Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Albany New York
531 am EDT Friday Oct 31 2014
a small high pressure system will produce dry and seasonably cool
weather across the region today. A potent system working over the
Great Lakes will dive to our south tonight and phase with another
disturbance offshore. The net result of this will be only light
precipitation in the form of rain showers...turning to snow
showers...mainly across the higher elevations. A powerful storm
offshore will drive the coldest airmass of the season over US by
Sunday along with gusty winds.
Near term /until 6 PM this evening/...
as of 530 am EDT...areas of low clouds and even some patchy fog have
developed. Temperatures range from the upper 20s to middle 30s with
little or no wind.
Through sunrise...temperatures will likely not fall all that much
more...with lows ranging from the middle 30s to middle 20s over the
remainder of the region. The wind will be light.
Filtered sunshine will start the day out today...with a general
increase in cloudiness...except mostly cloudy across southern
The h20 water loop depicted two disturbance to our south and west
respectively. The one to our south was generating thunderstorms off
the South Carolina coast. Meanwhile the strong one was ironically
lighter precipitation in the form of showers across Michigan. The
second storm had much less moisture to work with.
The impulse to our south will move northeast and away from our
region. The other disturbance will move to our south. A weak area of
ascent will develop by late in the day...but due to a dry atmosphere
very little if any shower activity is expected today.
Due to the cloud cover and limited mixing...temperatures will run a
shade cooler than normal. Look for highs 50-55 in the
valleys...45-50 higher terrain.
The wind will be light mainly out of the south under 10 miles per hour.
Short term /6 PM this evening through Sunday night/...
the aforementioned strong upper level disturbance will dive further
southeast tonight and eventually phase with the aforementioned
system offshore. The deep moisture (with precipitable waters over an inch) looks
to remain well offshore. Confidence in this scenario is increasing
as the 00z European/Canadian and the GFS (and its all ensemble
members) indicate a similar scenario keeping the ocean storm and
most of its precipitation to our east.
What this will mean for US in only scattered light showers
tonight...but even most of these should hold off late enough to not
impact all the trick or treaters. It might be marginally cold enough
for a snow flakes in the Adirondack but any accumulations should be
extremely minor at the freezing level looks to remain above 3000
feet and the precipitation light.
Saturday...as phasing commences well to our southeast...it will
remain overcast with perhaps a few additional showers. Again these
will be light and in most cases...rain...with any snow showers
confined to the highest terrain.
By Saturday night...a powerful ocean storm will be off Cape Cod. It
looks as if its heavy bands of precipitation (both the warm and cold
conveyor belts and associated banding) will stay to our east. Light
precipitation on its outer edge will skim mainly our eastern
terrain...but a few of these could work into the Hudson Valley and
points east. By this time...h850 temperatures will dip well below
zero everywhere and freezing levels will eventually close to the
ground. Therefore...most of what fall Saturday night should be
snow...but there will not be much of it. A coating to a couple of
inches is possible (but not certain) over mainly the higher terrain.
While a dusting cannot be ruled even on the valley floors...it
Temperatures will dip into into the lower to middle 30s in the
valleys...20s higher terrain. A gusty wind up to 30 miles per hour will add to
Sunday...any lingering snow showers...mainly over the higher
terrain...look to be gone by afternoon. In fact...clouds look to
give way to increasing sunshine. Nevertheless it will be a downright
cold and windy day with highs no better than middle or upper 40s in the
valleys...middle 30s to lower 40s higher terrain. With good
mixing...northwest wind gusts could reach 30-35 miles per hour over the higher
terrain...Mohawk Valley and capital region.
The wind will slowly abate Sunday night as high pressure builds
south of region...but not completely. Assuming the sky remains
mostly clear (which we think it will) temperatures look to dive into
the 20s across most areas...upper 20s valleys and lower to middle 20s
over the higher terrain.
Long term /Monday through Thursday/...
a quiet start to the long term period as high pressure at the
surface and upper level ridging take control of our weather these
two days. A weak warm front passing well to the north and west of
the forecast area may produce an isolated shower on Tuesday across
the western Adirondacks. Mainly clear skies expected Monday and
Monday night...with a slow increase in clouds on Tuesday. After a
chilly start in the 20s...highs Monday will generally be in the 40s
to lower 50s. Lows Monday night in the upper 20s to middle 30s. Highs
Tuesday in the upper 40s and 50s.
A cold front will approach the region Tuesday night...and move
through on Wednesday. Models indicate a lot of the precipitation associated
with this front will be Post-frontal. Have forecast probability of precipitation to increase
by Wednesday to slight chance over the southeast zones...ranging up
to 40 percent over the northwest.
The front will wash out after it moves to the south of the Albany
forecast area Wednesday night. However...a strong upper level trough
will drop southeast across the Great Lakes...along with a weak
surface low...and move across the region late Wednesday night and
Thursday. As a result...have forecast the chance of showers to
increase to 35 to 40 percent in all areas by late Wednesday
night...and to 40 to 50 percent on Thursday. There are some models
differences with this system. The GFS has a much stronger trough and
much better chance of precipitation. The European model (ecmwf) trough is fairly weak and only
shows scattered precipitation.
It will remain mild across the region Tuesday night through
Thursday. Lows Tuesday night will be 35 to 45. Highs Wednesday in
the upper 40s to near 60. Lows Wednesday night in the upper 30s to
middle 40s. Highs Thursday in the upper 40s and 50s.
Aviation /10z Friday through Tuesday/...
mainly VFR conditions will persist across the kalb/kgfl/kpou/kpsf
taf sites through the end of the taf period ending at 06z Saturday.
The exception will be the possibility of MVFR fog conditions at
kgfl/kpsf for a few hours early this morning. Otherwise...mainly
clear skies to start the taf period will give way to increasing
clouds on Friday...with mainly a broken/overcast deck of 4000 to 5000 feet
across the region most of Friday and Friday night.
Winds will be calm or light and variable through a couple of hours
after sunrise...then easterly at 5 kts or less thereafter.
late Friday night: moderate operational impact. Chance of rain showers.
Saturday: moderate operational impact. Chance of rain showers.
Saturday night: low operational impact. Slight chance of rain showers.
Sunday: low operational impact. Windy.
Sunday night: no operational impact. No sig weather.
Monday: no operational impact. No sig weather.
Tuesday: no operational impact. No sig weather.
no significant fire weather issues are expected through Saturday. Relative humidity
values will generally around or greater than 50 percent...especially
at night when values will 75-90 percent.
Today will start with filtered sunshine followed by increasing
clouds. It should remain dry. Scattered showers mainly late tonight
through early Saturday night with lots of clouds. Some of these will
be in the form of snow showers...especially Saturday night. Any real
accumulations will be limited to the higher terrain where up to a
couple of inches could collect in a few spots.
The wind will light and variable today and tonight. The wind will
turn north to northwesterly and increase to 10-20 miles per hour late Saturday
night with gusts to 30 miles per hour.
On Sunday...sunshine returns but it will be windy and cold with
gusts out of the northwest 30 miles per hour or higher. It will be cold that
day as well. Relative humidity values will drop into the 30s valleys...and 40s
Dry weather will hold into early next week with moderating
no widespread hydrologic concerns over the next five days.
Mainly dry weather is expected today..before an upper level
shortwave trough produces some scattered rain and snow showers
Friday night and Saturday and Saturday night.
Any precipitation over the next few days will be light...and basin
average amounts will generally be a tenth of an inch or less through
early Sunday. Some of the precipitation will actually fall as light
Dry weather Sunday will continue into early next week with no big
precipitation makers in sight.
River levels will hold steady or slowly fall through the weekend.
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.