Special Weather Statement, NWS Buffalo, NY

Area Forecast Discussion
National Weather Service Buffalo NY
133 AM EDT Tue Aug 18 2020

.SYNOPSIS...
Colder air moving in behind a frontal boundary will bring a period
of lake effect showers and isolated thunderstorms overnight. A
few more showers will be possible again Tuesday afternoon. But
overall, the remainder of the week should be dry and
refreshingly cooler when compared to the relatively warm and
humid summer.

&&

.NEAR TERM /THROUGH TODAY/...
Showers associated with surface frontal boundary sliding south and
east of the area. Renewed convection getting its act together east
of Lake Ontario. Latest CAMs suggesting that the bulk of the
convection through sunrise will be east of Lake Ontario with ample
fetch, although there may also be lake effect clouds or brief
showers east of Lake Erie too. As is typical for this time of year,
any locations that cool enough to approach the dewpoint overnight
may see some patchy ground fog, with more concentrated fog in
typical inland river valleys and where the rain occurred this
evening.

On Tuesday, any lake effect showers or clouds will be replaced by a
more summer-like pattern with ample inland cumulus and lake shadows
in a NW flow.  There may be a brief window for a lake breeze-forced
line along the Thruway from Buffalo to Rochester late in the day
that will move SE and fall apart.  But otherwise, most areas should
remain dry and much cooler when compared to the recent warm summer.
Highs should only be a few degrees cooler over a 24hr period, but
dewpoints will continue to slide downward through the 50s making for
a comfortable afternoon.

&&

.SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
Plenty of cold air will continue to be advected into the area
Tuesday night with 850mb temperatures falling to +8C. Additionally,
high pressure will continue to build east into the region from the
north central Plains acting to dry things out across Western New
York. A few leftover lake breeze induced showers along the Southern
Tier will dwindle off at the start of Tuesday evening before
completely drying out. Temperatures Tuesday night will drop into the
50s with the warmer temperatures occurring along the lower elevation
in close proximity of the lakes.

High pressure will continue to build overhead Wednesday and Thursday
allowing for the dry conditions to prevail. Temperatures will
gradually climb in these couple of days. Highs on Wednesday will be
in the low to mid 70s, while Thursday will see highs in the mid to
upper 70s.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
To start of the extended, the large upper level trough over the east
half of the CONUS will have begun to lift northeast into Canada
allowing the long wave pattern overhead of the area to become more
zonal. At the surface however, high pressure will continue to
influence the dry conditions occuring across the region Friday and
the first half of Saturday.

A shortwave over eastern Manitoba will progress east through the
longwave zonal pattern this weekend. As such, the associated surface
front associated with the shortwave will track across the forecast
area late Saturday through Sunday, marking a period of showers and
storms. With the exit of the frontal boundary Monday, a return of
dry weather is expected as high pressure will work its way east from
the Upper Great Lakes.

Temperatures will be on the warm side throughout the period. Expect
highs in the low to mid 80s each day. The only exception will be
Sunday, as the frontal passage will keep things on the cooler side
and cause highs will reach upper to low 80s.

&&

.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
Expect VFR conditions overnight with some overnight MVFR ground fog
or local IFR in valley fog or where rain occurred this evening. Lake-
driven convection east of Lake Ontario will likely remain south of
KART.

On Tuesday, expect mostly VFR conditions. There may be a broken line
of showers on a lake breeze boundary from about KBUF-KROC late in
the afternoon that would move SE with time.

Outlook...
Wednesday through Friday...VFR except for AM inland river valley fog.
Saturday...VFR, but with a chance of inland showers.

&&

.MARINE...
A few showers and isolated thunder will be possible overnight.
Waterspouts will be possible with any stronger showers/storms,
especially on the eastern end of Lake Ontario through Tuesday
morning. High pressure will then build across the region later
Tuesday and persist through much of the week.

&&

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

&&

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

Hazardous Weather Outlook
National Weather Service Buffalo NY
543 AM EDT Mon Aug 17 2020

NYZ001>008-010>014-019>021-085-180945-
Niagara-Orleans-Monroe-Wayne-Northern Cayuga-Oswego-Jefferson-Lewis-
Northern Erie-Genesee-Wyoming-Livingston-Ontario-Chautauqua-
Cattaraugus-Allegany-Southern Erie-
543 AM EDT Mon Aug 17 2020

This Hazardous Weather Outlook is for western and north central New
York.

.DAY ONE...Today and tonight.

No hazardous weather is expected at this time.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday.

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

This product, along with other watches, warnings, advisories, and
statements issued by the National Weather Service office in Buffalo
can be found on the internet at http://www.weather.gov/buf

LEZ020-LOZ030-SLZ022-024-180945-
Upper Niagara River and Buffalo Harbor-Lower Niagara River-
Saint Lawrence River from Cape Vincent to Ogdensburg-
Saint Lawrence River from Ogdensburg to Saint Regis-
543 AM EDT Mon Aug 17 2020

This Hazardous Weather Outlook is for portions of Lake Erie, Lake
Ontario and Saint Lawrence River.

.DAY ONE...Today and tonight.

No hazardous weather is expected at this time.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday.

