139
FXUS61 KALY 151835
AFDALY

AREA FORECAST DISCUSSION
National Weather Service Albany NY
235 PM EDT Tue Jul 15 2025

.SYNOPSIS...
Dry weather will persist into early Wednesday afternoon as
dangerous heat and humidity return. Chances for showers and
thunderstorms then increase late Wednesday afternoon into
Wednesday night with the passage of a warm front. Dangerous heat
and humidity linger into Thursday, though not quite to the
extent of Wednesday, as an unsettled pattern ensures additional
chances for showers and thunderstorms through the end of the
work week. Saturday will be the nicest of the next seven days
with much cooler conditions and another brief period of dry
weather.

&&

.DISCUSSION...
Key Messages:

 - Dangerous heat and humidity return Wednesday with heat index
   values ranging from 95 to 100 throughout portions of the
   Hudson and Mohawk River Valleys where a Heat Advisory is now in
   effect.

 - Additional Heat Advisories possible for Thursday with heat
   index values looking to reach the mid/upper 90s.

 - An unsettled pattern will lead to multiple rounds of showers
   and possible thunderstorms beginning late Wednesday afternoon
   through early next week.

Discussion:

High pressure dominating the surface beneath mid- to upper-level
ridging aloft will ensure dry conditions through early Wednesday
afternoon. The amplification of said ridge, however, will see
850 mb temperatures increase to about +17C to +19C, translating
to surface air temperatures reaching the low 80s to low 90s. And
while forecast soundings show a fair amount of mid-level dry
air present tomorrow, a steeper subsidence inversion and the
advection of warm, moist air through deep southerly flow will
pose a detriment to the amount of mixing that will take place.
And, unlike today, predominantly southerly winds will not favor
downsloping and subsequent drying that could limit the rise of
dewpoints. Therefore, with heat index values looking to reach
95 to 100 throughout portions of the Hudson and Mohawk River
Valleys, a Heat Advisory is in effect from noon to 8 PM
tomorrow.

Late tomorrow afternoon, tranquility comes to an end as the
surface high slides north and east while a stationary boundary
currently sitting just off to our south lifts north and eastward
as a very diffuse warm front/dewpoint boundary. Meanwhile, the
ridge aloft is forced to also shift eastward as a shortwave
disturbance sinks south and east from the eastern Great Lakes. Scattered
showers and thunderstorms look to develop late tomorrow
afternoon/early tomorrow evening as cyclonic vorticity
advection increases in response to the upper impulse and low-
level convergence increases as a result of the weak boundary. At
this time, the two forcing mechanisms do not look to intersect,
leading to more widely scattered showers tomorrow night. Latest
CAMs have also adopted this solution, so confidence has
therefore increased in this element of the forecast. It is
possible, with some elevated instability, that some embedded
rumbles of thunder could occur, however, the severe threat is
slim to none with very little shear and very marginal lapse
rates.

Southwesterly flow Thursday will force the continuation of
dangerously hot and humid conditions, though to a lesser extent
than Wednesday. This will be especially true if any showers
and/or thunderstorms from Wednesday night linger farther into
the morning Thursday. However, at present, we expect heat
indices to reach the mid to upper 90s especially throughout
portions of the Hudson River Valley, so additional Heat
Advisories may be necessary. Outside of the heat, additional
rounds of showers and thunderstorms are expected throughout the
day Thursday as yet another upper-level shortwave rotates
through the region atop a surface frontal system. Shortly ahead
of the cold front associated with the surface low traversing
southern Quebec, a pre-frontal trough will track through the
region, generating an initial batch of showers and thunderstorms
late Thursday morning. Along and ahead of the incoming cold
front and attendant shortwave aloft, a secondary round of
showers and thunderstorms comes Thursday afternoon into Thursday
evening, with the possibility of some of these being stronger to
potentially severe in magnitude. A bit more shear than we have
seen recently and high DCAPE values indicate the potential for
strong to locally damaging wind gusts being the primary hazard.
However, with this being a very conditional threat dependent on
the extent of convection Wednesday night and Thursday morning,
confidence is not yet high in this element of the forecast.
However, we will continue to monitor this closely going forward.

The loss of daytime heating Thursday should put an end to the
threat for thunderstorms with mere lingering showers into
Thursday night and Friday morning as the aforementioned cold
front and upper-level shortwave track through the region. This
being a true cold front, Friday will begin the cooling trend
heading into the weekend, putting an end to the oppressive heat
and humidity. Highs will therefore be in the 70s to low 80s.
Saturday will then be one of the best days, if not the best
weather day, of the 7 day period with surface high pressure and
ridging aloft building in to once again reinforce dry conditions
regionwide. Favored conditions will, unfortunately, be short-
lived, however, as unsettled conditions return and bring back
the chance for showers and possible thunderstorms Sunday and
possibly into Monday. However, differences in the medium to
long range guidance make for a low-confidence forecast
especially for Monday. Highs will remain in the 70s and 80s,
though, so the continuation of non-oppressive heat is fairly
confident.

&&

.AVIATION /17Z TUESDAY THROUGH SATURDAY/...
Through 18Z Wednesday, VFR conditions prevail through at least
02Z/Wed. Then, clear skies within the lingering muggy air mass will
likely allow patchy fog to develop leading to intermittent MVFR and
IFR Vsbys at all terminals toward 05-07Z/Wed at KGFL/KPSF before
more frequent intervals of IFR/LIFR Vsbys/Cigs develop after
08Z/Wed. Intermittent periods of MVFR vis may also develop at KALB
and KPOU. IFR/VIS fog then lifts into a low stratus deck by 12-14
UTC before giving way to VFR flying conditions at all sites.

Outlook...

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

&&

.ALY WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...Air Quality Alert until midnight EDT tonight for NYZ032-033-
     038-042-083.
     Heat Advisory from noon to 8 PM EDT Wednesday for NYZ038-040-
     041-043-049-050-052-053-059-060-064>066-083-084.
MA...None.
VT...None.

&&

$$

SYNOPSIS...Gant
DISCUSSION...Gant
AVIATION...Speciale