WX in text

133
FXUS61 KBUF 271510
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
1110 AM EDT Thu Mar 27 2025

.SYNOPSIS...
High pressure ridged north across the area from the Mid-Atlantic
region will drift east toward then off the VA/NC coast this
afternoon and tonight. This will provide us with mainly dry weather
today, with a passing weak cold front then bringing a brief round of
rain and snow showers to areas east of Lake Ontario this evening.
Elongated low pressure will then extend eastward across our area
later Friday through the weekend, bringing more widespread unsettled
weather that will feature periods of rain for most areas, and
possibly some mixed precipitation across the North Country. Expect a
large north to south range in temperatures over the weekend owed to
a wavy frontal boundary draped across the area. This will be
maximized on Saturday with daytime highs near freezing toward the
Saint Lawrence Valley, and upper 60s to near 70 across the western
Southern Tier.

&&

.NEAR TERM /THROUGH FRIDAY/...
Surface-based ridging will slowly drift east across eastern New York
and New England this afternoon and tonight. Meanwhile, another
northern stream shortwave and its attendant weak/relatively moisture-
starved cold front will quickly dive southeastward across Ontario
and Quebec, with this next surface boundary crossing our region this
evening. The approach of this system may help to trigger a few
widely scattered rain showers across the western Southern Tier late
this afternoon into early this evening, with the North Country
likely seeing a brief round of scattered to numerous rain and snow
showers this evening owing to its closer proximity to the base of
the supporting shortwave, somewhat better moisture and some modest
upsloping. Across the higher terrain of the Tug Hill and western
Adirondack foothills, this could lead to some fresh minor snow
accumulations of under an inch.

Prior to the arrival of this system, expect largely dry conditions
today with warm air advection helping high temps to rebound into the
upper 30s to mid 40s east of Lake Ontario and to the mid 40s to
lower 50s elsewhere, with a brief period of breezy conditions
(featuring wind gusts up to 30-35 mph) likely across far western New
York later this afternoon into early this evening right out ahead of
the surface cold front. Conditions will then dry out again later
tonight as a narrow wedge of high pressure builds in behind the
departing front, with overnight lows ranging in the upper 20s to
lower 30s south of Lake Ontario and in the mid to upper 20s across
the North Country.

On Friday the narrow wedge of high pressure will drift eastward into
New England, while broad low pressure over the Plains states
elongates and extends northeastward across the Upper Mississippi
Valley. As this occurs, the surface warm front attendant to the low
will snake its way eastward across the southern Great Lakes, with
this boundary reaching western New York by later Friday afternoon.
The corresponding increase in moisture and isentropic upglide will
bring thickening clouds to our area, along with increasing chances
of rain showers to areas south of Lake Ontario during Friday
afternoon. This will particularly be the case across far western New
York, where showers should become likely (60 PoPs) by late
afternoon. Otherwise, we can expect a decent north-south gradient in
temperatures during Friday, with highs ranging from the upper 30s to
around 40 across the North Country, to the lower 50s across the
southern Tier and interior Finger Lakes.

&&

.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
Confluent flow of the southern and northern branches of the jet
stream this period, that become zonal flow over our region, will
allow for a wavy frontal boundary that will bring sharp differences
in surface temperature and weather type to our forecast area.

Surface low Friday night will ride along a warm frontal boundary
that will extend across Lake Ontario. Southerly flow within the warm
sector Friday night will maintain mild temperatures and just plain
rain showers developing for WNY, while northeast flow and a narrow
warm nose aloft will transition snow to a freezing rain or a cold
rain scenario for counties east of Lake Ontario. By Saturday morning
the warm nose aloft should be sufficiently deep enough to allow for
just freezing rain or plain rain east of Lake Ontario. The northeast
flow will lock temperatures around the freezing mark Saturday within
the Saint Lawrence Valley which could prolong the freezing rain.

As the low shifts eastward, a narrow bubble of high pressure will
push the frontal boundary southward for Saturday night. While this
may alleviate the freezing rain threat for the north country some,
the northeast flow Saturday night south of Lake Ontario, with near
freezing air temperatures trapped north of the escarpment may allow
for some pockets of freezing rain.

