149
FXUS61 KALY 132017
AFDALY

AREA FORECAST DISCUSSION
National Weather Service Albany NY
417 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 /6 AM MONDAY MORNING 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 of high temperatures exceeding 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 with our
next forecast package. Flash flood guidance values are once
again rather high at 2-3" in 3 hours and soil moisture is low 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.
As the main trough axis arrives by late afternoon enhancing
forcing for ascent with guidance even suggesting a secondary
low develops along the boundary, coverage and intensity of heavy
rain will likely further raising flooding concerns. 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
these areas. 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. More clouds in
the mid-Hudson Valley and NW CT may limit the potential to hit
the 95F criteria so less confidence there.

&&

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

- Heat Index values or "feels-Like" temperatures may reach the
  mid 90s to low 100s in the valley areas for the middle to end
  of this week.

- Watching Thursday - Friday for increased chances for
  thunderstorms and potential severe weather.

Discussion:

Wednesday will likely be the hottest day of the week. With weak
ridging building overhead resulting in southwest flow aloft,
850 hPa isotherms build back to +18 to +20C. Therefore, there is
a 50 - 80% probability of high temperatures exceeding 90F for
elevations mainly below 1000 ft. Dew points will also be back on
the rise given the flow regime and current peak heat index
values range from the upper 90s to low 100s. HeatRisk values
continue to be in the "major" range for Wednesday. While most of
the day will be dry, clouds increase through the day as our
ridge slides to our east and the boundary stalled to our south
gradually lifts back northward as a warm front. Chances for
rain and storms return late Wed P.M into Wed night as a
shortwave tracks through the Saint Lawrence River Valley with
forcing for ascent spreading into the hot and humid air mass. By
Thursday, we remain in the very warm and moist air mass but
increased cloud coverage could reduce high temperatures a few
degrees so not as confident as Wednesday in needing heat
advisories. Given additional shortwaves tracking within the
westerly flow regime, POPs trend from chance to likely on
Thursday for showers and thunderstorms. Timing of shortwaves
remain uncertain so not expecting a complete washout but periods
of rain/storms are possible. Similar to Wed night, Thursday
night will not provide much relief from the very warm and muggy
air mass with overnight lows only dropping into the low to mid
70s (60s higher terrain).

As discussed in the previous discussion, we will need to closely
monitor the Thursday evening - Friday time for our next
potential severe weather event. A potent cold front and
shortwave trough looks to track through the region and with it
entering into such a warm and moist environment, instability
will be more than sufficient to support strong updrafts while
the forcing will provide strong lift and shear to support
organized convection. Timing will be key as a later day or
overnight arrival of the sfc boundary and shortwave will limit
the overlap with peak heating/instability and thereby limit
severe potential. Zonal flow then ensues for the weekend as sfc
high pressure ushers in drier air and a relief from the
heat/humidity.

&&

.AVIATION /20Z 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 continues to show increasing low-
level moisture pooling ahead of the incoming slow moving boundary
with PWATs nearing 2.0" and warm cloud depths >12 kft. Mid-
level flow remains weak and fairly parallel to the approaching
cold front supporting the potential for backbuilding and
training storms late this afternoon into tonight for areas
north/west of the Capital District. Our flash flood watch
remains in effect through 5 AM for southern Herkimer County as
there are pockets of lower flash flood guidance values near 1-2"
in 1 hour. With such efficient warm rain processes at play,
rainfall rates could reach up to 1-2" per hour and locally up to
3" if rain persist over a long enough time. The flood threat is
greatest for the more urban areas, as well as low-lying and
poor drainage areas in southern Herkimer County. WPC has
maintained their marginal to slight risk for excessive rainfall
to the northwest of the Capital District through tonight.

Coverage of rain and thunderstorms with locally heavy downpours
increases tomorrow afternoon, mainly from the Capital District
south and east in western New England, the mid-Hudson Valley and
the eastern Catskills which will remain in the highly moist and
warm/buoyant sector ahead of the boundary. We and neighboring
WFOs collaborated with WPC to have the excessive rainfall
outlook upgraded in this area to a slight risk (level 2 of 4)
for Monday. We continue to monitor the potential for isolated to
scattered flash flooding, given increased potential for storms
to train or persist over a given area resulting in higher
rainfall rates reaching 1-2" per hour (locally higher even up to
3" not ruled out). The greatest flooding risk once again will
be for the more urban, poor-drainage, and low-lying areas
through Monday evening.

&&

.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