593
FXUS61 KALY 131843
AFDALY

Area Forecast Discussion
National Weather Service Albany NY
243 PM EDT Thu Aug 13 2026

.WHAT HAS CHANGED...
Added some patchy fog to the major valleys north/northwest and
northeast of the Capital Region tonight.  Also added patchy
radiational mist/fog to the Hudson, Mohawk and CT River Valleys east
of the southern Greens Fri night-Sat morning.

Expanded isolated/widely scattered threat for an afternoon
shower/thunderstorm on Fri. Any thunderstorms are not expected
to be severe.

With the cool mid-August air mass building in Fri night-Sat morning
with near ideal radiational cooling conditions continued the trend
to cooler temps below the NBM values by 2-4 degrees and closer
to the MAVMOS numbers.

&&

.KEY MESSAGES...
1) A few isolated thunderstorms are expected across northern areas
this afternoon, but the overall threat for severe thunderstorms is
low for the rest of the afternoon into early tonight.

2) Isolated to widely scattered showers and thunderstorms will
impact the region on Friday, but are not expected to be severe.

3) Cooler temps will be in place this weekend, as confidence is
increasing for a widespread rainfall from showers and some
thunderstorms Sunday into Monday.

&&

.DISCUSSION...
KEY MESSAGE 1...

West to northwest flow aloft continues over NY and New
England with a mid and upper level trough over the Northeast.  500
hPa temps are about -13C based on the 12Z sounding from KALY.  Temps
are near to slightly cooler than normal.  Dewpoints continue to be
in the upper 50s to mid 60s. MLCAPE values based on the 17-18Z
SPC RAP analysis are in 500-1000 J/kg range over eastern NY and
western New England. 500 hPa winds are around 50 KT, so the 0-6
km bulk shear is 50-60 KT, but there is a lot of dry air aloft.
Also, the mid level lapse rates are generally less than 6C/km.
We are also located on the unfavorable right exit region of the
mid/upper level jet streak. Updrafts may not become tall enough
for a robust severe threat, unless a rogue severe cell occurs
tapping into more instability. However, with the strong 700-500
hPa winds some gusty winds /35-50 mph/ or sub-severe hail under
penny-size could occur especially from the Capital Region north
and east into the Berkshires and southern VT. Near normal PWATs
around an inch with fast steering winds aloft should reduce any
hydro threat. The showers/thunderstorms should diminish quickly
by sunset with the skies becoming mostly clear to partly cloudy
with a sfc high ridging in from the Lower Great Lakes Region.
Some radiational mist/fog may form north of Albany in the Upper
Hudson Valley, also in the Mohawk Valley, narrow valleys in the
southwest Adirondacks and east of the southern Greens where
patchy fog was added. Some residual clouds may inhibit fog
formation further south. Low temps fall into the 50s with some
upper 40s over the southern Greens and the Adirondack Park.

KEY MESSAGE 2...

Another impulse in the west to northwest flow moves across eastern
NY and western New England tomorrow. The deep shear in the 0-6
km continues to be strong at 50-60 KT. The residual cold pool
aloft coupled with weak or modest instability with the latest
HREFs showing mean SBCAPEs mainly less than 500 J/kg should
allow for a slight to low chance for a brief shower or
thunderstorm. PoPs were kept mainly in the slight to low chance
range range. Again, the limited instability should inhibit any
severe threat and the thunderstorms are not expected to be
severe, as we agree with general thunderstorm forecast from SPC.
Breezy northwest winds should allow dewpoints to fall into the
50s to lower 60s and high temps will be near to slightly below
normal with mid 60s to mid 70s over the hills and mtns, and
upper 70s to lower 80s in the valleys. rain or greater, so will
continue to monitor model QPF trends.

KEY MESSAGE 3...
The skies will become mostly clear/clear with a
surface anticyclone building in from southeast Ontario. Some
patchy radiational mist/fog will likely develop in the major river
valleys.  Lows will fall into the mid 40s to mid 50s across the
forecast area, as we trended closer to the cooler MAVMOS values.
Would not be surprised if a few readings in the west/southwest
Adirondacks fall close to 40F. After a chilly start for mid-
August, temps rebound into the upper 60s to upper 70s (slightly
below normal) across the forecast area with mostly sunny
conditions due to the strong sfc high building in overhead.
Humidity levels will be pleasant for mid-August.

Low and mid level heights fall Sat night into Sun, as a low
pressure approaches from the Great Lakes Region and Ohio. Mid
and high clouds increase Sat night, as it will not be quite as
cool as the previous night. Low and mid-level warm advection
increases ahead of the approaching wave and warm front for
showers to increase in the late morning into the afternoon from
west to east. PoPs were continued in the likely to categorical
range (55-85%) from the afternoon into the early evening.
Periods of rain with a few thunderstorms continue into the
overnight. PWATs rise back above normal. The latest NBM
indicates that the 24-hr probabilities for >0.50" of rainfall
ending 12Z/Mon are in 50-70% range across eastern NY and
western New England. The chances for >1" of rainfall for the
24-hr period ending that same time frame are 25-40%. The
rainfall continues Sun night into Mon morning, as a secondary
wave may form near Long Island/southern New England. WPC
continues a Marginal Risk (Level 1 of 4) in the Excessive
Rainfall graphic, so we will have to monitor for some heavier
rainfall elements that may cause some ponding of water on
roadways or poor drainage flooding of low-lying areas. Temps
continue to run cooler than normal to close the weekend with the
increasing clouds and rain cooled air.

&&

.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
Through 18Z Friday... VFR conditions will prevail across all
terminals for this TAF period, with some lingering low-to-mid
clouds and northwesterly winds as high pressure begins to build
in across the region through this afternoon and evening. Winds
should remain light overall except for KPSF, which could see
some gusty winds throughout this afternoon. Skies will gradually
clear and winds will weaken into the overnight period, with the
potential for some radiational mist/fog in the early morning
hours of Friday, particularly at KGFL and KPSF. This could bring
brief vis drops to IFR at those terminals from 08Z-12Z. Any
mist/fog that does develop should burn off shortly after sunrise
on Friday, giving way to VFR conditions through the end of the
TAF period. Winds will slightly strengthen but remain light
through this period, prevailing out of the northwest to north at
all terminals.

Outlook...

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

&&

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

&&

$$

DISCUSSION...15
AVIATION...23