591
FXUS61 KALY 100826
AFDALY

AREA FORECAST DISCUSSION
National Weather Service Albany NY
426 AM EDT Wed Jul 10 2024

.SYNOPSIS...
Today will be an active weather day, with severe weather and heavy
rain possible as the remnants of Beryl interact with a warm front.
Hot and humid weather is expected today, with above normal
temperatures and humidity expected to continue through at least
early next week. Each day Thursday through early next week will also
feature at least a slight chance for a few showers or thunderstorms.

&&

.NEAR TERM /THROUGH TONIGHT/...
**Heat Advisory until 8 PM this evening for portions of the
 Capital District, mid Hudson Valley and southern Taconics, and
 southern Litchfield County**

**Flood Watch for Flash Flooding from noon today through noon
 Thursday for the southern Adirondacks and western Mohawk
 Valley through northern Lake George area**

As of 4:25 AM EDT, Our weather is currently quiet albeit warm
and muggy with our region under the influence of an upper ridge.
With partly to mostly cloudy skies, it is quite mild, with
temperatures still in the mid to upper 70s for some valley
areas. Overnight lows will only be a few degrees below current
temperatures. Current satellite imagery shows some areas of
clearing south of I-90, which is where we are most likely to see
some patchy fog through the next few hours. Additionally, some
low stratus is expanding into Litchfield County and the southern
Taconics. A few showers are possible towards daybreak, mainly
in the western Mohawk Valley or Adirondacks, as a warm front
lifts north through the region.

Today is shaping up to be a very active weather day, with
dangerous heat, severe weather, and potential flooding...

Today, the remnants of Beryl and an associated 1000 mb low will
track from the Ohio Valley into the Great Lakes region. This
will help to lift a warm front northwards through the region,
although it may stall out across the Adirondacks. This will put
most of our area in the warm sector, where showers and
thunderstorms are expected this afternoon. Then, tonight, the
system`s cold front tracks through the region. Showers and
storms should taper off behind this cold front after 06z.

Will first address the severe threat today. SPC has maintained
the slight risk for most of our area, but has added portions of
the far western Mohawk Valley to an enhanced risk. We will
quickly see instability increase this morning, with up to around
2000 J/kg of MLCAPE expected for areas south of the warm front
later today. This will overlap with 40-50+ kt of deep-layer
shear, with the greatest shear values from the Mohawk Valley
through the ADKs, upper Hudson Valley, and into southern VT,
which will be in the vicinity of the warm front. Low-level shear
is also impressive, with 20-25 kt of 0-1 km shear near the warm
front along with long, clockwise curving hodographs. Here, 0-1
km SRH values will be between 100 and 200 m2s2 this afternoon,
with low-level flow backed to the southeast. The primary threat
with storms will be damaging winds, but given the impressive
low- level shear a few tornadoes will also be possible in these
aforementioned areas that will be closer to the warm front. An
isolated tornado cannot be ruled out further south, but the
probability is lower here with higher LCLs and more mid-level
dry air and less low-level shear.

The severe threat will persist into tonight, with the low-level
jet strengthening this evening ahead of the cold front.
Luckily, instability will be decreasing by this time. With
supercells possible near the warm front, a few instances of
large hail will also be possible despite the very warm and moist
airmass. Greatest coverage of storms through the day will be
across the northern half of the CWA as large- scale forcing is
unimpressive further south, but a broken line of storms is
expected to track across the region tonight ahead of the cold
front, although this line of storms will weaken the further east
it gets.

The other threat today will be for flooding and flash flooding,
with WPC maintaining a moderate risk for excessive rainfall
leading to flash flooding across portions of the ADKs, Mohawk
Valley, and upper Hudson Valley. There is a slight risk for
excessive rainfall for most of the rest of the region with a
marginal for the Mid Hudson Valley and western CT. We will have
strong forcing through the column (CVA, right entrance of the
upper jet, mid-level FGEN and the surface warm front)
overlapping with an anomalously moist airmass. PWAT values are
currently expected to be in the 2.2 to 2.4" range, which is near
or above the daily record high for today. Warm cloud depths of
12-13 kft also signal the potential for very heavy rain.
Luckily, storms will be moving relatively quickly, but training
of storms is expected along and north of the warm front, which
is where the potential for flooding and flash flooding is
highest. Please see the hydro section for more details on the
flood threat and potential impacts.

As for timing of the severe and flood threats, showers and
storms move into the region by mid to late morning, with chances
for thunder and heavy rain persisting into tonight. Behind the
cold front tracking into our region tonight, a mid-level dry
slot moves overhead after 06z tonight which should help to end
the severe threat. This will also end the heavy rain threat, but
lingering hydro issues are possible into tomorrow morning as
runoff makes its way into rivers, creeks, and streams.

Last but not least, the heat advisory was expanded northwards to
include southern Litchfield County and portions of the Capital
District, where heat index values of 95-100F are possible today
thanks to the combination of temperatures in the upper 80s to
around 90 and dew points in the 70s. Tonight will once again be
mild with lows mainly in the 60s (terrain) to 70s (valleys)

&&

.SHORT TERM /THURSDAY THROUGH FRIDAY/...
Thursday, the upper low and surface low associated with the
remnants of Beryl track to our north, but should be weakening.
With substantial mid-level drying and very little instability,
we are not expecting much in the way of heavy rain or thunder
tomorrow, although some lingering showers will be possible,
especially for our northern areas closer to the upper low. The
cold front will also stall over our region, likely near the
Hudson Valley, and may also act as a focus for the development
of a few afternoon showers or an isolated thunderstorm. It will
feel a tad cooler due to slightly lower humidity values,
although temperatures will still be well into the 80s for many
valley locations.