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

This product, along with other watches, warnings, advisories, and
statements issued by the National Weather Service office in Buffalo
can be found on the internet at http://www.weather.gov/buf

LEZ040-041-LOZ042>045-062>065-180945-
Lake Erie nearshore waters from Ripley to Dunkirk-
Lake Erie nearshore waters from Dunkirk to Buffalo-
Lake Ontario nearshore waters from the Niagara River to Hamlin Beach-
Lake Ontario nearshore waters from Hamlin Beach to Sodus Bay-
Lake Ontario nearshore waters from Sodus Bay to Mexico Bay-
Lake Ontario nearshore waters from Mexico Bay to the Saint Lawrence
River-
Lake Ontario open waters from the Niagara River to Hamlin Beach-
Lake Ontario open waters from Hamlin Beach to Sodus Bay-
Lake Ontario open waters from Sodus Bay to Mexico Bay-
Lake Ontario open waters from Mexico Bay to the Saint Lawrence River-
543 AM EDT Mon Aug 17 2020

This Hazardous Weather Outlook is for portions of Lake Erie and Lake
Ontario.

.DAY ONE...Today and tonight.

There is a chance for waterspouts this morning and again tonight.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday.

Hazardous weather is not expected at this time.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

This product, along with other watches, warnings, advisories, and
statements issued by the National Weather Service office in Buffalo
can be found on the internet at http://www.weather.gov/buf

Special Weather Statement
National Weather Service Buffalo NY
1003 PM EDT Mon Aug 17 2020

NYZ019-020-180300-
Chautauqua-Cattaraugus-
1003 PM EDT Mon Aug 17 2020

...A STRONG THUNDERSTORM WILL AFFECT CATTARAUGUS AND EAST CENTRAL
CHAUTAUQUA COUNTIES...

At 1002 PM EDT, a strong thunderstorm was located 10 miles southwest
of Gowanda and moving southeast at 10 mph.

Winds in excess of 40 mph and pea size hail are possible with this
storm.

Locations impacted include...
Salamanca, Allegany State Park, Ashford, Franklinville, Ashford
Hollow, Hinsdale, Great Valley, New Albion, Dayton, Conewango,
Ellington, Leon, Carrollton, Randolph, Napoli, Little Valley,
Delevan, East Otto, Cattaraugus and Ischua.

This includes Interstate 86 between exits 15 and 21, and near exit
27.

If outdoors, consider seeking shelter inside a building.

Torrential rainfall is also occurring with this storm, and may cause
localized flooding. Do not drive your vehicle through flooded
roadways.

Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

This storm may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.

LAT...LON 4239 7926 4245 7890 4244 7888 4244 7884
      4246 7880 4246 7877 4247 7874 4251 7850
      4231 7831 4217 7831 4201 7897
TIME...MOT...LOC 0202Z 324DEG 10KT 4236 7908

Reynolds

Special Weather Statement
National Weather Service Buffalo NY
1055 PM EDT Mon Aug 17 2020

NYZ019-020-180400-
Chautauqua-Cattaraugus-
1055 PM EDT Mon Aug 17 2020

...A STRONG THUNDERSTORM WILL AFFECT SOUTHWESTERN CATTARAUGUS AND
SOUTHEASTERN CHAUTAUQUA COUNTIES...

At 1054 PM EDT, a strong thunderstorm was located 12 miles north of
Falconer and moving southeast at 10 mph.

Winds in excess of 40 mph and pea size hail are possible with this
storm.

Locations impacted include...
Jamestown, Salamanca, Allegany State Park, Falconer, Jamestown West,
Frewsburg, Stockton, New Albion, Gerry, Conewango, Ellington, Leon,
Carrollton, Randolph, Napoli, Little Valley, Celoron, Cattaraugus,
Cassadaga and East Randolph.

This includes Interstate 86 between exits 11 and 23.

If outdoors, consider seeking shelter inside a building.

Torrential rainfall is also occurring with this storm, and may cause
localized flooding. Do not drive your vehicle through flooded
roadways.

Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

This storm may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.

LAT...LON 4200 7925 4232 7944 4242 7894 4207 7857
      4200 7920
TIME...MOT...LOC 0254Z 316DEG 9KT 4230 7913

Reynolds

Special Weather Statement
National Weather Service Buffalo NY
321 AM EDT Tue Aug 18 2020

NYZ006-180745-
Oswego-
321 AM EDT Tue Aug 18 2020

...A LINE OF SHOWERS AND EMBEDDED THUNDERSTORMS PRODUCING VERY
HEAVY RAINFALL WILL AFFECT CENTRAL OSWEGO COUNTY...

At 316 AM EDT, radar indicated showers and embedded thunderstorms
were located along a line extending from near Mexico Point State
Park to 7 miles west of Oswego. Movement was east at 20 mph.

Winds in excess of 30 mph are possible with these storms.

Locations impacted include...
Oswego, Fulton, Nine Mile Point, Mexico Point State Park, Battle
Island State Park, Hastings, Scriba, Volney, Palermo, New Haven,
Minetto, Mexico, Parish, Amboy Center, Furniss and Fruit Valley.

This includes Interstate 81 between exits 33 and 34.

Torrential rainfall is occurring with these showers and
thunderstorms storms, and may cause localized flooding. Do not
drive your vehicle through flooded roadways.

LAT...LON 4334 7588 4333 7631 4333 7661 4342 7662
      4343 7662 4345 7663 4341 7664 4342 7669
      4345 7665 4353 7649 4352 7622 4339 7586
TIME...MOT...LOC 0716Z 284DEG 15KT 4345 7629 4344 7665

TMA