National Weather Service Weather Forecast Office

• Home
• Site Map
• News
• Organization
• Search for: NWS All NOAA 

-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KBUF 061048
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
648 AM EDT Thu Aug 6 2020

.SYNOPSIS...
High pressure will provide dry weather today. A weak upper level
disturbance will then bring an increase in clouds and a chance of
showers to Western NY late tonight, then much of the region on
Friday. A few showers may linger into Saturday east of Lake Ontario,
while mainly dry weather returns to Western NY. Cooler temperatures
late this week will give way to increasing warmth and humidity by
early next week.

&&

.NEAR TERM /THROUGH TONIGHT/...
IR satellite imagery showing a few patches of high cirrus drifting
across the eastern Great Lakes this morning. River valley fog
in the typical locations across the Southern Tier will dissipate
by mid morning. Temperatures this morning are the coolest we
have seen since late June, with 50s in most areas and even some
upper 40s across the cooler Southern Tier valleys and North
Country.

High pressure will remain draped from the Midwest into the eastern
Great Lakes today, providing dry weather and a good deal of
sunshine. Some patches of high/thin cirrus will continue to drift
east across the area, and scattered diurnal cumulus will also
develop along and inland of the lake breeze boundaries. Temperatures
will be a few degrees warmer than yesterday, with highs in the upper
70s at lower elevations and low to mid 70s on the hills and along
the Lake Ontario shore.

Tonight a weak mid level trough will approach from the west and
begin to sharpen with time, reaching Lake Erie and central Ohio by
12Z Friday. Increasing southerly flow ahead of this trough will
capture a plume of moisture across the Ohio Valley and mid Atlantic,
spreading it north towards western and central NY late tonight. DPVA
and isentropic upglide will increase ahead of the mid level trough
late tonight, providing an increase in large scale forcing. There
remains some differences in model guidance with timing and placement
of rain potential, with many of the high-res WRF runs being on the
faster and farther west side of the guidance envelope, while the GFS
is a little slower and farther east. Given the model differences,
went with a compromise solution with POPS reaching the western
Southern Tier first around midnight, then spreading north towards
the NY Thruway by late tonight. The increase in clouds will keep
lows in the upper 50s to lower 60s across Western NY, while less
cloud cover across the North Country allows lows to drop into the
lower 50s.

&&

.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
An upper level trough will approach the area Friday, then slowly
cross the lower Great Lakes region Friday night through Saturday.
Meanwhile, an area of low pressure will slowly move northeast from
the Delmarva to the southern New England coast along a stalled
frontal boundary during the same time. Guidance continues to show
better chances for precip across our area on Friday, especially
across the southern half of our forecast area closer to the deeper
moisture associated with the surface low. Forcing and moisture
provided by the two above-mentioned features will be enough to
produce some occasional light showers/isolated storms across much of
the Southern Tier and Finger Lakes region, thus have raised PoPs
into the low likely range for these areas, with slight chance and
chance PoPs further north.

Upper level trough will cross the area Friday night and Saturday,
while surface low pressure slowly makes its` way northeast toward
the southern New England coast. Deeper moisture associated with the
slowly departing low will begin to pull eastward, however with the
upper trough overhead, there will still be the chance for some
scattered light showers from the Genesee Valley east Friday night
into Saturday morning. The upper trough will move into New England
Saturday afternoon, while surface low pressure continues northeast
along the New England coast. With the better forcing and moisture
exiting east of the area, this should allow for any lingering light
showers/isolated thunderstorms across the eastern half of our
forecast area to taper off by late in the day. High pressure will
build in for Saturday night with dry weather expected.

Otherwise, temperatures will remain within a few degrees of average.
Highs will be in the mid to upper 70s on Friday, with upper 70s to
low 80s on Saturday.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
High pressure centered over the central Appalachians Sunday morning,
will slide east off the Mid Atlantic coast by Monday. Despite a weak
shortwave embedded in the quasi-zonal flow aloft crossing the area
on Sunday, expecting a dry finish to the weekend as there will be
little in the way instability or available moisture. A weak warm
front will cross the area Sunday night, however with continued
limited moisture to work with and little in the way of upper level
support, expecting mainly dry conditions with just the chance of a
few isolated light showers. A southwesterly return flow of warmer,
more humid air will ensue on Monday as surface high pressure slides
off the Mid Atlantic coast. There will again be a lack of any upper
level energy on Monday. However, with low level moisture/instability
on the increase due to the more humid airmass in place, there will
be the chance for a diurnally driven storm or two Monday afternoon.

After a dry start to Monday night, chances for showers and storms
will gradually increase through the night as a cold front approaches
from the west. The best chance for showers and storms will come on
Tuesday as the cold front moves into the lower Great Lakes region.
With the addition of upper level support, some of these storms may
be on the stronger side. A few lingering showers and storms will be
possible into Tuesday night, before high pressure builds into the
region on Wednesday, bringing a return to dry weather.

We`ll really start to feel the return of the heat and humidity,
especially to start the new work week, with the warm and humid
conditions lasting through mid week. High temperatures will be
mainly in the lower to mid 80s. However, the warmest day of the next
week will Monday, when highs will range from the mid and upper 80s
to the lower 90s. The combination of heat and humidity will allow
apparent temperatures to climb into the low and possibly mid 90s
across the lake plains south of Lake Ontario, Genesee Valley and
Finger Lakes region.

&&

.AVIATION /12Z THURSDAY THROUGH MONDAY/...
IR satellite imagery showing a few patches of high cirrus level
clouds drifting across the eastern Great Lakes this morning.
Areas of fog will continue across the river valleys of the
western Southern Tier with local IFR, and some of this may
impact KJHW briefly as the fog begins to lift out of the valleys
below the hilltop airfield. The fog will dissipate by mid
morning, leaving VFR to prevail through the rest of the day with
nothing more than high cirrus.

A mid level trough will approach from the west tonight, reaching
Lake Erie and Ohio by 12Z Friday. An area of deeper moisture ahead
of the trough over PA will begin to move northward, bringing an
increase in mainly VFR level clouds late tonight across the Southern
Tier, along with a chance of showers.

Outlook...

Friday...Areas of MVFR and local/brief IFR with showers likely and a
chance of thunderstorms.
Saturday...Areas of MVFR with a chance of showers east of Lake
Ontario, VFR elsewhere.
Sunday through Monday...Mainly VFR.

&&

.MARINE...
High pressure will bring light winds today with local lake
breezes producing onshore flow this afternoon. Northeast winds
will increase on Lake Erie tonight through Friday, producing
very choppy conditions especially southwest of Sturgeon Point.
Winds and waves are expected to remain below Small Craft
Advisory criteria. East to northeast winds will increase a
little on Lake Ontario as well, with a light chop along the
south shore of the lake. Light winds will return for Saturday.

&&

.BUF WATCHES/WARNINGS/ADVISORIES...
NY...None.
MARINE...None.

&&

$$

SYNOPSIS...Hitchcock
NEAR TERM...Hitchcock
SHORT TERM...JM
LONG TERM...JM
AVIATION...Hitchcock
MARINE...Hitchcock