Stowe

000
FXUS61 KALY 011057
AFDALY

Area Forecast Discussion
National Weather Service Albany NY
657 AM EDT Sat Aug 1 2026

.WHAT HAS CHANGED...
While there remains uncertainty in the exact placement of the
heavy rainfall axis for Sunday night into Monday, the latest
probabilistic and ensemble guidance indicates only a very low 
chance for exceeding 2 inches in 24 hours across eastern NY and
western New England. However, given recent heavy/locally extreme
rainfall this pas week, be prepared for potential isolated to 
scattered flash flooding impacts in eastern and western New
England.

There is now a marginal risk (level 1 of 5) for severe weather
on Monday focused in the mid-Hudson Valley into western New
England.

&&

.KEY MESSAGES...
1) There is a medium to high chance for widespread rain and
thunderstorms across eastern NY and western New England tomorrow 
afternoon through Monday resulting in isolated to scattered 
instances of flash flooding. Areas most at risk for flash 
flooding will be those that received high rainfall amounts this
past week.

&&

.DISCUSSION...
KEY MESSAGE 1...

After some isolated diurnally driven showers and thunderstorms
this afternoon, ridging becomes established over the western
Atlantic downstream of a split flow pattern. While a broad 
northern branch trough tracks through southern Canada, a cut-
off low in the southern branch slowly tracks through the
Midwest. As was discussed in the previous discussion, there
remains discrepancies on whether these two features phase or
not tomorrow into tomorrow night which will determine where the
heavy rainfall axis sets-up. Latest trends still indicate the
northern branch will help focus and direct the initial moisture
axis and forcing for ascent around the Saint Lawrence River 
Valley tomorrow, supporting periods of rain and thunderstorms.
While the most widespread rain/storms looks to occur mainly 
west of eastern NY, a few weak embedded shortwaves tracking 
within the strengthening south to southwesterly flow over the 
Northeast will likely support scattered showers and 
thunderstorms. As the northern and southern branch features 
interact, a nearly full latitude trough develops upstream, 
allowing the wind regime to tap into the Gulf and advect a very
moisture rich air mass into the Northeast. In fact, PWATs 
increase towards 2" or within the 99th percentile of the NAEFS 
model climatology for this time of year. Thus, any isolated to
scattered thunderstorms that develop will be capable of
producing heavy downpours. With 20-30kts of deep layer shear, cannot
completely rule out brief damaging winds from any storm that can
grow upscale; however, ample cloud coverage in a highly moist
environment should keep lapse rates weak and thus limit instability,
keeping any severe storms isolated. We are not currently outlook
in SPC's Day 2 Convective Outlook but remain in general thunder.

Heading into Sunday night, the northern branch in southern
Canada looks to slow down and strengthen, even taking on a 
negative tilt while the once cut-off low escapes into the TN 
Valley and weakens as it becomes sheared out. Latest guidance 
shows a jet streak over the Northeast developing Sunday night
with the continued unidirectional southerly winds over the 
Northeast maintaining a rich supply of warm air and moisture 
advection. Showers and embedded convection expand eastward 
Sunday night into eastern NY and western New England ahead of 
the approaching parent trough; however, there is increasing 
consensus in a secondary sfc low developing in the favorable 
equatorward entrance region of the jet streak. Where this 
feature develops will be key as it looks to focus the 
moisture/forcing leading to a heavy rain axis late Sunday night
into Monday morning. There remains discrepancies on where this 
axis develops with one cluster favoring the mid-Hudson Valley, 
NW CT into New England while a second cluster shows it further 
northwest into more of eastern NY. 

Given the recent heavy/locally extreme rainfall much of
eastern NY experienced this past week, most soils are saturated
and rivers/streams are elevated. 1hr and 3hr flash flood
guidance values remain low ranging from 1 to 2.5 inches so if
these values are exceeded, flash flooding concerns will 
increase. Given the anticipated highly moisture rich environment
with forecast soundings showing high freezing heights 12-13kft 
and tall/skinny CAPE, efficient warm rain processes will be at 
play likely supporting high rainfall rates, especially within 
the heavy rain axis. However, unlike the recent heavy rain 
event, this seems to be a more progressive pattern as the trough
continues to swing eastward into Monday. Thus, even if heavy 
rain can persist over a given area, it does not look to last 
multiple hours which lowers the potential for widespread 
flooding concerns. In addition, latest probabilistic guidance 
shows just a few isolated spots with very low values for 24hr 
rain amounts between 8PM Sunday and 8PM Monday exceeding 2 
inches with even the 90th percentile for most of eastern NY and 
western New England under 2 inches in 24hrs. Therefore, WPC maintained
its marginal to slight risk for excessive rainfall in the Day 3
Outlook (12 UTC Mon to 12 UTC Tues) messaging isolated to 
scattered flash flooding. The slight risk is focused in the eastern
Catskills, mid-Hudson Valley and NW CT where the heavy rain 
axis looks to set-up late Sunday night into Monday but given 
continued discrepancies on the exact placement, this could 
change in future updates. Regardless of the slight risk 
location, it is important to be prepared for the potential for 
isolated to scattered flash flooding Sunday night into Monday in
eastern NY and western New England. Areas that were hard hit 
with heavy rain this past week will be most vulnerable to 
renewed flooding concerns. 

SPC also introduced a marginal risk for severe weather in the 
Day 3 Outlook for Monday focused mainly south and east of the 
Capital District given the potential for storms to grow upscale 
as the trough axis pushes through in the afternoon within the 
highly moist environment and 30-35kts of deep layer shear.  
Damaging winds is the primary hazard from any severe storm.

&&

.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
Through 12Z Sunday... Radiational fog/mist this morning will 
leave some lingering IFR/MVFR cigs and vis over the first few 
hours of the period, particularly at KGFL, KPOU, and KPSF. This 
should quickly burn off by 14Z, giving way to VFR conditions at 
all terminals. Winds will slightly strengthen but remain light 
out of the south, with some BKN high clouds and a few fair 
weather cumulus at all terminals throughout this afternoon and 
evening. There is potential for drops in cig and vis categories 
early Sunday morning at all terminals due to mist/fog 
formation, reflected by TEMPO groups, but confidence for whether
this will actually occur will increase with future TAF cycles.

Outlook...

Sunday Night: High Operational Impact. Likely SHRA...TSRA.
Monday: High Operational Impact. Definite SHRA...TSRA.
Monday Night: Low Operational Impact. Slight Chance of SHRA...TSRA.
Tuesday: Low Operational Impact. Slight Chance of SHRA...TSRA.
Tuesday Night: Low Operational Impact. Slight Chance of SHRA...TSRA.
Wednesday: Moderate Operational Impact. Chance of SHRA...TSRA.
Wednesday Night: Moderate Operational Impact. Chance of SHRA...TSRA.
Thursday: High Operational Impact. Likely SHRA...TSRA.

&&

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

&&

$$

DISCUSSION...31
AVIATION...23