Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

Area forecast discussion 
National Weather Service Albany New York
1005 PM EST Sat Nov 22 2014

a weak disturbance will bring a light wintry mix to the
region especially north of the capital region overnight...followed
by milder weather on Sunday. Sunday night...a stronger warm front
will push north with widespread rain. It will be followed by very
mild weather for a November Monday. A cold front will pass through
the northeast Monday night...with a return to fair and seasonable
weather midweek.


Near term /through Sunday/...
as of 1005 PM EST...the Winter Weather Advisory has been canceled for
Schoharie...Albany and western Rensselaer counties. Temperatures are in
the middle 30s to l40s...and the dewpoints have risen enough that the
predominant ptype will be plain rain. However...the advisory
continues for the Mohawk Valley...northern reaches of the capital
district...northern Berks northward into southern Vermont...the Lake George northern
Saratoga region...and the southern dacks until 5 am for sleet and
freezing rain.

Large surface T/dew point spreads continue with sleet/-fzra/-ra being
reported north of the region with plain a weak middle level
impulse focuses the light wintry mix across the region. The kalb 00z
sounding nicely shows the warm nose between 875 hpa and 775 hpa.
The weak isentropic lift will keep the spotty showers going to the
south of the advisory area until 09z-12z. The probability of precipitation and weather were
attempted to be retooled based on observations and a precipitation-
thickness tool. Lows tonight will be in the u20s to m30s and be
rising after 06z/sun. Any ice accretions will be light with a
coating to a stray tenth. Sleet accums will be a coating to a
couple of tenths in a few spots.

During the day on Sunday...mainly dry weather is expected. There
could be an early morning rain shower over the Adirondacks...
otherwise no precipitation is expected. It will remain fairly cloudy during
the morning hours...but there should be more breaks of sun as the
day GOES on thanks to building heights...especially in the afternoon. Warming
temperatures aloft and breaks of sun will allow for warmer temperatures than
recent days...with highs generally in the 40s for most
locations...with even a few readings near 50 in the middle Hudson


Short term /Sunday night through Tuesday night/...
the model suite (nam/GFS/Gem/ecmwf)is in good agreement during the
short term period. Sun nt large 500hpa trough in the Great Plains
triggers a major cyclogen event in the Great Lakes (i hear a 1972 Gordon
Lightfoot song). This intense storm lifts NE toward James
Bay...dragging a warm front and a period of steady rain through the region
sun nt...ending Monday morning. In its wake a 16 hpa SW surface wind
gradient is across fca...and very mild air is pumping NE into region.

Monday nt the systems trailing cold front and the 500hpa trough mv across
region. GFS brings this through around 00utc...with the others implying
a later to ovrnt frontal passage. Given the close to parallel nature of the
cold front to the 50hpa flow...forecast will go with the overnight
frontal passage...and rain showers with frontal passage. Given the dynamics...available moisture a
rumble or two of thunder cant be ruled out but cant exactly get
excited about mu cape of 200 j/kg at this time.

Afternoon Monday nt frontal passage...intense surface low races NE into qb..and fca is
mostly in the dry slot Tuesday as the last pieces of the 500hpa trough
pass across New York/new eng. Surface flow remains west-southwest much of the day. So
most of fca will see breezy fair return to seasonable temperatures. Lake
effect may begin into the west Adirondacks...with a better chance Tuesday
nt as the surface/h850 flow turns W-WNW.


Long term /Wednesday through Saturday/...
there is quite a bit of spread and uncertainty in the extended
portion of the coastal low may track close to the
coast Wednesday night through Thanksgiving. The mean upper level
trough keeps temperatures cold and below normal for the Holiday weekend
into early next week.

Wednesday...most of the medium range guidance has an h500 upper
level trough east of the MS River Valley with a strong low-level
baroclinic zone along the middle Atlantic coast...or just off the East
Coast. The GFS has low pressure forming east of the Carolinas and
moving north/NE out to sea with some light over running snow/snow
showers perhaps impacting extreme eastern New York and western New England in the
afternoon/early evening. The can ggem is even further east with the
storm evolution and track. The 12z European model (ecmwf) is the furthest west of
the envelope of solutions...and it would be phasing some northern and southern
stream upper level energy for a Miller type-a storm track from near
the Carolinas Wednesday PM to just southeast of the Delaware-Maryland-Virginia region by 00z/Thu.
This type of storm track and evolution would be a big problem for
the Wednesday PM travel into Thanksgiving day. Over running precipitation would be
spreading well north and west of the ongoing cyclogenesis into much
of upstate New York. For now...we have chance probability of precipitation from the capital district
east...and slight chance to the north and west with some light snow or
a mix of light snow/rain to the south. It should be noted most the
gefs members and its mean are either east of the 12z operational GFS
or are in agreement with it. The wpc track is close to the GFS and
the gefs mean. We will continue a mention of the storm in the severe weather potential statement
at this time. Highs on Wednesday will range from the u30s to l40s in the
valleys and u20s over the hills and mountains

