NWS Forecast Discussion

000
FXUS61 KBGM 212249
AFDBGM

Area Forecast Discussion
National Weather Service Binghamton NY
649 PM EDT Tue Aug 21 2018

.SYNOPSIS...
A low pressure system will drag a cold front through the area
tonight bringing showers and isolated thunderstorms. A few
showers will linger into Wednesday, then a large high pressure
will build into the area and bring dry weather into the
weekend.

&&

.NEAR TERM /THROUGH WEDNESDAY/...

A Warm front aloft is moving through the region. Upward motion
associated with the upper jet structure passes west of the area
so the showers are tending to weaken as they move east into the
more stable air and deepening marine layer. So, expect fairly
widespread showers this evening into the overnight, with mainly
light to moderate rain. A rumble of thunder can not be ruled
out. However, showers and thunderstorms heading toward our
region from the southwest this evening are decaying as they
enter a very stable environment. The early evening update took
into account a more concentrated window for shower chances from
the mid evening to the early morning hours and did increase QPF
slightly in the Poconos where a batch of moderate showers is
heading for.

Our forecast area may briefly get into the surface warm sector
as the appears to be a surface wind shift just ahead of the
front. But being at the diurnal minimum for convection and
especially severe weather, the threat seems to be minimal for
severe storms. There is some low level shear, and capes briefly
hit around 500 j/kg so cells will need to be watched. Model
radar depiction is not all that impressive so again it may not
be a big deal at all. In any case, timing brings the front
through the eastern zones by about 12Z.

Northwest surface flow under the upper trough will result in
unsettled weather for Wednesday with scattered light showers.
Thunder cannot be ruled out but it should be very isolated.

&&

.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY NIGHT/...
215 PM update...

The models agree on a much-needed clearing pattern. A surface
high pressure system will expand out of the Ohio Valley while an
elevated trough slides off the east coast.

The presence of the trough will keep temperatures on the cool
side for Thursday, with highs only in the lower to middle-70s.
Weak ridging aloft will push temperatures to between 75 and 80
degrees Friday.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
220 PM Update...

A low pressure system moving through Ontario will bring the
chance for an afternoon or evening thunderstorm across our far
western forecast area on Saturday.

By Sunday, NY and PA will be firmly in the warm sector with
westerly flow aloft. While a chance exists for thunderstorms on
Sunday, we are sticking to chance POPs due to most of the
forcing remaining well north of the NY border. The presence of
the westerlies suggests any storms which form will produce
gusty winds rather than downpours.

Very little change is expected on Monday. The cyclone will
continue to spin over Ontario and Quebec as an anticyclone
pushes westward from the Atlantic into the Carolinas.

&&

.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
Marine layer has overrun the area bringing MVFR ceilings to many
of the stations. Showers are breaking out as well, ahead of a
warm front moving through aloft. Spotty MVFR ceilings and
visibilities are expected into the evening. Winds will begins
to come around to the west toward morning as the surface warm
front and cold from come through back to back. Expect more
showers with the fronts. Isolated thunder is possible, but
coverage is not enough for inclusion in the TAF at this time.
Plenty of moisture and instability left behind the front for
MVFR ceilings to linger into Wednesday.

Outlook...

Wednesday morning...Restrictions probable in lingering lower
ceilings/showers.

Wednesday afternoon through Sunday...Mainly VFR. Early morning
fog possible, especially KELM.

&&

.BGM WATCHES/WARNINGS/ADVISORIES...
PA...None.
NY...None.

&&

$$
SYNOPSIS...DGM
NEAR TERM...DGM/MWG
SHORT TERM...DJP
LONG TERM...DJP
AVIATION...DGM

NWS BGM Office Area Weather Forecast Discussion