570
FXUS61 KALY 141945
AFDALY

AREA FORECAST DISCUSSION
National Weather Service Albany NY
345 PM EDT Wed Aug 14 2024

.SYNOPSIS...
Scattered thunderstorms diminish after Susanetta
tonight, with patchy fog developing as temperatures cool into the
50s and 60s. Tomorrow will be very similar to today with highs in
the 70s to low 80s and scattered afternoon showers and
thunderstorms. Friday will feature dry conditions, but humidity
levels increase ahead of a frontal system that will bring unsettled
conditions throughout the weekend and possibly into early next week.

&&

.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
As of 3:45 PM EDT...Current GOES 16 WV imagery shows an upper
disturbance located to the northeast of our region, while
surface analysis shows a backdoor cold front approaching from
the northeast. With north/northwest flow across our region,
upslope flow and terrain-induced convergence boundaries have
lead to the development of scattered thunderstorms beneath the
cold pool aloft. Shear is relatively weak, but with mostly clear
skies daytime heating has allowed MLCAPE values to increase to
1000 to 2000 J/kg with the highest values in the Mohawk Valley.
This, combined with near dry adiabatic low-level lapse rates,
may allow for some gusty winds or small hail, although the
threat for more widespread severe weather remains on the low
side. Temperatures are near the daytime highs with upper 70s to
mid 80s for most places, although some areas that have received
a shower or storm have seen temperatures drop into the 60s due
to rain-cooled downdrafts.

As we head through the evening into tonight, coverage of showers
and storms should begin to diminish with the loss of daytime
heating. High pressure will build in from the west, so skies are
expected to become mostly clear and winds light to calm. This
will set the stage for favorable radiational cooling conditions,
and we therefore undercut NBM lows by a few to several degrees.
Most places should see lows similar to last night, in the 50s
to around 60. Patchy radiation fog, some locally dense, is
expected especially in the typical sheltered river valleys and
in areas that see rain this afternoon and evening.

&&

.SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/...
Thursday and Thursday night will be very similar to today and
tonight. Thursday starts off seasonably cool with some patchy
fog, but the fog should mix out shortly after daybreak.
Temperatures rise through the 70s into the low 80s by early
afternoon. However, the upper low and stalled cold frontal
boundary will remain off to our east/northeast. With the cold
pool aloft nearby and N/NW flow, we will once again see
scattered afternoon showers and storms develop, especially over
the high terrain due to upslope enhancement and along any
terrain-induced low-level convergence boundaries. Instability
looks slightly less impressive than what we are seeing today,
although with around 1000 J/kg of MLCAPE and steep low-level
lapse rates, we could see a few instances of small hail and/or
gusty winds once again.

Thursday night, showers and storms once again diminish with the
loss of diurnal heating. High pressure remains overhead and
ridging builds aloft over our region, so we will once again see
favorable conditions for radiational cooling. Lows are expected
to be just a degree or two warmer than the previous night, with
low 60s for the valleys and 50s elsewhere. Patchy radiation fog,
locally dense in river valleys and areas that see rain during
the afternoon and evening, will once again be possible.

Friday and Friday night...The surface high slides off to the
east. The ridge aloft will be overhead to start the day, but
also slides east of the region overnight as upper troughing digs
into the Great Lakes region. The ridge overhead and subsidence
should keep us dry through the day Friday, although mid and high
clouds begin to increase through the afternoon. Flow turns more
southerly around the periphery of the high, and the airmass
aloft will be warmer, so high temperatures are expected to also
be a few degrees warmer than previous days with mid to even
upper 80s in the valleys with upper 70s to around 80 for the
higher elevations. It will also turn more humid with dew points
in the mid to upper 60s. Friday night, clouds continue to
increase with increasing chances for showers as the upper trough
and an associated occluded front slowly track towards our region
from the west. It will be warmer than previous nights with lows
mainly in the 60s.