Thursday night, we continue to dry out as surface high pressure
builds in from the southwest and an upper ridge backs into the
region from the east. It will be slightly cooler with lows in
the 60s for most valley areas and perhaps even a few upper 50s
across the high terrain. We may also have some patchy fog
around, especially where there are breaks in the clouds.

Friday, an upper shortwave tracks eastwards from the Great
Lakes region while a separate shortwave moves up the east coast
on the backside of the upper ridge. The day should start off
relatively dry with the surface high nearby, but as these
features approach chances for showers and perhaps a couple
thunderstorms increase Friday afternoon. Most likely area for
showers or a storm will be for the Mid Hudson Valley and
southwestern New England, with the stalled frontal boundary
helping to focus some of these showers. Friday will be slightly
cooler with highs in the 70s for the higher elevations and mid
80s for the valleys.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
Upper level shortwave will be passing across the Northeast for
Friday night into Saturday, while a surface wave of low pressure
moves from the mid Atlantic coast northeast towards eastern New
England.  Some showers and thunderstorms will be possible for areas
south and east of the Capital Region, with the best chance for
thunder during the afternoon and evening hours on Saturday.  It will
continue to be fairly warm and muggy, with Saturday highs well into
the 80s once again.

Behind this departing wave, a brief stretch of rain-free weather is
expected for Sat night into Sunday with zonal flow aloft.  However,
it will remain hot and humid, with Sunday`s highs into the low 90s
in valley areas and some heat index values could get be getting
close to advisory criteria once again.

More active weather is anticipated during next week, as fast moving
shortwaves sliding through the zonal flow aloft bring some chances
for showers and thunderstorms, especially during the afternoon and
evening hours.  Temps aloft remain high, so each day will feature
above normal temps with valley highs well into the 80s to low 90s.
With dewpoints in the upper 60s to near 70, heat index values will
be in the 90s each day.

&&

.AVIATION /08Z WEDNESDAY THROUGH SUNDAY/...
IR satellite imagery and surface obs show widespread mid level
clouds are in place over the region.  Based on upstream satellite
imagery and model soundings, will expect these clouds to continue to
be in place over the region through the rest of the overnight hours.
Despite high dewpoints and calm winds, will not forecast any
radiational fog through the rest of the overnight due to the
cloud cover in place and will keep flying conditions VFR for all
sites sites with bkn-ovc cigs around 15 kft and calm winds with
no precip.

A warm front will be lifting across the region during the day on
Wednesday.  KPOU/KPSF will quickly get in the warm sector, so
there`s little threat for any precip there through most of the day,
as the boundary should be north of that area.  Meanwhile, KGFL has
the best chance for seeing some showers and possible t-storms,
mainly between 15z and 20z. Any t-storm could contain gusty winds
and will include a PROB30 there for IFR conditions within a
thunderstorm and gusty winds over 30 kts.   KALB may be okay as most
of the activity will be north and west of there, but will mention a
VCSH during the afternoon in case a shower or t-storm gets close.
Outside of any convection, it will be VFR with south to southeast
winds of 5 to 10 kts and sct-bkn cigs around 4-6 kft and another
layer around 12-15 kft.

Another round of convection is expected with the storm`s cold front
during the evening hours.  This will again have the highest coverage
near KGFL, although a stray shower or t-storm could get also get
further south by the late evening.  Most of the time, flying
conditions will be VFR, but cannot rule out brief IFR conditions
within any shower or t-storm, which may also contain gusty winds.

Outlook...

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

&&

.HYDROLOGY...
A warm front interacting with the remnant moisture from TC
Beryl today and tonight will bring potential areas of heavy
rainfall to eastern NY and western New England. The Weather
Prediction Center has highlighted much of our region in a threat
for excessive rainfall in the Marginal to Slight Risk
categories Wed and Thu, and moderate risk for the southern
Adirondacks, western Mohawk Valley, and the Lake George Region.

The Mohawk Valley through the ADKs and upper Hudson Valley are
currently expected to see a widespread 1 to 3 inches of rain,
with some locally higher amounts of 4 to potentially 6 inches
possible. These higher end amounts would likely be very
localized to parts of the ADirondacks if/where multiple rounds
of heavy rain occur. Most of this rain will fall between noon
today and 2 AM Thursday morning. Rainfall rates may exceed 2
inches per hour where the heaviest rain falls.

A flood watch for flash flooding remains in effect for the
southern Adirondacks and northern Lake George Region, and has
also been expanded to include portions of the western Mohawk
Valley. Some river flooding may be possible as well depending on
if some of these higher amounts are realized, but the latest
MMEFS and NERFC guidance shows no main stem river flooding.

Confidence has increased in the timing and location of the
heaviest rainfall amounts, although a shift further northwards
with the heaviest rain from the current forecast still cannot be
ruled out. If this were to be the case, the heaviest rainfall
amounts would likely end up along or north of our county warning
area border with BTV.

&&

.ALY WATCHES/WARNINGS/ADVISORIES...
CT...Heat Advisory until 8 PM EDT this evening for CTZ013.
NY...Heat Advisory until 8 PM EDT this evening for NYZ052-053-059-
     060-064>066.
     Flood Watch from noon EDT today through Thursday morning for
     NYZ032-033-038>040-042-043-082-083.
MA...None.
VT...None.

&&

$$

SYNOPSIS...Main
NEAR TERM...Main
SHORT TERM...Main
LONG TERM...Frugis
AVIATION...Frugis
HYDROLOGY...Main/NAS