Area Forecast Discussion
Issued by NWS Buffalo, NY

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
467
FXUS61 KBUF 251508
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
1108 AM EDT WED MAY 25 2016

.SYNOPSIS...
Summertime weather is on its way with highs climbing through the 70s
and into the 80s by this weekend.  Along with the warmer
temperatures, an increase in humidity will also bring back
increasing chances of showers and thunderstorms each day leading up
to and into the Memorial Day weekend.

&&

.NEAR TERM /THROUGH TONIGHT/...
Satellite and radar imagery are highlighting a trough pushing across
the eastern half of Lake Ontario late this morning with enhanced
cloudiness and scattered showers. Some of these showers will glance
the southern and eastern shores of Lake Ontario and the Saint
Lawrence River Valley into the early afternoon. Otherwise
temperatures are steadily climbing with the warm spots of Rochester
and Dansville in the Genesee Valley and cooler locations like
Buffalo and Watertown with westerly flow off the lakes. Have bumped
up temps a few degrees in these warmer spots.

Later this afternoon a few mesoscale models are hinting at some
isolated to scattered convection developing near peak heating. These
areas look to again be mainly focused across Ontario but low level
convergence at the western end of Lake Ontario as southwesterly
winds up the Lake Erie basin meet more westerly winds along the
Niagara peninsula could provide focus for a few of these storms.
Similar conditions of low level convergence will give a chance of
widely scattered convection across the Saint Lawrence Valley later
this afternoon. A sharp cap at 925mb per 12z BUF RAOB should inhibit
most, if not all, convection south of Lake Ontario this afternoon.

Surface high pressure and upper ridging pattern resume control of
the forecast area tonight as the weak trough will shift east to New
England. Higher dewpoints thanks to SW flow will help to hold the
low temperatures up again with lows in the mid 50s across the
eastern Lake Ontario counties and Southern Tier, and to the lower
60s for the lake plains and urban areas.

&&

.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
On Thursday a weak mid level trough will cross the region and
combine with a broad warm advection regime to provide weak large
scale ascent. Moisture and instability will continue to slowly
increase across the area, with MUCAPE approaching 1000J/kg by the
afternoon. The combination of large scale ascent and increasing
instability will support scattered showers and a few thunderstorms,
developing first across western NY by late morning or midday, then
spreading east during the afternoon. The best coverage should be
found from the Southern Tier into the Finger Lakes and central NY,
with less coverage northeast of the lakes as stable lake shadows
develop. Even with the stable lake shadows, given the large scale
ascent it may not remain completely dry northeast of the lakes.

Expect highs to reach the lower 80s in most areas, with a few mid
80s readings possible from the warmer spots of the Genesee Valley
into central NY. A southwest flow will keep the Buffalo area and
Jefferson county shore a little cooler.

Thursday night the mid level wave pushes into eastern NY and New
England and diurnal instability diminishes. This should bring a
general west to east tapering off of scattered showers and
thunderstorms. Overnight it will be mainly dry, although a few
spotty showers or isolated thunderstorms still cannot be ruled out
in the weak warm advection regime, especially if any convectively
generated vorticity maxima from upstream drift into the region. Lows
will be quite mild, with mid 60s on the lake plains of western NY.

Friday there will be little or no large scale ascent as the mid
level ridge builds strongly into the lower Great Lakes region.
Moderate instability will develop by afternoon, and this may support
widely scattered thunderstorms along and inland of the lake breeze
boundaries. 850mb temps rise to around +16C, which will support mid
80s in most areas with a few upper 80s possible from the Genesee
Valley to central NY.

Friday night scattered thunderstorms will slowly diminish in
coverage, with most areas becoming mainly dry after midnight. Expect
another very mild night with lows in the upper 60s on the lake
plains.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
An extended period of mid summer warmth and humidity will continue
through the weekend and into early next week. The heat will peak
over the weekend, with a modest pull back in temperatures early next
week. Most days will feature a few widely scattered showers and
thunderstorms, but there will be plenty of rain free time as well.

A broad trough will remain in place over the west, with a strong
downstream ridge dominating the eastern half of the nation. High
pressure will take up residence off the southeast coast in the
classic Bermuda high location, allowing heat and humidity to pump
northward on persistent deep layer southwest flow.

The ridge will remain overhead Saturday and Sunday and prevent much
in the way of large scale ascent. Diurnal instability will support
widely scattered showers and storms each afternoon and evening,
especially along and inland of the lake breeze boundaries. By late
Sunday and Monday there is some potential for an influx of Atlantic
moisture as well, associated with a weak system along the southeast
coast. A weak mid level trough will also cross the area Monday,
potentially increasing coverage and organization of showers and
thunderstorms.

By Tuesday both the GFS and ECMWF 00Z runs build high pressure into
the Great Lakes with a bubble of somewhat drier air, which will
reduce the potential for any convection.

&&

.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
Widespread VFR conditions will continue to prevail today and tonight
with general ridging of high pressure overhead. A weak trough
passing across the area could bring an isolated shra to KART early
this afternoon. Some widely scattered convection is possible later
this afternoon across the Niagara Peninsula which may move near KIAG
and the Saint Lawrence Valley but the vast majority of the region
will be rain free.

Outlook...

Thursday through Monday...Mainly VFR with a chance of showers and
thunderstorms.

&&

.MARINE...
A ridge of high pressure will remain across the lakes, continuing
mainly fair weather with breezy westerly winds. Some isolated to
scattered showers and thunderstorms will be possible this afternoon
over Lake Ontario. Winds and waves outside of any storms will remain
fairly negligible through the next few days. The tranquil pattern
will continue through the end of the week, although a few
thunderstorms may produce locally higher winds and waves at times
each day from Thursday through next weekend.

&&

.CLIMATE...
The first extended period of summer`s warmth will be upon us this
weekend. Temperatures will climb well into the 80s, of which some
of these daily readings may near record levels. Listed below are
the records for our three climate stations.

BUFFALO...

Friday.....May 27th...Record High Maximum...89F...1978
......................Record High Minimum...69F...1991

Saturday...May 28th...Record High Maximum...86F...2012
......................Record High Minimum...69F...1911

Sunday.....May 29th...Record High Maximum...87F...1987
......................Record High Minimum...68F...1987


ROCHESTER...

Friday.....May 27th...Record High Maximum...92F...1978
......................Record High Minimum...70F...1918

Saturday...May 28th...Record High Maximum...93F...1911
......................Record High Minimum...68F...1939

Sunday.....May 29th...Record High Maximum...92F...2006
......................Record High Minimum...69F...1908


WATERTOWN...

Friday.....May 27th...Record High Maximum...87F...1960
......................Record High Minimum...67F...1991

Saturday...May 28th...Record High Maximum...85F...2012
......................Record High Minimum...64F...1987

Sunday.....May 29th...Record High Maximum...87F...2012
......................Record High Minimum...63F...2006


A climatic day is between 1 AM EDT to 1 AM EDT.

Temperature records for Buffalo and Rochester date back to 1871,
while records for Watertown start in 1949.

&&

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

&&

$$

SYNOPSIS...SMITH
NEAR TERM...SMITH/WCH
SHORT TERM...HITCHCOCK
LONG TERM...HITCHCOCK
AVIATION...SMITH/WCH
MARINE...SMITH/WCH
CLIMATE...THOMAS



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.