Brattleboro, Vermont 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

154
FXUS61 KALY 071809
AFDALY

AREA FORECAST DISCUSSION
National Weather Service Albany NY
209 PM EDT Sat Jun 7 2025

.SYNOPSIS...
Additional showers and thunderstorms are expected today,
some of which could produce locally heavy rainfall leading to
isolated to scattered flash flooding, especially from the
Capital District south and eastwards. Tomorrow will be mainly
dry and less humid. Monday will start off dry, but rain chances
increase Monday afternoon into Tuesday ahead of our next cold
frontal passage.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Key Messages:

 -Additional moderate to heavy rain expected early this morning
  into this afternoon. Flood watch extended through 3 PM
  Saturday from the Capital District south and eastwards.

Discussion:
.Update...As of 6:20 AM EDT...Moderate to heavy rain is now
moving through the western Mohawk Valley and southeastern ADKs.
This is associated with a frontal boundary that ended up
slightly further north and west than previously expected, so
PoPs were adjusted upwards here through the next few hours.
Rainfall rates with this convection have been up to around 0.75"
per hour in our CWA, but higher rates of around 1.5" per hour
(per MRMS imagery) have occurred upstream. Flash flood guidance
values here are as low as 1.5" per hour, so we will have to
monitor these potentially heavier rates as they move in over the
next few hours, especially in Montgomery County which has seen
the heaviest rainfall so far this morning. The heavier rain
should then spread south and eastwards as we head through the
morning. Aside from adjustments to PoPs to better align with
current radar, just minor adjustments with this update. Please
see below for more details on flood potential today...

.Previous...Currently, GOES 16 WV imagery shows a broad upper
trough N/NE of the Great Lakes, with a separate upper shortwave
tracking from the Ohio Valley towards the Mid Atlantic. At the
surface, a broad remnant low circulation remains over northern
PA, with a wind shift boundary stretching from the Southern Tier
northeastwards into Central NY. Numerous showers and storms are
developing in the vicinity of this boundary as the southern
upper shortwave approaches. Patchy dense fog remains across the
region this morning, but should dissipate within the next few
hours. The showers should then track southeastwards today,
exiting into southern New England by 3-5 PM. These showers will
pose a threat for isolated to scattered flash flooding, as well
as urban, poor drainage, and low-lying ponding of water...

The focus for the heaviest rain will be for areas in the Flood
Watch, or from the northeastern Catskills and Capital District
south and east. Ciro Alps shows low and mid-level moisture
advection into our region early this morning ahead of this
boundary. PWATs max out at 1.5 - 1.6" per the HREF mean, which
is above the 90th percentile 2-week moving average per the SPC
sounding climatology. Warm cloud depths reach 10-12 kft in this
moist environment. Instability is not overly impressive, but the
HREF mean indicates up to 500-750 J/kg developing south and
east of the Capital District after sunrise this morning. Given
the above setup, rainfall rates of up to 1-2" per hour look
possible today, with the HREF showing low (10%) probs for >3" in
6 hrs for some areas south and east of the Capital District.
Storm motions will be on the order of 15-20 kts today, but with
a somewhat boundary-parallel component to the upper flow some
training and backbuilding of cells will be possible today. The
threat for flash flooding will be greatest where any training
occurs, especially if this happens over urban areas and/or areas
that already saw significant rainfall amounts yesterday. Thus,
the flood watch was extended in time until 3 pm today and
expanded in area to cover more of the Mid Hudson Valley.

Lack of better instability and shear out ahead of this first
boundary this morning should prevent much of a severe threat
with any storms that develop. However, hi-res guidance,
especially the HRRR which is handing the current setup well,
indicated the potential for up to 750-1000 J/kg of SBCAPE
overlapping with >40 kt of deep-layer shear across portions of
the Mohawk Valley, ADKs, and upper Hudson Valley for a few hours
this afternoon and early evening. With the main upper trough
tracking by to the north and a secondary cold frontal boundary
dropping southwards, there may be enough forcing for ascent to
overcome low and mid-level dry air and result in convective
initiation. While confidence is admittedly low on how
widespread any storms will be. However, if storms can develop
here this afternoon (timing generally 4-8 pm), and take
advantage of this favorable parameter space, then we could see
a few instances of marginally severe wind gusts and/or
marginally severe hail despite the fact that SPC has opted not
to place this area in a marginal risk for severe weather. In
fact, with counterclockwise turning hodographs and steepening
low-level lapse rates, hail actually seems to be more of a
threat here than wind. Convection should die out quickly after
sunset. Highs today will be mainly in the 70s, with some upper
60s in the high terrain, and it will remain muggy.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/...
Tonight through Sunday...The upper shortwave trough/shortwave
move off to our east, and surface high pressure builds into the
region beneath confluent flow aloft. This will help to push a
cold frontal boundary south through the region, and it will
settle near the I-84 corridor by tomorrow. Rising heights aloft
keep us mainly dry through this timeframe, although a few
showers will be possible near the I-84 corridor tomorrow evening
ahead of our next system. Behind the cold front, winds turn to
the north and eventually the east as the surface high slides by
to the north. This will result in lower humidity with dew points
dropping back into the 50s, although temperatures will not be
much colder behind the front. Lows tonight will be in the 50s,
with highs tomorrow in the upper 70s to around 80 for most
areas.

