National Weather Service National Headquarters

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

-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KBUF 170840
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
440 AM EDT Wed Apr 17 2024

.SYNOPSIS...
-- Changed Discussion --
Showers will move from west to east across the region today and
tonight. A cold front will track across the region tonight and a few
thunderstorms are possible across western NY this evening. High
pressure will move into the region Thursday and Thursday night.
-- End Changed Discussion --

&&

.NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --
Regional radar shows an arch of precipitation from Upper Michigan to
Lake Huron to eastern Ohio this morning. Lightning has been reported
within this line across southern Ontario. Mid to high level clouds
will increase from west to east across western and north central NY.

A closed low is located over southern Minnesota this morning. This
large system will move east-northeast today and tonight and bring
unsettled weather to the forecast area. Initially, an upper level
ridge axis resides across western NY this morning. This ridge axis
will move east and reach the Hudson Valley by this evening.
Increasing southwesterly flow on the west side of the ridge axis and
increasing moisture will increase cloud cover across western NY this
morning. A band of rain showers that extend from southern Ontario to
eastern Ohio are at the nose of a 40kt low level jet. Mesoanalysis
and forecast soundings show weak elevated instability across
northern Ohio. Lightning was observed across southern Ontario and
may result in some rumbles of thunder across the western Southern
Tier through mid-morning. This area of showers will move across
western NY and by midday, rain showers will encompass most of
western NY with dry conditions remaining east of Lake Ontario. A dry
slot will start to work its way into western NY this afternoon. This
could open the window for some gusty downslope winds off the
Chautauqua Ridge, however gusts shouldn`t exceed 35 mph in
favorable locations. As the upper level ridge axis moves into
eastern New York, rain showers will move into the eastern Lake
Ontario region by late afternoon. High temperatures will reach the
mid to upper 60s across favorable downslope areas and to the upper
50s to low 60s across the remainder of the forecast area. Rainfall
amounts will average 0.1-0.25 inches across western NY today.

Surface low pressure will weaken as it moves from the U.P. of
Michigan to Northeastern Ontario tonight. Upstream convection will
move into far western NY, ahead of a trailing cold front this
evening. Instability will be decreasing with the loss of daytime
heating, however up to 500 J/Kg of MUCAPE is possible west of the
Genesee Valley. Shear profiles are favorable for organized
convection and any thunderstorms that develop may continue into far
western NY before weakening further east. There is a Marginal risk
of Severe Weather across Chautauqua county with the main concerns
being strong winds and large hail, mainly between 22z-02z. Showers
and any thunderstorms will move east overnight with drier weather
entering western NY behind the cold front. Rainfall amounts will
range with the potential for thunderstorms, however basin wide
averages of 0.25 to 0.50 inches are possible across the western
Southern Tier and the eastern Lake Ontario region. Lesser amounts
are expected from the Niagara Frontier to the Finger Lakes region.
-- End Changed Discussion --

&&

.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
-- Changed Discussion --
A progressive pattern will keep systems moving fairly rapidly from
west to east across the area through the period.

Weakening upper wave and associated surface occluded front will
finish slowly pushing through the eastern half of the forecast area
on Thursday. Supporting weak upper wave will lag behind its surface
reflection, so a few scattered showers will remain possible across
areas from the Genesee Valley west through midday/early afternoon,
before transient ridging nudges into western NY bringing a mainly
dry finish to the day there. Meanwhile, deeper moisture ahead of
this occluded boundary will keep steadier showers going east of Lake
Ontario through the morning hours, before tapering off to more in
the way of scattered activity in the wake of the boundary as its
upper level support swings through. With regard to rainfall amounts,
an additional one to two tenths of an inch will be possible from the
eastern Finger Lakes to the North Country, while less than a tenth
of an inch is expected for the western Finger Lakes and points
westward. Fairly seasonable temperatures with highs ranging from the
mid and upper 50s east of Lake Ontario to the low to mid 60s from
the Finger Lakes westward, cooler across the higher terrain.

