Area Forecast Discussion
Issued by NWS Binghamton, NY-- Highlight Changed Discussion --
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FXUS61 KBGM 221721
Area Forecast Discussion
National Weather Service Binghamton NY
1221 PM EST Wed Feb 22 2017
A southwest flow of mild air will be over our area into the
weekend. This will bnring temperatures well above normal for
February. Weak areas of low pressure will bring a low chance of
showers from time to time before a stronger system brings
widespread rain on the weekend.
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Updated at 1130 am. Scattered showers continue moving across
northeast Pa late this morning with mainly dry weather to the
north. Lots of breaks in the cloud cover have developed over the
Finger Lakes and these should work east across the rest of the
area later this afternoon. Temperatures are on track to reach the
50s in all areas. Previous discussion is below.
Updated at 9 am. Quick grid update to raise pops in northeast Pa
where a few showers have been moving across the area. Latest high
resolution guidance showing these showers moving off to the east
later this morning. Rainfall amounts will be a tenth of an inch or
less. Previous discussion below.
Weak little waves ripple along in the westerly flow while a
diffuse trof lingers in the area. This will bring low chance pops
to parts of the area today. HRRR shows the best chance for any
rain would be over the estrmem north...and over the southern third
pf the forecast area. Amounts will be quite light in any event.
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
Deep southwest flow aloft will keep the easterly movement of
surface features slow through the area. Frontal boundary running
from the mid Mississippi valley to the Great Lakes will creep
eastward as upper system race northeast in the upper flow. This
will keep a risk of showers at times...but more importantly keep
mild air over the forecast area through the short term. Expect
very little change in the weather through Thursday with the upper
ridge holding firm.
.LONG TERM /FRIDAY THROUGH TUESDAY/...
Southerly flow ahead of a strong midwestern low pressure center
will pull the +15C 925mb isotherm to the NY/PA border on Friday.
With a warm front to our north and a cold front approaching from
the Ohio Valley, mainly cloudy skies will be over our forecast
area with a few showers expected. Appreciable breaks of sunshine
would allow temperatures to make a run at 70 degrees, but this
seems unlikely. Even with the cloud cover most areas will reach
the lower 60s Friday afternoon.
A strong cold front will move through NY/PA on Saturday. Heavier
showers are expected along the front, including a slight risk for
a few thunderstorms in the abnormally warm/humid airmass. PWATs
are north of 1 inch, so we will need to watch for downpours in
heavy rain showers.
Much colder air filters down from Ontario Saturday night into
Sunday, changing rain showers over to snow showers. After wintry
temperatures return on Sunday and Monday, a temporary mild spell
is forecast ahead of another approaching cyclone, beginning on
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
Despite the light winds and scattered showers VFR conditions will
prevail over the region for much of the TAF period. Occasional
MVFR ceilings are possible in SYR and RME for the next few hours.
Conditions continue into Wednesday with little change with a weak
southwest surface flow and ridging aloft. Some MVFR ceilings are
possible aft 00Z as the sounding stabilizes and moisture gathers
below a weak inversion.
Thursday through Thursday night...Mainly VFR, except possible
spotty rain showers/brief restrictions Thursday onward.
Friday through Saturday...Restrictions from rainy frontal system.
Sunday...Possible restrictions from lake effect snow KSYR-KRME.
-- Changed Discussion --1215 PM UPDATE...
Significant warmup with increasing humidity still appears to be a
high confidence forecast as low pressure tracks to our west with a
deep southwest flow setting up. The melting of the remaining snow
pack therefore seems pretty likely. The upper reaches of the
Susquehanna and Delaware basins should lose generally 1 to 2
inches of SWE with some basins potentially higher. There may be
some limitation to a complete melting of the deepest snow cover
over N. Oneida county, but still expecting at least half of that
SWE will come out, which could easily be 3 inches.
This water alone is likely to push gauge monitored tributaries
and headwater rivers above their posted action/caution stages.
Additional rainfall would introduce the possibility for minor
flooding of the typical Spring melt season flood prone rivers and
streams. The Meteorological Model Ensemble Forecast System does
indicate a chance for minor flooding occurring at these more
sensitive forecast points along the Chenango, Tioughnioga and W.
Branch Delaware tributaries...as well as some of the most
sensitive locations on the main stem Susquehanna.
The chance for any flooding is highly dependent on forecast
rainfall, which in our opinion, may be overdone at this time as
the current track of the surface low would suggest that the warm
frontal rainfall on Friday-Friday night should be pretty light.
The trailing cold front expected on Saturday could make up for
that as it plows into an anomalous PWAT environment, but models
need some time to sort that out.
Bottom line is that the remaining melting snow will get flows
within striking distance of exceeding bankfull stages and any
properly located rainfall, in excess of about an inch, would get
a few of those more sensitive rivers to top flood stage. Official
forecasts show the river trends nicely, but are currently valid
only until 12Z Saturday. Crests would be later Saturday, or
Sunday. For now, we will remain conservative in our messaging
of this event, but our partners might want to dust off any flood
hazard and mitigation plans at this time.
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