NWS Forecast Discussion

000
FXUS61 KBGM 152015
AFDBGM

Area Forecast Discussion
National Weather Service Binghamton NY
415 PM EDT Wed Aug 15 2018

.SYNOPSIS...
Brief high pressure will provide a relatively quiet period of
weather today into Thursday morning before another frontal
boundary with showers and storms moves through Thursday
afternoon into Friday night. Conditions turn dry and quiet again
this weekend into early next week.

&&

.NEAR TERM /THROUGH THURSDAY NIGHT/...
Isolated convection is starting to pop across central New York
this afternoon. Coverage will remain isolated through late
afternoon due to weak forcing and will diminish quickly by late
afternoon/early evening. A surface trough moving through
northern New York Sate will bring a chance for scattered
convection in northern Oneida county through this evening. The
remainder of the overnight period will be dry with patchy valley
fog toward daybreak. Overnight lows will range in the mid/upper
60s.

Thursday/Thursday night...
The first part of Thursday will be mainly dry as a flat upper
level ridge remains over the area. During the afternoon surface
low pressure will move into southern Michigan as mid level waves
in the approaching upper level trough move into the western
forecast area. By late day will continue to indicate likely
POPs for showers in the far western forecast area and just
chance in the western Catskills and Poconos. Will also mention
the chance for thunder. Highs will range in the lower to middle
80s. Thursday night as the surface low moves east into southern
Ontario the associated warm front will bring a better chance
for showers as the night progresses. Due to forcing and some
instability will keep mention for a slight chance of thunder.
Precipitable water values increase to around 2 inches so
potential for heavy downpours also increases. This system is
more progressive than the one which impacted the region during
the past couple of days so the potential for flooding is less
than the previous storm although the soils across the area are
very wet and therefore sensitive to any rainfall.

&&

.SHORT TERM /FRIDAY THROUGH SATURDAY/...
410 PM Update...
Main concern will be for a cold frontal passage Friday
afternoon-evening that could include thunderstorms with gusty
winds and locally heavy rainfall.

Low pressure is set to track from between Lakes Huron/Ontario
early Friday morning, through northern New York in the
afternoon-early evening, onward to New England Friday night. It
will swing a cold front through our region in the afternoon-
evening, with a modest amount of unidirectional shear as well as
a moist environment with tall and skinny Convective Available
Potential Energy profile. The shear will allow some cell
organization and movement, with possible gusty winds. Given how
saturated our soils are, it really would not even take a
technically severe gust, to uproot some trees out of the
waterlogged ground.

Precipitable water values will be nearly 2 inches, with warm
cloud depths again around 12 kft or so. Thus yet again, the
resulting thunderstorms from this frontal passage will pose a
threat for locally heavy rainfall, especially considering how
sensitive and saturated our ground is from our recent very wet
pattern. The good thing is that this is a progressive front, not
a slow moving upper low. Thus the cells will be quick single
hits, still capable of isolated flash flooding, but not
repeatedly striking the same location as occurred in the last
couple of days. Creeks/small streams and areas of poor
drainage/urban locations will be susceptible to very quick
responses and possible flooding from locally heavy rain; exactly
where is not possible to pinpoint. However, larger streams and
main stem rivers should be fine since this will be a quick-
moving front.

A complicating factor, in terms of forecast uncertainty, will be
a pre-frontal trough that may take some of the energy away from
the front itself. Not sure which feature - the front or the
pre-frontal trough - will contain the bulk of the convection.
The trough may also cause enough cloud cover to limit
instability during peak heating hours, which could also hold
back additional storm development.

There is some possibility that showers-embedded thunder could
linger well into Friday night, as front progress gets slowed
awaiting passage of shortwave aloft. However, instability will
also be quite spent and there is not clear indication of jet
support aloft. Thus current expectations are that it will
diminish in the evening with very little overnight.

Saturday itself looks fairly dry as a surface high tries to edge
in, but there will still be a small chance of diurnal
instability showers-isolated thunder mainly east of I-81 as
shortwave finishes its departure.

&&

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
415 PM Update...
Welcome change to the overall pattern will continue, in that
instead of getting rain almost every day, we will instead get a
system once every several days. The pattern will feature a more
typical west-to-east progression with occasional wave passage;
not the amplified/cut off pattern that we had in recent times.

Sunday-Monday appear primarily dry with highs of 70s-near 80 and
lows in upper 50s-lower 60s. Sometime around Tuesday, perhaps
lingering into Wednesday, our next low pressure system and
frontal passage looks probable to occur with resulting showers
and thunderstorms. It is much too early to assess strength of
the convection and whether or not locally heavy rainfall will be
a threat. Temperatures through midweek should be close to
climatology.

&&

.AVIATION /20Z WEDNESDAY THROUGH MONDAY/...
Primarily VFR conditions are forecast for the next 24 hours.
Through late afternoon SCT/BKN fair weather cumulus around 4K
feet. Overnight just high clouds with brief MVFR restrictions in
fog possible at KRME/KITH/KBGM. At KELM, IFR fog will be
possible between 09Z-12Z. On Thursday conditions will remain VFR
through early afternoon then scattered convection late day
could bring some restrictions.

Northwest winds at 5-10 knots becoming light overnight then W/SW
on Thursday at 5-8 knots.

Outlook...

Thursday night through Friday night...Restrictions possible due
to showers and thunderstorms.

Saturday through Monday...Primarily VFR.

&&

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

&&

$$
SYNOPSIS...BJT/RRM
NEAR TERM...RRM
SHORT TERM...MDP
LONG TERM...MDP
AVIATION...RRM

NWS BGM Office Area Weather Forecast Discussion