Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Buffalo New York
148 am EDT Monday Sep 1 2014
it will remain muggy through the night...with areas of low clouds
and fog. A few spotty showers and thunderstorms are possible on
Labor Day...but the majority of the day should be rain free with
temperatures a little above average.
Near term /through today/...
this late evening regional radars display showers just now exiting
the Saint Lawrence valley...with the remainder of the County Warning Area dry.
A mean southwest flow will remain through the overnight time
period...and likely maintain an abundance of moisture in the low and
middle levels. This moisture will maintain partly to mostly cloudy
skies. As we cool some through the evening expect these clouds to
lower with low clouds and areas of fog likely across the higher
terrain. Will cut back some on the fog across the lower elevations
as these clouds through the overnight will likely limit the amount
of fog production...and will have patchy fog in the
forecast...especially to the south of Lake Ontario where some
clearing has occurred.
With the moist airmass overnight overnight lows will not drop too
much. Overnight lows...while still cooler than last night will range
from the low to middle 60s.
On Labor Day...expect at least the morning to be dry...as stratus
and fog gradually dissipate. Daytime heating will result in modest
ml convective available potential energy averaging 500 to 1000 j/kg during the afternoon.
However...there will not be much to focus the convection...with the
best chance probably along the lake breezes (south of Lake Ontario
and east of lake erie). In each case...coverage should be rather
spotty...with the vast majority of the day likely to stay dry.
Temperatures will be on the warm side...with highs in the upper 70s
to lower 80s.
Short term /tonight through Wednesday night/...
afternoon and evening precipitation should diminish from west to
east as Monday night progresses...but will be replaced from the west
by daybreak on Tuesday as a cold front approaches New York state.
As the portion of the cold front crossing New York state is quite a
great distance removed from it associated low pressure center...over
Hudson Bay on Tuesday morning...it will take the most of the day
for the cold front to move across the state with showers and
thunderstorms throughout much of the day. High precipitable water
values of 1.7"-1.9" Tuesday afternoon offers the risk of heavy
downpours with any thunderstorm. Sbcapes over 1000 j/kg combined
with lifted index values at -4c to -5c also point to the possibility
of storms. It will be another warm day with highs in the upper 70s
to lower 80s.
The cold front will slide south and east of the forecast area
Tuesday evening...taking the showers and storms with it. Although a
few showers will still be possible during the evening across eastern
areas...but it will dry out later Tuesday night as surface high
pressure starts to build east across New York state. Lows will be
generally in the upper 50s to lower 60s.
High pressure will follow the cold front on Wednesday with a drier
airmass...but not much cooler. Expect sunny skies throughout the
region and high temperatures in the middle to upper 70s...followed by a clear
night with lows in the 50s.
Long term /Thursday through Sunday/...
upper level ridging and surface high pressure will remain across the
region on Thursday. High pressure will then slide off the New
England coast by Friday. This will continue mainly dry conditions on
Thursday...then the next frontal system approaches for late in the
week and early weekend. Temperatures will be a bit above seasonal
normals through the end of the work week with highs in the upper 70s
to low 80s and lows in the lower 60s...then settle a bit closer to
normal with highs in the lower to middle 70s and lows in the middle 50s
during the weekend.
Aviation /06z Monday through Friday/...
fog and stratus will become more widespread across the region
overnight into early Monday morning. Extensive low level moisture
trapped beneath a weak subsidence inversion coupled with nocturnal
cooling will provide an environment favorable for both low stratus
and fog. IFR ceilings are already widespread across the higher terrain
of the southern tier...and expect this to expand north and east
through the rest of the night. The lower elevations from kbuf and
kiag to kroc should see a few hours of IFR ceilings between 09z-14z.
East of Lake Ontario MVFR ceilings will persist through 09z then may
partially clear late tonight.
As far as fog GOES...expect lower elevations to primarily
see just light br with a little too much mixing in the boundary
layer for more significant fog. The higher terrain of the southern
tier and Finger Lakes may see more widespread IFR fog where the low
stratus intersects the hilltops.
The fog and low stratus will burn off by middle to late morning Monday
with conditions improving to mainly VFR by midday. A few widely
scattered showers and storms may develop during the afternoon and
evening mainly across western New York with local MVFR/IFR in any heavier
showers...but the majority of the area will remain VFR.
Tuesday...showers and thunderstorms likely with associated brief
MVFR/IFR. Some storms may be strong.
Wednesday and Thursday...VFR.
Friday...mainly VFR. A chance of showers and thunderstorms.
with a relaxing pressure gradient and diminishing winds and waves
have ended the Small Craft Advisory for the Lake Erie shoreline this
evening. Expect a period of below Small Craft Advisory conditions on Labor Day across
the lakes and rivers as winds from the southwest remain below 15
knots. These winds will increase some on Tuesday ahead of a cold
front...such that Small Craft Advisory may be needed on Lake Erie for Tuesday.