By Sunday a deeper surface low to the west, and departure of the
bubble of surface high pressure over Canada will allow for the
frontal boundary to push northward, possibly such that air
temperatures will reach into the 40s for the SLV. This will end the
freezing rain event for the eastern Lake Ontario region. All told
several tenths of an inch of ice, especially for the SLV, is
possible from later Friday night through Sunday morning.

Meanwhile south of the frontal boundary a mild southerly flow will
send temperatures into the 50s and 60s Saturday, with potential for
a few 70s Sunday. Greatest uncertainty to air temperatures Saturday
and Sunday will be the NYS Thruway and points northward, within the
vicinity of the frontal boundary.

A 60 to 65 knot LLJ at 2-3K feet may bring strong wind gusts to the
hill tops, and possibly the lake plain of WNY Saturday. Shallow
mixing heights with mostly cloudy skies will limit the very strong
gusts from reaching the surface, though some breaks of sunshine near
the state line and Southern Tier may allow for gusts to reach into
the 30 if not 40 mph range Saturday.

&&

.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
Sunday night mild air will linger over our region with showers, and
potentially a few WNY thunderstorms on MUCAPE values of 200 to 400
J/KG. A lot of uncertainty to the temperatures Sunday night through
Monday. While thermal profiles will be above freezing, supporting
just plain rain showers, there is a spread among the NBM 25th and
75th percentiles of 25 to 30 degrees. A sharp cold front will plow
across our region either late Sunday night or Monday, sending
temperatures back into the 20s and 30s, with rain ending with a
little snow. Rain (and eastern Lake Ontario snowmelt) through the
weekend and into Monday will give rises to area creeks and rivers.
The ensemble river forecasts of the GEFS and NAEFS suggest these
creeks and rivers, both the Buffalo Metro creeks, Genesee River
watershed and the Black River east of Lake Ontario, should remain
within their banks, though high flows are anticipated early next
week. Dry air Monday night and Tuesday will limit the lake effect
response, with areas outside lake clouds sunny Tuesday. The next
system from the west will approach our region later Wednesday.

&&

.AVIATION /15Z THURSDAY THROUGH MONDAY/...
VFR flight conditions and largely dry weather will prevail today.
Meanwhile initially light winds will freshen out of the southwest as
a weak cold front approaches, with this likely leading to some 25-30
knot gusts downwind of Lake Erie late this afternoon into early this
evening.

The weak cold front will then cross our area this evening. For most
locations its passage will merely be marked by a modest increase in
cloud cover and a transition to lighter westerly winds, though areas
east of Lake Ontario should see a brief period of scattered to
numerous rain and snow showers and possible MVFR. Following the
passage of the front, dry and mainly VFR conditions will then return
for the balance of tonight.

Outlook...

Friday...VFR initially...then deteriorating to MVFR/IFR south of
Lake Ontario with rain showers becoming likely across far WNY by
later Friday afternoon.
Friday night through Sunday...MVFR/IFR with periods of rain, with
mixed precipitation likely at times east of Lake Ontario.
Monday...VFR/MVFR with rain showers likely.

&&

.MARINE...
A cold frontal passage will bring another uptick in winds later
today and tonight, with a brief (6-12 hour) period of Small Craft
Advisories to account for this. These headlines will be followed by
another ridge of high pressure and a return to quieter conditions
later tonight and Friday morning, before freshening easterlies
develop across Lake Ontario Friday afternoon out ahead of an
approaching warm front. These may eventually require the issuance of
another Small Craft Advisory for southwestern portions of the Lake
for later Friday afternoon and Friday evening.

&&

.BUF WATCHES/WARNINGS/ADVISORIES...
NY...None.
MARINE...Small Craft Advisory from 5 PM this afternoon to 11 PM EDT
         this evening for LEZ020-040-041.
         Small Craft Advisory from 5 PM this afternoon to 5 AM
         EDT Friday for LOZ042.
         Small Craft Advisory from 8 PM this evening to 8 AM EDT
         Friday for LOZ043>045.

&&

$$

SYNOPSIS...JM/JJR
NEAR TERM...JM/JJR
SHORT TERM...Thomas
LONG TERM...Thomas
AVIATION...JJR
MARINE...JM/JJR

NWS BUF Office Area Forecast Discussion