970
FXUS61 KBUF 091023
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
623 AM EDT Sun Jun 9 2024

.SYNOPSIS...
Widespread rain will end from west to east early this morning, but
the mainly dry weather will be brief, with another deep trough
crossing the area this afternoon producing occasional showers and
scattered thunderstorms. Scattered showers and cool temperatures
will continue through Monday. A drying and warming trend will then
develop through the middle of the week.

&&

.NEAR TERM /THROUGH TONIGHT/...
Radar imagery showing widespread light to moderate rain from the
Genesee Valley eastward as of 1030Z this morning. The back edge of
the rain is advancing quickly east, with rain now ending across
Western NY.

A deep mid level closed low will continue to move east across
southern Quebec today through tonight, with the trailing trough axis
digging through the Great Lakes today, and into New England tonight.
This will keep a cool and unsettled pattern in place to finish out
the weekend.

A well defined baroclinic wave (marked by a nice baroclinic leaf
signature on IR satellite) will continue to move northeast across
the area early this morning. A wide area of enhanced frontogenesis
and deformation in the low/mid levels will be topped by large scale
ascent from DPVA and height falls from the approaching trough, and
strengthening upper level divergence from a passing upper level jet
streak. The wave is moving quickly, with the widespread rain
tapering off from west to east during the early to mid morning as
the wave moves east towards eastern NY and New England.

A brief window of drier air and subsidence will build into the
eastern Great Lakes for a few hours mid to late morning, with a
short stretch of mainly dry weather and even some sunny breaks. It
will turn quite breezy again today, with gusts in the 25-35 mph
range.

Another strong mid level vorticity maxima will then rotate through
the longwave trough and cross Lake Ontario and western/central NY
during the afternoon. The increase in large scale ascent and
moisture along with steep low/mid level lapse rates will bring
increasing coverage of showers this afternoon. A well defined near
surface convergence zone will setup from the Niagara Frontier east
across the Genesee Valley and northern Finger Lakes, marking the
boundary between the general WNW flow and the WSW flow forced by a
backing of winds by the Lake Erie breeze. This convergence zone will
act as the initial low level focus for increasing showers during
early to mid afternoon, with the resulting area of showers then
moving southeast across the rest of the area. The cool air aloft and
steep lapse rates coupled with synoptic scale forcing will support
scattered thunderstorms as well, a few of which may produce gusty
winds and small hail.

Showers will decrease in coverage from northwest to southeast this
evening as the vorticity maxima moves southeast of the area.
Overnight, additional weaker shortwaves, deepening moisture, and
even some lake induced instability will support a few more scattered
showers, increasing in coverage towards Monday morning.

&&

.SHORT TERM /MONDAY THROUGH WEDNESDAY/...
An upper level trough over the Northeast will become elongated down
to the central Appalachians Monday through Tuesday. An upper level
ridge will nose into the Great Lakes region Tuesday night while a
shortwave trough moves across the Mid-Atlantic region. The ridge
will flatten out across the forecast area into Wednesday.

Cool, northwest flow with 850mb temperatures falling to +3C will
result in the coolest day of the recent stretch of unsettled weather
on Monday. Highs will reach the low to mid 60s across the lower
elevations and upper 50s to near 60 across the higher terrain. A
500mb trough axis and deep layer moisture will move across the
forecast area Monday. The cooler airmass may create lake induced
instability and scattered to numerous rain showers will track from
the Lakes to inland areas, with showers lingering the longest across
southeast portions of the forecast area Monday.

Showers will come to an end Monday evening. The upper level trough
will remain across the region through Tuesday night. Drier air and
low level subsidence will be increasing across the region, however
mostly cloudy conditions will persist most of the time. Tuesday will
begin the warming trend across the region with highs in the upper
60s to low 70s, mid to upper 60s across the higher terrain. Finally,
the elongated trough will move east of the region Wednesday. This
will promote dry and warmer weather with highs in the mid to upper
70s.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
A trough will deepen across the Great Lakes region as an upper level
ridge builds across the Rockies late in the work week. A strong,
southerly flow will promote warm weather Thursday through Friday. An
area of low pressure is expected to track across northern Ontario
and Quebec Thursday through Friday with a cold front impacting the
region during this time. There is low confidence in the timing of
the front, however this should bring a period of scattered showers
and thunderstorms. An area of high pressure is expected to move into
the region this weekend with medium confidence of dry, fair
weather.

Temperatures will begin above normal mid-week and fall to near
normal for the weekend.

&&

.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
Widespread rain will quickly taper off from west to east through mid
morning. A brief period of low stratus will persist for a few hours
after the rain ends with areas of MVFR/IFR CIGS. These low clouds
will quickly scatter out through mid to late morning with most areas
returning to VFR.

There will be a brief break in the rain following the early morning
exit of the widespread rain from the frontal wave. Midday into the
afternoon, another mid level trough will move southeast across the
area, and combine with modest daytime instability and lake/terrain
generated low level convergence boundaries to generate another area
of showers and scattered thunderstorms crossing the area from
northwest to southeast. Expect areas of MVFR CIGS/VSBY to develop,
with local/brief IFR in thunderstorms.

The more organized showers and scattered thunderstorms will taper
off this evening, although a few scattered showers may linger
overnight. CIGS/VSBY should improve back to VFR initially in the
evening, but areas of MVFR CIGS will likely develop overnight in
stratus.

Outlook...

Monday...Areas of MVFR with scattered showers.
Tuesday through Thursday...Mainly VFR.

&&

.MARINE...
Westerly winds will ramp up again today, with another round of Small
Craft Advisory conditions on both lakes. Winds will decrease on Lake
Erie this evening, but Small Craft Advisory conditions will continue
much of tonight on Lake Ontario. Winds will be somewhat lower
Monday, but still expect choppy conditions on both lakes.

More favorable winds and waves for boating will return by the middle
of the week.

&&

.BUF WATCHES/WARNINGS/ADVISORIES...
NY...Beach Hazards Statement from 11 AM EDT this morning through
     Monday morning for NYZ004.
     Beach Hazards Statement through Monday morning for NYZ005>007.
     Beach Hazards Statement from 11 AM EDT this morning through
     this evening for NYZ010-019-085.
MARINE...Small Craft Advisory from 11 AM this morning to 8 PM EDT this
         evening for LEZ020.
         Small Craft Advisory from 11 AM this morning to 11 PM EDT
         this evening for LEZ040-041.
         Small Craft Advisory from 11 AM this morning to 5 AM
         EDT Monday for LOZ042.
         Small Craft Advisory from 11 AM this morning to 11 AM EDT
         Monday for LOZ043>045.

&&

$$

SYNOPSIS...Hitchcock
NEAR TERM...Hitchcock
SHORT TERM...HSK
LONG TERM...HSK
AVIATION...Hitchcock
MARINE...Hitchcock