287 
FXUS61 KBUF 061437
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
1037 AM EDT Mon Sep 6 2021

.SYNOPSIS...
A cold front will cross the region today causing a few more showers, 
mainly inland and east of Lake Ontario, while sunny weather is 
expected for the Niagara Frontier this afternoon. Dry weather
will return for Tuesday, before the next chances for showers 
and a few thunderstorms arrive Tuesday night and Wednesday.

&&

.NEAR TERM /THROUGH TONIGHT/...
An upper level trough with an associated cold pool is nearly 
overhead, while an associated cold front is moving east across 
the lower Great Lakes region. This setup, together with 
relatively warm waters over the Great Lakes, is setting up lines
of convection that are moving ESE over the region. The last 
line has already moved through the Niagara Frontier. So, that 
region should see increasingly sunny skies through at least 
early afternoon. 

Meanwhile, convection continues further inland, with the strongest 
storms east of Lake Ontario (SPC marginal risk area).  Main concern 
there for the next few hours will be fast moving storm segments, 
some with some rotation.  

A few more showers may try and form later this afternoon along the 
cold front and along lake breeze boundaries, but those would be 
widely scattered and short-lived. 

Shower chances will continue for areas southeast of both lakes 
tonight due to cool west-northwesterly winds flow across the water 
surface. These chances will gradually peter out as surface high 
pressure pushes invades the area.

&&

.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
High pressure will drift across the region Tuesday supporting dry 
weather. South-southwest flow will pickup in the afternoon ahead of 
the next system, with associated warm advection and downslope flow 
helping temperatures reach to around 80 on the lake plains of 
Western New York. Cooler air aloft will linger for the North 
Country, with highs ranging from the mid 70s at lower elevations to 
upper 60s higher terrain.

A sharp mid level trough and closed low will then advance from near 
Lake Superior Tuesday night to near James Bay Wednesday evening, 
with a vertically stacked surface low taking a similar track. A 
surface cold front will surge east across the eastern Great Lakes 
late Tuesday night and Wednesday. Strong convergence along the front 
coupled with increasing large scale ascent ahead of the trough will 
produce a band of showers and possibly a few gusty thunderstorms, 
entering Western NY late Tuesday night and then advancing east 
across the rest of the area through the first half of Wednesday.

A dry slot behind the cold front will bring a return to mainly dry 
weather from west to east later Wednesday. It will become quite 
breezy Tuesday night and Wednesday as the cold front crosses the 
area, with gusts of 25-30 knots expected northeast of Lakes Erie 
and Ontario.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
The longwave pattern across North America will still be quite 
amplified at midweek, but will become much more zonal next weekend. 
A strong ridge over the 4 corners at midweek will flatten and 
spread east, dominating much of the southern 2/3 of the nation by 
next weekend, with zonal westerlies setting up along the US/Canadian 
border.

Looking at the details, a mid level trough and associated cool air 
aloft will advance slowly east across the Great Lakes and New 
England Wednesday night through Friday. A series of shortwaves 
moving through the longwave trough will bring a chance of a few 
showers at times. Cool air aloft may also support lake effect rain 
showers east and southeast of the lakes. The trough will move east 
of the area Friday night and Saturday, allowing for a return to 
dry weather.

Temperatures will run a little below normal through mid to late 
week, with highs generally in the lower 70s for lower elevations and 
mid to upper 60s for higher terrain. Lows will generally be in the 
50s, with some 40s possible in the cooler Southern Tier Valleys and 
North Country if skies clear enough at night. A warming trend will 
start next weekend as the pattern becomes more zonal and warm 
advection begins.

&&

.AVIATION /15Z MONDAY THROUGH FRIDAY/...
The most active line of thunderstorms moved east of the KART as of 
14Z, although one more weak line still exists roughly from KJHW to 
KFZY. This should continue to move east over the next several hours 
as the main cold front moves in.  There may be some widely scattered 
showers with the front and/or along developing lake breeze 
boundaries, but these should be relatively short-lived. Overall, VFR 
flight conditions should prevail across all TAF sites.

Tonight, any leftover showers will move east of the forecast area 
and allow for VFR conditions for most areas as surface high pressure 
enters the state.  Some inland valley fog however may be possible 
late tonight. 

Outlook...

Tuesday. VFR. 
Wednesday...Areas of MVFR in showers.
Thursday and Friday...Mainly VFR with a chance of showers.

&&

.MARINE...
Colder air aloft arrived overnight resulting in a chance of 
waterspouts across Lake Erie early this morning through mid morning, 
and all day on Lake Ontario. Best chances for waterspouts will be 
with the showers and storms along a cold front as it crosses the 
region.

Additionally, winds will increase through this morning on Lake Erie, 
and during the day today on Lake Ontario as the previously mentioned 
cold front crosses the lakes. The increase in winds and waves has 
resulted in small craft advisories for all but the Niagara River and 
St. Lawrence River. 

The higher waves today into this evening have also resulted in the 
issuance of Beach Hazard Statements for most of the Lake Erie and 
Lake Ontario shoreline zones as outlined below.

&&

.BUF WATCHES/WARNINGS/ADVISORIES...
NY...Beach Hazards Statement through late tonight for NYZ003-006-
     007.
     Beach Hazards Statement through late tonight for NYZ004-005.
     Beach Hazards Statement until 8 PM EDT this evening for NYZ001-
     002.
     Beach Hazards Statement until 5 PM EDT this afternoon for 
     NYZ019-085.
MARINE...Small Craft Advisory until 5 PM EDT this afternoon for LEZ040-
         041.
         Small Craft Advisory until 5 AM EDT Tuesday for 
         LOZ043-044.
         Small Craft Advisory until 2 AM EDT Tuesday for LOZ042-045.

&&

$$

SYNOPSIS...EAJ/Zaff
NEAR TERM...EAJ
SHORT TERM...Hitchcock/TMA
LONG TERM...Hitchcock
AVIATION...EAJ/Zaff
MARINE...EAJ/JLA/SW