681
FXUS61 KBUF 062103
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
503 PM EDT Mon May 6 2024

.SYNOPSIS...
High pressure will build across the region providing fair and dry
weather through Tuesday. A warm front will cross the region
Tuesday night through early Wednesday with some showers and a
chance of thunderstorms. Unsettled weather will then last the
rest of the week as a trough of low pressure slowly crosses the
Great Lakes.

&&

.NEAR TERM /THROUGH TUESDAY/...
Cirrus will continue to move from west to east across the CWA this
evening. Will still see plenty of sunshine with temperatures in the
60s to low 70s in spots. Much cooler near the influence of the cool
lakes, so bring a sweater if headed there this evening.

Tonight...high pressure will drift east from the Great Lakes into
Ontario and Quebec, maintaining dry and quiet weather across our
region. The high clouds will clear out and winds will be calm,
resulting in good radiational cooling conditions. Lows in the low to
mid 40s in most areas.

The surface high pressure ridge axis will gradually slide east
into New England, but it will keep the area rain-free during the
day Tuesday. Clouds will increase from the southwest during the
afternoon, with a small chance of a shower across the Western
Southern Tier towards sunset. Otherwise, pleasant and warm with
highs in the 70s inland. Cooler along the south shores of Lake
Ontario and Lake Erie due to a northeasterly lake breeze.

&&

.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/...
Tuesday night, a warm front extending from stacked low pressure
centered near North Dakota will move across the region from
southwest to northeast. This front is likely to generate some
convection upstream, with its remnants moving across our area.
Ample elevated instability to support some thunderstorms with
this, especially Tuesday evening. Although precipitation will be
convective, model agreement supports 70-80% PoPs for our area.

Showers will linger into Wednesday, especially east of Lake
Ontario where the front will be last to exit. However, most of
the day will be rain-free, especially across Western NY.
Following the warm frontal passage, temperatures will be above
normal with highs in the low to mid 70s for lower elevations south
of I-90. For Wednesday night, it appears our region will be in
between systems, with mainly rain-free weather. Chances for
showers will increase from the west late in the night.

The stacked low will finally open into a trough aloft and begin
to track slowly eastward Wednesday night through Thursday night.
With this, a surface reflection is forecast to track near the
NY/PA border Thursday night. Models typically struggle with the
progression of upper level systems like this, and there is some
model agreement on the track and timing but fairly good
agreement that there will be widespread showers as this system
moves through. Chances for thunderstorms will be mainly along
and south of the track of the low where there will be some
instability. Meanwhile, there will be higher chances for
precipitation north of the track since it will be more
stratiform precipitation there. This will also bring cooler
weather with below normal high temperatures on Thursday.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
Mid/upper-level troughing overhead and surface low pressure off the
New England coastline at the start of Friday will slide eastward
through the course of Friday and Friday night...allowing ridging at
all levels to build eastward from the Upper Lakes. This will allow
showers to mostly taper off from west to east through Friday
night...though cyclonic/upslope flow may still keep a few of these
going into later Friday night east of Lake Ontario and across the
higher terrain of the Southern Tier/Finger Lakes. Otherwise the cool
cyclonic flow will result in decidedly below normal highs mostly in
the lower to mid 50s Friday...with lows of 40-45 then following for
Friday night.

On Saturday ridging at the surface and aloft will slowly drift east
into eastern New York and western New England...while the next mid-
level trough drops across the Upper Great Lakes. For the most part
the aforementioned ridging should result in mainly dry conditions
prevailing...though there could be a few lingering showers across
our far eastern zones on the western fringes of the departing
initial trough...as well as across far western New York later in the
day as the leading edge of the next mid-level trough begins to
impinge upon the area. Meanwhile some partial sunshine and modest
airmass modification should allow highs to climb back into the mid
50s across the higher terrain and the upper 50s to lower 60s
elsewhere.

The next mid-level trough will then drop across the area Saturday
night and Sunday while bringing a commensurate increase in shower
potential...with the latter likely to peak Sunday afternoon in
conjunction with daytime heating/destabilization of the lower
levels. After that disagreement rapidly increases amongst the medium
range guidance on how quickly this trough flattens out/departs...and
with the resulting forecast uncertainty in mind will keep a general
chance of showers in the forecast through Sunday night and Monday.
As for temps...these should climb back to near normal levels (highs
in the mid-upper 60s and lows in the mid-upper 40s) by the end of
the period.

&&

.AVIATION /21Z MONDAY THROUGH SATURDAY/...
High clouds streaming across the area will move out tonight.
Otherwise...VFR flight conditions to continue across area
terminals.

Tuesday...some mid-level clouds will approach from the west lake
but VFR is likely to remain in place.

Outlook...

Tuesday night...VFR/MVFR. Showers with a chance of thunderstorms.

Wednesday...VFR/MVFR. A chance of showers and thunderstorms.

Thursday...VFR/MVFR. Showers likely with a chance of thunderstorms.

Friday...MVFR. Showers likely.

Saturday...Mainly VFR. A slight chance of showers.

&&

.MARINE...
Surface high pressure with negligible winds and waves through
Tuesday night. Onshore winds will pick up during the afternoon hours
due to lake breeze circulations. Southwest winds will briefly pick
up on Lake Erie on Wednesday behind a warm front. Then low pressure
passing by to the south will cause easterly winds to increase
Thursday and Thursday night with a potential for low-end small craft
headlines.

&&

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

&&

$$

SYNOPSIS...Apffel/Hitchcock
NEAR TERM...AR/Apffel
SHORT TERM...Apffel/SW
LONG TERM...JJR
AVIATION...AR/Apffel
MARINE...Apffel