NWS Area Forecast Discussion

FXUS61 KBUF 160656

Area Forecast Discussion
National Weather Service Buffalo NY
256 AM EDT Mon May 16 2022

A warm and humid airmass will remain in place before a strong cold
front crossing the Great Lakes today will bring a chance of severe
thunderstorms, especially from the Genesee Valley eastward. This
cold front will also bring much cooler conditions to our region
by Tuesday along with some lingering showers east of Lake Ontario.
Winds could be breezy on Tuesday as well.


General subsidence found between an exiting shortwave over New
England an approaching cold front over southern Ontario/Lake Erie
will supply western and north central New York with fair dry weather
early this morning. High (and eventually mid level) cloud cover will
gradually increase from west to east. Otherwise it will stay mainly
dry with mins mid 50s to lower 60s.

A strong, negatively-tilted shortwave trough with sharply curved
increasing upper jet will move into western New York beginning later
this morning. Associated surface cold front will enter western New
York this morning, before reaching central New York by early
afternoon. Thus far most convection upstream is occurring in wake of
front, anafront type setup. Eventually though, with building MLCAPES
1000-1500J/kg additional convection is expected to blossom quickly
along and ahead of the front, with the potential for strong to
severe storms looking increasingly favorable by midday, mainly from
the Genesee Valley on to the east. Wind profiles with increasing
upper jet look resulting in deep layer shear over 40 kts are
favorable for discrete cells containing all storm modes and hazards
midday into early afternoon centered from the Genesee Valley to
western Finger Lakes (mean storm motion southwest to northeast).

Then, as low-level shear increases and becomes perpendicular to the
front/convection, expect the convection to become more linear as it
moves to southeast of Lake Ontario and across the North Country.
This activity will have better chance of producing straight line
damaging winds but still contain a small risk of brief spin up in
QLCS type setup. SPC continues to highlight our area from Genesee
valley eastward with a slight risk and enhanced risk for severe
storms. Enhanced wording has been maintained for the convection.
Heavy downpours will be a factor as well, though this would likely
be mainly in training storms as storms will not be slow moving.

The threat for severe storms will end over western NY by early
afternoon, across the Genesee valley by mid afternoon and should be
completely out the Finger Lakes, southeast Lake Ontario and
North Country by 6-7 PM.

Does seem that colder air aloft and steeper mid-level lapse
rates along with another shortwave in back side of upper trough
could support an additional cluster of isolated to scattered
showers and a few thunderstorms late afternoon, early this
evening over far western NY. Do not expect severe weather with
these though.


A negatively tilted mid-level trough axis will track across the
eastern Great Lakes Monday evening. A cold front will be exiting the
North Country Monday evening while it`s associated surface low moves
towards Quebec. Ongoing convection across the North Country will
move east and the threat for severe weather will come to an end.
Behind the sharp cold front, cold air advection will be ongoing
across western and north central NY. Northwest winds are just off
parallel to the isotherms so cold air advection will be on the
slower side the first half of the night. A secondary cold front will
track across the region the second half of the night and colder air
filters into the region. Lows Monday night will reach the mid 40s.

The region remains under the mid-level trough Tuesday and another
potent shortwave trough will track from southern Ontario to the
eastern Great Lakes Tuesday. An increase in moisture and increased
upward motion will result in cloudy conditions by the afternoon.
Showers are possible across the North Country through the afternoon
Kept the forecast mainly dry for western NY however wouldn`t be
surprised if some congested strato-cu and isolated showers form. A
west-northwest wind will increase to 15-25 mph by the afternoon.
Highs will only reach the mid to upper 50s to low 60s across the
lake plains.

An upper level ridge over the Central U.S. will build across the
Great Lakes Tuesday night through Wednesday bringing dry weather.
Lows Tuesday night will reach the upper 30s to low 40s. At this
time, the surface high is expected to stay west of the region
Tuesday night, if it builds further east than lower temperatures are
possible. Highs Wednesday will reach the low to mid 60s.

The ridge will build again Wednesday night while warm air advection
takes place. Chances for showers increase across western NY
overnight. Lows Wednesday night will fall to the low to mid 40s
across the North Country to the mid to upper 40s across western and
central NY.


Warm air advection is the main story for most of the Long Term
Period with above-normal temperatures Thursday through Saturday
and summer-like high temperatures Friday and Saturday.

A warm front will likely move through the region Thursday. As zonal
flow continues aloft, some showers and storms are possible into
Thursday night. The upper level pattern gets a little messy as
embedded convectively induced shortwave troughs move around a
building ridge near the eastern Great Lakes. Showers and storms are
possible especially during Friday afternoon and evening with highs
reaching the mid to upper 80s. The pattern becomes amplified
Saturday as a sharp cold front tracks west to east across the Great
Lakes. The chance for showers and storms increases Saturday and
Saturday night. Strong storms are possible during this time. The
cold front will track across the region by Sunday and mostly dry but
cooler conditions will close out the weekend.


VFR conditions will continue early this morning. A strong cold front
will track east reaching far western counties around 12z Monday. Mid
to high level clouds will increase in coverage ahead of the front.
Clouds will lower to MVFR across far western NY later this morning
while showers and embedded thunderstorms move into the region,
impacting IAG, BUF and JHW.

The front will then track to the Genesee valley by early afternoon
and exit the eastern Lake Ontario region very early this evening. A
band of heavy showers and scattered thunderstorms (MVFR/IFR
conditions) will accompany the front this afternoon, impacting ROC
and ART. Brief period of strong to severe storms with hail and wind
gusts over 40 kts are possible at ROC early this afternoon and at
ART mid to late afternoon.

Tonight a few showers and isolated thunderstorms may impact far
western terminals (IAG, BUF and JHW) very early while off and on
showers may move across through the night at ART. Localized MVFR
conditions could occur during heavier showers but otherwise VFR
conditions are expected.

Tuesday through Friday...Mainly VFR.


Cold front crosses eastern Lake Erie and Niagara River this morning
and crosses Lake Ontario this afternoon. Showers and thunderstorms
will accompany the front, some of which could prompt Special Marine
Warnings this afternoon across Lake Ontario and thunderstorms are
expected to intensify. Winds and waves briefly could touch Small
Craft Criteria especially southeast Lake Ontario late today
behind the front and the storms.

Better chance of more prolonged higher-end Small Craft Advisory
conditions develops late tonight through Tuesday night (lasting
longest on Lake Ontario) as colder air arrives and mixing increases
behind the cold front.






NWS BUF Office Area Forecast Discussion