Special Weather Statement, NWS Buffalo, NY

Area Forecast Discussion
National Weather Service Buffalo NY
1013 PM EDT Fri Aug 2 2019

.SYNOPSIS...
High pressure over the region through the weekend will support
mainly dry weather. The only small chance of rain will be each
afternoon over the Southern Tier and also on Saturday toward the St.
Lawrence River as a weak front slides across. Plan on comfortable
humidity levels and near normal temperatures to continue through
the weekend.

&&

.NEAR TERM /THROUGH SATURDAY/...
Regional radar shows a few showers across Allegany county late this
evening. This activity will continue to weaken and eventually
end around midnight. Clouds will clear out late tonight and fog
is likely across the valleys of the western Southern Tier.
Elsewhere, mostly clear and calm conditions expected. Low
temperatures will fall to the upper 50's to low 60's.

Much the same conditions look to be persisting through the day
on Saturday as a weak short wave trough and associated cold
front start to approach from the northwest. This will start to
increase the chance of of a shower across the outlet of Lake
Ontario, Thousand Islands, and North Country. For the rest of
the area, conditions look to remain dry as southwesterly flow
increases.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/...
The weak cold front will then slowly sag southward across our
area Saturday night and early Sunday morning...before settling a
little further southward across Pennsylvania through the
remainder of Sunday. While some widely scattered convection
could persist into early Saturday evening across the North
Country...the weak nature of the boundary and nocturnal
stabilization of the boundary layer should result in a largely
dry frontal passage. Following the front... Canadian-sourced
high pressure and drier air will then build back across our
region and bring a return to largely dry weather for Sunday and
Sunday night...with just a few more isolated showers or storms
possible across the Southern Tier/interior Finger Lakes on
Sunday as diurnal heating interacts with a lingering ribbon of
moisture behind the front.

Looking out into the last third of this period...the above
mentioned surface ridge will only begrudgingly slip off to our
southeast Monday and Monday night...with lingering associated
subsidence and dry air resulting in continued fair dry weather.

With respect to humidity levels...these will remain fairly
comfortable/tolerable through this period...with the overall
flow pattern across our region helping to effectively block any
significant return of low level moisture. This will result in
surface dewpoints ranging from the mid 50s to lower 60s...with
the highest humidity levels coming Saturday/Saturday evening out
ahead of the cold front...and again Monday night as a southwesterly
return flow begins to set up on the backside of the departing
surface ridge.

As for temperatures...highs will peak at slightly above normal
levels in the lower to mid 80s on Saturday out ahead of the cold
front...with modest cool air advection in its wake then temporarily
knocking these back to the mid-upper 70s on Sunday...before airmass
modification allows readings to climb back to near normal levels in
the upper 70s and lower 80s on Monday. Meanwhile...lows in the upper
50s to lower 60s Saturday night will settle back into the 50s areawide
Sunday night owing to favorable conditions for good radiational
cooling under the surface ridge...before rebounding into the lower
to mid 60s Monday night owing to the aforementioned developing
southwesterly return flow.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
While it will be warm and somewhat humid when we open this period on
Tuesday...the good news is that the overall pattern will continue to
feature a ridge over the west and troughiness over the Great Lakes
region. This scenario will keep true sultry weather suppressed
well to our south and west. In fact...the trend during this four day
period will be to have temperatures and humidity levels lower with
time.

Unfortunately...there will be at least the chance for some showers
and thunderstorms each day. That being said...the vast majority of
this period should be rain free. This should especially be the case
across the lake plains. As far as some day to day details...

A slow moving cold front will settle south across our region later
Tuesday into Wednesday morning. This should be the time period with
most unsettled weather...but even then there will be relatively
large gaps of dry weather. H85 temps in the teens will guarantee
warm and humid weather for Tuesday with max temps of 80 to 85...then
the edge in the warmth will be taken off Wednesday as slightly
cooler air starts to filter south from Ontario.

During the Wednesday night to Thursday night time frame...the front
should be far enough to our south to encourage MAINLY dry weather.
Ensemble guidance is still hinting that the boundary could be close
enough to support a shower or thunderstorm though...with the
greatest chance being found over the Southern Tier. For what its
worth...the operational GFS is notably more unsettled with the
stalled front positioned over Pennsylvania versus Virginia.

As we end the week...there is a suggestion that a robust shortwave
in the northern branch will make its way into our region from the
Upper Great lakes. This would once again increase our chance for
some showers and thunderstorms while introducing a very cool airmass
for the ensuing weekend. In fact...ensemble guidance suggests
that cooler than normal weather will persist through the second
full week of the month.

