818
FXUS61 KALY 250158
AFDALY

AREA FORECAST DISCUSSION
National Weather Service Albany NY
958 PM EDT Tue Sep 24 2024

.SYNOPSIS...
The two week stretch of dry conditions over much of
eastern New York and western New England will not be allowed to
extend past this evening as showers look to spread into the region
from northwest to southeast overnight tonight. But unsettled
conditions will be short lived as yet another period of dry weather
looks to begin Friday into the upcoming weekend.

&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
.UPDATE...As of 0955 PM EDT, we`re beginning to see rain
showers moving into portions of Herkimer and Hamilton counties
as a band of WAA builds into central New York. Rainfall amounts
across that area have ranged from a few hundredths to near a
quarter of an inch (mainly in persistent bands of showers).
Latest CAMs including the HRRR have been handling the evolution
of showers well, so have updated POPs to reflect obs and newer
guidance over the next few hours. Previous discussion below...

.PREV DISCUSSION [0400 PM EDT]...Tranquility persists this
afternoon as part of the last day of the recent two-week stretch
of dry conditions across much of eastern New York and western
New England. Visible satellite imagery shows mostly to partly
sunny skies across the region with the most consistent coverage
south and east of Albany courtesy of easterly flow driving
coastal clouds inland. And though a cirrus shield has reached
the western edge of our CWA in advance of a low pressure system
currently situated in the Ohio Valley, a hole or minimum in
cloud coverage has existed for much of the afternoon from Albany
northward due to enhanced subsidence and possible downsloping
effects with high pressure adjacent to the northeast.

Throughout the remainder of the afternoon/evening and into the
overnight, the high over Atlantic Canada will gradually slide
south and east as upper- level ridging aloft is forced to
deamplify and also shift south and east as an upper level trough
digs into the Mississippi Valley. By tomorrow morning, the
trough looks to split as the southern portion deepens and closes
off into an upper-level cutoff low in the Mississippi Valley and
the northern portion remains a positively-tilted shortwave about
the base of an upper low in northern Canada. The aforementioned
surface low currently in the Ohio Valley will gradually track
north and east into the northeast Great Lakes/southeast Ontario
as the axis of the shortwave aloft digs farther south into the
same area. Warm air advection ahead of the attendant warm front
associated with the low paired with favored synoptic-scale
forcing for ascent at the leading edge of the shortwave will
allow showers to develop and track into the region by tonight.
Showers will spread into the region more or less from west to
east, bringing the initial accumulations of what will be much
of the region`s first accumulating rainfall in over 14 days.

Showers tonight will be relatively light in nature, impacting
areas mainly north and west of Albany. Extensive cloud cover as
a result of the advancing system will make for more mild
temperatures in comparison to last night with upper 40s to low
50s anticipated.

&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/...
Showers continue into the day Wednesday as the shortwave
propagates farther eastward and the surface low continues its
progress northward whilst the cutoff low sinks farther into the
deep south. Southwesterly flow across the area will align with
the southwest to northeast axis of moisture extending
northeastward from the Gulf of Mexico, bringing plenty of fuel
to sustain rounds of showers throughout the day and into
Wednesday night. The heavier showers look to come Wednesday
evening into Thursday morning as upper-level flow increases in
response to the deepening and closing off of the upper wave into
an upper low. Increased divergence aloft and upslope flow could
lead to some heavier downpours in higher terrain regions of the
Southwest Adirondacks and Southern Greens, but with the recent rain
deficit, there are no hydro concerns at this time. It is also
possible that some embedded thunderstorms develop Wednesday
afternoon/evening as latest CAMs are indicating some elevated
instability within the environment. However, no severe weather
is anticipated.

Showers continue into Thursday morning as a weak cold front
swings through the region, but gradually begin to wane in
spatial coverage as the upper low moves east into southeast
Quebec, taking with it the better forcing. By Thursday night,
primarily dry conditions will be reinforced across the region as
heights increase in the wake of the upper low with high pressure
ridging building over the Midwest and into Ontario.

High temperatures Wednesday will be the cooler of the period
with extensive cloud cover and rain-cooled air, reaching only
the mid 50s to mid 60s. Low temperatures Wednesday night will
only dip into the low to mid 50s with pockets of upper 40s above
1500 ft and upper 50s in valley areas. Highs then warm Thursday
to the mid/upper 60s to low 70s with pockets of low 60s across
higher terrain regions. Thursday night will feature lows in the
low to upper 50s with upper 40s in the Southwest Adirondacks and
highest peaks of the Eastern Catskills and Southern Greens.

&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...
Another prolonged period of dry weather is anticipated across
the long term forecast period as upper-level ridging builds in
across the region Friday into Saturday and remains in place
through early next week as an Omega block sets up Monday into
Tuesday. Though the closed low in the Deep South will track
north through the Mississippi Valley through the weekend, the
high pressure ridging it encounters will keep it at bay, leading
to little to no impact for our region.

High temperatures will
be fairly similar throughout the period with mid/upper 60s to
low 70s across much of the region outside of pockets of low 60s
possible across higher terrain. Low temperatures will generally
fall to the upper 40s to low 50s each night of the period.

&&

.AVIATION /02Z WEDNESDAY THROUGH SUNDAY/...
Through 00z Thursday...VFR conditions to start the period will
slowly deteriorate through the night, as low clouds and chances
of rain showers increase with an approaching system. The first
chance will come around 25.10z mainly at ALB/GFL as low-level
lift increases, with MVFR ceilings and visibilities also
expected. Guidance is in agreement of a brief break in activity
through midday, though MVFR and scattered IFR ceilings will
persist at all terminals. A more widespread moderate to heavy
rain will arrive towards the end of the TAF cycle and will be
accompanied by low-end MVFR to IFR conditions, though these
should hold off until after 26.00z.

The winds will be light from the east to southeast at less than
10 KT tonight, and then will be southeasterly at 5-10 KT after
12Z Wednesday.

Outlook...

Wednesday Night: High Operational Impact. Likely SHRA...TSRA.
Thursday: High Operational Impact. Likely SHRA...TSRA.
Thursday Night: Moderate Operational Impact. Chance of SHRA.
Friday: No Operational Impact. NO SIG WX.
Friday Night: No Operational Impact. NO SIG WX.
Saturday: No Operational Impact. NO SIG WX.
Saturday Night: No Operational Impact. NO SIG WX.
Sunday: No Operational Impact. NO SIG WX.

&&

.CLIMATE...
Having last recorded measurable precipitation on September 9,
the dry spell in Albany reached 14 days on Monday, September 23.
This is the first two-week dry spell in Albany since May 11-25,
2021, when a trace of precipitation was observed over 15 days.

Furthermore, every day in the current dry spell has seen zero
precipitation, marking the first absolute dry spell of at least
14 days since October 4-26, 1963.

Tuesday, September 24 is expected to extend the dry spell to 15
days before widespread rain ends the streak on Wednesday.

&&

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

&&

$$

SYNOPSIS...Gant
NEAR TERM...Gant/Speck
SHORT TERM...Gant
LONG TERM...Gant
AVIATION...Speck
CLIMATE...Picard