&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
Long term period begins at 12z Saturday the upper trough over
the Great Lakes shifting eastwards through the weekend. At the
surface an occluded front will slowly track through the region
Saturday into Sunday. PWATs climb to 1.6-1.8", which is 1-2
sigma above normal for mid August. The overlap of forcing and
moisture will lead to scattered to numerous showers and a few
thunderstorms Saturday and especially Sunday. The best
instability remains west of our region Saturday, and shear does
not look overly impressive Saturday and Sunday. However, with
the moist airmass in place, locally heavy rainfall will be
possible with any thunderstorms. Due to mostly cloudy skies it
won`t be overly warm with highs in the 70s to around 80 both
days, although it will be humid with dew points in the upper 60s
to around 70. Overnight lows will be mainly in the 60s, and
shower chances will continue each night with the upper trough
and surface front nearby. Will also mention that what is
currently Hurricane Ernesto is expected to track well to our
east over the Atlantic and is currently not expected to result
in any impacts to our area.

Monday through Wednesday...Monday, chances for showers and
thunderstorms look to continue as the upper trough and
associated upper deformation axis will be tracking over our
region. Highs should be similar to the previous couple days and
it will remain humid. Then, a stronger cold front is expected to
track through the region Monday night into Tuesday. While the
exact timing is uncertain, we should see a drying and cooling
trend behind the cold front as high pressure builds into the
region from the west. For days 8-14, the CPC is leaning towards
slightly above normal temperatures and precipitation.

&&

.AVIATION /19Z WEDNESDAY THROUGH MONDAY/...
VFR conditions continue at all terminals this afternoon but we
are monitoring isolated to scattered showers and thunderstorms
developing in the Upper Hudson Valley and southern Adirondacks
that are tracking from north to south. While a brief shower or
storm can impact any terminal this afternoon, GFL and PSF have
the best chance of experiencing a shower/storm and we included
TEMPO groups at both sites from 19 to 00 UTC with potential for
MVFR visibility during any short-lived shower/storm. Also small
hail is possible with any stronger storm. Since there is a
lower potential for a storm to reach the valley areas, we only
included -SHRA for ALB in the TEMPO group this afternoon with
MVFR visibility and VCSH in POU which is further removed from
the best forcing for ascent.

Any shower or storm will diminish by around 00 UTC but with
skies clearing this evening, fog will likely quickly develop at
GFL and PSF, similarly to last night. Since both terminals may
experience a brief shower/storm, we show IFR visibility and
ceilings occurring an hour or two earlier than last night,
arriving between 01 and 04 UTC. Once IFR fog and ceilings
ensues, it will likely be maintained through 11 - 13 UTC. Less
confidence at ALB where rain may not occur so only show MVFR
visibility there. Since POU experience IFR cigs/vis last night
and conditions will be similar tonight, show IFR conditions
ensuing by the pre-dawn hours (07-09 UTC) and continuing through
12-13 UTC.

We should have VFR conditions return by 12 - 13 UTC and lasting
through the majority of the TAF period but additional
showers/storms are expected to develop by the end of the TAF
period, especially at GFL, with showers/storms traveling again
from north to south.

Outlook...

Thursday Night: No Operational Impact. Patchy FG.
Friday: No Operational Impact. NO SIG WX.
Friday Night: Moderate Operational Impact. Slight Chance of SHRA.
Saturday: Moderate Operational Impact. Breezy. Chance of SHRA...TSRA.
Saturday Night: High Operational Impact. Likely SHRA...TSRA.
Sunday: High Operational Impact. Likely SHRA...TSRA.
Sunday Night: Moderate Operational Impact. Chance of SHRA...TSRA.
Monday: High Operational Impact. Likely SHRA...TSRA.

&&

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

&&

$$

SYNOPSIS...Gant/Main
NEAR TERM...Main
SHORT TERM...Main
LONG TERM...Main
AVIATION...Speciale