Brattleboro, Vermont 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

978
FXUS61 KALY 230802
AFDALY

AREA FORECAST DISCUSSION
National Weather Service Albany NY
402 AM EDT Fri May 23 2025

.SYNOPSIS...
Our stretch of unseasonably cool temperatures along with cloudy
skies continues today and even tomorrow. Patchy drizzle this
morning turns into more organized areas of light rain showers
this afternoon into tonight with diurnally driven showers
tomorrow. Temperatures gradually warm back for the second half
of the holiday weekend with additional chances for scattered
showers on Sunday.

&&

.NEAR TERM /THROUGH TONIGHT/...

Our coastal low continues to exit north/east into the Gulf of
Maine early this morning, taking the organized bands rain with
it. However, plenty of low-level moisture will remain trapped
underneath the low-level inversion seen on the 00 UTC ALY
sounding today as broad troughing persist aloft. We therefore
will unfortunately not see improvements to our sensible weather
today as cloudy skies, unseasonably cool temperatures and patchy
drizzle/very light showers persist through this morning. As our
coastal low matures, the parent trough shifting east of the
Great Lakes will absorb this secondary shortwave. This will
result in an inverted trough axis developing to our west and as
it pivots eastward through the our area this afternoon into
tonight, expecting a more organized area of rain to progress
from the Southern Tier and Catskills eastward into the mid-
Hudson Valley, Capital District into western New England before
lifting northward. We increased QPF amounts compared to the
previous forecast to 0.10 to 0.20" mainly along and north of
I-90 as latest guidance indicates a tightening baroclinic zone
develops, supporting a more organized area of rain. Steady rain
this evening gradually weakens as the trough axis shifts
further east but light showers continue overnight, especially
along the favored western facing slopes of the southern Greens,
Taconics, and northern Catskills, as westerly flow along the
southern periphery of the broad troughing aloft continues.

Otherwise, temperatures today will once again fall well below
normal by roughly 20 degrees and struggle to rise out of the
low to mid 50s. Given widespread clouds and showers tonight, not
expecting much a diurnal temperature change with overnight lows
in the 40s (upper 30s in the southern Adirondacks and southern
Greens).

&&

.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...

Broad troughing persists aloft on Saturday and with the cool
pool overhead, expecting diurnally and cold air advection driven
isolated to scattered showers. The highest potential for
showers will be in the western facing slopes of the western
Adirondacks, southern Greens, Taconics, and northern Catskills
as northwest flow off Lake Ontario also advects lake moisture
south/eastward. Areas south/east of the Capital District have
the highest potential to remain mainly dry and just out of the
reach of daytime showers as showers weaken as they leave the
terrain. Otherwise, mostly cloudy skies once again with somewhat
breezy west to northwest winds as high pressure building into
the Great Lakes tightens the sfc pressure gradient aloft. The
breezy winds should enhance boundary layer mixing a bit so that
temperatures end up a few degrees warmer compared to the
previous few days, especially in the mid- Hudson Valley which
should remain dry. Even still, temperatures should end up 10 -
15 degrees below normal.

We finally trend milder by Sunday as north-northwest winds
advect a milder air mass that spills overtop an omega block
setting up over the Rockies. Even though the cold pool and core
of the trough that has plagues us the past few days drifts into
the Canadian Maritimes by Sunday, broad troughing persists over
the Northeast and, if you can believe it, yet another shortwave
from Ontario rotates along its southern periphery. This
maintains slight chance and chance POPs (15 - 40% chance) for
showers, especially during the afternoon when the stronger
forcing for ascent from the incoming shortwave/tough axis pushes
into our region. Otherwise, skies should breaks for some
limited sun ahead of the shortwave and with warmer temperatures
aloft and somewhat breezy northwest winds continuing, boundary
layer mixing should allow temperatures to rise into the 60s (50s
higher terrain). While this is still cooler than normal for late
May, it is an improvement compared to the recent stretch of
chilly weather.

Note that despite the chance for showers in the forecast for
Saturday and Sunday this holiday weekend, we are not expecting
a washout and there will be dry periods, especially in valley
areas. Most incoming showers should be isolated to scattered in
nature and last for a relatively short period. The exception is
the higher terrain areas of the western/southern Adirondacks,
Taconics, northern Catskills and southern Green, especially
western facing slopes, where rain showers should be more
persistent and where we have a more pessimistic forecast.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
The Memorial Day forecast is becoming more optimistic as guidance
continues to trend drier. Though some showers may be unavoidable
especially early Monday afternoon, given the energy pulsing about
the western flank of the persistent upper low off the coast of Nova
Scotia, NBM probabilities for 12-hour precipitation of at least
0.01" peak only at 15-40%. The greatest probabilities lie in
Southwest Adirondacks and Southern Greens where upslope enhancement
could overcome counteracting subsidence from an incoming surface
high. That said, without much in the way of forcing and warming
temperatures aloft, any showers will be very light and highly
scattered in nature. And, decreasing cloud coverage across much of
the region throughout the day with high temperatures in the low 60s
to low 70s will certainly make for more pleasant conditions to those
of late.

Shower activity ceases late Monday afternoon/early Monday evening as
high pressure builds in from the west. Regionwide dry conditions
will then persist through at least Tuesday with temperatures
moderating into the mid/upper 60s to mid 70s. The remainder of the
extended forecast retains a fair amount of uncertainty in terms of
our next chances for rain. There are clear signals in the guidance
that indicate the development of another closed low pressure system
in the Upper Midwest/Northern Plains by Tuesday morning, but the
depictions of the evolution of this system are varied such that some
sources keep us dry into Wednesday and others produce rain by
Wednesday morning. Additionally, there are hints at a weak
disturbance producing light showers ahead of this main system, but
this solution, too, is variable amongst the guidance. Therefore,
capped PoPs at slight chance to chance beginning Wednesday through
Thursday. Regardless of the outcome, this does not look to be
impactful rain. At this point it is more a question of spatial
spread. Highs Wednesday will primarily be in the 60s with Thursday`s
values similar to those of Tuesday. Lows throughout the period will
largely be in the 40s and 50s.

&&

.AVIATION /07Z FRIDAY THROUGH TUESDAY/...
Through 06z Saturday...MVFR to VFR conditions prevail across the
terminals this morning with low stratus prominent courtesy of
multiple adjacent low pressure systems supplying moisture into
the region. This past evening`s showers have significantly
decreased in spatial coverage and will continue to do so over
the next couple of hours before filling back in again later this
morning and this afternoon. With the atmosphere beginning to
moisten, any VFR ceilings are anticipated to gradually lower to
MVFR heights by this afternoon/evening especially at KPOU and
KPSF and with rainfall at KALB and KGFL. Winds throughout the
period will generally be light and variable at KALB and KGFL
with sustained speeds remaining under 10 kt. KPOU and KPSF look
to have a bit more directionally focused wind out of the west to
west-southwest also at sustained speeds below 10 kt.

Outlook...

Saturday Night: No Operational Impact. NO SIG WX.
Sunday: Moderate Operational Impact. Chance of SHRA.
Sunday Night: No Operational Impact. NO SIG WX.
Memorial Day: Low Operational Impact. Slight Chance of SHRA.
Monday Night: No Operational Impact. NO SIG WX.
Tuesday: No Operational Impact. NO SIG WX.
Tuesday Night: Low Operational Impact. NO SIG WX.
Wednesday: Moderate Operational Impact. Chance of SHRA.

&&

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

&&

$$

SYNOPSIS...Speciale
NEAR TERM...Speciale
SHORT TERM...Speciale
LONG TERM...Gant
AVIATION...Gant