320
FXUS61 KALY 191021
AFDALY

Area Forecast Discussion
National Weather Service Albany NY
621 AM EDT Sat Sep 19 2026

.WHAT HAS CHANGED...
Outside of the ADKs, bumped up temps and dew points a couple degrees
through the rest of the night as high clouds have been a little
thicker/more widespread than previously expected. For Sunday,
the excessive rainfall outlook has been trimmed back
significantly, with only the I-84 corridor in the marginal risk
now. This better agrees with local messaging that flash
flooding is not expected. Forecast for early next week has also
trended drier. Watching a potential coastal storm towards the
very end of the forecast period.

&&

.KEY MESSAGES...
1) Dry, cool, and pleasant weather is expected today.

2) A low pressure system will bring widespread rain to the
region Sunday, followed by drier and cool weather for the first
half of the week.

3) A coastal storm is expected to track somewhere near the east
coast late next week, but confidence is very low whether or not we
will see any impacts from this system.

&&

.DISCUSSION...
KEY MESSAGE 1...As of 2:45 AM EDT...Despite sfc high pressure
building into southern Canada, a weak upper impulse is leading
to fairly widespread high clouds across the region early this
morning. These high clouds should gradually move off to the
south /southeast over the next few hours, but have been thick
enough to keep temperatures a few degrees warmer than previously
expected for most of the region. The exception is the ADKs,
where there have been more breaks in the clouds and temperatures
are already in the upper 30s to low 40s per latest NYS mesonet
obs. For the rest of the region, lows will be mainly in the 40s,
with some 50s possible near I-84. This means temps will drop
several more degrees between now and sunrise as the high clouds
clear out and winds gradually weaken. Today looks like a
beautiful early fall day. With the sfc high sliding overhead, we
will see dry conditions with just some scattered high clouds
around. Humidity will remain low with highs in the 60s.


KEY MESSAGE 2...Tonight into tomorrow, a sfc low will develop along
a stalled frontal boundary over the Ohio Valley in response to
another upper shortwave. This sfc low will track south of the region
on Sunday, bringing widespread rain to the region. As the sfc low
strengthens, so will the LLJ that will help advect more moisture
into the region. PWATs rise to 1.5 - 1.75" per the latest HREF,
which is high for mid to late September, albeit not
exceptionally so. The sfc warm front remains south of our
region, but with the sloping mid-level warm front lifting north
into the Mid Hudson Valley, there will be plenty of warm
advection/isentropic lift to provide forcing for ascent, as will
the right entrance region of an upper jet streak passing by to
our north. Rainfall amounts have ticked up slightly for northern
areas, which are now expected to see a general half to three
quarters of an inch. From around I-90 south, 0.75 to 1.5" of
rain is expected, with some locally higher amounts possible
closer to the I-84 corridor near the best mid-level forcing.
With rain leading to wetbulb cooling Sunday, highs will struggle
to make it out of the 50s for most areas.

Our thinking regarding hydro issues has not changed for Sunday:
aside from some nuisance ponding of water in the typical low-
lying, urban, and poor drainage areas, hydro issues are not
expected. We collaborated with WPC to have the marginal risk
ERO trimmed back significantly with only the I-84 corridor now
included. This now better aligns with our local messaging that
given the lack of instability, stratiform nature of the rain,
and high FFG values, flash flooding is not expected Sunday. In
fact, this rain will be beneficial for most areas, especially
the Mid Hudson Valley where <0.25" of rain has fallen in the
last 5 days.

Rain tapers to showers and comes to an end Sunday evening/night as a
strong (1030 mb) sfc high builds E/SE into southern Canada beneath
confluent upper flow. This sfc high will be the main driver for our
weather through the first half of the week as it slowly drifts N/NE
of our region, and will result in cool, dry E/NE flow. NBM has
finally caught onto the drier solution we mentioned yesterday for
Monday - Wednesday, as the strong sfc high should suppress any
precip south of our region with low to mid-level dry air in
place. The only exception is possibly Tuesday morning, when a
few showers can`t be ruled out near the immediate I-84 corridor
with a passing upper disturbance. Given cool E/NE flow, highs
each day will be mainly in the 50s (terrain) to 60s (valleys)
with lows in the 30s (terrain) to 40s (valleys) each night.


KEY MESSAGE 3...Guidance has been hinting at a upper trough or
closed upper low tracking from the Ohio Valley off the Mid-Atlantic
coast late next week, and given that there has been some consistency
in this signal for a few days we felt it deserves to be mentioned.
As the ULL moves off the coast, a sfc low is expected to develop and
strengthen as it tracks to the northeast. Some of yesterday`s
12/18z guidance and tonight`s 00z guidance indicates that the
sfc low could come close enough to the coast to result in at
least some rain for our area. Given that moisture looks quite
abundant with this coastal low, we will continue to monitor
closely over the coming days. That said, guidance is notorious
for struggling with the placement of these closed upper lows in
the medium to long range, so confidence in the track of the
coastal low is quite low. Additional forecast changes should be
expected over the coming days.

&&

.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
Through 12z Sunday...As of 6:20 AM EDT, flying conditions are VFR at
all terminals. Can`t totally rule out some very brief MVFR vsbys
with mist at GFL through around 12z, but confidence in this
happening is low. No longer expecting any fog/mist at PSF either.
Today, VFR conditions prevail with just FEW to SCT high clouds
around. Some patchy fog/mist may develop at GFL/PSF tonight, but
should dissipate prior to daybreak as mid and high clouds increase
and thicken ahead of our next weather system. In fact, this system
could bring some showers with MVFR vsbys during the last few hours
of the TAF period, especially for ALB/GFL/POU. Widespread rain then
expected Sunday beyond the end of the TAF period. Winds will be at
around 5 kt from the N/NE today, becoming light and variable late
this afternoon through the first half of tonight. Winds increase to
around 5 kt from the SE at POU/PSF and to around 10 kt with gusts of
15-20 kt at ALB after 06z tonight.

Outlook...

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

&&

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

&&

$$

DISCUSSION...35
AVIATION...35