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fxus61 kbgm 230017 
afdbgm

Area forecast discussion
National Weather Service Binghamton New York
717 PM EST Wed Feb 22 2017

Synopsis...
a southwest flow of warm air will bring well above normal
temperatures for the next several days. Weak areas of low
pressure will bring occasional chances for rain showers, before a
stronger system brings widespread rain and even a chance of
thunder Saturday. Temperatures will be cooler Sunday and Monday.

&&

Near term /through Thursday/...
7 PM update... we've retained the mention of a few sprinkles over
the twin tiers for another couple of hours this evening, perhaps
until 8 or 9 PM. Afterwards, the sprinkles should dissipate
completely.

The rest of the night we should see partly-mostly cloudy skies,
with some cloud debris occasionally traversing the region.
However, both recent satellite loops and the latest high
resolution moisture guidance from the models indicate that much
of the thicker cloud cover may stay over western and northern New York
overnight, and not make much inroads into the forecast area. If
this comes to fruition, we may have to make later adjustments to
go more on the partly cloudy side. Also, with less cloud cover,
may come a slightly better chance for patchy radiation fog towards
morning, especially with higher dew points creeping into the
area. We'll further evaluate the latest trends a bit later on
this evening.

Previous discussion... a small patch of showers will affect areas
near the New York/PA border west of I-81 through late this afternoon.
Otherwise, mild air will continue to work slowly into the area
from the southwest tonight. Dew points are still relatively low
over central New York and northeast PA, but dew points as high as
the lower 50s are not very far away, already reaching northeast
Ohio, southwest New York and northwest Pennsylvania. This moist air will
be pulled into our area ahead of a weak cold front on Thursday.
Increasingly moist air over cold ground will result in patchy fog
development late tonight along with areas of low clouds. Meanwhile
an area of low and mid- level clouds will be advecting toward the
area from the west- southwest. Putting this all together it looks
like a fairly cloudy and mild night setting up across the area
tonight with lows ranging from the upper 30s east of I-81 to the
upper 40s over the central Finger Lakes.

A weak cold front will limp southeast toward the area on Thursday
passing southeast of the area late Thursday / Thursday evening.
Ahead of the front temperatures will soar into the lower to mid
60s. Record highs tomorrow are 60 at bgm, 69 at avp and 68 at syr.
So at this point it looks like the record high at bgm will be in
serious jeopardy, but temps may stay just short of the records at
syr and avp. Scattered showers will probably develop along and
ahead of the weak cold front Thursday afternoon with the best
chance being over upstate New York.

&&

Short term /Thursday night through Saturday night/...
4 PM update...
unusual near-record warmth to continue, with main concern being
combined snowmelt and period of moderate rain on Saturday which
could lead to minor flood problems for some parts of the area.
Please read the hydrology section below for more specifics on this
potential. The Binghamton daily record highs will be within reach
Friday-Saturday whereas we ME fall a few degrees shy for Syracuse
and Avoca. Friday record high minimums are in the mid 40s-near 50,
and these may actually be approached as well. See climate section
below, for more details.

Deep southwest flow will prevent frontal boundary movements from
penetrating through the region until strong cold frontal passage
Saturday afternoon. This will keep very warm temperatures
persisting across the area during the short term period.

Shallow front will stall out over our area Thursday evening, and
then push northward as a warm front late Thursday night into
Friday ahead of the deep low pressure in the Midwest. The frontal
movement will be forced by an embedded shortwave passing through
which despite fairly stable low levels, will include some elevated
instability aloft; perhaps even a few hundred j/kg. So along with
likelihood of showers developing early Friday from Finger Lakes
across much of central New York, there could be a few rumbles of
thunder.

Friday afternoon through Saturday morning we will be deep within
anomalous warm sector resulting in mid 50s-mid 60s for highs and
then temperatures holding in the 50s all the following night into
Saturday itself. Dewpoints themselves will reach into the lower
50s which no doubt will feel strangely humid. Pressure gradient
will also greatly steepen Friday night-early Saturday ahead of the
main low. The elevated dewpoints and increasing southerly wind
will be quick to melt almost all remaining pockets of snow.

Strong cold front with ample forcing and right entrance region of
jet will combine to bring solid batch of showers and gusty winds
Saturday. Heavier showers are expected along the front, including
a slight risk for a few thunderstorms in the abnormally warm/humid
airmass. Though we are advertising an areal average of 4 to 8
tenths of an inch of rain, models depict a ribbon of precipitable
water in excess of an inch along the front. This is about three
Standard deviations above normal, and likewise for the southerly
magnitude of 850mb winds, so we will need to watch for downpours
and potential for localized rain amounts beyond an inch.

&&

Long term /Sunday through Wednesday/...
5 PM update...
strong upper wave will take on negative tilt while surging through
the region Saturday night, bringing abrupt and gusty cold air
advection while changing lingering rain showers over to snow
showers but with only nominal slushy accumulations mainly in
central New York.

Sunday through Monday will be a temporary return to chilly near
normal temperatures. Lake effect snow showers will occur in parts
of central New York. Also, while the 12z GFS model actually
depicts our area on the north side of a wave which would result in
an accumulating snow Monday, the European model (ecmwf) and gemglobal models do
not so for now we are only maintaining slight/low chance of snow.

Overall west-southwest flow will continue, and thus the cool air
will be unable to manage a longer stay. We get back into warmer-
than-normal temperatures into midweek along with rain again
becoming the primary precipitation type to accompany any systems.

&&

Aviation /00z Thursday through Monday/...
a period of IFR-fuel alternate required restrictions are quite
possible early Thursday morning, in patchy areas of lower clouds
and fog.

Otherwise, we're looking at the likelihood of VFR/unrestricted
conditions through the valid taf period. At this time, we're
expecting the mass of lower clouds across portions of western New York
and northwest PA this evening to stay removed from the kelm,
ksyr, kith, krme, kbgm, and kavp terminals. Also, light
showers/sprinkles near the PA/New York border could briefly impact kelm
and kbgm, but should be unrestricted in nature.

As far as winds are concerned, they should be light overnight and
early Thursday, generally 5 kt or less. Winds will pick up out of
the S-SW Thursday afternoon, increasing to 10-12 kt, with gusts of
20-25 kt. Winds may shift into the west-northwest late in the day at krme,
ksyr, and kith.

Outlook...

Thursday night...possible restrictions from lower ceilings,
especially cny.

Friday...mainly VFR.

Saturday...restrictions developing from a rainy frontal system.

Sunday...possible restrictions from lake effect snow showers at ksyr-
krme, with mainly VFR elsewhere.

Monday...possible restrictions in light rain or snow.

&&

Hydrology...
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 north. 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 West.
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 precipitable water 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.

&&

Climate...
the next few days will feature near-record warmth. Here are the
daily records to keep an eye on for our official climate sites.

Syracuse
daily record highs 67/1984 for 23rd, 65/1906 24th, 66/1957 25th.
Record high minimums 49/1930 23rd, 44/1985 24th, 43/1957 25th.

Binghamton
daily record highs 60/1985 for 23rd, 63/1984 24th, 58/1956 25th.
Record high minimums 44/1985 23rd, 51/1985 24th, 43/1961 25th.

Scranton (avoca)
daily record highs 69/1985 for 23rd, 71/1985 24th, 67/1930 25th.
Record high minimums 48/1985 23rd, 50/1985 24th, 46/1930 25th.

&&

Bgm watches/warnings/advisories...
PA...none.
New York...none.

&&

$$
Synopsis...mdp
near term...mlj/mse

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