Sunday night through Monday...Deep upper troughing moves into
the western Great Lakes, while an upper shortwave becomes
negatively tilted as it rounds the eastern periphery of this
upper trough/upper low. This will allow for a surface low to
track northwards through the eastern Great Lakes Sunday night,
and it will lift the aforementioned frontal boundary back north
as a warm front as it does so. While this could result in some
scattered showers, there is uncertainty about the coverage (or
lack thereof) of these showers with a strengthening ridge of
high pressure at the surface building in from the E/NE and
another area of low pressure off the east coast potentially
blocking the better moisture transport from reaching our region.
It may take a while for the warm front to lift north of our
region with some cold air damming due to the low-level easterly
flow, but we should eventually break out into the warm sector
Monday, especially for southern areas. Highs will be mainly in
the 60s (terrain) to 70s (valleys). With an overall lack of
large-scale forcing, Monday looks relatively dry, although there
could be a few scattered showers for western areas in the
afternoon ahead of an approaching front. More details on this
frontal passage in the long term below...

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
Key Messages:

- High probability (60-80%+) of showers/thunderstorms Monday night
into Tuesday.

Discussion:

Strong upper level trough across Great Lakes region with associated
cold/occluded front approaching Monday night into Tuesday brings
showers and thunderstorms across the region. Depending on the exact
timing of main frontal passage, there could be some stronger
thunderstorms given strong mid level wind fields (H500 winds 40-
60KT) and rapid cooling aloft. In the wake of frontal system,
persistent upper level troughing across SE Canada should keep breezy
conditions along with additional isolated/scattered
showers/thunderstorms Wednesday-Thursday, mainly during the
afternoon hours for areas north of I-90. It also looks quite breezy,
with NBM probs for wind gusts >30 mph over the 24 hour period ending
2 AM Thursday and 2 AM Friday as high as 30-50% within the Mohawk
Valley and Capital Region and 50-80% for higher elevations across
the Berkshires.

Changeable temperatures through the week, with below normal temps
Tuesday with clouds/showers (highs 60s/70s) trending closer to
normal for Wed-Fri (daytime highs 70s/lower 80s, nighttime lows
50s/lower 60s).

&&

.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
Main concern this afternoon continues to involve current
MVFR/IFR restrictions and renewed chances for showers as a cold
front moves through the area. Latest satellite shows clearing
skies to the north this afternoon, which may result in isolated
storms that could impact GFL later today. For now, have
maintained PROB30 mention for now. Otherwise, main swatch of
rain moving east this hour with drier weather expected this
afternoon and evening. Considering the amount of rain that has
fallen in recent days, along with clearing skies aloft, fog
development is likely overnight at ALB/POU/PSF. Overall
confidence for fog development at GFL remain lower this
afternoon due to the possibility of weak north winds overnight.
Drier air will move into the area after sunrise which will
result in a return to VFR conditions after 15z for forecast
locations.

Outlook...

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

&&

.ALY WATCHES/WARNINGS/ADVISORIES...
CT...Flood Watch until 3 PM EDT this afternoon for CTZ001-013.
NY...Flood Watch until 3 PM EDT this afternoon for NYZ047>054-
     058>061-063>066.
     Air Quality Alert until midnight EDT tonight for NYZ032-033-
     038-042.
MA...Flood Watch until 3 PM EDT this afternoon for MAZ001-025.
VT...Flood Watch until 3 PM EDT this afternoon for VTZ013>015.

&&

$$

SYNOPSIS...Main
NEAR TERM...Main
SHORT TERM...Main
LONG TERM...KL
AVIATION...Gitro