208
FXUS61 KALY 270615
AFDALY

Area Forecast Discussion
National Weather Service Albany NY
215 AM EDT Mon Jul 27 2026

.WHAT HAS CHANGED...
Lowered forecast max temps slightly for Wed, given expectation
for abundant clouds and at least occasional showers/rain. Should
steady rain occur most of the day, some locations may only reach
the mid 60s to lower 70s for max temps.

&&

.KEY MESSAGES...
1) Isolated showers/thunderstorms today become more numerous for
Tuesday, with some potential for training heavy downpours and
Marginal to Slight Risk for flash flooding, mainly south of
I-90.

2) Coastal low likely brings periods of rain for Tuesday night
into Wednesday night, some of which may be heavy, especially
near and south of I-90. Locally heavy rainfall could bring
isolated to scattered instances of flash flooding, however
threat for river flooding remains very low at this time.

&&

.DISCUSSION...
KEY MESSAGE 1...

Lead upper level disturbance and cold pool aloft may bring
isolated to scattered, mainly afternoon showers/thunderstorms
today, with best chances across higher terrain areas mainly west
of the Hudson River. Slow storm movement could allow for locally
heavy downpours to occur.

As main upper level trough approaches from west Tuesday,
increasingly upper level diffluent flow and low level
convergence will allow for greater coverage of
showers/thunderstorms, especially during the afternoon and
evening hours. Nearly uni-directional low/mid level flow will
allow for some training of showers/thunderstorms, leading to
potential locally heavy rainfall, especially across the SE
Catskills and mid Hudson Valley/NW CT regions, as well as across
portions of the Mohawk Valley and SW Adirondacks. Latest HREFs
suggest 3-hour probs for >1" rainfall as high as 70-90% across
the SW Adirondacks/Mohawk Valley region between 21Z/Tue-00Z/Wed,
and 30-70% elsewhere. Similar 3-hour probs for >3" rainfall are
10-30% across SW Adirondacks/Mohawk Valley and SE Catskills/mid
Hudson Valley after 18Z/Tue, highlighting areas with greatest
chances of heaviest rainfall.

Flash Flood guidance is generally quite high across the region
due to fairly dry antecedent conditions, with 1 hour FFG
generally 1.5-2.5", and 3-hour FFG generally 2.5"-3.5", highest
for areas north of I-90. As such, despite the locally heavy
rainfall potential, overall high FFG suggests mainly isolated to
scattered instances of flash flooding expected (Marginal to
Slight Risk per WPC), with greatest chances mainly south of
I-90 where FFG is slightly lower.


KEY MESSAGE 2...

Digging upper level trough is expected to develop into a closed
low somewhere across central/southern NY or northern PA
Wednesday before slowly advancing east southeast Wednesday night
into Thursday. Depending on exactly where this sets up, and
resulting surface features track, bands of moderate to heavy
rainfall may pivot north and west into the region Wednesday into
Thursday. Rainfall should be mainly stratiform, although some
elevated instability could allow for some embedded convective
elements.

Overall rainfall amounts of 1-3" are currently expected from
today through Thursday morning, with greatest amounts across the
SE Catskills due to enhancement from upslope flow. Locally
higher amounts of 3-4" could occur in these areas, and any other
locations where heavier rainbands set up and stall and/or pivot.

Despite this heavy rainfall, overall groundwater storage
capacity remains fairly high across the region, which should
allow the ground to soak it up with low chances for river
flooding. Latest MMEFS (ensemble river forecasts) do not suggest
any river flooding in eastern NY/western New England assuming
widespread rainfall amounts remain under 4-5". So, although
localized ponding of water in some urban/poor drainage areas,
and isolated/scattered instances of possible flash flooding
where any training heavy downpours occur, the threat for river
flooding appears very low at this time.

&&

.AVIATION /06Z MONDAY THROUGH FRIDAY/...
Through 06z Tuesday...VFR conditions at KALB and KPOU continue
through 18z. Patchy fog can develop at KGFL/KPSF between
8z and 11z bringing brief periods of IFR visibilities. Patchy
fog diminishes by 11z with VFR conditions returning through 19z.
Continued mention of MVFR conditions in PROB30 groups for
scattered non-severe thunderstorms this afternoon between 18z
and 23z. Winds continue to be calm this morning, becoming
southerly to southwesterly between 5 and 10 knots for this
afternoon. Winds become calm once again after 28/00z.

Outlook...

Tuesday Night: High Operational Impact. Definite SHRA...TSRA.
Wednesday: High Operational Impact. Definite SHRA...TSRA.
Wednesday Night: High Operational Impact. Definite SHRA...TSRA.
Thursday: High Operational Impact. Likely SHRA...TSRA.
Thursday Night: Low Operational Impact. Slight Chance of SHRA.
Friday: Low Operational Impact. Slight Chance of SHRA...TSRA.
&&

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

&&

$$

DISCUSSION...24/31
AVIATION...05