Scientific Forecaster Discussion
fxus61 kbgm 221923
Area forecast discussion
National Weather Service Binghamton New York
323 PM EDT Tue Aug 22 2017
a cold front will sweep through the area tonight with strong to
severe thunderstorms affecting portions of the region through
this evening. Pleasant weather will return on Wednesday with
clearing skies and lower humidities. Clouds and a few sprinkles
will be possible again on Thursday.
Near term /through Wednesday/...
convective event underway this afternoon as formidable low
pressure system/cold front arrives from the upper Great Lakes.
Looks like we are going to have to battle two distinct lines of
developing convection which the models have been struggling
to differentiate today. The first line now affecting The Finger
lakes to north central PA may tend to fizzle a bit late this
afternoon as we've lost some instability over the southern tier
New York. A second line developing over western New York is much better
forced with a deep plume of moisture, stronger convergence and
shear. We're still counting on this one to sweep through most of
the Tornado Watch area this evening where ehi values will be
increasing from 21z-00z. Timing of thunderstorm activity into
our far eastern New York zones and across nepa may be late enough to
preclude much threat of severe weather, but there is still a
risk, so this area will have to be monitored for watch
Fairly confident that much of the activity will be out of the
region shortly after 03z and have made adjustments to pops/wx to
move out the bulk of lingering rainfall aside from low chances
for scattered showers overnight.
Wednesday will be Post frontal and breezy with modest cold
advection and drier dewpoints. Temperatures in the 70s.
Short term /Wednesday night through Thursday night/...
a broad trof remains over the region during this time as high
pressure builds in from the Great Lakes. This will force our
area to be under cool northerly advection and thus marginally
unstable across cny due to lake temperature differentials and
colder air aloft. Diurnal heating and some weak waves rotating
around the broad trof could trigger widely scattered showers and
sprinkles on Thursday.
Nearly fall like temps with highs in the 70s and lows in the
50s...possibly even some upper 40s in the colder rural areas.
Long term /Friday through Tuesday/...
high pressure builds in for a rather uncharacteristic mainly
rain free extended period of time for these parts. Mainly dry
weather and unseasonably cool conditions should prevail through
the weekend and into early next week within a pattern such as
what is being shown. Several of the medium range models are
trying to float some tropical systems into the Gulf states and
offshore of the southeast Atlantic early next week. Although these
appear to be a non-issue for US at this time, the model trends
do bear close monitoring for any changes.
Aviation /18z Tuesday through Sunday/...
airports will be affected by thunderstorm activity into early
evening, followed by ceilings varying on the VFR-MVFR edge for a
time tonight. Gradual clearing is expected overnight with the
potential for patchy fog, although drier air moving into the
area may alleviate very dense fog. Breezy and drier on Wednesday
with broken VFR ceilings developing after 14z.
Winds S-SW 15-30 kts becoming west-northwest around 10 kts tonight and
then northwest 10-20 kts and gusty on Wednesday. Winds variable with
possible gusts in excess of 50 kts in any thunderstorms tonight.
Wednesday through Sunday...mainly VFR.