Area Forecast Discussion
Issued by NWS Binghamton, NY-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
FXUS61 KBGM 192000
Area Forecast Discussion
National Weather Service Binghamton NY
300 PM EST Thu Jan 19 2017
-- Changed Discussion --High pressure overhead tonight will shift to the northeast and make
way for a weak warm front which will trigger a period of rain Friday
afternoon through Saturday morning. Mild temperatures under weak
high pressure late Saturday into Sunday expected before a coastal
low pressure system develops late Monday and Tuesday with widespread
rain or snow.
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.NEAR TERM /THROUGH FRIDAY NIGHT/...
-- Changed Discussion --Main concerns in the near term are centered around the continued
threat for drizzle this evening...areas of fog tonight and Friday
morning...and the onset of rain showers, south to north later in
the day Friday...continuing into Saturday morning.
High pressure at the surface and a high amplitude upper level ridge
axis across the region this afternoon has allowed for enough large
scale suppression to trap the low level moisture in place, and keep
the low clouds around longer than previously expected. There are a
few locations...in the Catskills and the Allegheny Mtns where cloud
cover is beginning to scatter out, but as the sun begins to set,
cool nwly flow continues and the low level inversion collapses, the
extent of the low clouds should persist into tonight. There is also
the threat for fog tonight as a fairly moist near-sfc layer combines
with a suppressive atmosphere, very light/calm winds and an
The ridge is expected to shift off to the ne Friday morning and
allow a return s/swly flow to develop. This flow will usher in a
slightly warmer air mass aloft...and may initially act to enhance
the inversion and presence of low clouds and patchy fog. However as
the deep layer forcing and moisture arrive ahead of an upper
trough/sfc warm front...most of the low clouds and fog should begin
to lift and mix out. Don`t expect any sunshine and dry weather
though. This next system will swing northward with WAA and weak
isentropic lift allowing a broad swath of rain to develop across PA
Friday afternoon and push nwd through central NY Friday evening and
night. The system will weaken through the overnight hours with much
of the heaviest rain occurring Friday afternoon/evening in ne PA and
into the srn tier of NY. At this time rainfall amts are expected to
range from quarter inch along the NY/PA border south...to a tenth of
an inch to the north. At this time it looks like the thermal
profiles will remain warm enough for all rain.
Temperatures will fall into the lower 30s tonight under the cloud
cover...and into the upper 20s where skies are not as cloudy. Highs
tomorrow will rise into the upper 30s and lower 40s. Will likely see
not much fluctuation of temperatures into Friday night with lows
only dropping into the mid 30s.
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.SHORT TERM /SATURDAY THROUGH SUNDAY/...
Fairly quiet weather through most of the short range period. Upper level
ridging will be dominant over the area however there will be
abundant low level moisture with stratus so not expecting much
sunshine. Temperatures will be quiet mild for this time of year
with highs in the 40s both days and lows Saturday night in the
30s. By Sunday afternoon, we do bring a chance of rain into NE PA
as well as the southern tier as a coastal low begins to approach.
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
The main story during this period will be large coastal low which
still has a good chance of impacting the area with rain/snow.
However still early to be confident in the forecast details.....
The big change with the 12z model cycle is that the GFS has trended
farther S/E with the coastal low allowing colder temperatures to
filter into the area faster from the NE. This is in line with the
trend we`ve also seen with the ECMWF and GEM Global models. That
said, the system is still several days out with the energy that
will initiate this system still over the Pacific so it is early to
have high forecast confidence. That said, in the bigger picture,
models in overall good agreement in tracking broad coastal low
from the SE States late Sunday northeastward to around the
Delmarva region by late Monday...bringing the storm`s precip
shield into the forecast area from south to north Sunday night
into Monday. At the same time, trend will be for colder air from
the NE to filter into the region which will also be aided by the
dynamic cooling from the system itself. This all said,
temperatures will still be be very marginal so in terms of the
gridded forecast, will forecast rain changing to mixed rain/snow
Sunday night into Monday with mostly snow by Monday night. If
colder trend continues, however, it is possible change to snow
could occur earlier. Also still early to be confident in liquid
precip amounts since CWA looks to be near the N/W edge of the
storm`s heaviest precip. However, potential still exists for
significant amounts. Best chance of seeing heaviest snow amounts
looks to over the Poconos and the Catskills.
Coastal system winds down to rain/snow showers by Tuesday as low moves
east of New England. There will likely be a brief break before a
weaker system brings a chance for rain/snow showers by later
Wednesday into Thursday. Temperatures generally remaining warmer
than normal for this time of year with highs in the 30s and a
narrow diurnal range in temps.
.AVIATION /20Z THURSDAY THROUGH TUESDAY/...
Shallow moisture remains trapped under a subsidence inversion this
afternoon...so IFR to MVFR ceilings continue. Expecting fuel
alternate ceilings and temporary IFR conditions tonight. There may
be patchy fog development tonight as well...with IFR to MVFR vsbys
possible. Light west to northwest winds become variable to near
Friday through early Saturday...Restrictions develop in rain
Friday afternoon-night followed by lingering lower ceilings into
Late Saturday through early Sunday...Mainly VFR.
Late Sunday through Monday...Restrictions in rain, possibly mixed
with snow at times.
Tuesday...Visibility restrictions likely in snow and blowing