Henrietta, New York 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

921
FXUS61 KBUF 152319
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
719 PM EDT Thu May 15 2025

.SYNOPSIS...
A broad wave of low pressure aloft will gradually shift east of the
region later today, with scattered showers and thunderstorms
developing during the afternoon. The next closed low will then
gradually cross the Great Lakes over the weekend, resulting in
several additional opportunities for showers/thunderstorms through
at least Saturday night. Much cooler and generally drier weather
behind this system expected to last through the first half of next
week.

&&

.NEAR TERM /THROUGH FRIDAY/...
Diurnal activity associated with the passage of a weak short
wave trough will continue to wane as we get deeper into the
evening. What is on radar as of 7 PM is generally concentrated
in the Souther Tier, and this is likely to remain the case for
the next hour or two before all areas go dry. As this activity
dies off, skies will scatter out for the remainder of the
evening areawide.

Upstream, impressively well-developed convective activity is
ongoing over the western Great Lakes area. This activity is
featured in all hi-res model guidance making a trek toward WNY
through the night. It will arrive in the pre-dawn hours, however
it will likely be decaying as it does so. The boundary forcing
it will be becoming more strung out as it approaches our area,
and instability will be waning due to a poor arrival window in
the diurnal cycle. SPC has our area in a marginal risk for
severe weather with the passage of this boundary centered around
12z/8 AM in WNY, and this is probably more bullish than seems
necessary at this juncture. Nonetheless, there may well still be
thunderstorms along the boundary as it shifts through the CWA
early Friday morning.

Convective activity along the boundary continues to move
eastward on Friday morning with less and less fanfare as it does
so. In its wake, ample boundary layer moisture will remain due
to a poor air mass change. Because of this, as mid-level clouds
start to peel off, scattered showers and thunderstorms would
seem to be possible again as up to roughly 1000 J/kg of MLCAPE
will still be around to work with from the Genesee Valley
eastward. Shear will be lacking by afternoon, and mid-level flow
drops off too, so the threat for severe by afternoon would seem
quite low.



&&

.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/...
Upper level low over Minnesota Friday night will drop east-southeast
across the Great Lakes through Saturday night before lifting north
into New England Sunday and Sunday night. This being said, the
surface low currently over the mid-Atlantic will have exited east
while the surface low correlating with the aforementioned upper
level low over the upper Great Lakes will place a surface cold front
across the central Great Lakes and into the Ohio Valley Friday
night. This front will pass across the region Friday night through
Saturday, supporting showers and a few thunderstorms. A few
thunderstorms Saturday morning may become severe, especially along
the cold frontal boundary as there will be increasing values of
effective bulk shear and steep lapse rates.

In the wake of the frontal passage Saturday afternoon across the
west, a drier and cooler airmass will filter across the region with
winds becoming quite breezy. However, the area won`t be completely
dry as lake breeze boundaries develop and support a few showers and
thunderstorms north and south of the boundaries. Meanwhile with the
front remaining across the eastern half of the area, showers and
thunderstorms will continue Saturday afternoon across the northern
Finger Lakes and eastern Lake Ontario region.

As the upper level low and corresponding trough settles across the
eastern Great Lakes region Saturday night and pulls northeast into
New England Sunday, cool moist air rotating across the area will
support scattered showers to linger.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
An upper level low and corresponding trough will lie across New
England Monday with a ridge building to the west across the upper
Great Lakes, placing the region in the entrance region of the trough
across the Northeast through at least Wednesday. The next closed
upper level low will then develop by mid-week. Long range model
guidance continues to have timing, development and placement
discrepancies with this mid-week system. This all being said, expect
a skinny ridge of surface high pressure to lie across the Great
Lakes through the first few days of the new work week. Then, expect
increasing chances for showers and thunderstorms to develop
Wednesday and last through Thursday.

Otherwise, temperatures next week will average a good ten degrees
cooler than normal due to the placement of the upper level trough
overhead.

&&

.AVIATION /23Z THURSDAY THROUGH TUESDAY/...
VFR conditions dominate this evening outside of the remaining
shower and thunderstorm activity that has moved east of KJHW.
This activity will continue to diminish through the evening. All
sites will continue to be VFR until a line of convection starts
to enter from the west generally around 08z or so. There is
still ample uncertainty as to how decayed this line will be as
it approaches the area, however it seems that KJWH/KBUF/KIAG
have the best chance of seeing thunder as it crosses in the
predawn hours and gradually decays, especially as it moves east
of KROC. Behind this line, a period of MVFR or near IFR cigs are
likely at all sites until better mixing arrives after 16z.
Scattered showers and embedded thunderstorms will be around
after 16z generally KROC eastward as well.

Outlook...

Saturday...Mainly VFR/MVFR. Restrictions likely at times with
periodic showers and thunderstorms.

Sunday...Mainly VFR with scattered showers east of KROC.

Monday and Tuesday...Mainly VFR.

&&

.MARINE...
Generally light winds and waves are evident over the lower Great
Lakes this evening. Some marine fog development is likely
overnight, especially over Lake Ontario.

A line of showers and thunderstorms will cross the area late
tonight through Friday morning. After that line passes on Friday
morning, dry conditions over the lakes look to resume.

&&

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

&&

$$

SYNOPSIS...PP
NEAR TERM...Fries
SHORT TERM...EAJ
LONG TERM...EAJ
AVIATION...Fries
MARINE...Fries