809
FXUS61 KALY 112003
AFDALY

AREA FORECAST DISCUSSION
National Weather Service Albany NY
403 PM EDT Fri Jul 11 2025

.SYNOPSIS...
Given continued hot and humid conditions, isolated to scattered
showers and thunderstorms are expected each afternoon into the
early evening today through the weekend with locally heavy
downpours and gusty winds. A slow moving cold front Sunday
afternoon into Monday will increase coverage of showers and
thunderstorms with our next stretch of dangerous heat during the
middle of next week.

&&

.SHORT TERM /REST OF TODAY THROUGH MONDAY/...
Key Messages:

- Isolated to scattered thunderstorms are possible each
  afternoon today through Monday across most of eastern NY and
  western New England, with some thunderstorms producing gusty
  winds and heavy rainfall. Higher coverage of storms Sunday
  afternoon into Monday.

- Heat Advisories may be needed for some of the major valley
  locations on Sunday.

Discussion:

With a weak warm front hung up over the region today, morning
clouds broke for some afternoon sun with the weak forcing and
warm/humid air mass supporting isolated to widely scattered slow moving
showers and thunderstorms this afternoon. Temperatures rising
into the mid to upper 80s and dew points around 70 have led to
heat index values in the upper 80s to around 90 with SB CAPE
values per the SPC mesoscale analysis impressively between 1.5 -
3k J/kg. However, deep layer shear is quite weak only near
15-25kts with slightly stronger values 25-30kts in the Upper
Hudson Valley and southern VT. Upper level forcing is virtually
zero given flat ridging aloft but the weak sfc front and
differential heating boundaries in the presence of rather high
instability can support isolated taller/stronger updrafts and
storms resulting in heavy downpours, lightning, and gusty
winds. Localized flooding is possible where storms are
particularly slow moving and downpours continue. SPC removed
their marginal risk as the overall severe threat is very low.
High res guidance shows shower/storm coverage diminishing with
the lose of daytime heating this evening but a few
showers/storms may continue overnight as weak shortwaves overtop
the ridging aloft. The warm and muggy air mass continues
tonight so any areas that saw rain during the day could see
patchy fog, especially where clouds can partially clear.

Hot and humid weather continues tomorrow and Sunday with daytime
highs rising into the mid to upper 80s with valley areas around
90. Dew points in the upper 60s to low 70s will keep heat index
values (or the "feel-like" temperature) elevated as well
peaking in the low to mid 90s each afternoon. A few spots in
valley areas could hit the 95F heat index criteria for a heat
advisory but coverage does not look high enough to warrant
advisories at this time. We collaborated with neighboring WFOs
and others agree it is marginal. Otherwise, our weak boundary
stalls overhead into tomorrow oriented north to south around
the Hudson River. This will likely serve as the focus for
additional diurnally driven isolated to widely scattered
showers and thunderstorms. Tall skinny SB CAPE values should
once again be decently strong 1500 to 2000 J/kg and with a few
weak shortwave rounding the top of the upper level ridge, high
res guidance show more widespread coverage of showers and storm
compared to today, especially along the stalled boundary. Weak
shear 20-25kts and warm mid-levels/weak lapse rates should limit
severe potential and SPC continues us only in the "general
thunder" category. However, with PWATS 1.75 - 2", shear vectors
oriented parallel to the stalled weak boundary and overall weak
flow through the column, heavy downpours from slow moving storms
could result in localized flooding, especially if storms are
nearly stationary or backbuild over an area. Thus, WPC maintains
nearly our entire area in the marginal ERO for tomorrow.
Shower/storm coverage weakens once again after sunset followed
by another warm and muggy night.

The weak warm front finally washes out by Sunday but the main
cold front will be slowly approaching from the west. Guidance
is in good agreement keeping this boundary displaced well to our
west through most of the day with southerly winds maintaining
the humid and very warm air mass. As the boundary nears the
western Mohawk Vally and western/southern Adirondacks after
18-21 UTC into the evening, shower and storm coverage increases.
SPC maintains its marginal risk in the convective outlook given
the stronger forcing intersecting the unstable air mass ranging
1-2.5k J/kg and slightly steeper mid-level lapse rates
5.5-6C/km. We collaborated with WPC to trim out the slight risk
in the ERO from the western Mohawk Valley as flash flood
guidance values range 2.5-3" in 3 hours. Even though the humid
air mass support heavy downpours and slow moving storms, it is
unlikely that such high rainfall values will occur over a large
enough area to warrant a slight risk. Overall shear remains weak
20-25kts but all else considered could be enough to support
weak line segments. Thus SPC maintained its marginal risk. Areas
further east including the Capital District, Upper/mid-Hudson
Valley and western New England should be mainly dry during the
day but POPs for showers/thunderstorms trend upwards after 00
UTC Monday as the boundary gradually slides eastward.

