177
FXUS61 KALY 150514
AFDALY

AREA FORECAST DISCUSSION
National Weather Service Albany NY
114 AM EDT Thu Aug 15 2024

.SYNOPSIS...
Scattered thunderstorms diminish after sunset 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 THIS MORNING/...
.UPDATE...Based on current radar showing isolated showers and
storms near the St. Lawrence/Lewis counties border, added
mention of isolated PoPs to far N. Herkimer county as some of
this activity may drift south/east near the Lewis/Herkimer
border over the next few hours. Otherwise, dry conditions with
patchy fog expected the rest of the night.

.PREV DISCUSSION[1015]... Showers and thunderstorms beneath the
cold pool aloft have diminished following the loss of diurnal
heating. A few lingering orphaned anvils from earlier convection
are exiting southward within cyclonic flow about the upper low
over Atlantic Canada, before skies largely clear outside of
scattered cirrus coverage overnight as high pressure builds in
from the west. The clearing trend in concert with decreasing
winds will allow for efficient radiative cooling, dropping
temperatures near to dewpoints in the 50s across much of the
region. Radiation fog is expected to develop within sheltered
valleys and where earlier rain showers have provided additional
low- level moisture. Any fog will quickly dissipate after
sunrise.

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 THIS 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 /05Z THURSDAY THROUGH MONDAY/...
Through 00Z Friday...VFR conditions across the region will
continue this evening. A few showers and very isolated
thunderstorms are tracking southward across portions of the
region, but will end in the coming hours following the loss of
daytime heating. No further impacts from showers and storms are
expected at area terminals. Sct- bkn coverage of orphaned anvils
from earlier thunderstorms will persist for a few hours, before
skies trend clearer after 03-06Z Thu.

Areas of dense fog are expected to develop overnight,
particularly within sheltered valleys and where rain fell in
earlier showers. GFL/PSF remain the most likely sites to see
IFR/LIFR fog, with conditions rapidly deteriorating after 03-04Z
Thu. POU may also see IFR/LIFR conditions within fog, though
confidence is lower in onset timing, more likely after 06-09Z
Thu. ALB may only see VCFG, but restricted vsbys cannot be ruled
out nearer to sunrise. Any fog will quickly dissipate after
sunrise, with VFR conditions returning to all terminals after
12-13Z Thu. Diurnal rain showers will again develop,
particularly over areas of terrain, after 16-18Z Thu.

Winds will rapidly diminish this evening to calm or light and
variable at all terminals by 03-04Z Thu, and continuing through
the remainder of the overnight period. Winds increase to 4-8 kt
out of the west to northwest at ALB/POU/PSF after 12Z Thu, while
south to southwest winds at 3-6 kt are expected at GFL.

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/Picard/JPV
SHORT TERM...Main
LONG TERM...Main
AVIATION...Picard