Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Albany New York
710 PM EST Friday Dec 26 2014
high pressure over the southeast states will move off the
coast tonight into Saturday...as a cold front approaches from the
Great Lakes region for Saturday night and Sunday. This front will
bring some clouds for late Saturday into Sunday...along with some
rain showers for valleys...and rain or snow showers for higher
elevations. Fair weather...and more seasonable temperatures should
return by early next week.
Near term /until 6 am Saturday morning/...
as of 700 PM EST...with clear skies and light winds across all but
the far northern part of the forecast area...temperatures in some places
have already dropped to near or below the previously forecast lows
for tonight. Although clouds will move in again later tonight and
temperature drop will slow down or possibly reverse...will need to
lower overnight lows by 4 to 6 degrees across most of the region
based on current temperatures...and one or two degrees in far northern
Have also adjusted the sky cover grids to reflect current conditions.
the combination of clear skies this evening...and light to calm
wind...should allow temperatures to drop off rather quickly through
midnight. However...low clouds are expected to gradually redevelop
and slowly build back east and S across the southern Adirondacks
after midnight. The southern edge of these clouds are expected to
reach just north of Interstate 90 by daybreak...and into southern
Vermont/northwest Massachusetts. There is some possibility that the southern extent
reaches further south...as suggested by the latest NAM and rap13
h925 relative humidity fields...but for now...have the southern edge a bit
Once the lower clouds redevelop/expand across the southern
Adirondacks...there is a small possibility that some patchy
drizzle develops as the low level moisture interacts with the
higher terrain. Have indicated some slight chance probability of precipitation across the
western Adirondacks to account for this small possibility after
Forecast min temperatures are generally a blend of the mav/met MOS...with
upper 20s to lower 30s expected in most areas.
Short term /6 am Saturday morning through Monday night/...
Saturday...low clouds should initially remain mainly north of
Interstate 90 in the morning...with partly to mostly sunny skies
expected for areas mainly S and east of Albany. However...low level
warm advection may allow for the low clouds to expand further S
and east in the afternoon. So...the best chance for sunshine will be
in the morning hours...and mainly S and east of Albany...with clouds
more prevalent to the north and west of Albany. Right in the capital
region...it appears that some breaks of sun could occur in the
morning...before clouds become more dominant in the afternoon.
Despite the increasing clouds...little in the way of precipitation is
expected through around sunset...when some rain showers
may eventually develop/reach the western Adirondacks. Maximum temperatures
are expected to reach the middle 40s to around 50 from Albany and
points S and east...and mainly upper 30s to middle 40s to the north and west.
Sat nt-sun...a cold front will approach from the Great Lakes
region...and pass southeast across the forecast area Sunday morning. Some
light showers are expected to immediately precede and accompany
the frontal passage...with the best chance across the western
Adirondacks...and west facing upslope areas of southern Vermont and
western Massachusetts. Some snow may mix in across the western Adirondacks
toward and just after daybreak Sunday as colder air follows in the
wake of the front. Rain showers should shift south and east Sunday
morning...becoming confined to the southeast Catskills...middle Hudson
Valley...southern Berkshires and northwest CT by Sunday afternoon. Some
wet snow could occur across higher elevations of the southeast Catskills
and western Berkshires before showers end late Sunday. As for
temperatures...Sat nt should be rather mild due to increasing
clouds...low level warm advection...and also a developing
south/southwest wind. The mildest temperatures are expected within the
immediate Hudson River valley...where temperatures may remain above 40
through much of the night. Elsewhere...expect min temperatures to fall
into the Lower/Middle 30s...mainly due to wet bulb effects once rain
showers occur. Most min temperatures should remain above the freezing
mark. For Sunday...expect maximum temperatures in valleys to reach the
Lower/Middle 40s...and possibly 45-50 across the middle Hudson Valley.
Higher elevations will remain cooler...generally in the upper 30s
to lower 40s...with temperatures across higher elevations of the southern
Adirondacks and southern Vermont possibly falling in the afternoon
through the 30s.
Sunday night...there remains some possibility of a weak wave
developing along the southward moving cold front across the Middle
Atlantic States late sun nt into early Monday. This may allow some
light precipitation to expand back into portions of the middle Hudson Valley
and northwest CT sun nt. This is a very low probability...with most
current guidance suggesting any precipitation remain south of our region.
Have indicated some slight chance probability of precipitation across extreme southern areas
to account for this small possibility of precipitation...but again...at
this time...most sources of guidance suggest it remains to the
south. Temperatures for sun nt should fall into the 20s across most
areas...with some teens possible across portions of the southern
Adirondacks. Persistent high and middle level clouds may limit how
cold it gets despite cold advection...so have generally sided
closer to...or a bit above the slightly milder mav MOS.
Long term /Tuesday through Friday/...
after a long period of above normal temperatures...the long term period
will feature a return to normally cold temperatures and mainly dry weather
/exception to this will downwind of Lake Ontario with a return of
lake effect snow/.
Global models continue to trend toward a couple of shots with Arctic
air for the last few days of 2014. The first piece of this colder
air arrives Monday as a large high pressure...near 1050mb building
into Montana...extends its influence eastward across the Great Lakes
region and New England. H850 temperatures are prognosticated to drop back to
between -10c to -15c Monday into Tuesday. This will equal too
surface temperatures near seasonable normals.
The next shot of colder air arrives Wednesday as the h850 temperatures
drops back a few more degrees. This along with a near parallel flow
through the low-middle troposphere will favor lake effect snow
redeveloping downwind of Lake Ontario. We will keep probability of precipitation into
portions of the dacks through the middle week period with lake effect
snow showers. The remainder of the region will be mainly dry and
Overall...temperatures near normal and precipitation below normal
expected during this long term period of the forecast.
Aviation /00z Saturday through Wednesday/...
with high pressure generally in control across the region...
expect mainly VFR conditions at the kgfl/kalb/kpsf/kpou taf sites
through the taf period ending at 00z Sunday. Early in the taf period
mainly just scattered hi clouds are expected. Later tonight low level
moisture across northern New York and southern Canada will gradually
spread southward and a mainly VFR clouds deck will spread across the
the taf sites. At kgfl the cloud deck is most likely to be in the
MVFR range and have forecast MVFR ceilings after about 07z. At kalb/kpsf
the cloud deck should remain in the low VFR range. Kpou may remain
mainly clear or just get scattered clouds during the day Saturday.
Surface winds will be calm or light and variable tonight...then
south to southwest at 8 kts or less on Saturday.
Saturday night: no operational impact. Chance of rain showers.
Sunday: no operational impact. Chance of rain showers.
Sunday night: no operational impact. No sig weather.
Monday: no operational impact. No sig weather.
Monday night: no operational impact. No sig weather.
Tuesday: no operational impact. No sig weather.
Tuesday night: no operational impact. No sig weather.
Wednesday: no operational impact. No sig weather.
most river levels are now receding across the region.
A cold front is expected to bring some showers of mainly
rain for valleys...rain/snow across higher elevations...for Sat nt
into early Sunday. At this time...it appears that liquid equivalent
amts should remain under one quarter of an inch...therefore having
negligible effects on receding river levels.
Generally dry conditions...and colder temperatures...are expected
into at least early 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.