The boundary continues to slowly track overhead into Monday
resulting in widespread chance POPs that trend to likely
(especially from the Capital Region eastward into western New
England) by Monday afternoon. Lapse rates again will be marginal
ranging 5.5-6C/km but the warm and muggy air mass will again
support sufficient SB CAPE values, especially as any capping
erodes in response to the incoming boundary. 0-6km shear again
will be weak at around 20 kts so severe weather potential looks
minor at best but given stronger sfc forcing, we will maintain a
close eye on storm growth/coverage. Heavy downpours and
potential localized flooding again will also be possible given
PWATs 1.5-2" and slow nature of any storms. Higher cloud
coverage on Monday will keep temperatures a bit lower compared
to the weekend with daytime highs only in the low to mid 80s but
with elevated dew points, it will still be muggy/uncomfortable.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
Key Message:

- Confidence is increasing that valley areas will experience
  dangerous heat index values (or "feel-like" temperatures) in
  the mid 90s to around 100F Wednesday - Thursday. There is a
  40-50% chance that daytime high temperatures both days will
  exceed 90 degrees in valley areas.

Discussion:

The main story for the long term will be the next potential
stretch of dangerous heat returning for the middle to end of
next week. After the boundary from Monday exits, a weak sfc
anti-cyclone builds into the Northeast by Tuesday into
Wednesday. As the ridging shifts into New England by the middle
to end of the week, southwest flow becomes reestablished
resulting in 850 hPa isotherms rising 1.5-2 standard deviations
above normal per the NAEFS and ENS. This combined with increased
insolation and higher humidity values continues to increase
concerns for another period of dangerous heat with heat index
or "feel-like" temperatures exceeding 95F. The NWS HeatRisk
already highlights much of eastern NY and western New England in
its "major" risk both days meaning that sensitive populations
will be more prone to heat-related illnesses including heat
stroke and heat exhaustion. Overnight temperatures will not
provide much relief from the heat with only a 10% chance that
valley areas drop below 70 degrees Wednesday night. This
upcoming heat event will likely not be as extreme as the event
we had in June but confidence is increasing that we will need
heat advisories.

&&

.AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
Flying conditions are currently VFR for all sites. Some
scattered showers are starting to develop and some pulse showers
or t-storms are possible through the early evening hours. Have
included a PROB30 for KALB and KPSF based off the latest CAMs,
as a brief shower or possibly a t-storm could impact these
sites. Any shower or t-storm would be rather brief, but could
contain heavy rainfall, lowering visibility to IFR/MVFR range
for a short time. While severe storms aren`t anticipated, winds
could be gusty within any shower or t-storm as well. Otherwise,
it will stay VFR with just sct cigs around 4-6 kft and southerly
winds around 5 to 10 kts.

Any shower or t-storm will dissipate by evening, allowing for
dry conditions overnight. Initially, it will be VFR with a
mostly clear sky and just some passing cirrus. However, some
late night stratus (and possibly some fog) will develop for the
late night hours and towards daybreak on Saturday for all sites.
This will likely result in MVFR conditions, although brief IFR
cannot be ruled out.  Winds will be light to calm overnight.

Once again stratus dissipates on Saturday morning (probably by
the mid-morning hours), VFR conditions will return for all sites
with a mostly sunny sky and just few-sct cumulus clouds. Some
passing pulse-like afternoon showers or t-storms can`t be ruled
out again on Saturday afternoon. South to southwest winds will
be around 5 kts on Saturday.

Outlook...

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

&&

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

&&

$$

SYNOPSIS...Speciale
NEAR TERM...
SHORT TERM...Speciale
LONG TERM...Speciale
AVIATION...Frugis