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Area forecast discussion 
National Weather Service Albany New York
524 am EDT Friday Mar 27 2015

Synopsis...
slightly colder air will filter into the region today in the wake
of a cold front with some breaks of sunshine but also a chance of
rain and snow showers. An upper level disturbance is expected to
trigger scattered snow showers tonight into early Saturday with
the potential for minor accumulations. Even colder air will follow
to close out the weekend.

&&

Near term /until 6 PM this evening/...
as of 520 am EDT...precipitation continues to fall across southeast portion
of forecast area as low pressure wave number 2 moves northeast from the New
Jersey coast. Will continue with scattered showers across
southeast portion of forecast area with rainfall mainly on the light side.
Meanwhile the Arctic front to the north has moved into New York
state just south of Lake Ontario and continues to progress slowly
southeast. Expect more snow and rain showers to develop ahead of
this feature across the northern half of the forecast area in the next few
hours. As for temperatures they will slowly rise from current readings in
the upper 20s to upper 30s.

Today will feature a tale of two cold fronts. Cold front number
one has drifted just south of the forecast area with several waves of low
pressure rippling northeastward along the frontal boundary.
Meanwhile cold front number two which is an Arctic cold front is
situated just south of Lake Ontario dropping southeastward with a
wave of low pressure moving up the Saint Lawrence River valley.
These two frontal boundaries will combine to produce scattered
rain and snow showers throughout the day with mainly snow showers
across the higher terrain and a mixture of snow and rain showers
at lower elevations. Highs today will be even cooler than
yesterday by a few degrees ranging from the low to middle 30s
northwest with a few upper 20s across the western Adirondacks to
the middle 40s southeast. Any light snow accumulation generally an
inch or less will be confined mainly to the western Adirondacks.

&&

Short term /6 PM this evening through Sunday night/...
for tonight and Saturday an upper level positively tilted trough
withassociated vorticity maxes will be moving through the region
resulting in snow showers through Saturday morning. These
scattered snow showers are expected across the entire forecast area and most
locations should have a fresh dusting of snow on the ground by
Saturday morning. The snow should taper off by late Saturday
afternoon as the trough starts to pull away from the region.
Expect lows tonight to range from the upper single digits
northwest to middle 20s southeast with highs on Saturday in the middle
20s to middle 30s.

A large ridge of high high pressure will crest to our south over
the Tennessee Valley Saturday night into Sunday. The sky should
clear out but it will be a cold both Saturday night and Sunday.
Expect lows Saturday night to range from the single digits
northwest to middle teens southeast with highs on Sunday only in the
30s to lower 40s despite plenty of sunshine.

On Sunday night a clipper type system will be moving quickly east
into southeast Canada dragging a cold front into western New York.
Expect clouds to increase during the evening hours with snow
developing from west to east across the forecast area after midnight. Some
light snow accumulations are expected across the bulk of the forecast area by
late Sunday night ranging from a dusting to a few tenths of an
inch in the valleys up to 2 inches across the western Adirondacks.
Lows Sunday night will be in the 20s to around 30.

&&

Long term /Monday through Thursday/...
the extended forecast continues to have a mean long-wave trough
impacting the northeast with several disturbances in the northwest flow
bringing light precipitation events. It will be cooler than normal...and
some of these disturbances will likely bring some light snow to
parts of the forecast area as we leave March...and enter April.

Monday-Monday night...the first upper level trough digs S/southeast across
southeast Quebec and into upstate New York and northern New England in the morning.
Some weak isentropic lift ahead of the surface low will focus some snow
showers especially north and west of the capital region early
on...and then the boundary layer will warm enough for a mix of rain
and snow showers. The cold front will quickly follow in the late
afternoon and early evening. It will become brisk and cold. Highs
on Monday will be in the middle and u40s in the valleys...and u30s to l40s
over the higher elevations. Temperatures at h850 will fall to -10c to -12c
in the cold advection in the wake of the front Monday night. Lows will
fall into the 20s with a few l30s in the middle Hudson Valley...and a
few teens over the southern dacks. Any snow accumulations look light
with an inch or two over the southern dacks region.

Tuesday...the upper level trough axis moves downstream...and some
weak ridging from the south will nudge in. However...another middle-
level impulse in the northwest flow will be moving across the central Great
Lakes. Some weak warm advection ahead of this clipper type low will
bring a slight chance of showers west of the Hudson River valley prior
to sunset. Overall...should be a dry and cool day with highs in the
m30s to l40s north and west of the capital region...and middle and u40s
to the south and east.

