545
FXUS61 KALY 131934
AFDALY

AREA FORECAST DISCUSSION
National Weather Service Albany NY
334 PM EDT Sun Jul 13 2025

.SYNOPSIS...
Warm and muggy today with a slowly approaching cold front
resulting in scattered showers and thunderstorms mainly north
and west of the Capital District before more widespread rain
and storms capable of heavy rain and brief gusty winds arrive
early this evening. Our front continues to slowly advance
eastward through the day tomorrow supporting additional areas of
rain and thunderstorms, especially for areas south and east of
the Capital District. Heavy rain leading to localized flooding
is the primary concern before confidence increases for another
period of dangerous heat for the middle to end of this week.

&&

.SHORT TERM /TODAY THROUGH TUESDAY/...
Key Messages:

- Isolated to scattered flash flooding and severe thunderstorms
  possible late this afternoon into this evening north and west
  of the Capital District.

- Isolated to scattered flash flooding and severe thunderstorms
  are once again a concern tomorrow for areas mainly near and
  south and east of the Capital District. Areas where heavy rain
  or storms can repeatedly impact will have the highest risk for
  flooding.

- There is a 50 to 75% chance for high temperatures to exceed 90
  degrees on Tuesday in valley areas. Such warm temperatures
  combined with moderate humidity may result in heat index
  values nearing the 95F heat advisory criteria.

Discussion:

Morning clouds have given way to breaks of afternoon sun with
insolation combined with very warm temperatures and high dew
points in the low 70s contributing to ML CAPE values already
ranging from 1000 - 2000 J/kg with SB CAPE values over 2000 J/kg
north and west of the Capital District. While overall shear
remains quite low, latest water vapor imagery shows broad
troughing positioned well to our north and west in Ontario very
gradually pressing southeastward. A sfc trough just downwind of
Lake Ontario is also sliding eastward and is serving as a focus
for afternoon convection. As heights slowly fall late this
afternoon into early this evening in response to the approaching
parent trough, convection will increase in coverage and likely
grow upscale given the very unstable environment. Shear remains
weak given weak flow through the column but with a conveyor
belt of slightly stronger westerlies advancing eastward ahead of
the trough, deep layer shear is progged to increase to 20-25kts
closer to 21 - 03 UTC. While we will be moving past peak
heating, the high instability coincide with gradually improving
forcing for ascent and increased shear will likely result in
increased storm coverage and potential for storms to become
better organized/grow upscale. Therefore, SPC has upgraded
their Day 1 outlook to a slight risk (level 2 to 5) for the
western Mohawk Valley into western Adirondacks where this
overlap is most favorable through early evening. Given high
PWATs near 2" and tall skinny cape seen in forecast soundings,
wet microbursts capable of damaging winds is the primary concern
from any severe storm with outflow boundaries also capable of
gusty winds and spawning additional storms. Besides severe
weather potential, isolated to scattered flash flooding is
another hazard we will monitor closely. Weak unidirectional flow
nearly parallel to the boundary in the highly moist environment
with FZ heights nearly 13kft will easily support efficient warm
rain processes so any storms that are slow moving or
train/repeatedly impact an area can lead to flooding, especially
in low-lying, urban or poor drainage areas. Isolated to
scattered flash flooding cannot be ruled out especially if
convection or heavy rain persists or backbuilds over an area and
we agree with the slight risk (level 2 to 4) in WPC`s Day 1
Excessive Rainfall Outlook. However, given high 3-hrly flash
flood guidance (FFG) values 2-3", flash flooding will likely be
limited to the typical trouble spots.Heading into tonight,
convection will gradually weaken as we approach Midnight and
areas of rain/storms push down the Mohawk Valley. While periods
of rain and storms continue along the boundary overnight, severe
weather and flooding should diminish.

We are start Monday with the boundary around the Capital
District with clouds and stratus widespread once again. The very
warm and moist buoyant sector will now be positioned from the
Capital District south and east into western New England, the
mid-Hudson Valley and the eastern Catskills. As clouds give way
to break of sun eroding the low-level inversion and PWATs
remain high around 2" (nearly 2 standard deviations above normal
per the NAEFS), ML CAPE will once again quickly increase to
1-2k J/kg. As instability increases by midday into the early
afternoon so will the coverage of convection and heavy rain.
Similar kinematics to Sunday, the very weak flow oriented
parallel to the boundary and high FZ heights supportive of
efficient warm rain processes will easily result in heavy
downpours with rain potentially training/backbuilding or
repeatedly impacting a given area. This raises concerns for
isolated to scattered flash flooding and we collaborated with
WPC to increase the ERO to a slight risk (level 2 of 4) from the
Capital District south and east. No flood watch issued on this
shift given we already have a flood watch out for Herkimer
County for tonight but we will re-evaluate the need on our next
forecast package. Flash flood guidance values are once again
rather high at 2-3" in 3 hours but the 12 UTC HREF shows 40-50%
chance of exceeding 2" of rain in 3 hours tomorrow P.M into
early evening with the probability match mean even showing 10%
chance of exceeding 3" in 3 hours. Deep layer shear is again
weak ranging 20-25kts with mediocre lapse rates 5-5.5C/km but
given potential for wet microbursts resulting damaging winds,
we collaborated with SPC to introduce a marginal risk in this
area. Heavy rain and storm coverage shifts in our far southern
zones including Dutchess/Litchfield County by early evening but
activity should wane shortly after Midnight.