Wednesday night into Thanksgiving...the exact track of the coastal or
oceanic cyclone is the big issue here. The European model (ecmwf) would have a major
storm with the cyclone deepening to 989 hpa just S/southeast of NYC at
06z/27 to 983 hpa just NE of kbos by 12z/27. The h850 circulation
would close off over upstate New York and New England during the day with
persistent snowfall. Again...the GFS is further to the east and out
to the Atlantic with the storm with a 992 hpa surface cyclone near Nova
Scotia by 12z/27. Some light snow is definitely possible Wednesday night
into Thursday on the northwest side of the cyclone with the middle and upper level
deformation zone. Stay tuned on this storm system over the next few
days. Lows Wednesday night will be in the m20s to l30s...and highs on Thursday
will range from the l30s to l40s in most locations.

Thanksgiving night into Friday...a cold front and an upper level
trough moves across the region with a reinforcing shot of cold
air...and a chance of snow showers Thursday night. Cold and brisk
conditions will be likely on the busy shopping day on Friday...some
westerly upslope/lake effect snow showers and flurries will be
possible for the western dacks...and southern greens during the day. Lows
will be mainly in the 20s with some teens over the southern dacks...southern
greens...and the eastern Catskills. Highs on Friday will be below normal
in the 20s over the mountains...and u20s to mainly m30s in the valleys.

Friday night into Saturday...surface high pressure will try to ridge in
from the Tennessee Valley with the cold weather persisting...but a short-wave
in the west/northwest flow aloft may trigger more isolated-scattered upslope snow
showers and flurries mainly north and west of the capital
district. Below normal temperatures will continue on the Holiday weekend.


Aviation /03z Sunday through Thursday/...
a weak thermal trough and an upper level disturbance will bring
some light mixed precipitation to eastern New York and western New England
overnight. High pressure will ridge back in from the south and
east tomorrow afternoon.

VFR conditions will lower to MVFR ceilings/visibilities in the mixed precipitation
of -ip/-fzra/-ra for kalb/kpsf/kgfl north and east. The ceilings may
briefly lower to high MVFR ceilings between 03z-08z/sun at kpou...but not
much precipitation is expected there. The best chance of a period of -fzrapl
is at kgfl and kpsf between 01z-08z/sun. The ceilings and visibilities will
lower to MVFR levels in the mixed precipitation. Kalb will have some -ra
around between 01z-05z with some MVFR ceilings visibilities.

Temperatures will climb well above freezing at kgfl/kpsf towards
daybreak...and expect all the taf sites to have VFR conditions
return in the late morning through the afternoon.

The winds will be from the south to southwest at 5-10 kts tonight
with some gusts in the 15-20 knots range at kalb and kpsf. Expect
southerly winds of 5-10 kts tomorrow in the late morning through
the afternoon.


Sunday night: high operational impact. Definite rain showers.
Monday: high operational impact. Likely rain showers...ra.
Monday night: moderate operational impact. Chance of rain showers.
Tuesday: no operational impact. No sig weather.
Tuesday night: no operational impact. No sig weather.
Wednesday: low operational impact. Slight chance of
Wednesday night: moderate operational impact. Chance of snow.
Thanksgiving day: low operational impact. Slight chance of


no significant hydrologic problems are expected over the next
several days.

A light wintry mix will impact the region...mainly for areas
north of Interstate 90...for late this afternoon into tonight.
Basin average liquid equivalent of precipitation will be a quarter of an
inch or less...which will have little effect on area rivers and
streams. Along with a milder air mass...a more widespread precipitation
event...this time in the form of liquid rainfall...will impact the
region Sunday night into Monday. Rainfall amounts will generally
be around a half inch or so...locally higher across the southeast
Catskills/middle Hudson Valley and northwest CT. This may allow for some
minor rises on rivers and streams...but no flooding is
anticipated. Behind this rain event...cooler and drier air will
move back into the region for much of the upcoming 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.


Aly watches/warnings/advisories...
New York...Winter Weather Advisory until 5 am EST Sunday for nyz032-033-
Massachusetts...Winter Weather Advisory until 5 am EST Sunday for maz001.
Vermont...Winter Weather Advisory until 5 am EST Sunday for vtz013>015.


near term...frugis/wasula
short term...Snyder
long term...wasula

National Weather Service Glossary of Abbreviations