Area Forecast Discussion
Issued by NWS Buffalo, NY
FXUS61 KBUF 222331
Area Forecast Discussion
National Weather Service Buffalo NY
731 PM EDT Sat Apr 22 2017
Skies will gradually clear overnight, as a ridge of high pressure
builds into the region, with a cool crisp night tonight followed by
sunny skies and warmer temperatures Sunday. The next chance for
precipitation will be Monday night into Tuesday, as a low pressure
system drifting up the Eastern Seaboard sends Atlantic moisture back
across New York state.
.NEAR TERM /THROUGH SUNDAY/...
Skies should clear out overnight however, as the aforementioned
trough and low level moisture completely clear the area, and the
upper level jet that is advecting the high clouds overhead shifts
slightly to the east overnight. With Western New York already on the
edge of this high cloud shield, it is reasonable to assume that
clearing from west to east should follow overnight. With this
clearing and light winds as high pressure moves overhead,
temperatures will fall sharply overnight, with widespread lows in
the 30s, and some locales in the Southern Tier and North Country may
just touch the upper 20s. Given the light winds/radiational cooling
and moist ground from recent rains, but considering lack of overall
moisture depth in the dry airmass, have added some patchy areas of
frost to the forecast given low temperatures in the mid 30s or
After a chilly start to the day, things will warm up nicely on
Sunday, which should prove a marked contrast to the dreary
conditions of the last couple of days, as high pressure noses across
the region. Abundant sunshine will allow temperatures to warm into
the low to mid 60s, with some locations in the valleys of the
Southern Tier and the Genesee valley creeping into the upper 60s.
The one exception will be immediately downwind of the lakes, where
the clear skies should promote the formation of the lake breeze in
the afternoon, helping to depress temperatures along the shorelines
east/northeast of both lakes, with highs only topping out in the
upper 40s to mid 50s.
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/...
Sunday night through Monday night should remain dry, with the
forecast region centered between a cold front stalled across
southern Canada, and a SE storm system. Temperatures Sunday night
will dip into the lower 40s and upper 30s, while Monday night will
be a few degrees warmer as clouds begin to increase across the
region from the south. Highs Monday will be seasonable, in the 60s
across the region. The one cool spot will be along the southern Lake
Ontario shoreline where a northeast flow will bring cooler lake air
temperatures inland, keeping communities along the shoreline in the
low to mid 50s.
Tuesday and Tuesday night will bring the next chance for rain
showers. The southeast area of low pressure, with support from an
upper level closed low, will pull both Atlantic and Gulf of Mexico
moisture northward. As the surface low tracks northeastward along
the SE Atlantic coastline, outer bands of rain showers will pass
across the Eastern Great Lakes region early morning hours of Tuesday
and into the evening hours. Highest chances for showers will be
across the interior So. Tier, Finger Lakes region, and then the
southern Tug Hill. Total rainfall with this event will generally be
a third of an inch or less, with little to no rain falling across NW
portions of the CWA. Southeast winds, and temperatures of +6 to +9C
at 850 hPa will yield highs in the upper 60s across the Niagara
Frontier, and along the downslope Lake Erie shoreline, while across
the interior So. Tier/Finger Lakes and southern Tug Hill region,
thicker clouds and showers will hold temperatures to the upper 50s
to lower 60s. Lows Tuesday night will drop back into the upper 40s
to lower 50s, with some patches of fog possible where rain fell.
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
On Wednesday low pressure off the mid-Atlantic coast will gradually
weaken while a mid-level shortwave digs across Wisconsin. 12Z model
consensus is slightly slower with this shortwave, and keeps our
region under the influence of a subtle ridge. This should keep the
area dry Wednesday, with temperatures climbing into the 70s in most
Model guidance starts to close off the approaching shortwave
Wednesday night which should further delay its arrival. Timing also
differs, with the 12Z ECMWF slower than other guidance. Consensus
timing supports a chance of showers across far western areas late
Wednesday night, but it now appears the cold front will move across
the region on Thursday when there will be a better chance for
showers and thunderstorms. Also, the slower ECMWF would result in
much warmer temperatures on Thursday. It is possible it will be
significantly warmer (or colder) depending on the timing of the
High pressure will briefly build into the region behind the cold
front with dry weather and lows dropping into the 40s on Thursday
Then on Friday the boundary will stall and strengthen as a baroclinic
zone develops between an upper level ridge off the Southeastern
Coast and a trough across the mid-west. Forecast confidence
decreases at this point, due to the close proximity of this
sharpening boundary. In contrast with previous guidance, most 12z
operational runs have trended considerably colder and keep our
region along or just on the cold side of the boundary. This would
result in high temperatures mainly in the 60s for Friday and
Saturday, but there still are several GFS ensemble members which put
our region into the warm sector so 80s are still not out of the
question depending on the position of this front. Otherwise
there will be a persistent chance of showers, and possibly a
thunderstorm along the frontal boundary on Friday and Saturday.
.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
Lingering mid/high level cloud cover will thin and clear from
northwest to southeast overnight. The clear skies and light winds
will lead to fine aviation conditions with plentiful VFR conditions
through the day Sunday. Some light frost is possible overnight
tonight, with a slight chance of valley fog in the Southern
Tier, although dry enough air aloft should keep this minimal and
away from the JHW. Winds on Sunday will be dominated by typical
southwesterly lake breezes at IAG/BUF/ART.
Sunday Night and Monday...VFR.
Tuesday and Wednesday...Mainly VFR with a chance of showers.
Thursday...VFR/MVFR with a chance of showers and thunderstorms.
High pressure moving into the region will result in tranquil
conditions on the lakes through Sunday night. Northeasterly winds
will freshen on Monday, as a slow moving area of low pressure moving
up the Eastern Seaboard draws closer to the lakes, reorienting the
pressure gradient across the area. This will produce choppy
conditions along the southern shores of the lakes Monday afternoon
into Monday evening, though conditions should relax somewhat by
Tuesday, as winds shift to the southeast.