Tuesday finally turns drier as weak high pressure and shortwave
ridging from the Ohio Valley builds eastward. Our boundary
stalls just to our south and some lingering showers/clouds
could graze our southern zones so 20-30% were introduced in this
area. Otherwise, we will need to monitor the heat on Tuesday and
potential need for heat advisories. While northwest winds in the
wake of the front will usher in slightly lower PWATs/humidity,
dew points remain in the upper 60s. Given much more sunshine
for areas from the I-90 corridor northward, daytime highs will
likely rise into the upper 80s to low 90s in valley areas
resulting in peak heat index values flirting with the 95F
criteria. The higher insolation will support deeper boundary
layer mixing helping to reduce dew points during peak heating
and overall coverage of 95F+ heat index values but it certainly
will be close and bares monitoring.


&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
Key Message:

- Heat Index values or "feels-Like" temperatures may reach the
  mid 90s to 100F in the valley areas Tuesday through Thursday.

Discussion:

Coming soon.

&&

.AVIATION /19Z SUNDAY THROUGH FRIDAY/...
Through 18z Monday...Mix of VFR to MVFR conditions is expected
initially with conditions trending more to VFR in the next 1-2 hours
as low clouds become more scattered. Attention then turns to the
west as showers and storms develop across central NY along and ahead
of a slow moving front. PROB30 groups have been maintained in this
TAF for KGFL/KALB from 00-06Z Monday as some guidance maintains a
low potential for showers and storms to make it into the terminals
vicinity, though confidence remains higher at KGFL where MVFR
visibilities are possible in showers. Later tonight, southerly flow
should have a marine layer advance inland with ceilings dropping to
MVFR/IFR levels for all terminals. Some visibility reductions to
MVFR are also expected, particularly for KPSF. This marine layer
will gradually mix out during the morning, but a return to VFR
conditions is not expected until the end of the TAF period. WInds
will be out of the south/southeast around 5-10 kts with gusts near
20 kts at KALB, and will decrease to around 5 kts or less tonight.

Outlook...

Monday Night: Low Operational Impact. Slight Chance of SHRA.
Tuesday: No Operational Impact. NO SIG WX.
Tuesday Night: No Operational Impact. NO SIG WX.
Wednesday: Low Operational Impact. Slight Chance of SHRA...TSRA.
Wednesday Night: Low Operational Impact. Slight Chance of SHRA...TSRA.
Thursday: Moderate Operational Impact. Likely SHRA...TSRA.
Thursday Night: Low Operational Impact. Slight Chance of SHRA...TSRA.
Friday: Moderate Operational Impact. Chance of SHRA...TSRA.

&&

.HYDROLOGY...
CIRA ALPW satellite imagery already shows increasing low-level
moisture across our region, and PWAT values are expected to increase
to 1.8-2.0" ahead of the approaching cold front with warm cloud
depths >12 kft. Mid-level flow will not be overly slow at around 30
kt, but the flow will be fairly parallel to the approaching frontal
boundary, so backbuilding and training of storms will be possible.
Given the above, we collaborated with WFO BGM and BUF to issue a
flash flood watch from 2 PM this evening through 5 AM for southern
Herkimer County, as flash flood guidance is relatively lower here
compared to surrounding areas. Rainfall rates could reach up to 2"
per hour. The flood threat is greatest for the more urban areas, as
well as low-lying and poor-drainage areas. WPC has maintained their
marginal to slight risk for excessive rainfall to the northwest of
the Capital District today.

Additional showers and thunderstorms with locally heavy rainfall
are possible again tomorrow, mainly from the Capital District
south and eastwards. WPC has placed this area in a marginal risk
for excessive rainfall Monday. We will continue to message the
potential for isolated flash flooding, with the greatest threat
once again for the more urban, poor-drainage, and low-lying
areas.

&&

.ALY WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...Flood Watch through late tonight for NYZ038.
MA...None.
VT...None.

&&

$$

SYNOPSIS...Speciale
NEAR TERM...
SHORT TERM...Speciale
LONG TERM...Speciale
AVIATION...Speck
HYDROLOGY...Main/Speciale