734
FXUS61 KALY 122318
AFDALY

Area Forecast Discussion
National Weather Service Albany NY
718 PM EDT Sat Sep 12 2026

.WHAT HAS CHANGED...
Rainfall amounts have increased from the Capital Region/I-90 north
and west tonight through tomorrow morning.  The highest amounts are
still expected closer to the I-84 corridor prior to 8 am  tomorrow,
where a Marginal Risk for Excessive Rainfall continues for the
southeast Catskills, mid Hudson Valley, southern Taconics and NW CT.
WPC QPF was used for tonight-tomorrow, as the NBM values were too
low.

Min temps were lowered across the northern zones Mon night with
radiative cooling environment with upper 30s to lower 40s for lows
and pockets of mid 30s in the southern Adirondacks.

&&

.KEY MESSAGES...
1) Showers and embedded thunderstorms will become widespread across
most of the area tonight into Sunday morning. Localized downpours
are expected especially for areas near and south of I-90.

2) A cold front will bring isolated to widely scattered
thunderstorms mainly areas north and west of the Capital Region and
southern VT Sunday afternoon and evening. A few storms could produce
damaging winds and/or large hail.

3) It will be a mostly dry and cool start to next week with slightly
below normal temperatures, with the next chance for showers arriving
mid to late week.

&&

.DISCUSSION...
KEY MESSAGE 1...
High pressure continues to move east of New England this
afternoon, as a warm front approaches from the lower Great Lakes
Region and Ohio Valley. A short-wave trough lifts
north/northeast towards the Piedmont/Mid Atlantic Region
tonight. The isentropic lift increases ahead of the warm front
for showers to break out and few t-storms ahead of the boundary
tonight initially north and west of the Capital Region, and then
expanding south and east across the region as a weak low tracks
towards Long Island. Showalter index values lower to 0 to -2C
on the NAM/EC and the latest mean MUCAPEs from the HREFS are
generally <300 J/kg. Elevated instability is present. PWATs rise
+1 to +3 STDEVS above normal into the 1.5-2.0" range with
highest values values south and east of the Capital Region
towards I-84. Some dynamical support from the right entrance
region of an upper level jet streak over southeast
Quebec/northern NY will help enhance the rainfall overnight
coupled with efficient warm rainfall processes with high
freezing levels or warm cloud depths. Some of the guidance
continues to show some low/mid-level FGEN, but varies in the
placement. The latest 3-km NAM looks like an outlier with a QPF
bullseye of a few inches further north to the northern reaches
of the Capital Region/Saratoga Region/srn VT. An uptick of QPF
is supported by the CAMs and WPC and we have a half an inch to
an inch from the Capital Region north and west with slightly
lower amounts over the southern Dacks to account for any bands
of heavy showers/t-storms.

The heavier rainfall amounts still look to be south and east of
I-90 towards the mid Hudson Valley/NW CT and the southeast
Catskills towards the I-84 corridor with 1-1.5" with locally
higher amounts of 2" or so. The good news is that gridded FFG
values in these areas are 1.8-2.5"/hr or 2.5-3.5"/3 hrs. The
6-hr FFG values are mainly 3-5"/6 hr in these areas. Latest
HREFs indicates the heaviest rainfall for the southern most
areas would be in the 12Z-18Z (8 am to 2 pm)/Sun time frame
with probs >1" in 6 hrs 30-40% for portions of Dutchess,
Berkshires and Litchfield Counties. 2" and 3" probs/6 hrs are
lower. These same areas 12Z-15Z (8 to 11 am) Sun indicate
rainfall probs >1" 70-90%; 50-70% up to the Capital
Region/northern Taconics/southern VT and >3" rainfall in 3-hrs
only 10-20% for portions of the mid Hudson Valley, southern
Taconics and Litchfield Hills, NW CT. Ponding of water on
roadways, poor drainage flooding of low-lying and urban areas
looks like the greatest threats still. Rainfall rates may
briefly peak at 0.5-1"/hr. The dry antecedent conditions will
also help keep the flash flood threat low. Isolated flash
flooding can not be ruled out in these areas (closer to I-84 and
the mid Hudson valley/southern Taconics/NW CT south and east),
where the Marginal Risk is in effect tonight into early tomorrow
morning. A ERO Day 2 Slight Risk glances southern Litchfield Co
in Day 2. The rainfall should diminish in the late morning.
Lows fall back into the 50s to lower 60s

KEY MESSAGE 2...

