in from southeastern Canada Thursday night into Friday
with unseasonably cold air for middle September with areas to
widespread frost north and west of the capital region. High
pressure will remain in control Friday into the first part of the
weekend with fair and dry weather.

&&

Near term /until 6 am this morning/...
as of 330 am...cold front is continuing to progress slowly east
southeastward into the region. Light rain showers are now
beginning to move southward from the northern Adirondacks into
portions of the central and western Adirondacks. Showers will be
light in intensity as they progress southward with weak forcing
along the cold front. With cloud cover moving in...temperatures
will hold steady in the middle 40s across the region.

&&

Short term /6 am this morning through Saturday night/...
as we go through the day today...influences of a large surface
high over southern Ontario will begin to move into the region
behind the passing cold front bringing tranquil weather into the
region with high temperatures on today remaining below average.

Thursday night...freeze warning headlines have been posted for the
Adirondacks along with frost advisory headlines for the Lake
George Saratoga region...Washington County and southern Vermont.
As the surface high pressure moves east across western Quebec in
conjunction with a eastward progressing upper level trough with
the axis over northern Maine...this will enhance northerly wind
flow over the area through the overnight hours leading up to 12z
Friday. H850 and h925 winds show cold air advection that will be further enhanced
down the lower Champlain Valley and northern Hudson Valley due
to the positioning of the two synoptic feature steering the
velocity of the wind flow. Winds will only be between 5 to 10
knots which is why frost is still possible in the headline areas
along the northern valley areas.

As we go from Friday into Saturday night...a large synoptic high
pressure will dominate our weather pattern. Latest 18/00z model
and probabilistic data show the center of a large surface high
pressure will move southeast out of Canada across our area and
toward the Atlantic coast by Saturday afternoon. As the
progression toward the eastern coastline is in progress....our
winds will shift to more of a southerly to southwesterly direction
which will allow temperatures to rebound toward average by the
time we head into the first half of the weekend. High temperatures
will range from the middle 50s to middle 60s on Friday. As we head into
Saturday...temperatures will range from the middle 60s in the high
terrain to lower and middle 70s in valley locations.

&&

Long term /Sunday through Wednesday/...
the end of this weekend will feature a sharpening of the trough
which will assist with a cold frontal passage during the day.
Showers will accompany the front as per collaboration...we will keep
probability of precipitation into the likely category. As for temperatures...with a strong
southerly wind and h850 temperatures into the lower teens...highs should be
rather mild with mainly 70s to around 80f in the middle Hudson Valley
and portions of northwest CT...mid-upr 60s for the dacks.

Frontal passage occurs during the evening as cold advection is
underway Sunday night. Those h850 temperatures are prognosticated to slip back
into the lower single digits heading into early Monday morning.
Shower activity will diminish greatly...however...deep cyclonic flow
will keep the small chance for isolated/slight chance probability of precipitation Sunday
night into Monday. Temperatures will settle back to below normal
with overnight lows ranging from 45-55f...and highs Monday from middle
50s across the dacks to upper 60s for the middle Hudson Valley and northwest
CT.

Monday night into Tuesday...latest global models suggest another
fast moving clipper type system will track across the St Lawrence
Valley and push another cold front across the region. Moisture will
be rather limited this go around so probability of precipitation will be restricted to only
slight chance.

Thereafter...large ridge of high pressure begins to evolve east of
the Mississippi River valley with h500 heights climbing toward
590dm. The European model (ecmwf) wants to sneak down a backdoor cold front late
Thursday but confidence is rather low at this time as we will keep
our weather dry. Temperatures will rebound and perhaps climb above
normal.

&&

Aviation /08z Thursday through Monday/...
a cold front located across southeast Canada will drift southward across
the taf sites later this afternoon. Some clouds will accompany its
passage...and may linger for several hours in its wake.

Through daybreak...areas of ground fog with IFR/LIFR conditions are
expected at kpsf. Elsewhere...although there is a possibility for
intermittent visibility reductions due to shallow ground fog
development...the potential is low enough to limit mention in
tafs...especially as middle level clouds increase across northern taf sites.

After daybreak...any fog/stratus should lift by 13z. VFR conditions
are then expected for the remainder of Thursday into Thursday
evening. There will be clouds moving through with bases in the
5000-7000 feet range above ground level...possibly lowering to 3500-4500 feet above ground level after
22z/Wed.

As for rain chances...there is a slight chance that a few sprinkles or
some drizzle could occur with or just behind the frontal passage at
kgfl/kalb...but overall probability too low to mention at this time.

Light/variable winds will trend into the northwest to north through
early afternoon at 5-10 knots...then shift into the north to northeast
as the front passage at 8-12 knots...with some gusts of up to 20-25 knots
possible later this afternoon into early tonight.



Outlook...

Friday night: no operational impact. No sig weather.
Saturday: low operational impact.Breezy no sig weather.
Saturday night: no operational impact. No sig weather.
Sunday: high operational impact. Chance of rain showers.
Sunday night: high operational impact. Likely rain showers.
Monday: low operational impact. Slight chance of rain showers.
Monday night: no operational impact. No sig weather.
Tuesday: no operational impact. No sig weather.



&&

Fire weather...
a cold front will move across eastern New York and western New
England early this morning with only isolated to widely
scattered showers and a reinforcing shot of cold air. High pressure
will ridge in from southeastern Canada Thursday night into Friday
with unseasonably cold air for middle September with areas to
widespread frost...north and west of the capital region.

Relative humidity values will range from 40 to 60 percent Thursday afternoon. The
relative humidity values will increase to 90 to 100 percent Friday morning with
frost and dew formation.

The winds will be light to calm tonight...and then increase from
the northwest to north at 5 to 15 miles per hour tomorrow...and the become
light to calm Thursday night.

The next chance for showers arrives for the latter half of the weekend.

&&

Hydrology...
no widespread Hydro problems are expected for the next 5 days
ending on Monday.

A cold front with limited moisture to work with...will produce a few
scattered hundredths over the Hydro service area late tonight into
tomorrow. High pressure will produce dry weather late Thursday
into Saturday.

A slow moving cold front may bring a chance of showers Sunday into
Monday with variable amounts of rainfall from the medium range guidance
at this time.

Rivers and streams will likely recede slightly over the next 5
days with limited rainfall expected.

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.

&&

Climate...
cold night expected for this Thursday night into Friday morning.

Here are some record low temperatures for September 19th...

Albany ny: 32 degrees in 1959 (records date back to 1874)
current forecast: 41

Glens Falls ny: 31 degrees in 1995 (records date back to 1949)
current forecast: 33

Poughkeepsie ny: 33 degrees in 1990 (records date back to 1949...
however data is missing from January 1993 - July 2000)
current forecast: 45

&&

Aly watches/warnings/advisories...
CT...none.
New York...frost advisory from 1 am to 8 am EDT Friday for nyz041-043-083-
084.
Freeze warning from 1 am to 8 am EDT Friday for nyz032-033-042.
Massachusetts...none.
Vermont...frost advisory from 1 am to 8 am EDT Friday for vtz013>015.

&&

$$
Synopsis...lfm
near term...lfm
short term...lfm
long term...bgm
aviation...kl
fire weather...lfm/bgm/wasula
hydrology...lfm/bgm/wasula
climate...National Weather Service staff

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