Scientific Forecaster Discussion
fxus61 kbgm 202303
Area forecast discussion
National Weather Service Binghamton New York
703 PM EDT Tue Mar 20 2018
clouds are increasing over the area this evening. A coastal
storm will impact the region starting late tonight bringing
several inches of snow to parts of northeast Pennsylvania and
Sullivan County in New York state. The rest of the area will
remain cloudy and cold with scattered flurries or a few snow
showers through Friday.
Near term /through Wednesday night/...
400 PM update...
Clouds are increasing from south to north across the forecast
area this afternoon. Temperatures are cold, mainly in the 30s
at this time. Thus far any snow has remained south of our
area...from about State College to Allentown PA as of 3 PM.
Moisture will continue to spread north in response to two low
pressure systems; one over the Ohio Valley and one off the
Carolina coast. Very dry air and large dew point depressions
over our area will keep the snow at Bay for most locations
through the evening hours...however a few flurries or light snow
is possible down toward Hazleton.
Later tonight, additional energy will phase into the system over
the Ohio Valley, developing a closed mid/upper level low near
Louisville Kentucky. At the same time, another surface low will begin
to develop off the Virginia coast. Snow will gradually spread
north, first into southern Luzerne County after 12-3 am,
reaching Scranton and the I-84 corridor around or just before
daybreak. The northward progress of the snow will be halted by
very dry air feeding into the area on brisk north winds. The
snow should eventually reach far southern Susquehanna County,
central Wayne County, and Sullivan County New York after 8am
Wednesday. Bands of snow will continue to rotate around the
strengthening low pressure system through the day on Wednesday.
Snow is not expected to make it north of the New York/PA border,
extending east to far northern Sullivan County. As has been
advertised over the past few days, there will be a very sharp
line between accumulating snow and no snow at all.
The low is progged to reach 990mb just east of Ocean City Maryland
Wednesday afternoon, as it becomes captured by the mid and upper
level circulation. The steadiest/heaviest snow will just scrape
the far southern/eastern portion of our County Warning Area...in southern
Luzerne and Pike counties. Upgraded the previous Winter Storm
Watch to a Winter Weather Advisory for Luzerne, Pike,
Lackawanna, S. Wayne and Sullivan (ny) counties. Used a blend of
the latest NAM, CMC-reg, GFS, ec and wpc guidance for quantitative precipitation forecast and
snow amounts...as guidance was in generally good agreement, but
had subtle differences. Snow totals will be greatest over the
far southern parts of these counties and over the higher
elevations. Snow amounts will vary greatly over small distances
within the advisory counties. The highest amounts and therefore
the best confidence was for Luzerne and Pike counties, where 3-5
inches, with local amounts up to 7 inches are expected.
Scranton and Honesdale are forecast to only get 1-3 inches...but
there will be higher amounts over the eastern/southern parts of
these counties...over the Pocono plateau...where 3-5 inches are
expected. This was a lower confidence forecast for Sullivan
County NY, as this area looks to be right on the far northern
edge of the system. Advisory level amounts will likely be
confined to locations south and east of Monticello...with
northern portions of Sullivan County only receiving 1-3 inches
Snowfall rates will not be particularly heavy in our area with
this system...although its possible that parts of the Poconos,
especially in Pike County see rates up to 1" per hour for a time
on Wednesday. Otherwise rates will mainly be 1/2" per hour or
less in the advisory area. Snow may also have a difficult time
accumulating on paved surfaces during the day on Wednesday,
again, mainly because rates are not expected to be all that
heavy. Temperatures will hold in the 30s through the day
Wednesday, falling into the 20s Wednesday evening and night.
North winds of 10-20 mph, with a few gusts up to 30 mph are
expected over the higher terrain...and this could cause some
localized blowing/drifting snow...mainly in the Poconos.
Outside of the advisory area, some light snow or flurries will
be possible across the northern tier of PA from Bradford,
Wyoming, Susquehanna and northern Wayne counties. Any snow
amounts are expected to be mainly less than 1 inch here. Across
central New York (except Sullivan county) expect cloudy skies with
just a few flurries and minimal to no accumulation through the
near term period.
The low exits to the east Wednesday evening, and the snow should
also pull east, tapering off and ending by midnight across our
eastern zones. There could be a few left over flurries in The
Finger lakes/central New York as the cold north flow moves over Lake
Ontario. Overnight lows in the 20s, with breezy northwest winds
Short term /Thursday through Friday night/...
a few mid-level shortwaves along with a upper level low will
pass through the region during this time period. While moisture
looks fairly limited, enough moisture coupled with the
northwest flow may provide an increase in clouds with some
flurries. The best chance for anything more than flurries would
be Friday afternoon as lapse rates steepen some to provide an
BUFKIT analysis also shows the potential for some
strong northwest wind gusts as well on Thursday in the 20-25 mph
range. Met/mav guidance was incorporated in this timeframe
though the blend looked about 1-2f too warm given the northwest
flow with highs.
Long term /Saturday through Tuesday/...
Our region will be in between a low pressure system tracking
through the Ohio Valley and a high pressure system moving across
Hudson Bay. Modeling over the past couple of days has trended
toward more influence from the high pressure system keeping any
significant influence from the Ohio Valley low pressure system
south of the region this weekend. For now, will continue with
low or slight chances of precipitation on Sunday. Modeled
925/850 mb temps will slowly begin to modify giving an
indication of a slow warming trend. Highs should be in the 30's
and low 40's with temperatures starting out each day around 20
for most of the region.
Monday through tuesday:
The high pressure system will move offshore allowing for a
warmer southerly flow to become dominant. A gradual warming
trend will continue. Nudged temperatures above model consensus
as well given the degree of warm air advection and the potential
for more in the way of sunshine. Highs both days should be well
into the 40's for most places after starting out in the 20's
for most locations. The next cold front should hold off till
Aviation /00z Wednesday through Sunday/...
VFR conditions this evening and most of the overnight hours with
MVFR cigs and IFR vsbys in snow developing in and around kavp
after 12z Wed morning. May see several hours of fuel alternate
required cigs and IFR vsbys in slightly heavier snow before the
snow tapers off between 21-00z. All other terminals in central
New York should remain VFR with only a high cloud deck filling in
through the day Wednesday.
East to northeast winds at 5 to 10 kts this evening becoming
north to northeast tonight, then continuing into Wednesday with
a few gusts to around 20 kt from kelm and kbgm south to kavp in
Wednesday evening...improving conditions at kavp; New York terminals
Late Wednesday night through Thursday...minor ceiling
restrictions and perhaps a stray flurry possible from cool northwest
flow off of the Great Lakes, mainly New York terminals.
Thursday night through Sunday...mainly VFR.
PA...Winter Weather Advisory from 5 am Wednesday to midnight EDT
Wednesday night for paz044-047-048-072.
New York...Winter Weather Advisory from 7 am Wednesday to midnight EDT
Wednesday night for nyz062.