Tuesday night into Wednesday...some disagreement on the track and
placement of the short-wave as it moves across or near the forecast
area. The GFS has it moving across west-central PA and New York...and bringing
some light rain to snow from roughly the I-90 corridor south. The
European model (ecmwf) has it a little further north by 06z/Wednesday moving just over NYC.
There is decent cyclonic vorticity advection with this disturbance
for a period of light snow or snow showers for most of the area.
Light snow accums of 1 to 4 inches may occur based on the European model (ecmwf)...as
the best qg lift occurs at night...and the column will be cooling
quickly. This is supported well by the cold low and middle-level
thicknesses. The light snow should end quickly during the
morning...with clearing skies and warming temperatures. April looks to
start with some accumulating snow everywhere...and it is not a joke.
Lows will range from the middle 20s to l30s from the Mohawk
Valley...Saratoga area south and east...and upper teens to l20s
north. Highs on Wednesday will rebound into the 40s most
locations...except the southern dacks and southern greens where middle and u30s
are likely. A few 50f reading may occur in the middle Hudson
Valley...as high pressure quickly builds in.

Wednesday night into Thursday...some weak ridging builds in late Wednesday into
Wednesday night...but the next system in the active middle level flow brings
some scattered rain and snow showers back into eastern New York and western New England
late Wednesday night into Thursday. An occluded front moves through during the
late morning and afternoon...as the surface wave moves north of the
region. Temperatures will still run a little below normal to close the
long term.

&&

Aviation /09z Friday through Tuesday/...
the cold front remains close enough to the eastern Seaboard that a
wave of low pressure moving along it this morning will bring some
showers into locations just south of the capital region. An upper
level low west of the region will keep clouds around throughout
the day and into tonight.

Flight conditions vary for kgfl/kalb/kpou/kpsf this morning with a
mixture of MVFR and IFR conditions north of kpou. Kgfl and kpsf
continue to have residual low level moisture with IFR visibilities at
kgfl...and IFR/low MVFR ceilings at kpsf. Kpou has risen to VFR
levels...but some showers may move back in between 06z-10z with
MVFR ceilings/visibilities returning. Kpsf will also continue to have
IFR/MVFR conditions prior to 12z. The trend for kalb/kgfl will be
for high MVFR/low VFR levels by 12z.

After 12z...expect VFR conditions for most of the sites with some
lingering high MVFR ceilings are kpsf. Some drier air will be
filtering in from aloft...but the upper low will remain upstream
and broken-overcast skies in the 3.5-5 kft above ground level range will be common. Some
snow showers may reach kgfl...as a weak surface trough approaches the
area late this afternoon and early this evening. Ceilings may lower
back to MVFR levels around 20z...and a vcsh group was used.

The winds will be light from the north to northwest at 7 kts or less this
morning. The winds will increase from north to northwest at 5-10 kts with a
few gusts to 15-20 kts at kalb/kpsf.

Outlook...
Friday night-saturday: moderate operational impact. Chance -shsn.
Saturday night-Sunday night: no operational impact. No sig weather.
Monday-Monday evening: moderate operational impact. Chance
-shsn/-shra.
Monday late night-tuesday: no operational impact. No sig weather.

&&

Fire weather...
slightly colder air will filter into the region today in the wake
of a cold front with some breaks of sunshine but also a chance of
rain and snow showers. An upper level disturbance is expected to
trigger scattered snow showers tonight into early Saturday with
the potential for minor accumulations. Even colder air will follow
to close out the weekend.

&&

Hydrology...
no Hydro issues are expected through the next 5 days.

Rainfall and liquid equivalent of snowfall which fell on Thursday
through the overnight generally ranged from a third of an inch to
three quarters of an inch with isolated amounts close to an inch.
No Hydro problems resulted from this rainfall despite some
snowmelt...due to the relatively cold temperatures which were in
place across the region.

For the next 5 days temperatures are expected to average below
normal with mainly above freezing during the day and below
freezing at night. Thus this will result in a gradual snowmelt
although we will be adding a little snow to the snowpack with
systems expected to impact the forecast area tonight into Saturday morning
and again Sunday night into Monday morning.

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...
CT...none.
New York...none.
Massachusetts...none.
Vermont...none.

&&

$$
Synopsis...hwjiv/11
near term...11
short term...11
long term...wasula
aviation...wasula
fire weather...hwjiv/11
hydrology...hwjiv/11

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