739
FXUS61 KBUF 170915
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
515 AM EDT Fri May 17 2024

.SYNOPSIS...
A trough of low pressure will slowly cross the area today and
tonight bringing a soaking rainfall to much of the region along with
the chance for a few thunderstorms. A few showers may linger into
Saturday before high pressure then builds across the area Sunday
bringing a dry finish to the weekend. Above normal temperatures will
continue for the end of the work week into this weekend.

&&

.NEAR TERM /THROUGH TONIGHT/...
After a dry start to the day, a trough of low pressure to our west
will move into far western NY later this morning, then slowly track
east across the Genesee Valley and Finger Lakes this afternoon into
this evening. Meanwhile, mid and upper level ridge axis will shift
just to our east while amplifying a bit, and stubborn surface high
pressure remains wedged in across New England. This setup will lead
to a slowing of the system`s eastward progression and eventually
also a weakening of the system as it tries to push into eastern NY
this evening into tonight as it runs into the aforementioned high
pressure ridged across New England. In terms of sensible weather,
this will translate to a band of showers with some embedded thunder
slowly moving from west to east across areas south of Lake Ontario
this afternoon into this evening. Better instability remains across
western NY, especially with the timing being during the hours of
daytime heating. This will lead to some enhanced convection with the
chance for thunderstorms that could contain some locally heavy
downpours across western NY. Convection will weaken as it moves
toward the eastern Lake Ontario this evening as daytime instability
wanes and the system encounters high pressure anchored to the east.
The trough will continue to linger overnight with chances for some
scattered light showers and possibly and rumble of thunder, mainly
from the Genesee Valley eastward.

QPF amounts continues to trend upward across western NY owed to the
slowing down of the system and favorable diurnal timing. Highest
rainfall totals today through tonight will be across areas from the
Genesee Valley westward, where basin average rainfall looks to now
average from around one half to three quarters of an inch, with
localized higher amounts within any areas of embedded convection.
Much lower amounts east of the Genesee Valley with a tenth to a
quarter of an inch.

Highs today will remain above normal with mainly low to mid 70s
expected, upper 60s higher terrain. Lows tonight mid to upper 50s.

&&

.SHORT TERM /SATURDAY THROUGH MONDAY NIGHT/...
Residual effects from the slow departing mid-level shortwave in
concert with diurnal heating will allow for a few showers to blossom
on Saturday. The best potential for showers will be found across the
S. Tier, and possibly along any lake breeze boundary. High
temperatures Saturday will be found in the low to mid 70s.

High pressure aloft (500mb) will begin to amplify across the region
beginning Saturday evening with dry weather expected overnight.

High pressure will continue to dominate the rest of this time frame
with dry weather Sunday through Monday night.

Temperatures will climb well above normal with highs firmly in the
mid to upper 70s Sunday, then upper 70s to low-mid 80s Monday.

&&

.LONG TERM /TUESDAY THROUGH THURSDAY/...
High pressure looks like it will maintain dry weather for most
locales on Tuesday. However...an isolated shower or thunderstorm
can`t ruled out. This will all depend on the trough approaching from
the west, or advertised shortwave energy rippling along the western
edge of the mid-level ridge. Have low end chance PoPs for now across
the Southern Tier. Mild day is on tap with highs in the upper 70s to
low-mid 80s.

A better chance of showers and thunderstorms looks on tap for
Wednesday through Thursday. This will come as the trough and
associated cold front arrives across the region. Still lots of
uncertainty this far out with timing issues but unsettle weather
looks like it will return. Additionally...it appears that it will
usher in some cooler temperatures or back to near normal atleast for
late May.

&&

.AVIATION /09Z FRIDAY THROUGH TUESDAY/...
Aside from valley fog that formed overnight, VFR flight conditons
and dry weather in place to start the day, before conditions start
to deteriorate from west to east from later this morning on.

Otherwise, a trough of low pressure off to the west will move into
the region today with worsening conditions for the second half of
the day into the evening. Mainly VFR flight conditions are expected
to hold on through at least midday with thickening and lowering mid
level decks through the morning hours in advance of the approaching
system. Showers and associated MVFR CIGS will move into the western
Southern Tier (KJHW) early to mid afternoon, then spread northeast
across the Niagara Frontier (KBUF/KIAG) mid to late afternoon, and
eventually into the Genesee Valley (KROC) by late afternoon/early
evening. IFR CIGS are then expected to develop across the western
Southern Tier (KJHW) late afternoon/early evening, then into the
Niagara Frontier (KBUF/KIAG) early evening, and eventually into the
Genesee Valley (KROC) by late evening. Meanwhile, a few showers may
make it into the eastern Lake Ontario region (KART) by late in day
into the evening hours with associated low VFR CIGS.

MVFR/IFR VSBY will also be possible within any heavier convection/
thunderstorms across areas south of Lake Ontario this
afternoon/evening.

Outlook...

Saturday...Areas of MVFR with a chance for showers.
Sunday through Tuesday...Mainly VFR. An isolated shower Tuesday on
Lake Erie lake breeze.

&&

.MARINE...
A weak pressure gradient will continue the generally light winds
through this weekend into the start of next week. A light offshore
southeasterly flow will increase some today as a weak trough of low
pressure slowly crosses the Lake. Following the passage of the weak
system, winds will remain light through Tuesday. The next system
will be a stronger cold front that will cross the Lake toward mid
week bringing the next notable increase in winds and waves.

&&

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

&&

$$

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