Clouds will begin the day from most of the region. A lull in
the rainfall is expected from the late morning into the early to
mid pm. A prefrontal sfc trough and a cold front will be
approaching from the west. Dewpoints will be in the 60s to
around 70F in a few spots. The cold front is associated with a
strong mid and upper level trough. Isolated- scattered showers
and isolated- widely scattered thunderstorms will likely develop
in the mid- late pm into the evening from northwest to
southeast across the forecast area. CAMS continue to struggle in
convective initiation and coverage. The best chance for some
stronger storms to develop may be from the Capital Region and
southern VT north and west associated with heights falls aloft
and mean SBCAPEs on the HREFs are in the 750-1250 J/kg range
with 0-6 km shear around 40-45 KT. The mid level lapse rates
look marginal at 6-6.5C/km in these areas. The timing does not
look great for a widespread severe threat, but an isolated
threat with a few storms with damaging winds/marginal hail if
enough heating and the better shear/CAPE overlap with the
frontal forcing/upper level support. The better chance of
showers and thunderstorms across the majority of the region
looks like the late pm and night time period prior to midnight
with the mid and upper level jet moving across southeast Canada.
SPC continues the Marginal Risk for most of eastern NY and
western New England (mainly north and west of the mid-Hudson
valley, southern Taconics and NW CT). In the wake of the front.
Strong cold advection occurs and it will become breezy and less
humid. Lows in the 50s to around 60F with some mid/upper 40s in
the southern Dacks.

KEY MESSAGE 3...

A cooler and drier air mass returns to open the week. Dewpoints
fall in the 40s to lower 50s on Monday. It will become breezy
with west/northwest winds 10-15 mph with some gusts 20-30 mph.
Max temps will run below seasonal normals with mid 60s to lower
70s in the lower elevations and mid 50s to mid 60s over the
hills and mtns. The winds subside Mon night with high pressure
building in over NY and PA for near ideal radiational cooling
conditions. Lows fall into the 40s with some mid/upper 30s over
the southern Dacks, southern Greens and eastern Catskills. Some
patchy frost may occur in the southern Dacks. We lowered mins
below the NBM values closer to the GFSMOS numbers for this time
frame. The fair and dry weather looks to last through the mid
week until Thu when the next chance of showers and a few
thunderstorms arrive with a cold front. Similar max temps for
Tue as Mon, but then temps start to modify closer to seasonal to
slightly above normal readings for Wed and Thu.

&&

.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
Although flying conditions are currently VFR with just sct-bkn
mid and high level clouds in place, IR satellite imagery and
upstream surface observations shows ceilings will become bkn-ovc
around 5-6 kft over the next few hours for all sites. Radar
imagery shows widespread showers over south-central NY and
western and central PA and this shower activity will be heading
into the area for the overnight and into Sunday morning. A few
showers are possible for KGFL and KALB as early as 04z-08z, but
most of this activity will be fairly light. Still, within any
showers, MVFR cigs/visibility can be expected, so have included
TEMPOs to account for this. Meanwhile, showers probably won`t
arrive until after 08z for KPSF and KPOU, however, these sites
have a better chance of steadier and heavier showers for the
late night hours and into the morning on Sunday. For these
sites, IFR conditions are expected, especially for visibility,
from about 08z through 15z or 16z. A brief period of IFR
visibility can`t be totally ruled out for KGFL and KALB, but it
looks to be more likely for the southern two terminals. For the
overnight and into Sunday morning, south to southeast winds will
generally be around 5 kts for all sites.

There should be a gradual improvement back to VFR conditions by
Sunday afternoon. Even after showers end, there will be some
lingering MVFR cigs, but it should go back to VFR somewhere
between 18z and 21z. However, another broken line of showers and
possible thunderstorms could impact the region for late Sunday
into Sunday evening. This is more likely to impact KGFL and
KALB, so will include PROB30 for those sites. Within any
thunderstorm, brief gusty winds and IFR visibility can be
expected. Otherwise, south to southwest winds will continue to
be 5 kts for all sites, with winds gradually become westerly or
northwesterly by Sunday evening into Sunday night.

Outlook...

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

&&

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

&&

$$

DISCUSSION...15
AVIATION...27