&&

.AVIATION /02Z SATURDAY THROUGH WEDNESDAY/...
VFR conditions will generally remain in place across the forecast
area through the TAF period. Mostly clear skies and light winds may
result in some fog overnight tonight at KJHW.

Outlook...
Saturday through Monday...Mainly VFR.
Tuesday...Mainly VFR, except in isolated thunderstorms.

&&

.MARINE...
High pressure will give way to a mostly dry frontal passage on
Saturday night. Behind this front, winds will increase markedly
from the northeast at 15 to 20 kts, especially across Lake
Ontario. This will bring waves up toward 3 feet along the
southern shore before conditions improve Sunday onward with the
return of high pressure.

&&

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

&&

SYNOPSIS...Fries/JLA
NEAR TERM...Fries/HSK/JLA
SHORT TERM...Fries/JJR
LONG TERM...RSH
AVIATION...Fries
MARINE...Fries

Hazardous Weather Outlook
National Weather Service Buffalo NY
351 AM EDT Fri Aug 2 2019

NYZ001>008-010>014-019>021-085-030915-
Niagara-Orleans-Monroe-Wayne-Northern Cayuga-Oswego-Jefferson-Lewis-
Northern Erie-Genesee-Wyoming-Livingston-Ontario-Chautauqua-
Cattaraugus-Allegany-Southern Erie-
351 AM EDT Fri Aug 2 2019

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

.DAY ONE...Today and tonight.

The probability for widespread hazardous weather is low.

.DAYS TWO THROUGH SEVEN...Saturday through Thursday.

The probability for widespread hazardous weather is low.

.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

LEZ020-040-041-LOZ030-042>045-062>065-SLZ022-024-030915-
Upper Niagara River and Buffalo Harbor-
Lake Erie nearshore waters from Ripley to Dunkirk-
Lake Erie nearshore waters from Dunkirk to Buffalo-
Lower Niagara River-
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-
Saint Lawrence River from Cape Vincent to Ogdensburg-
Saint Lawrence River from Ogdensburg to Saint Regis-
351 AM EDT Fri Aug 2 2019

This Hazardous Weather Outlook is for the New York waters of Lake
Erie, Lake Ontario, and the Saint Lawrence River.

.DAY ONE...Today and tonight.

The probability for widespread hazardous weather is low.

.DAYS TWO THROUGH SEVEN...Saturday through Thursday.

The probability for widespread hazardous weather is low.

.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

JJR

Special Weather Statement
National Weather Service Buffalo NY
849 PM EDT Fri Aug 2 2019

NYZ020-021-030130-
Cattaraugus-Allegany-
849 PM EDT Fri Aug 2 2019

...AN AREA OF STRONG THUNDERSTORMS WILL AFFECT SOUTHEASTERN
CATTARAUGUS AND SOUTHWESTERN ALLEGANY COUNTIES...

At 848 PM EDT, strong thunderstorms were clustered near St.
Bonaventure, or near Olean, moving northeast at 15 mph.

Winds in excess of 30 mph and half inch hail are possible with these
storms.

Locations impacted include...
Olean, Allegany State Park, Allegany, Cuba, St. Bonaventure, Weston
Mills, Hinsdale, Friendship, Bolivar, Portville, Richburg, Knapp
Creek, Rock City Park, Limestone, Haskell Flats, West Clarksville,
Little Genesee and Ceres.

This includes Interstate 86 between exits 24 and 29.

LAT...LON 4200 7876 4228 7817 4207 7797 4200 7819
TIME...MOT...LOC 0048Z 237DEG 11KT 4203 7848

Welch

Special Weather Statement
National Weather Service Buffalo NY
1053 PM EDT Fri Aug 2 2019

NYZ013-021-030330-
Allegany-Livingston-
1053 PM EDT Fri Aug 2 2019

...A STRONG THUNDERSTORM WILL AFFECT SOUTHERN LIVINGSTON AND
NORTHEASTERN ALLEGANY COUNTIES...

At 1052 PM EDT, a strong thunderstorm was located 7 miles west of
Dansville, moving north at 10 mph.

Winds in excess of 30 mph...heavy downpours...and half inch hail are
possible with this storm.

Locations impacted include...
Dansville, Letchworth State Park, Mount Morris, Conesus, Groveland,
Nunda, Ossian, Canaseraga, Leicester, Ossian Center, Swain, Sonyea
and Dalton.

This includes Interstate 390 between exits 4 and 7.

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

LAT...LON 4251 7798 4279 7791 4271 7760 4268 7760
      4267 7759 4253 7769 4253 7772 4249 7772
      4245 7775
TIME...MOT...LOC 0252Z 199DEG 9KT 4255 7784

JJR