586
FXUS61 KALY 210913
AFDALY

AREA FORECAST DISCUSSION
National Weather Service Albany NY
513 AM EDT Sat Sep 21 2024

.SYNOPSIS...
Morning clouds break for partly sunny skies today
with continued mainly dry and seasonably warm conditions before
skies trend clearer through the day tomorrow and temperatures turn
a bit cooler. Our long stretch of dry weather then comes to an end
by the middle to end of this week as unsettled conditions develop
and chances for showers increase Tuesday through the end of the
week.

&&

.NEAR TERM /THROUGH TONIGHT/...

Our coastal low will continue to spin southeast of Cape Cod
today maintaining east-northeast flow but high pressure building
southward through eastern Quebec into northern New England will
finally help steer it further out to sea. Early stratus clouds
will dissipate by mid to late morning giving way to partly sunny
skies as high clouds continue to spill eastward ahead of a warm
front pushing through western PA/NY with some mid-level clouds
as our backdoor front stalls overhead. Given the increased cloud
coverage, temperatures should be slightly cooler than yesterday
with highs rising into the mid to upper 70s in eastern NY
(still above normal for late September). Highs will be cooler in
the mid-60s to low 70s in western New England where morning
stratus linger the longest. East-northeast winds in western New
England will also be a bit breezy with sustained winds 6-10kts
given closer proximity to the coastal low and incoming high.

Guidance is in good agreement that a weak shortwave rotating
around what is left of the parent closed low in New England will
track into our region but given lackluster moisture and weak
overall forcing, any isolated showers look limited to the
Adirondacks. Given weak/light nature of any showers, we
maintained a dry forecast but may need to introduce some slight
chance POPs in future updates depending on radar trends.

Stratus clouds redevelop this evening, especially in western
New England, as our backdoor front washouts out as it slides
further west through the Mohawk Valley/western Adirondacks and
our coastal low continues to slowly exit southward. High
pressure centered in eastern Quebec expands and gains control of
the Northeast. Given anticipated cloud coverage, did not
include any fog mention. Overnight lows remains a bit mild with
lows in the upper 40s to mid 50s thanks to clouds.


&&

.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...

Upper level ridging from the Ohio Valley amplifies as it builds
into western/central NY on Sunday providing increasing
subsidence that allow early clouds to give way to clearing
as high pressure over Quebec maintains control at the sfc. All
of these features will give us a pleasant Sunday and first day
of autumn with high temperatures reaching into the low to mid
70s in the valley with mid to upper 60s in the higher terrain
and hill towns. Temperatures cool off noticeably towards sunset
given clear skies.

Clear skies continue Sunday night supporting efficient
radiational cooling but as the upper level ridge axis flattens
and slides into western New England, cirrus clouds should spread
eastward overnight. Still expecting a chillier night as cirrus
clouds likely will not hinder radiational cooling much with temperatures
dropping into the mid to upper 40s for much of the area (around
50 in the immediate valley areas).

Upper level ridging continues to flatten on Monday as a weak
shortwave trough in Ontario and associated weak warm front from
western PA/NY pushes eastward. High pressure centered in
eastern Quebec maintains a strong hold over the Northeast as
the warm front remains to our west. Thus, only expecting
increasing clouds through the day Monday with most showers
remaining to our west. Included slight chance and chance POPs
in the southern Adirondacks Monday P.M given some uncertainty but
the best warm air/moisture advection remains to our west. Thus,
POPs may may very well be removed in future updates. Otherwise,
southeast winds become a bit breezy at times as the pressure
gradient tightens between the Canadian high and weak low
tracking through the southern Great Lakes. High temperatures
will end up a few degrees cooler compared to the weekend with
daytime highs reaching into the mid to upper 60s with low 70s in
the valley.

Skies remain cloudy Monday night which will keep temperatures a
bit elevated in the low to mid 50s in the valley with upper 40s
in the higher terrain and hill towns. As the sfc warm front near
closers, the leading edge of the stronger warm air/moisture
advection along the sfc convergence advances eastward leading
to increasing POPs from west to east Monday night. However, with
high pressure keeping a strong hold over the Northeast, we
capped POPs at only chance in eastern NY with slight chance in
western New England as some guidance indicates showers weaken
or even diminish as they run into the sfc high. Will continue to
monitor trends.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
A wetter, unsettled period continues through much of next week as
persistent upper-level troughing develops over much of the eastern
CONUS. An initial upper trough over the Northern Plains on Tuesday
will track eastward, with ensemble guidance continuing to suggest
troughing will eventually move into Southeast Canada while a cutoff
low develops somewhere from the Southern Plains into the Ohio Valley
Thursday into Friday. Details aside, troughing moving toward the
Northeast will see repeated chances for rain, initially arriving
from the west on Tuesday, and spreading eastward through Wednesday
and Thursday. Chances for additional showers on Friday remain
dependent on the relative placement of upper lows over New England
and the MS/OH Valleys, and are a low confidence forecast at this
lead time.

Beneath persistent upper troughing, temperatures look to remain
steady at seasonable levels through the period. Afternoon highs will
reach the upper 50s to mid 60s in high terrain and mid 60s to low
70s at lower elevations each of Tuesday through Friday afternoons,
while lows in the upper 40s to mid 50s are expected Tuesday through
Friday nights.

&&

.AVIATION /08Z SATURDAY THROUGH WEDNESDAY/...
Through 06Z Sunday...VFR cigs at terminals along the Hudson will
trend toward MVFR at 2-3 kft as low clouds associated with a surface
low off Cape Cod slowly extend westward from New England, while MVFR
cigs persist at PSF. Elevated low cloud coverage will lessen the
potential for the development of any radiation fog, but there
remains a conditional threat for restricted vsbys within fog if the
low cloud deck remains east of ALB/GFL/POU, however that is
considered the less likely scenario at this point.

Following sunrise, low cloud coverage will decrease as diurnal
mixing initiates, however sct strato-cu coverage at 3-5 kft will
continue through much of the day. Bkn cigs at 2-5 kft are again
expected late Saturday afternoon into Saturday night as a weak upper-
level system approaches from the west, but no other impacts are
anticipated at area terminals.

Calm to light and variable winds tonight will increase out of the
north to northeast at around 5 kt after 12-15Z Sat, turning
increasingly out of the east at 5-10 kt through 00Z Sun. Light east
winds at less than 5 kt are expected into Saturday night.

Outlook...

Sunday Night: No Operational Impact. NO SIG WX.
Monday: No Operational Impact. NO SIG WX.
Monday Night: Moderate Operational Impact. Chance of SHRA.
Tuesday: Low Operational Impact. Slight Chance of SHRA.
Tuesday Night: Moderate Operational Impact. Chance of SHRA.
Wednesday: Moderate Operational Impact. Chance of SHRA.
Wednesday Night: High Operational Impact. Likely SHRA.
Thursday: Moderate Operational Impact. Chance of SHRA.

&&

.ALY WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
MA...None.
VT...None.

&&

$$

SYNOPSIS...Speciale
NEAR TERM...Speciale
SHORT TERM...Speciale
LONG TERM...Picard
AVIATION...Picard