Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

Area forecast discussion 
National Weather Service Buffalo New York
736 PM EDT Thursday Aug 27 2015

Synopsis...
high pressure will build across the region tonight and Friday
and provide our region with fair and dry weather...along with
increasing amounts of sunshine and more normal temperatures
on Friday. A disturbance will then pass across the region this
weekend and bring the chance for a few showers...before
middle Summer-like warmth returns for next week.

&&

Near term /through Friday/...
synoptically speaking...the large-scale pattern across our region
during the near term period will remain rather simple. Lingering
broad/weak upper level troughing tonight will give way to a zonal
flow on Friday...while at the lower levels surface high pressure
will build east from Michigan into New York state. As a result...
we can expect quiet and dry weather to prevail through the period.

With respect to cloud cover...fairly widespread cumulus and strato-cumulus late
early this evening will diminish a bit in coverage tonight as we
lose diurnal heating. Suspect that at least some of this cloud cover
though will still manage to hang on through tonight given both the
degree of cloud cover seen on current satellite imagery...and 12z
guidance trends towards greater amounts of lingering moisture below
about 850 mb. For this reason...have elected to maintain at least
partly cloudy skies through tonight...before finally clearing out
the lower clouds on Friday as renewed daytime heating/ mixing and
subsidence helps to finally mix out the leftover low level moisture.
This will lead to mostly sunny skies area-wide by Friday afternoon...
with just some high cirrus pushing into the region in advance of the
next system pushing into the upper Great Lakes.

Dependent upon the exact amount of cloud cover leftover later
tonight... the potential still exists for some patchy fog to
develop within the southern tier valleys overnight. While our
confidence in this is not quite as high as it was earlier today
given the aforementioned greater amount of expected cloud cover...
this cannot be ruled out either. With this in mind...have retained
the mention of patchy fog from our p previous continuity.

With respect to temperatures...expect lows tonight to range from
the upper 40s across the coolest interior portions of the southern
tier/north country to the lower and middle 50s elsewhere. On
Friday... some modest warming of our airmass should then allow
highs to recover back into the lower to middle 70s across the vast
majority of the area... though a developing onshore flow will
likely keep temperatures along the Lake Ontario shoreline confined to
around the 70 degree mark...and the highest terrain east of Lake
Ontario may still struggle to break out of the 60s.

&&

Short term /Friday night through Sunday night/...
high pressure moves off the Atlantic coast while a weak low over
the upper Great Lakes approaches from the west. The system lifts a
warm front across the region so expect an increase in cloudiness
overnight Friday night and Saturday.

While the warm front will produce fairly widespread cloud cover
the chance for any precipitation will mainly be limited to the
western sections late in the day Saturday and Saturday night.

The low is forecast to weaken quite a bit as it moves across the
lower Great Lakes Sunday/Sunday night thus will confine chance
probabilities to the Niagara Frontier and western southern tier.

The strengthening southerly flow will allow for more seasonable
temperatures. Temperatures Friday night will be in the 50 and upper 50s
to low 60s Saturday night. Highs will climb back to around 80 on
Saturday and in the low 80s on Sunday.

All that being said...the spread of model solutions/strength of
this Great Lakes system really lowers the confidence factor in
this weekends forecast.

&&

Long term /Monday through Thursday/...
broad upper level ridging will shift to the eastern U.S. As we move
into next week as troughing develops across the Pacific northwest.
While this should result in warm temperatures and generally dry
conditions across the Great Lakes next week several weak middle level
impulses will pass through the region. Thus have kept kept a slight
chance of showers/thunderstorms across inland western New York during the
afternoons Monday and Tuesday. Otherwise expect mostly dry and
increasingly warm conditions next week with highs climbing into the
middle 80s and lows ranging from the upper 50s across higher elevations
to the middle 60s near the lakes.

&&

Aviation /00z Friday through Tuesday/...
expect general VFR conditions to continue to largely prevail under
scattered-broken strato-cu. While a little patchy IFR valley fog remains
possible across the southern tier late tonight...the development of
such remains uncertain...and will be highly dependent upon the
amount of cloud cover that remains.

On Friday...any fog that does manage to develop should dissipate
within a couple hours after sunrise. Otherwise...any leftover VFR
strato-cumulus should finally mix out as high pressure settles directly
overhead...before some high cirrus begins overspreading the region
during the afternoon. Bottom line...flight conditions should again
be predominantly VFR during Friday.

Outlook...
Friday night and Saturday...mainly VFR.
Saturday night and Sunday...mainly VFR with a chance of showers/
associated brief MVFR.
Monday and Tuesday...mainly VFR.

&&

Marine...
west winds in the 10-15 knot range on the lakes will diminish
tonight as high pressure builds into the region. After
that...relatively light winds and minimal waves are expected to be
the rule from Friday on through at least the first part of the
weekend.

&&

Buf watches/warnings/advisories...
New York...none.
Marine...none.

&&

$$

Synopsis...jjr/rsh
near term...jjr/rsh
short term...Levan
long term...Levan/wood
aviation...jjr/rsh
marine...jjr

National Weather Service Glossary of Abbreviations