Area Forecast Discussion
Issued by NWS Buffalo, NY
FXUS61 KBUF 251440
Area Forecast Discussion
National Weather Service Buffalo NY
1040 AM EDT THU AUG 25 2016
A mid-level wave will bring scattered showers and thunderstorms
across the region this evening, with a few thunderstorms possibly
producing severe wind gusts and heavy rain. High pressure will then
build in for Friday through the weekend bringing a dry stretch of
weather with above normal temperatures.
.NEAR TERM /THROUGH TONIGHT/...
This morning`s mid-level wave and associated area of precipitation
is exiting the forecast area to the east with an area of low clouds
lingering across western and central NY. As subsidence increases
behind the departing wave, expect a period of fair weather with some
breaks in the cloud cover to produce some filtered sunshine early
this afternoon. This is supported by upstream VIS/IR imagery with
clearing skies over southern Ontario and Lake Erie. The only concern
through this afternoon is a small chance for showers to develop
along the lake breeze boundary southeast of Lake Ontario and east of
Lake Erie. Otherwise today will be rather muggy with highs in the
80s and dew points around 70.
Another round of showers and a few thunderstorms is likely to
develop ahead of the front. Instability will be limited ahead of
this, with CAPES long and thin due to warm air in the mid-levels.
Even so, there may be enough momentum from upstream convection to
advect into Western areas this evening before weakening as it
moves east into Central New York. This trend is generally captured
by mesoscale guidance, but there is disagreement on the track of
this which lowers forecast confidence. In general, model
consensus suggests the best chance for this is across the Western
Southern Tier early this evening. There is a marginal risk for
severe weather with this, with a modest 30kt flow at 700mb
providing enough shear to support a few strong to severe storms.
With precipitable water values forecast to be near 2 inches these
also could contain heavy rain, but the progressive nature of this
should help mitigate the risk for flooding.
Showers will end from west to east late tonight, with some patchy
fog possible. Lows will be in the upper 60s to lower 70s.
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
The forecast area will see a return to a quiet and dry regime moving
into the weekend as a cool front slides across the area Friday
morning and an amplifying upper level ridge moves overhead, ensuring
plenty of sunshine for Friday and Saturday. We will see temperatures
in the upper 70s to lower 80s Friday and Saturday. Drier air and
clear skies will allow for cooler temperatures Friday night, with
lows in the upper 50s to lower 60s, while by Saturday night
southerly flow returns, signaling the return of increasingly warm
and humid air to the region, reflected in lows in the mid to upper
60s along the lake plains. There will be valley fog forming across
the Southern Tier, with the clear skies and cooler temperatures,
moisture supplied by the warmer waters of the rivers and lakes of
the region. There may also be a return of valley fog on Saturday
night, but to lesser degree with increasing clouds blanketing the
area and blocking the radiational cooling.
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
Surface ridging over the southeast will relax a bit across the
region as a shortwave moves through the Upper Great Lakes into
Canada and its trailing cold front approaches the area to begin this
Sunday should be the hottest day with 850mb temperatures nearing
+20C. This will translate into surface highs in the upper 80s across
the higher terrain to the lower 90s across the lake plains. In
addition to the heat, humidity levels will also ramp up as southerly
flow picks up and draws moisture up across the region. This will
introduce a chance of a few afternoon showers and thunderstorms
inland from the lakes especially along any lake breeze boundaries.
Sunday night, as the front begins to enter Western and North Central
New York expect increasing chances for additional showers and
Looking into next week, the front is forecast to slowly slide south
through Western and North Central New York Monday. Although, how
fast this occurs and how far the front pushes south is uncertain at
this point. The GFS moves the front out with surface high pressure
building into the region with mainly dry weather through Wednesday.
The ECMWF stalls the front just to our south over Pennsylvania which
will keep a slight chance of a few showers and thunderstorms across
the Southern Tier through late Tuesday. Overall, despite the
differences it looks to be primarily dry after Monday with high
temperatures above normal, low 80s.
.AVIATION /15Z THURSDAY THROUGH MONDAY/...
Late this morning an area of low cloud cover lingers across WNY and
CNY behind this morning`s area of precipitation. This will result in
continued MVFR conditions across much of the TAF sites, with IFR
across the higher terrain of the Southern Tier, through mid-day.
However, satellite imagery reveals a break in the clouds cover over
southern Ontario and Lake Erie where drier air is advecting into the
region. This will support CIGS improving to VFR with some areas of
MVFR by this afternoon.
Mainly VFR conditions will then persist until the next wave arrives
late afternoon or early evening. This will bring another chance for
showers and possibly a thunderstorm. Showers and storms will move
from west to east and could bring strong wind gusts and locally
heavy rainfall, along with localized MVFR/IFR conditions.
BUFKIT forecast soundings suggest there may be some low moisture
trapped beneath an inversion late tonight. This may result in
some fog, especially in areas which do get rain today and in the
typical Southern Tier valleys.
Friday thru Sunday...Mainly VFR.
Monday... Mainly VFR with a chance of showers and thunderstorms.
Southwesterly winds will increase at the northeast end of Lakes Erie
and Ontario again this afternoon. Winds will approach - but are
expected to fall just short of - Small Craft Advisory levels. A cold
front will ease its way across the Lower Lakes tonight. This feature
will bring a few rounds of showers and thunderstorms through
tonight, which may produce locally higher winds and waves.
After this high pressure will build across the region with
fair weather and fine boating conditions expected for Friday and