Scientific Forecaster Discussion
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Area forecast discussion
National Weather Service Buffalo New York
853 PM EST Fri Nov 22 2019
high pressure centered over the Central Plains will drift by to
our south through Saturday. This will result in fair weather
and lighter winds for the first half of the weekend. The second
half of the weekend could include a little rain and or wet
snow...as a storm system will pass well to our south.
Near term /through Saturday/...
the upper level trough axis has shifted into New England which
has effectively stripped away the deeper moisture associated
with this feature. As a result, lingering showers have all but
tapered off this evening. With 850mb temperatures around -8c
there is still ample lake induced moisture to cause some lake
effect clouds, but it's not cold enough beneath the inversion to
support precipitation. Expect mainly dry conditions for this
evening, with perhaps a flurry east of Lake Ontario. It will
remain mostly cloudy until later tonight when winds shift to the
southwest and start to bring in drier boundary layer air which
has not been modified by the lakes.
Winds will also diminish as the surface low exits into the
Canadian Maritimes and high pressure builds in from Ohio. Lows
tonight will mainly be in the mid to upper 20s, with some cooler
temperatures where skies clear out early.
High pressure drifts by quickly Saturday, which will take the
brief cold chunk east of the area on Saturday. This will end
instability off the lakes, and an uptick at 850 mb combined with
turning flow to the south should allow temperatures to recover
nicely on Saturday with a decent amount of sunshine for many
High cloudiness will start to increase from the southwest on
Saturday afternoon as the next system start to approach the area
for the short term period.
Short term /Saturday night through Tuesday/...
model trends continue to keep low pressure tracking well to our
southeast across Virginia and off the mid Atlantic coast Saturday
night. This will keep our forecast area on the northern and
northwestern fringe of the main precip shield, with still the chance
of a few rain and snow showers possibly making it as far north as
the western southern tier and Finger Lakes region.
Low pressure will continue moving northeast toward the southeastern
New England coast on Sunday, eventually passing right over or just
east of Cape Cod. Any lingering light rain or snow showers
associated with this system will pull east of the area by midday as
the low pulls away, leaving the remainder of the day to be mainly
Air aloft over Lake Ontario during the first half of Sunday night
may briefly become just cool enough to induce a few weak lake
enhanced rain and snow showers across the Eastern Lake Ontario
region. Warm advection will then ensue during the second half of the
night as a warm front approaches from the southwest. Aside from a
few lingering rain/snow showers east of Lake Ontario, conditions
should remain dry.
A warm front will push northeast across the area on Monday, however
the combination of high pressure nudging in across the area from the
south and better forcing associated with the warm front remaining
off to the northwest of the area should help keep mainly dry weather
in place from Monday into Tuesday.
Otherwise in terms of temperatures, expect a general warming trend
through the period. This will translate to daytime highs on Sunday
in the upper 30s to lower 40s, then making into the upper 40s to
lower 50s by the time Tuesday rolls around. The same trend can be
expected for the overnights, with lows in the upper 20s to lower 30s
Saturday night, only dropping back to the mid 30s to near 40 by
Long term /Tuesday night through Friday/...
warm, wet and windy conditions to start the period will transition to
much cooler conditions for Wednesday night through Thanksgiving day,
with upslope and lake effect/enhanced snow showers across the area.
Tuesday night and Wednesday an upper level trough will push eastward
across the Great Lakes into New England, while the GFS/Gem/ECMWF
continue to show associated deepening low pressure tracking from
southern Michigan to New England, just to the northwest of our area.
Were this scenario to actually play out (which is still far from a
certainty given the distant time frame and continued model
differences), western and north central New York could be in line for
another round of widespread rain showers, followed by a strong to
potentially high wind event later Tuesday night into Wednesday. Just
to reiterate, high winds are still far from any certainty as there
are many factors that have yet to come together before significant
winds can come to fruition. This will continue to be closely
monitored over the coming days.
Following this potentially significant system, a west-northwesterly
to northwesterly flow of colder air will result in temperatures
falling back to a bit below average, and could also support some
upslope and lake effect/enhanced snow showers east/southeast of the
lakes from Wednesday night through Thanksgiving day. This said, the
exact timing, placement and amounts from these are extremely
difficult to pinpoint this far out, and as such have just continued
to cover these with some chance pops. Drier air will then try to
push into the area bringing mainly dry weather to close out the
week, with just a few lingering snow showers possibly hanging on
east of Lake Ontario through Friday.
Aviation /02z Saturday through Wednesday/...
there will be plenty of strato-cumulus through this evening,
with this deck MVFR across higher terrain, and low VFR across
the lower terrain. These clouds will diminish and lift northward
with a wind shift which will expand VFR flight conditions.
On Saturday, backing winds will lift a narrow band of lake
effect clouds northward...with these clouds possibly bringing a
few hours of MVFR ceiling heights to the east and then northeast
of the Great Lakes. Otherwise, expect VFR flight conditions
during the day.
Saturday night and Sunday...mainly VFR.
Monday and Tuesday...VFR.
Tuesday night and Wednesday...MVFR with rain showers likely and
possible gusty winds/llws.
winds will continue to diminish through tonight, with small
craft advisories in place as outlined below. These will drop off
from west to east as high pressure builds in from Ohio. High
pressure will provide negligible winds and waves late Saturday
and into Sunday.
The next potentially significant system is forecast to track
across the lower Great Lakes on Wednesday. This is likely to
require at least small craft headlines and possibly gales.
Marine...Small Craft Advisory until 1 am EST Saturday for lez040-041.
Small Craft Advisory until 3 am EST Saturday for
Small Craft Advisory until 1 am EST Saturday for loz042.