Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Buffalo New York
1048 PM EDT Thursday Aug 27 2015
high pressure will build across the region overnight
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/...
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.
The widespread strato-cumulus from the early evening has diminished in
coverage...and this has led to partly cloudy to moonlit skies across
the region. The trend from the infrared and 11-3.9u imagery suggests that
this trend will continue through the wee hours of the morning...
however a pronounced subsidence inversion based at 5k feet does not
support total clearing. The clearing trend will add to the
confidence for some valley fog across the southern tier though.
With respect to temperatures...expect lows overnight 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 /03z Friday through Tuesday/...
expect VFR conditions to continue to prevail under scattered-broken strato-cumulus
through the wee hours of the morning. The only potential issues will
be an increasing likelihood for valley fog across parts of the southern
tier. This could result in MVFR to IFR conditions at both kjhw and
kelz between 08 and 12z.
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.
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.
west winds in the 10-15 knot range on the lakes will diminish
tonight as high pressure will build across 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