Scientific Forecaster Discussion
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Area forecast discussion
National Weather Service Buffalo New York
152 am EDT Tue Sep 26 2017
high pressure will keep dry weather and midsummerlike warmth across
our region through most of Wednesday. An approaching cold front may
finally bring a chance of a few light showers late Wednesday and
Wednesday night...with much cooler temperatures then following for
Thursday right on through next weekend.
Near term /through today/...
overnight, high pressure will remain across the region with fair
weather and light winds. Infrared satellite imagery shows high clouds
streaming into western New York. These are thin enough for some
radiational cooling to occur, but may limit this a bit and also
may limit (but not prevent) the development of radiation fog.
Fog will be most widespread in the southern tier valleys and
also the Saint Lawrence valley. Otherwise it will be a very
mild, and muggy night by late September standards...with lows
ranging from the lower 60s across the north country and interior
portions of the southern tier to the mid and upper 60s
On Tuesday...Hurricane Maria will be slowly moving northward offshore
of the Carolina coastline...while a modest midlevel trough presses
from the northern plains into the upper Mississippi Valley. Meanwhile
our region will continue to lie in The Squeeze play/ridging separating
these two systems...albeit with the main upper ridge axis sliding a
bit to our south and weakening slightly. With a little bit more in
the way of low level moisture available to work with and strong
heating of our very warm and humid airmass again expected...it is not
entirely out of the question that (as suggested by some guidance) we
could pop an isolated afternoon shower or two across interior sections
of far western New York...though with the mid levels remaining very
dry and possibly capped...will continue to advertise a dry forecast
for now. Otherwise it will be another mostly sunny and unseasonably
warm to hot day with widespread highs in the 85-90 range again
anticipated...with the warmest readings most likely to lie from the
Genesee Valley eastward...where supporting 850 mb temps will be the
warmest. Record highs for September 26th are 87f at Buffalo
(1959)... 89f at Rochester (1900)...and 82f at Watertown
(1970)...with the Watertown record currently appearing in serious
jeopardy and the records at Buffalo/Rochester likely to at least be
very closely approached.
Short term /tonight through Thursday night/...
Tuesday night and Wednesday will be the last of the recent Summer-
like warmth for the region. In addition, some areas will see their
first chance for rain in about 2 weeks arriving Wednesday with one
or two prefrontal frontal troughs and/or afternoon lake breeze
boundaries. The front itself will likely be a dry frontal passage
for western New York. Expect it to ease into the region Wednesday evening
with scattered convection well ahead of it over central New York.
Thursday should be dry but with ample strato-cumulus under an
upslope northwest flow. It's possible a few sites might see a
sprinkle or two, but the main story will be the ~20f drop in daytime
high temperatures. While it may feel cool, the highs, mostly
in the 60s, will actually get US back our normal climatology.
Thursday night should be similarly dry with a continued drop in
temperatures resulting in lows in the 40s overnight. This will
coincide with a surface ridge dropping from the upper Great Lakes
region into western New York overnight.
Long term /Friday through Monday/...
a sharp longwave trough axis and secondary surface cold front will
drop across our region Friday or Friday night as a more progressive
pattern develops over the Continental U.S.. this will bring a chance of rain
showers and another shot of cold air advection. 850 mb temperatures
are forecast to drop to near zero c behind the secondary cold front
with a north to northwesterly flow over the lakes. Expect this
airmass to be sufficiently cold enough to contribute to some lake
driven rain showers behind the cold front Friday night into
High temperatures will generally be in the lower to mid 60s Friday
with even cooler temperatures expected Saturday, with highs
struggling to get to 60 degrees. Overnight lows will generally
be in the 40s, with the typically cooler interior valleys and
north country dipping into the 30s by Saturday night.
High pressure will again build into the region late in the weekend
and into early next week. A warming trend is expected during this
time which could last into at least mid next week, with
temperatures warming back to at least 5 to 10 degrees above
normal, but not quite to the extent we are currently experiencing.
Aviation /06z Tuesday through Saturday/...
the main concern for aviation will again be the potential for
radiation fog. With high pressure across the region winds will
be light which will generally support radiational cooling and
potentially fog. However high clouds have spread into western
New York this evening which may hinder and/or slow fog
development. The most widespread fog is expected to be in the
typical southern tier valleys (near jhw) and the Saint Lawrence
valley (near art). IFR or lower flight conditions are likely at
these spots, however patchy fog cannot be ruled out anywhere
late tonight. Also, flight conditions may vary considerably in
radiation fog, with vsby changing frequently in fog.
Any fog will quickly burn off by mid-morning with widespread
VFR conditions today through this evening. Patchy fog is
possible tonight, but should be less widespread and mainly
confined to the southern tier valleys (jhw).
Wednesday...mainly VFR with a chance of showers in the
Thursday through Saturday...mainly VFR...with a chance of
showers Friday and Saturday.
high pressure will remain in place across the lower Great Lakes
right through Wednesday morning. This will provide a long stretch of
very light winds and flat wave action with ideal boating conditions,
but not much wind for sailing.
A cold front will cross the region late Wednesday. Northwest winds
will increase in the wake of the cold front, and may bring a round
of advisory-worthy winds and waves to lakes Erie and Ontario late
Wednesday through early Thursday.