Brattleboro, Vermont 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

874
FXUS61 KALY 141814
AFDALY

AREA FORECAST DISCUSSION
National Weather Service Albany NY
214 PM EDT Wed May 14 2025

.SYNOPSIS...
An upper level low will slowly approach from the south
and west this afternoon into Thursday bringing some showers and a
few thunderstorms. Temperatures will be near normal today with
abundant cloud cover. Expect temperatures and humidity levels to
increase Thursday into Friday, as a warm front brings a renewed
threat of showers and thunderstorms on Friday.

&&

.NEAR TERM /THROUGH TONIGHT/...
.Update as of 118 pm EDT...Some isolated to scattered light
rain showers have slowly moved south and west of the Capital
Region associated with upper low over the OH Valley. A few
hundredths have been noted in the NYS Mesonet up to the
Helderbergs and northern Catskills with a few hundredths to a
tenth of an inch or so near I-84. A few rumbles of thunder may
be near KPOU and I-84. We removed the PoPs north and east of the
Tri Cities with low- level dry air with the east /southeast
flow off the western New England higher terrain due to the
strong onshore flow due to the offshore/downstream ridge. It
will continue to be mostly cloudy/cloudy. Some sunshine has
filtered through from Albany north up the upper Hudson River
Valley into the Lake George Region. Temps have reached their
highs so we increased to lower to mid 70s there. Highs elsewhere
will be in the 60s to around 70F with some upper 50s over the
eastern Catskills.


.PREV DISCUSSION[0356]...
Tonight...The upper low is forecast to become a more
progressive open wave through tonight as it tracks north/east
into the mid Atlantic region and lower Great Lakes. So while the
trough will be weakening, there should be enough forcing along
with anomalous moisture still in place (PWAT anomalies of +1 to
+2 STDEV) to produce mainly scattered showers. The shower
activity should tend to decrease overnight. Rainfall through
tonight looks to range from around 0.10" to 0.30 with as much as
0.75" in the E. Catskills due to upslope flow. This amount of
rainfall will not result in any significant hydrologic
responses. Low temperatures will be mild again with mainly mid
to upper 50s.

&&

.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
Key Message:

- Strong thunderstorms possible on Friday.

Discussion:

Weakening upper level trough axis tracks northeast across our
area on Thu. With some breaks of sunshine expected during the
afternoon and slightly higher dewpoints in the upper 50s/lower
60s, some modest instability is forecast to develop with around
500-1000 J/Kg of SBCAPE from the HREF. NBM probabilities for
CAPE > 1000 J/Kg are < 20% across much of the area. With 0-6 km
shear only 15 kt or less, organized/severe storms are not
anticipated. Some storms may produce brief downpours though with
PWAT anomalies of +1 to +2 STDEV. Overall max coverage of
showers should be scattered, with isolated T- storms. With some
breaks of sun, high temperatures expected to reach the lower/mid
70s in most valley locations. Once diurnal heating is lost, any
showers should dissipate quickly after dark Thu night with dry
conditions the rest of the night. Lows will be mild again mainly
in the 55-60F range.

Fairly low confidence forecast shaping up for Fri, as most
guidance showing a cluster of convection moving into central NY
north of an eastward advancing warm front. If this activity
holds together, it would move through eastern NY/western New
England during the late morning to mid afternoon hours.
Instability may be somewhat limited based on the timing
especially for areas west of the Hudson Valley. Farther east
there may be enough time to sufficiently destabilize the
environment as temperatures rise to near 80F for moderate CAPE
of 1000-1500 J/Kg. This is conditional though. 0-6 km shear
forecast to increase to around 25-35 kt later in the afternoon
so storms may become organized with a sufficient buoyancy/shear
balance for some possible stronger storms. At this time the
Storm Prediction Center has a general thunderstorm outlook, but
will monitor trends in subsequent forecasts.

Showers and storms should wane Fri evening, as they shift east
of our region. We may get a break overnight, although upstream
activity associated with the frontal system approaching may
start to get close by Sat morning. Lows will be mild again
around 55-60F.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
Key Messages:

    - Chance of thunderstorms (25-40%) Saturday afternoon and early
      evening.

    - Moderate confidence (45-70%)in below normal temps early next
      week.

