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Area forecast discussion 
National Weather Service Binghamton New York
734 PM EST Monday Mar 2 2015

Synopsis...
high pressure will build in tonight giving US another clear and
cold night. A complex storm system will move into the Great Lakes
Tuesday and Wednesday and bring snow and mixed precipitation into
the forecast. The chance for precipitation will last through
Thursday night.

&&

Near term /through Tuesday/...
7 PM update... just cosmetic tweaks made to temperature/pop/wx grids this
evening...as the current forecast is in good shape.

Les is weakening at this time...as expected. As surface ridging slides in
overnight...residual -shsn/flurries should end altogether by 03-06z.
SC clouds should also have a tendency to sector out and contract
closer to the lake ont shoreline later this evening...leaving skies mainly
clear at that point.

The leading edge of higher level clouds...in advance of tmrw's
system...may begin to encroach on western/southern portions of the forecast area towards daybreak.

Previous disc... 300 PM EST update...
le showers are weakening as expected across the County Warning Area and are just
lingering across central New York. Expect for these showers to weaken
slowly and dissipate by midnight. At this time... temperatures are in the upper
20s and expect these to rise a few more degrees before sunset.
Temperatures are expected to fall shortly after sunset as surface high
pressure builds over the region... resulting in another cold
night with mostly clear skies.

Sky coverage will start to increase around 12z Tuesday morning as the
next storm system approaches.

The next storm will explained in detail in the section below.

&&

Short term /Tuesday night through Wednesday night/...
300 PM EST update...
a complex winter storm still expected to impact the County Warning Area starting
Tuesday afternoon...

Weak cyclogenesis will develop early Tuesday morning over eastern
Colorado and will track northeast across the Great Plains... then
towards the Great Lakes region... and eventually north into Quebec
late Tuesday night. This weak low... Aka.. Lake runner... will
create a complex event.

This event is still expected to be a mix precipitation event. Precipitation will
start to fall quickly after 18z Tuesday as the 700mb middle level warm
front lifts north across the region. Behind the front... strong warm air advection
will begin to take place... which will induce strong isentropic lift
over much of the region. This low... the lake runner... appears to
be fairly weak and the majority of the precipitation be generated due to
isentropic lift/overrunning. The low level jet will be above 60 knots... thus
there should be no problem for moisture to condense resulting in
precipitation.

This system will start out as snow... with surface temperatures below
freezing at the surface. Precipitation will then quickly transition over to a
wintry mix of freezing rain/sleet as temperatures aloft will warm
dramatically and temperatures near the surface remain below freezing. The
temperature of the airmass will continue to rise through the
overnight aloft and at the surface. Thus... the mix precipitation will start
to transition over to rain. There are still a lot of uncertainties
on how quickly temperatures near the surface will rise above freezing. Thus... a
wintry mix precipitation may linger through early Wednesday morning across
portions to central New York and northeast Pennsylvania. Winds
will be gusty behind the warm front and will remain gusty through
the overnight. Expect winds to range from 10 to 20 miles per hour with gusts
around 30mph.

The low's cold front will move across the area Wednesday morning... which
will help wind down what activity is lingering in the morning. This
front is more so like a boundary as it will have weak cold air advection. This
frontal passage may create additional problems Wednesday afternoon/evening as it
may become stationary over the southeast portions of the County Warning Area. This front
may help generate additional showers during that time frame.

Tuesday-12z Monday... 2 to 4 inches of snow possible... along with up
to a quarter of an inch of ice. If the boundary lingers over NE
PA... could see a few more inches of snow... but confidence is not
high at this time that this will occur.

&&

Long term /Thursday through Monday/...
Thursday...NAM continues to be slower with the frontal boundary
dropping south through PA/New Jersey as its upper level trough is sharper
than the other models. Leaned toward the more progressive model
solutions but will include high chance probability of precipitation across NE PA during the
morning hours. As for the les initially flow looks more north-northwest with
high chance probability of precipitation across much of The Finger lakes region and central
southern tier. By afternoon low level flow backs and the activity
may become better organized. Increased probability of precipitation to low likely during
the afternoon under 300 low level flow. Maximum temperatures will be well
below normal under cold air advection on back side of system, primarily teens.

Thursday night through Monday...
medium range models indicate the northeast will remain in a mean
upper level trough through the period although heights within this
trough are rising indicating airmass modification. Overall no
significant storms are anticipated just a few northern stream
systems moving through southern Canada.

Thursday night into Friday, lingering lake effect snow showers
over the northern County Warning Area will lift north through this period and weaken.
Rest of area will be dry with lows Thursday night around zero and
highs Friday in the lower to middle 20s. On Saturday and again on
Monday, overrunning may produce some snow showers across parts of
central New York which may mix with rain showers on Monday.
Rest of area will remain primarily dry. Temperatures may warm to seasonal
values by late next weekend into the early week.

&&

Aviation /01z Tuesday through Saturday/...
a weakening lake band is skirting krme early this evening, along
with blowing snow. High pressure will build in overnight, clearing
skies across all terminals and dropping the winds down to light
and variable.

A storm system will spread snow across the terminals from
southwest to northeast tomorrow between 17z and 21z. The snow
will change over to sleet or freezing at kelm around 22z.
Additional mixed precipitation is forecast across the terminals
tomorrow night. Low MVFR to IFR conditions will persist within the
mixed precipitation.

Outlook...

Late Tue-Wed...restrictions from snow to start late Tuesday...then a
wintry mix Tuesday night...to perhaps a period of rain showers by early Wednesday.

Wednesday night...restrictions possible across NE PA and southern tier of
New York state due to snow.

Thursday-Thursday night...restrictions possible from snow showers...mainly
cny terminals.

Friday through Saturday...primarily VFR.

&&

Bgm watches/warnings/advisories...
PA...Winter Weather Advisory from 3 PM Tuesday to 7 am EST
Wednesday for paz038>040-043-044-047-048-072.
New York...Winter Weather Advisory from 3 PM Tuesday to 7 am EST
Wednesday for nyz009-015>018-022>025-036-037-044>046-
055>057-062.

&&

$$
Synopsis...kah
near term...kah/mlj
short term...kah
long term...rrm
aviation...djp

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