Forecast Discussion

570
FXUS61 KBUF 200021
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
821 PM EDT Sun Apr 19 2026

.WHAT HAS CHANGED...
Increased PoPs a bit at points tonight into Monday morning across
areas south of Lake Ontario.

&&

.KEY MESSAGES...
1) Significantly colder weather will continue through Monday night,
with unsettled conditions lasting into Monday morning.

2) Welcomed period of dry weather beginning Monday night.

&&

.DISCUSSION...
KEY MESSAGE 1...Significantly colder weather will continue through
Monday night, with unsettled conditions lasting into Monday morning.

A deep longwave trough will continue to dig across the Great Lakes
tonight and New England Monday...resulting in 850 mb temperatures
bottoming out near -12C Monday morning...before starting to slowly
modify Monday afternoon as low level ridging builds into the area.
This will result in well below normal highs in the upper 30s and
lower 40s today...with readings then struggling to get out of the
mid to upper 30s in most areas on Monday. Meanwhile lows both
tonight and Monday night will be in the 20s...with even some teens
possible across the interior of the Southern Tier and North Country
Monday night.

In terms of pcpn chances through Monday, a batch of showers will
come this evening...when a secondary cold front and a shortwave will
slip southeastward across the area...with these generating another
round of scattered to numerous showers that will change to all snow
over time with the loss of diurnal influences and continued cooling
of our airmass. The greatest coverage of these will be expected
south of Lake Ontario... with local maxima possible immediately
south/southeast of both lakes due to some additional lake
enhancement/upsloping. Another chance will come later tonight and
early Monday in the form of some scattered upslope and lake effect
snow showers across the higher terrain and southeast of the lakes.
This last batch will then fade out from northwest to southeast
during the balance of Monday as high pressure and drier air builds
across the area...with a dry night then following for Monday night.

In terms of snowfall accumulations...strong mid/late April diurnal
influences and the warm ground conditions (soil temps running in the
upper 40s to lower 50s per NYS Mesonet obs) will largely help
prevent these into the first half of the evening. The loss of
daytime heating and continued cooling of our airmass should then
allow for some minor accums of up to an inch on elevated/grassy
surfaces across the higher terrain tonight and very early
Monday...with renewed diurnal effects and the diminishing trend to
the pcpn then preventing much (if any) in the way of additional
accumulation after about mid Monday morning.

KEY MESSAGE 2...Welcomed period of dry weather beginning Monday
night.

A shortwave ridge will pass across our region Monday night, to be
followed by a dampening shortwave trough...that may bring scattered
showers to our region Tuesday night. Behind these two features a
more broad area of high pressure, both at the surface and aloft,
will build across our region through at least Friday morning...if
not longer. This broad area of high pressure will bring fair weather
with day to day warming.

While the majority of the ensemble members of the GEFS/ENS/GEPS do
maintain the ridge into the start of next weekend (with any
precipitation along frontal boundaries), there is a growing number
of ensemble members, especially among the GEFS, that develop and
strengthen a cut off low over the Northeast/eastern Canada. If this
scenario were to occur, cooler and unsettled weather would be likely
to persist for several days across our region.

&&

.AVIATION /00Z MONDAY THROUGH FRIDAY/...
A secondary cold front and a shortwave will slip southeastward
across the area this evening...with these generating another round
of scattered to numerous showers that will change to all snow over
time...with the greatest coverage of these expected south of Lake
Ontario. Flight conditions will lower to MVFR and possibly even some
IFR within these showers. Later tonight and early Monday some
scattered upslope and lake effect snow showers will then follow
across the higher terrain and southeast of the lakes...with
additional localized reductions to MVFR/IFR possible within these.
Outside of any showers...a general mix of MVFR/VFR will prevail.

On Monday high pressure and drier air will build across the area.
This will result in any leftover snow showers diminishing from
northwest to southeast...with flight conditions improving to VFR in
a similar manner.

Outlook...

Monday night...VFR.

Tuesday...Mainly VFR, with a chance of rain showers mainly late
Tuesday and Tuesday night.

Wednesday and Thursday...Mainly VFR.

Friday...Mainly VFR with a low chance of afternoon showers.

&&

.MARINE...
Elevated (15-20 knot) west to west-northwesterly winds across the
region will veer more northwesterly tonight following the passage of
a secondary cold front. On Monday winds will tend to diminish some
in the morning, then will back to westerly during the
afternoon...when another brief round of 15-20 knot winds will be
possible across eastern portions of Lake Ontario. Lighter winds will
then follow for Monday night as the axis of surface high pressure
crosses the Lower Great Lakes.

Given the above...Small Craft Advisories are in effect as outlined
below.

&&

.BUF WATCHES/WARNINGS/ADVISORIES...
NY...None.
MARINE...Small Craft Advisory until 11 PM EDT this evening for LEZ040-
         041.
         Small Craft Advisory until 2 PM EDT Monday for LOZ043.
         Small Craft Advisory until 2 PM EDT Monday for LOZ044-045.

&&

$$

DISCUSSION...JJR/Thomas
AVIATION...JJR
MARINE...JJR

NWS BUF Office Area Forecast Discussion