Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Binghamton New York
639 am EDT sun Aug 2 2015
high pressure will keep things quiet with near normal temperatures
to round out the weekend. However...a cold front will bring
showers and thunderstorms to the area Monday...especially
afternoon into evening. Some of those storms could contain strong
Near term /through tonight/...
0630 am update...added patchy valley fog in for early this
morning based on observation. Also made some minor adjustments to morning
temperatures and dew points.
315 am update...quiet weather continues for the near term. SW
flow develops for today as ridge flattens to the south and east
and low pressure moves into the Great Lakes. Skies will be partly
to mostly sunny with temperatures a little warmer than
Saturday...generally looking at highs in the 80 to 85 range with
comfortable humidity levels.
Mild SW flow ahead of approaching cold front continues tonight
resulting in a milder night with dew points creeping up slightly
as well. Lows will range from the low 60s over the Catskills to
the upper 60s over the lake plain. Middle and high clouds also start
to stream in but most likely showers and storms stay to the north
and west through the overnight period. We do indicate slight
chance / chance probability of precipitation only from The Finger lakes northward by the
Short term /Monday through Tuesday night/...
310 am update...
active day appears to be taking shape for Monday...with favorable
setup for clusters of strong to severe thunderstorms. The Storm
Prediction Center has placed our whole region into a slight risk
for severe...which is designated for when scattered severe
thunderstorms are possible.
This may turn out to be one our more organized events of the
season. Compared to other attempts at convective events this
year...it appears we will have steeper middle level lapse rates. In
addition to jet support...the main characteristic of this set up
is belt of 40-45 knots deep layer winds /2-6 km layer/ which for
August is noteworthy. Convective available potential energy will be modest...upper hundreds to
perhaps around a thousand j/kg...yet given support and shear it
should be more-than-adequate for thunderstorm development and
organization. If anything...timing in latest model suite has
become even more favorable for harnessing diurnal
heating...focused especially on the 4pm-10pm period.
Highs mainly 80s areawide...even some upper 80s at lower
elevations in northeast PA...along with dewpoints in the lower
60s. With well marked wave running into this warm and modestly
moist unstable air mass /on southern periphery of large upper low
dropping through Ontario/...given the above factors...scattered
severe thunderstorms appear probable. In addition to 0-3km and
0-6km bulk shear values supportive of good structure to the
storms...there will also be some dry air in the middle levels to
promote mixing down of strong winds. Our local analog
tool...comparing forecast convective parameters to past
events...returns several cases with damaging winds and even a
couple isolated tornadoes.
Once the storms exit Monday evening...quiet Monday night-early
Tuesday morning. However...another wave /and possible secondary
surface front/ will traverse southern the periphery of upper
low...for a few showers and thunderstorms to pop up during the day
Tuesday with the better chances in central New York. Highs Tuesday will
be down 4-7 degrees...to mainly middle 70s-near 80 range. With the
scattered convective activity heavily influenced by diurnal
heating...we should lose it quickly into Tuesday night...with lows
mainly middle 50s to near 60.
Long term /Wednesday through Saturday/...
3 PM update...
followed latest wpc guidance. Cool period with temperatures
mostly below normal. An broad upper level trough will keep it cool
but most of the time will be dry. A weak front crosses Tuesday PM
with a few showers. Wednesday dry then a surface low passes to the south.
Thursday the models have much more agreement with the track
brushing southern PA. Some disagreement on how far north the rain will
be but think it should make it only to NE PA and Sullivan County
New York. Friday dry then another wave drops southeast through the trough with
showers and thunderstorms for Saturday. Timing differences here
but normal for day 7 with GFS faster than Euro.
Aviation /10z Sunday through Thursday/...
any early morning mist or fog at kelm will quickly burn off with
today otherwise featuring partly to mostly sunny skies with VFR
for all sites. West/SW winds will increase to around 10 knots.
Some middle and high clouds begin to move in tonight but boundary
layer winds look to be too strong for any fog or mist to form so
expecting continuing VFR.
Mon-Tue...restrictions due to mainly afternoon thunderstorms possible.