916
FXUS61 KBUF 030552
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
152 AM EDT Mon Jun 3 2024

.SYNOPSIS...
Lingering moisture from departing low pressure will result in
areas of fog this morning. Weak high pressure will then build
across the region, resulting in mainly dry weather through
Tuesday, although an isolated shower or thunderstorm can`t be
ruled out during the afternoon hours. Above average temperatures
will prevail the first half of the work week before a cold
front brings showers and thunderstorms later Wednesday through
Thursday. The front will also usher in cooler temperatures by
late in the week.

&&

.NEAR TERM /THROUGH TONIGHT/...
Weak low pressure will exit off the New England coast, but it
will leave a lot of boundary layer moisture in its wake. This
will result in lots of cloud cover through this morning. Weak
flow at the surface will allow areas of fog to develop in some
areas, while in others there will just be low stratus but not
much fog. Steady early morning temperatures in the upper 50s to
lower 60s.

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, a partial
clearing and mainly dry weather today 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 range from the
mid 70s to low 80s.

Any showers will taper off by this evening, with rain-free
weather under weak ridging at the surface and aloft.
Considerable breaks in the cloud cover should allow radiation
fog to develop at some locations tonight. This could be locally
dense in the Southern Tier river valleys.

&&

.SHORT TERM /TUESDAY 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 most of Tuesday and 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 SUNDAY/...
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 /06Z MONDAY THROUGH FRIDAY/...
The main aviation concern is low stratus and the potential for
fog to develop through 13Z this morning. Latest TAFs trend more
optimistic on visibility, based on latest trends which have
shown stratus limiting drops in visibility. It remains a low
confidence visibility forecast, and the risk for cloud bases to
drop to the ground resulting in areas of fog still present.
However, now the more likely scenario is for KBUF and KROC to
drop to IFR cigs but for vsby to remain 2SM or greater. A few
lingering showers possible.

Stratus and fog will scatter or dissipate this morning, leaving
mainly VFR flight conditions this afternoon. Ridging at the
surface and aloft will support mainly rain free weather outside
of isolated showers or storms this afternoon which will be
driven by diurnal instability.

There`s risk for more localized (but possibly dense) fog
tonight. With light winds this will depend on breaks in the
mid-level clouds with the greatest risk for fog in the Western
Tier Valleys (including KJHW).

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/Apffel
NEAR TERM...AR/Apffel
SHORT TERM...JM
LONG TERM...EAJ
AVIATION...Apffel
MARINE...AR/Apffel