-- Discussion containing changed information from previous version are highlighted. --
959
FXUS61 KALY 241802
AFDALY

AREA FORECAST DISCUSSION
National Weather Service Albany NY
202 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 /THROUGH TONIGHT/...
.UPDATE...As of 2 PM EDT, low pressure situated in the Ohio
Valley has forced a cirrus shield to our western CWA border
while easterly flow to the east has driven clouds into the
region south and east of Albany. Temperatures currently span the
60s across much of the region and adjacent high pressure has
kept us dry thus far today. Few changes were needed with this
update. See the previous discussion for additional details.

.PREV DISCUSSION [0330 AM EDT]...Brief mid and upper-level
ridging are building overhead early this morning while surface
ridging noses into the region from the northeast, yielding yet
another dry day. Some low clouds will move into the Upper Hudson
and portions of western New England on easterly flow, while
cirrus coverage spreads to the northwest as a shortwave trough
approaches from the Ohio Valley, resulting in partly cloudy
skies becoming mostly cloudy by this evening.

Overnight tonight, the aforementioned shortwave will arrive from
the southwest on the eastern flank of an upper trough. A closed
upper-level low will develop over the Mississippi Valley while
its parent northern stream trough continues to progress eastward
into southeastern Canada. Locally, low-level flow turning out
of the southeast will encourage modest warm advection while
synoptic support for ascent increases ahead of the shortwave.
Rain shower coverage will initially be isolated, but will begin
to fill in toward Wednesday morning as the main northern stream
trough makes its nearest approach. This will mark the first
accumulating rainfall for most of the region in over two weeks.

Following morning lows in the mid 40s to low 50s, temperatures
will rise to near seasonal norms today, reaching afternoon
highs in the upper 50s to mid 60s in high terrain and mid 60s to
low 70s at lower elevations. Beneath overcast skies as rain
showers arrive, slightly more mild conditions are expected
tonight, as temperatures fall to lows in the mid 40s to mid 50s.

&&

.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
A positively-tilted upper-level trough will approach from the
west early Wednesday morning. A potent shortwave on its western
flank will continue to dive south over the Lower Mississippi
Valley as a closed low while the parent northern-stream trough
continues eastward from the western Great Lakes into southern
Quebec and northern Maine by Thursday evening. Rain showers will
be ongoing in areas north and west of Albany by early Wednesday
morning, and will continue to spread south and east through the
day, reaching their maximum coverage Wednesday night. Sufficient
elevated instability will be present to yield a few embedded
thunderstorms Wednesday night into Thursday, however severe
weather is not anticipated.

Cool temperatures are expected during rain showers on Wednesday,
with afternoon highs only reaching the mid 50s to mid 60s
across the region. A relatively narrow diurnal range will yield
mild overnight lows largely in the 50s. The surface cold front
will pass through the region Thursday morning, when low-level
flow will pivot out of the southwest to west, and then out of
the northwest by Thursday night. Despite the frontal passage,
temperatures may actually be warmer on Thursday than the day
before, with afternoon highs in the 60s in high terrain and low
to mid 70s at lower elevations as rain showers begin to exit
eastward, narrow but high-amplitude upper ridging builds to the
west, and skies begin to trend clearer through the afternoon.
Overnight temperatures look to remain seasonable, falling to
lows in the upper 40s to mid 50s across the region.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
Behind a departing shortwave, upper level heights will be rising
over the area for Friday, along with warming temps aloft. Upper
level ridge will be expanding eastward from the Great Lakes and
into the Northeast for the weekend into early next week, with
an Omega block setting up between the departing shortwave over
the western Atlantic Ocean and a closed low associated with a
decaying tropical system over the Ohio and Tennessee Valleys.

As a result, dry weather is expected for Friday through the
weekend, as any moisture thanks to the remnant tropical system
will remain well southwest of the area. Skies should be partly
to mostly clear each day, although some late night or early
morning fog will be possible for valley areas.

With the warm temps aloft and decent amount of sun, temps will
be a little above normal. Valley areas should see highs in the
low to mid 70s, with 60s for the high terrain. Overnight lows
will be in the 40s to low 50s, with no chance for any frost or
freeze conditions yet.

Next chance for measurable rainfall may not be until at some
point towards the middle of next week when the block breaks
down and the upper level low off to the west finally is able to
approach the area.

&&

.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
-- Changed Discussion --
Through 18Z Wednesday...VFR conditions continue this afternoon
at all the TAF sites with sct-bkn stratocumulus and sct-bkn
cirrus. Some cigs have reached close to high MVFR levels at KPSF
in the 3.0-3.5 kft AGL range.

An upper level disturbance and a low pressure system will gradually
approach from the Great Lakes Region and Midwest with thickening and
lowering clouds tonight with some showers reaching KALB-KGFL 09-
12Z/WED. Cigs will be lowering to MVFR levels in the 1.5-3.0 kft AGL
range with the showers. Stratus will also increase at KPOU-KPSF 05Z-
08Z/WED with cigs 1.5-3.0 kft AGL.  VCSH groups were used at KPOU
after 11Z/WED and a PROB30 were used after 15Z/WED at KPSF.  Cigs
will be widespread at 1-3 kft AGL at all the sites with some
instances of IFR at a few sites after 12Z/WED.

The winds have been east to southeast 6-12 KT with a few gusts 15-20
KT at KALB.  The winds will be light from northeast to southeast at
less than 10 KT tonight, and then will be southeasterly at 5-10 KT
after 12Z/WED.

Outlook...

Wednesday: Moderate Operational Impact. Chance of SHRA. Wednesday
Night: High Operational Impact. Likely SHRA...TSRA.
Thursday: Moderate Operational Impact. Chance of SHRA...TSRA.
Thursday Night: Low Operational Impact. Slight Chance of SHRA.
Friday to Sunday: No Operational Impact. NO SIG WX.
-- End Changed Discussion --

&&

.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
SHORT TERM...Picard
LONG TERM...Frugis
AVIATION...Wasula
CLIMATE...Picard