Area Forecast Discussion
Issued by NWS Buffalo, NY

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
FXUS61 KBUF 262148

Area Forecast Discussion
National Weather Service Buffalo NY
548 PM EDT Wed Oct 26 2016

A ridge of surface high pressure producing fair but chilly
temperatures over the region this evening will move eastward,
allowing for a storm system from the Central Plains to advance
eastward. This system will bring a mix of rain and snow to the
region tonight through tomorrow night, with higher elevations
potentially measuring snow. Another system may bring some rain
showers to the region late Friday night and into Saturday.


This afternoon a ridge of high pressure is found across the region,
bringing fair, but chilly weather. Upstream a surface low is found
nearing Illinois, with this feature continuing to deepen as it
resides ahead of an upper level shortwave.

This upstream storm system will advance towards Lake Erie tomorrow
morning, and then along the Southern Lake Ontario shoreline through
the day tomorrow. While light isentropic lift rain/snow showers are
possible this evening, the heavier precipitation will pass across
WNY after midnight as deeper moisture and enhanced convergence
arrives. This precipitation will reach the Eastern Lake Ontario
region during the daylight hours tomorrow. A cold front advancing
across the region through the midday hours will end the heaviest of
precipitation from west to east, though lingering low level moisture
will maintain at least some light precipitation/drizzle across WNY,
especially the upslope hills through the afternoon hours.

Winds... A low level jet of 40 to 50 knots around 925 hPa will be
found ahead of storm system tonight. While this LLJ is very common,
strong high pressure over eastern Canada will give an easterly
component to the winds tonight. While most areas will have nothing
more than a light easterly wind gust, the downslope region of Lake
Erie, this along the Lake Erie shoreline may develop wind gusts up
to 40 to 45 mph late tonight and early tomorrow morning as strong
southeasterly winds from the LLJ rush down the western slope of the
Chautauqua ridge.

Precipitation type... Cold air of -2 to -4c at 925 hPa will reside
across our eastern zones late tonight and early tomorrow morning. A
look at point soundings suggest that across Western New York a brief
mix of snow may mix with the rain at the onset, with no accumulation
outside of the highest peaks of the Southern Tier and Bristol Hills.
Eastward where cold air will be deeper in the lower levels there
will be potential for a minor accumulation. Across the Finger Lakes
region a few tenths of an inch of snow may accumulate late tonight
before changing to rain, while across the Tug Hill region several
inches of snow is possible across the Southern portion. Any snow
accumulation on a still warm ground will likely not last long as
slight warming temperatures tomorrow will change the snow over rain,
melting any accumulation.

Temperatures... Lows tonight will drop back to the lower to mid 20s
across the areas east of Lake Ontario, while incoming cirrus clouds
limit overnight cooling farther to the west where lows will remain
in the low to mid 30s. Highs on Thursday under a cloudy sky will
only rise about 10 to 15 degrees, with afternoon highs in the mid to
upper 40s across far WNY, and mid to upper 30s east of Lake Ontario.


Vigorous upper level wave pushes through the area during the evening
hours with associated surface low track across Lake Ontario and into
the northern Adirondacks, while a secondary low develops near Long
Island Sound. Expect steadier precipitation to taper off west to
east through the evening and as cooler air advects in from the
northwest. While the cold air will increase lake instability, drying
aloft and approaching upstream ridging should limit the lake effect
precipitation potential. Cold advection behind the departing low
will drop temperatures back into the 30s.

Ridging briefly sets up over the area Friday into Friday evening,
providing a brief break from the cloudiness before clouds increase
once more behind the ridge axis ahead of yet another approaching low
pressure system.

Well-defined northern stream shortwave and associated deepening area
of low pressure will become centered just north of Georgian Bay by
Saturday morning. Strong low to mid level return flow will gradually
increasing moisture, but with placement of the surface low well to
the northwest of the area would expect the bulk of the
isentropically driven precipitation to be move north of the region
Friday night.

The main impacts from this system look to be during Saturday as a
period of showers will develop into the area as a cold front
associated with the low crosses the region. Windy conditions will
develop with a strengthening pressure gradient as the system pushes
off to the north, with a strong 925 mb jet of 50 to 55 knots
crossing the lower Great Lakes. Model soundings suggest fairly
stable low levels, with lapse rates generally less than 6 C/km
therefore likely limiting any really high gusts from mixing down,
but still could be looking at gusts in excess of 40 mph.

The strong warm air advection ahead of the cold front will result in
a mild day Saturday with most temperatures peaking in the upper 50s
to mid 60s. After the sharp warm-up ahead of the front, temperatures
will fall back into the 40s Saturday night behind the front.


A weak shortwave will cross the region on Sunday bringing a few
scattered showers mainly south of the Lake Ontario shoreline. Behind
this departing wave, ridging will build in across the region for the
start of the next work week. This will bring a stretch of dry
weather and a warming trend. Highs will start out in the lower 50s
Sunday and will climb into the upper 60s by Tuesday as the ridge
crests the region and warm advection develops ahead of the next
approaching system for mid next week.


VFR flight conditions at 18Z will remain across the region for
another 12 to 18 hours before a storm system brings rain/snow to the

Low end VFR lake effect clouds this afternoon S and SE of Lake
Ontario will continue to fade through the early evening hours.
Meanwhile cirrus will continue to fill across the TAF region from
the Midwest, this ahead of a storm system that is nearing Illinois.
The storm system will track across the Ohio Valley tonight with the
center of the low residing over central Lake Erie Thursday morning.
Light, isentropic lift rain showers ahead of a warm front will reach
KJHW this evening, but we don`t expect much flight restrictions
until deeper moisture arrives around midnight.

Colder air will reside across eastern zones, and this will allow for
a rain/snow mix...and possibly for a period of time just plain snow
near the KART airfield. There is limited potential for rain/snow
across KIAG/KBUF/KJHW with no accumulation...with greater chances
eastward where a mention of snow will be placed in the KROC and
KART airfield.

The storm system will track across WNY tomorrow with IFR and
widespread MVFR flight conditions in light rain.


Thursday afternoon and night...widespread IFR/MVFR cigs with rain
diminishing from west to east.
Friday...Improvement to MVFR/VFR.
Saturday...VFR/MVFR with scattered to numerous showers developing.
Sunday...Mainly VFR with a chance of showers.


A storm system advancing over Lake Erie tomorrow morning, and then
just south of Lake Ontario through the day will bring Small craft
advisory winds to the lakes tonight and early tomorrow morning.
After a brief lull in winds, cold air rushing in behind the surface
low will freshen both winds and waves over the Eastern Great Lakes
such that SCA conditions will persist into Thursday evening and


MARINE...Small Craft Advisory from 11 PM this evening to 2 PM EDT
         Friday for LEZ040-041.
         Small Craft Advisory from 2 AM Thursday to 8 PM EDT
         Friday for LOZ043.
         Small Craft Advisory from 2 AM Thursday to 5 PM EDT Friday
         for LOZ042.
         Small Craft Advisory from 8 AM Thursday to 5 PM EDT Friday
         for LOZ045.
         Small Craft Advisory from 8 AM Thursday to 8 PM EDT Friday
         for LOZ044.



MARINE...THOMAS is the U.S. government's official web portal to all federal, state and local government web resources and services.