Area Forecast Discussion
Issued by NWS Buffalo, NY
FXUS61 KBUF 281317
Area Forecast Discussion
National Weather Service Buffalo NY
917 AM EDT Tue Mar 28 2017
A weak area of low pressure will cross the region today, bringing
scattered rain showers across the region, while also producing some
fog. A light northerly wind through tonight will maintain a cloudy
sky across the region, while Wednesday and Thursday should feature
mostly sunny skies. Temperatures will remain seasonable through the
.NEAR TERM /THROUGH TONIGHT/...
Surface analysis this morning displays two weak areas of low
pressure, one just to the north of Lake Ontario, and a second and
slightly stronger area of low pressure over OH/WV. Regional radars
display scattered rain showers across the Saint Lawrence Valley
associated with the first low. Additional rain showers that have
more coverage area are located across OH/PA and are just now
reaching the NYS line.
Temperatures of both air and dew point remain mild this early
morning. With a moisture rich environment and weak winds areas of
fog will likely form, thickest near the lake shores and hills of SW
NYS and Tug Hill region, and becoming more patchy across the Finger
For today a weak frontal boundary between these two areas of low
pressure will pass across the region. Along the front rain shower
activity will increase, along with some areas of fog forming as
surface dew points peak ahead of the front. Greatest chances for
rain showers will be across the So. Tier, closer to the weak surface
low. As this weak front passes today winds will veer to northerly by
this afternoon. While some fog may linger along the southern Lake
Ontario shoreline, the northerly winds will create a deck of low
stratus, with surface visibilities improving, but thick clouds
remaining. This northerly flow will continue through tonight as
surface high pressure nears the region, with clouds likely to linger
as moisture becomes trapped beneath a subsidence inversion.
Rain showers will also diminish through the afternoon and evening as
this surface high pressure nears the region, and surface low
pressures exit to the east. Overall total rain today and into this
evening will remain on the light side, with most areas remaining
below a quarter of an inch.
Temperatures today will be slightly cooler within the northerly wind
flow, with highs around normal, peaking in the upper 40s. Tonight
the lingering clouds will keep most areas just above the freezing
mark, though thin clouds, or even some late clearing across the
North Country will allow for overnight temperatures to drop to
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
High pressure transiting Hudson Bay will extend ridging into the
Great Lakes region during the mid-week period. This will provide a
period of quiet weather and at least some sunshine. However...things
start downhill again Thursday night...as a southern stream closed
low ejects from the southern Rockies. Associated precipitation will
begin to push into the region from the west on Thursday night.
Wednesday through Thursday...looks quiet...with an upper level
shortwave ridge axis moving overhead. Shallow cool air will be
pushing into the region on a general northerly low level flow with
850 mb temperatures down to around -8C. This will try to generate to
generate some lake clouds...especially south of Lake Ontario, though
a dry airmass will hinder this process. Still...expect no worse than
partly cloudy skies for Wednesday and Wednesday night with plenty of
locales mostly clear.
Thursday...high level then eventually mid clouds will be thickening
from southwest to northeast...as stronger warm advection shifts into
the mid Mississippi Valley and southern/eastern Great Lakes. A
tightening baroclinic zone over the region ahead of a developing
warm front should support at least some showers over the far western
counties later in the afternoon...while dry weather will persist
east of a Rochester to Canandaigua line.
Thursday night...a surface low will push from the mid Mississippi
Valley up into the Ohio Valley while a fairly strong warm front will
push north across our western counties. Fairly widespread rain will
blossom ahead of this feature...so have raised pops to 90 over the
west and to likely across the North Country. While some wet snow
could mix in for sites north and east of the Tug Hill...
accumulations are not anticipated at this point.
.LONG TERM /FRIDAY THROUGH MONDAY/...
The pattern will become more active again by the end of the week
after a few dry days. A mid level closed low will meander across the
Four Corners region through Tuesday, then eject ENE across the
southern Plains to the Ohio Valley by Friday. The 12Z guidance has
trended a little southward with the track of the ensuing surface
low, but still more than close enough for more rain over the region
This system will slowly pull out next weekend, with a few scattered
showers lingering into Saturday as the trough and surface low move
off the east coast, with northwest flow and wrap around moisture
hanging back across the Lower Great Lakes. Moisture and rain chances
should diminish by Sunday as the trough moves well off the eastern
seaboard. The 12Z GFS develops a few showers of rain and wet snow
later Saturday night and Sunday with a weak northern stream trough,
but for now favored the drier ECMWF solution for this time period.
Temperatures will likely run near to slightly above average through
the period, with highs generally in the upper 40s to lower 50s and
lows in the 30s.
.AVIATION /13Z TUESDAY THROUGH SATURDAY/...
For the 12Z TAFS flight conditions are starting to drop to IFR with
patchy fog, and low stratus developing.
A weak frontal boundary will cross the region between through about
noontime, and along this frontal boundary will be chances for
showers, along with areas of fog. Greatest chances for showers will
be towards the south, including the KJHW terminal. Flight conditions
will likely lower to IFR or lower for a 2 to 4 hour period around
sunrise, with a then northern flow maintaining IFR ceilings for a
period of time into the afternoon hours. These IFR CIGS will likely
remain longest across the So. Tier, including the KJHW terminal.
By tonight an area of high pressure will be funneling much drier air
across the region. This will thin the low stratus, that may remain
MVFR (IFR So. Tier) through Tuesday night.
Wednesday and into Thursday...VFR.
Thursday night into Saturday...MVFR/IFR with occasional rain showers.
A weak to modest pressure gradient across the Lower Lakes
Region will lead to continued relatively light winds and minimal
waves right through Tuesday. A somewhat stronger northerly flow
will then follow Tuesday night through Wednesday as strong
Canadian high pressure builds across the Great Lakes...however
winds and waves are expected to remain below advisory levels.