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FXUS61 KBUF 242246
AFDBUF

Area Forecast Discussion
National Weather Service Buffalo NY
646 PM EDT Wed Apr 24 2024

.SYNOPSIS...
Lingering clouds and patchy drizzle will clear out from north to
south this evening. An expansive area of Canadian high pressure will
then assure us of fair, dry weather Thursday through Friday. While
some showers will be likely this coming weekend, especially on
Saturday, a good amount of dry time will be built in. Looking
further down the road, we can look forward to a summer-like warm up
Sunday and Monday with the mercury surging well into the 70s and
even a few spots into the 80s.

&&

.NEAR TERM /THROUGH THURSDAY/...
...Unseasonably Cold Tonight...

Northerly upslope flow has slowed the progress of clearing, with
clouds still dominating everywhere south of Lake Ontario. Meanwhile
skies have cleared nicely east of Lake Ontario. Much drier air
poised just north of Lake Ontario will advect south this evening and
help to scour out the clouds, with clearing reaching the lake plains
by mid evening, then the higher terrain of the Southern Tier by late
evening and the early overnight. Some patchy drizzle will continue
through mid evening, mainly across the higher terrain of the
Southern Tier and western Finger Lakes.

Center of expansive area of Canadian high pressure over the upper
Great Lakes will expand southeast over the lower Great Lakes
overnight into Thursday. This will set the stage for a very chilly
latter April night, with cool airmass remaining in place Thursday.
The upside is that feature will provide dry weather, clearing skies
tonight/abundant sunshine Thursday, and mainly light winds. Lows
tonight will be mainly in the 20s away from the immediate
lakeshores, and even some teens in the normal cold spots of the
North Country. Despite plenty of strong April sunshine on Thursday,
highs will only recover into the upper 40s to low 50s in most areas.

&&

.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY NIGHT/...
Surface high pressure will remain camped over our region Thursday
night and Friday. Subsidence will limit cloud cover, and this lack
of cloud cover and light winds, with a dry lower atmosphere will
make for excellent radiational cooling conditions Thursday night,
with lows near freezing along the lakeshore, to lower 20s inland.

A warm front will near our region Friday night with increasing
clouds and rain showers reaching the western Southern Tier late.
Ahead of the rain, southeast downslope winds could reach 35 mph
along the Lake Erie shoreline.

Warm front enters our region Saturday, and accompanied by a
shortwave aloft a brief period of rain showers is expected. Basin
average rainfall will be on the order of a tenth to a third of an
inch. Some thunder may occur with limited MUCAPE values less than
500 J/KG, especially over Lake Erie and the Niagara Frontier.

A few showers, and perhaps a thunderstorm, may linger behind the
front later Saturday and Saturday night with again limited
instability. Mild Saturday night with lows in the lower 50s inland
and east of Lake Ontario, to near 60 across the favorable downslope
areas of WNY.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
Heading into the later half of the weekend and into the first half
of the new work week, a ridge will lie across the Great Lakes, while
a broad trough will span across the Rockies and Central Plains.
Additionally, a shortwave trough will will be in the midst of
passing north into the ridge. This pattern will translate to an
initial surface low (supported by the shortwave) to wash out across
northern Quebec, meanwhile another surface low will develop across
the northern Plains. These surface features combined with the
building ridge aloft, will support the initial surface low`s cold
front to stall out just north of the area, supporting a brief
glimpse at summer like conditions with temperatures warming up into
the 70s and afternoon diurnally driven convection. Expect similar
such conditions, though a few degrees warmer to prevail through
Monday as the second surface low traverses northeast across Lake
Superior.

As the surface low marches toward Quebec Monday night through
Tuesday, its attendant surface cold front will approach the region
from the west and then cross from west to east. Initially expect
some thunderstorms ahead of the front`s arrival Monday night and
then rain showers with the front`s passage Tuesday. Additionally
with the front`s passage Tuesday, expect temperatures to be cooler
than Sunday and Monday with highs ranging in the upper 60s to low
70s, though still well above average for the end of April.

A secondary cold front will then cross the area from north to south
Wednesday supporting a small chance for a few rain showers.

&&

.AVIATION /00Z THURSDAY THROUGH MONDAY/...
Northerly upslope flow behind a departing cold front will continue
to produce an expansive area of stratus across Western and Central
NY into this evening, with CIGS improving to VFR on the lake plains.
Areas of MVFR/IFR CIGS will continue across higher terrain through
mid to late evening before scattering out to VFR around midnight.
After that, VFR will prevail overnight through Thursday as high
pressure builds across the area with clear skies.

Outlook...

Friday...VFR.
Saturday...VFR/MVFR. Showers likely, with a slight chance of
thunderstorms.
Sunday and Monday...Mainly VFR. A chance of showers.

&&

.MARINE...
Northerly winds will continue to diminish overnight, with choppy
conditions on both lakes gradually improving.

Expansive high pressure centered over the upper Great Lakes this
evening will then gradually build across the lower Great Lakes
overnight and Thursday. This will significantly lower winds and
waves tonight. Local lake breeze circulations will develop Thursday,
with onshore winds along all the Great Lakes shorelines in the
afternoon. Northeast winds may continue to run 10-14 knots on Lake
Erie with some chop Thursday.

&&

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

&&

$$

SYNOPSIS...Hitchcock/JM/RSH
NEAR TERM...Hitchcock/JM
SHORT TERM...Thomas
LONG TERM...EAJ
AVIATION...Hitchcock
MARINE...Hitchcock/JM/RSH