Aforementioned transient ridging will then slide east across our
region providing a brief period of mainly dry weather Thursday
night. A few lingering scattered will light showers will remain
possible first half of the night east of Lake Ontario as surface
boundary that moved through on Thursday stalls just to our east,
then washes out overnight. Lows will mainly range from the mid to
upper 40s.

A northern stream system will then slowly strengthen as it moves
across northwest Ontario into central Quebec Friday and Friday
night. While this will keep the steadier synoptic precipitation north
of our area, it will push an associated strong cold front across the
area on Friday bringing a period of rain showers that will trek from
west to east across western and northcentral NY from later Friday
morning through the afternoon hours. Basin average rainfall will
average from a tenth to a quarter of an inch. Other than a few
lingering scattered light showers east of the Finger Lakes Friday
evening, a surface ridge will nose into the region bringing another
brief period mainly dry weather Friday night. Decent cold air
advection behind the front will cool things off a bit Friday night
with more seasonable lows ranging from the mid 30s to low 40s.
-- End Changed Discussion --

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
-- Changed Discussion --
A potent shortwave moving through the base of an upper level trough
will cross the area Saturday, while forcing a secondary surface cold
front across the region during the morning hours bringing renewed
chances for some scattered showers and maybe even a few wet flakes
across the highest terrain. The main supporting shortwave will cross
the area Saturday afternoon. With the cold pool residing aloft,
expect some uptick in shower activity Saturday afternoon with at
least scattered instability showers developing.

A large area surface high pressure will then build east across the
region Saturday night through at least Monday night bringing a
period of dry weather for the second half of the weekend and start
of the new work week. However, with broad troughing remaining in
place aloft, temperatures will remain on the cool side for Sunday,
before the airmass modifies some on Monday.

Models then diverge on the timing and location of the next system
possibly impacting the area by Tuesday into the mid week timeframe,
so will keep PoPs capped at low chance for now.

Temperatures will start out below normal for the first half of the
period, with highs mainly in the mid 40s to low 50s through the
weekend. Temperatures will rise to near normal by Monday, with above
average highs expected for Tuesday. This will translate to a range
of 50s across the area for Monday, with mid 50s to mid 60s by
Tuesday.
-- End Changed Discussion --

&&

.AVIATION /09Z WEDNESDAY THROUGH SUNDAY/...
-- Changed Discussion --
VFR conditions will continue across western and north central NY
this morning. Overall, mid to high level clouds will increase from
west to east this morning. Rain showers will enter western NY as a
warm front approaches from the west. Showers and lowering ceilings
will expand east resulting in low- end VFR to MVFR conditions across
western NY by this afternoon. VFR conditions will persist east of
Lake Ontario (KART) today. Unsettled conditions with degraded flight
conditions will continue into this evening with rain showers in
vicinity of Lake Ontario and the eastern Lake Ontario region. Mainly
MVFR conditions are expected across the region but IFR conditions
are possible across the Finger Lakes region and into central NY
(outside of TAF sites.)

Another round of showers with a chance of thunderstorms will enter
western NY this evening. Thunderstorms and heavy showers may result
in IFR or lower at KIAG, KBUF, and KJHW through this evening.
Confidence is low for coverage of convection, however best
chance will be near the NY/PA line and KJHW between (22z-03z.)

Outlook...

Wednesday night and Thursday...MVFR/VFR with showers likely.
Friday and Saturday...MVFR/VFR with a chance of showers.
Sunday...Mainly VFR.
-- End Changed Discussion --

&&

.MARINE...
-- Changed Discussion --
Easterly winds will increase today with Small Craft Advisory
conditions expected along portions of Lake Ontario, especially on
the western end ahead of an approaching warm front.

Winds turn more southerly on both Lakes behind the warm front by
Thursday.
-- End Changed Discussion --

&&

.BUF WATCHES/WARNINGS/ADVISORIES...
NY...None.
MARINE...Small Craft Advisory until 2 AM EDT Thursday for LOZ042-043.

&&

$$

SYNOPSIS...HSK
NEAR TERM...HSK
SHORT TERM...JM
LONG TERM...JM
AVIATION...HSK
MARINE...HSK/JM/TMA