632
FXUS61 KBUF 030222
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
1022 PM EDT Sun Jun 2 2024

.SYNOPSIS...
Scattered showers will gradually end tonight as weak low pressure
dissipates over the area. The system will leave behind plenty of
moisture, resulting in areas of low clouds and fog overnight through
Monday morning. Mainly dry weather returns Monday, although an
isolated shower or thunderstorm is possible in the afternoon. Above
average temperatures will prevail the first half of the week before
a cold front brings showers and thunderstorms later Wednesday
through Thursday, with the front ushering in cooler temperatures by
late in the week.

&&

.NEAR TERM /UNTIL 6 PM MONDAY EVENING/...
A mid level shortwave will move east across NY, reaching western New
England overnight while deamplifying with time. At the surface, a
remnant low has essentially dissipated across the eastern Great
Lakes. The weakening forcing and eastward progression of the
trough will allow remaining showers this evening to gradually
taper off and end overnight, although some patchy drizzle may
continue in areas of low clouds.

The washing out surface low will leave plenty of low level moisture
behind. Surface dewpoint depressions are already minimal across
Western NY, and forecast thermal and moisture profiles are quite
supportive of fog and low stratus development overnight, especially
across Western NY. Expect fog to gradually increase in coverage
after dark, and may become quite widespread across Western NY, the
Genesee Valley, and western Finger Lakes by late tonight.

Monday, areas of low stratus and fog will likely persist through the
morning commute, especially across Western NY where low level
moisture is forecast to be most widespread. The fog will dissipate
as the morning progresses. Otherwise, mainly dry weather will return
Monday as weak mid-level ridging builds into the region. That said,
an isolated shower or thunderstorm will still be possible during
peak heating where low level convergence is enhanced by differential
heating, terrain, and lake breeze boundaries. Highs will be found
solidly in the 70s to low 80s in spots.

&&

.SHORT TERM /6 PM MONDAY EVENING THROUGH THURSDAY/...
Ridging aloft will remain in place through Tuesday night keeping
mainly dry conditions intact, before a cold front slowly crosses the
region bringing showers and thunderstorms to western and
northcentral NY midweek. Meanwhile, surface high pressure will move
from eastern NY to the New England coast by Tuesday night allowing
for very warm and increasingly humid conditions through Wednesday,
before cooler weather starts to filter in across the region Thursday
in wake of a cold front.

Mainly dry weather is expected Monday night through most of Tuesday
night with high pressure surface and aloft in control of our
weather. Other than limited diurnal instability developing second
half of Tuesday possibly producing an isolated shower or
thunderstorm during the afternoon/early evening hours along and
inland of any lake breeze circulations, ridging will suppress most
if not all convection. Very warm Tuesday with highs averaging about
10 degrees above average, translating to low to mid 80s for much of
the area, slightly cooler highest terrain areas. Tolerable humidity
levels will hold on for one more day.

Mid/upper level ridge starts to break down and shift east late
Tuesday night and Wednesday as upstream deepening trough digs
southeastward across the upper and central Great Lakes. At the
surface, several boundaries extending from associated low pressure
over northwestern Ontario will cross the area from late Tuesday
night through Thursday. First will be a weak warm front that may
spark off a few showers/isolated storm east of the Finger Lakes late
Tuesday night/early Wednesday at moves through. Next up will be a
prefrontal trough Wednesday, although overall forcing appears to be
fairly weak with this feature. That said, a very moist airmass in
place behind the warm front combined with strong diurnal heating may
produce some scattered showers and thunderstorms, especially during
the afternoon and evening. Muggy and warm conditions continue
Wednesday, with similar temperatures to Tuesday, however temps will
be lower in areas that see more persistent showers and storms.

The main show this time around will be with the actual cold front as
it slowly moves east across the area Wednesday night through the
first half of Thursday. Severe weather threat with the cold front
looks low at this time, especially with the poor diurnal timing. The
more notable threat looks to be heavy rain with any stronger
thunderstorms (tall skinny CAPE profiles) owed to a slow moving
front combined with PWATs upwards of 1.50-1.75 inches. In fact, WPC
has our area outlined in a MRGL Risk (5%) for heavy rain during this
timeframe. Cold front should clear east of the area by Thursday
afternoon, however a cool/moist cyclonic flow aloft associated with
a "bowling ball" trailing upper level low combined with an
increasingly unstable environment owed to strong diurnal heating
will keep the likelihood for showers and storms going through the
peak heating hours of the day. The deeper moisture will have been
stripped away with the earlier cold frontal passage, significantly
lowering the overall heavy rainfall threat. Stronger steering flow
aloft will also keep storms moving right along, although steepening
low level lapse rates and better shear profiles may allow a few
stronger storms to develop. Change back to a cooler regime
starts Thursday, with highs mainly in the 70s.

&&

.LONG TERM /THURSDAY NIGHT THROUGH SATURDAY/...
Low forecast confidence for the Thursday night through Sunday
timeframe due to an upper level cut off low overhead of the Great
Lakes. Said upper level low will also allow a few embedded
shortwaves to round its base. This far our its hard to pinpoint the
exact location and timing of the shortwaves. Overall this will
support a persistent risk of showers and isolated thunderstorms each
day. Additionally, if the timing of the shortwave passages align
with peak diurnal heating there may be a threat that some
thunderstorms become frisky and turn severe. However on the
optimistic side of things there will be plenty of rain-free time
between shortwave passages.

With the upper level low overhead, expect a cooling trend as
continental polar air over Canada filters southeast across the Great
Lakes. Highs Friday through Sunday will range in the mid to upper
60s across the higher terrain and the low 70s elsewhere.

&&

.AVIATION /02Z MONDAY THROUGH FRIDAY/...
A mid level shortwave will move east of the area into western New
England overnight, while an associated weak surface low dissipates
over the eastern Great Lakes. Remaining showers this evening will
gradually taper off and end overnight as the system continues to
weaken, although some patchy drizzle may continue in areas of low
clouds.

The main concern overnight through Monday morning will be the
potential for widespread fog and low stratus. The washing out system
will leave behind abundant low level moisture, with forecast
soundings and model guidance quite supportive of widespread IFR in
fog and low stratus across Western NY, the Genesee Valley, and
western Finger Lakes overnight through Monday morning. The most
widespread IFR will likely be from about 06Z-13Z Monday.

The fog and low stratus will gradually evolve into an MVFR
stratocumulus deck as Monday morning progresses, then improve to VFR
in the afternoon as low level moisture mixes out. An isolated shower
or thunderstorm is possible Monday afternoon, but the majority of
the area will stay dry.

Outlook...

Tuesday...VFR.
Wednesday...Mainly VFR with a chance for showers and thunderstorms,
especially in the afternoon.
Wednesday night and Thursday...Areas of MVFR with showers and
thunderstorms likely.
Friday...VFR/MVFR with a chance of showers. Chance of a few spotty
thunderstorms Friday afternoon and evening.

&&

.MARINE...
A weak pressure gradient will continue to maintain light winds and
minimal waves into mid-week.

A cold front will cross the eastern Great Lakes Wednesday night and
Thursday with a few rounds of thunderstorms likely. West to
southwest winds will increase on the lakes behind the cold front
Thursday through Friday with choppy conditions developing.

&&

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

&&

$$

SYNOPSIS...AR/Hitchcock
NEAR TERM...AR/Hitchcock
SHORT TERM...JM
LONG TERM...EAJ
AVIATION...Hitchcock
MARINE...AR/Hitchcock