Discussion:

The weekend opens with a H500 closed/cut-off low over the western
Great Lakes Region. The warm front to the system and a short-wave in
southwest flow aloft increases clouds and bring showers and a chance
of thunderstorms to the region.  Some of the thunderstorms could be
on the strong side depending on sfc heating and the amount of
instability in place. Surface dewpoints rise into the mid 50s to mid
60s. MUCAPE values exceed 1000 J/kg on some of the medium range
guidance and ensembles with increasing deep shear.  Also, PWATS
exceed an inch and are 1 to 2 STDEVs above normal on the latest
NAEFS. Some locally heavy rain may occur from the Capital Region
north and east within a Marginal Risk for WPC`s Excessive Rainfall
graphic Sat-Sat night.  It will be humid with highs above normal in
the mid 70s to around 80F with mid 60s to lower 70s over the higher
terrain. The cold front approaches Sat night with additional
scattered showers and cooler weather to close the weekend.  Lows
fall back into the lower to mid 50s in the cold advection with some
40s over the higher terrain.

The closed/cut-off H500 low moves over the forecast area and then
slowly moves downstream.  The cyclonic vorticity advection and a
secondary cold front will trigger isolated to scattered showers. It
will be brisk and cooler.  NBM temps were in the 60s to lower 70s in
the valleys and 50s to lower/mid 60s over the hills and mtns.  H850
temps fall about -1 to -2 STDEVs below normal by Monday morning with
the actual H850 temps +1C to +5C over the region. Lows  will be in
the 40s with some mid/upper 30s over the southern Dacks.

The week opens with mainly dry, brisk, but cooler than normal
weather with northwest aloft in the wake of the mid and upper
trough.  A few light showers/sprinkles are possible north of the
Mohawk Valley and Capital Region.  Max temps will run 10-15 degrees
below normal with 50s to lower 60s and some 40s over the higher
terrain. The instability showers decrease quickly with decreasing
winds, as some 30s are possible over the mtns with lower to mid 40s
in the lower terrain areas.  Some patchy frost may occur in some
spots.  Some ridging builds in Tuesday with continued below temps,
decreasing winds and fair weather.  Then next system approaching
from the Midwest and western Great Lakes Region brings unsettled
weather back to eastern NY and western New England with an
increasing chance of rain associated with a warm front by the mid
week.

&&

.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
VFR conditions at GFL and ALB this afternoon despite overcast skies
as light showers track into the mid-Hudson Valley, Catskills,
and Mohawk Valley. MVFR ceilings continue at POU and PSF which
are closer to the showers with showers currently only reaching
POU. Showers remain light enough that VFR vis continues as well.
Showers will gradually lift northward early this evening reaching
ALB and PSF by 00 - 03 UTC. While ALB ceilings trend to MVFR,
the vis likely remains VFR at ALB and PSF given light
intensity. Showers weaken and become quite isolated as they
head towards GFL but still expecting MVFR cigs to develop by 02
to 04 UTC. MVFR cigs continue at ALB, PSF, and GFL through the
end of the TAF period with light showers ending overnight.
Showers at POU diminish towards 05 UTC but MVFR cigs deteriorate
overnight, becoming IFR by 05 - 07 UTC. IFR cigs continue through
15 UTC.

Southeasterly winds this afternoon remain sustained 5-10kts but
diminish overnight, becoming light and variable. The exception
is PSF where southeasterly winds remain sustained 5-9kts.

Outlook...

Wednesday Night: Moderate Operational Impact. Chance of SHRA.
Thursday: Moderate Operational Impact. Chance of SHRA...TSRA.
Thursday Night: No Operational Impact. NO SIG WX.
Friday: High Operational Impact. Likely SHRA...TSRA.
Friday Night: Moderate Operational Impact. Chance of SHRA...TSRA.
Saturday: High Operational Impact. Definite SHRA...TSRA.
Saturday Night: Moderate Operational Impact. Chance of SHRA.
Sunday: Moderate Operational Impact. Breezy. Chance of SHRA.

&&

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

&&

$$

SYNOPSIS...JPV/Wasula
NEAR TERM...JPV/Wasula
SHORT TERM...JPV
LONG TERM...Wasula
AVIATION...Speciale