Hartford, Vermont 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

614
FXUS61 KBOX 231112
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
612 AM EST Sat Nov 23 2024

.SYNOPSIS...
Low pressure will rotate northeast into the Canadian Maritimes
through tonight. Cloudy conditions, with steadier rains mainly in
eastern New England will continue through the afternoon. Gusty
northwest winds are expected by this afternoon as cloudy and
rainy conditions improve. Winds remain gusty into tonight and
into early on Sunday before lightening up. Pleasant Monday with
light winds, full sun and seasonably mild temperatures. A
frontal system passing to our northwest on Tuesday brings
another round of rain to Southern New England. Blustery, cooler
and dry weather then returns for Wednesday. Monitoring another
storm system that could move near Southern New England on
Thanksgiving or Black Friday.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
330 AM Update

Key Messages for Saturday

* Showers slowly exiting the area from west to east with the last
  showers exiting the east coast by mid-afternoon

* Strong northwest wind gusts from 35 to 45 mph develop this
  afternoon

Today

Low-pressure over The Gulf of Maine slowly departs east during the
day today. As this occurs showers this morning will slowly depart
the region from west to east. Generally expect a wet first half
of the day for areas east of I-495. West of that mark, showers
should come to an end by mid-morning. Cold/blustery conditions
develop this afternoon as northwest flow behind the departing
low invokes a CAA regime. Swallow mixing to about 1km/900 hPa
will allow stronger wind gusts from a 40 knot low-level jet to
mix down to the surface this afternoon. Expect periods of 35-45
mph gusts throughout the day today, with the strongest gusts
over the east coast, Cape, and Islands. High temps top out in
the mid to upper 40s, but the gusty northwest winds will have it
feeling much colder.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/...
Key Messages

* Drying out overnight with skies clearing from west to east

* Gusty northwest winds persist tonight into tomorrow, with stronger
  gusts over the east coast/Cape and Islands.


Tonight

Northwest flow advects a cooler/drier air mass over southern New
England tonight. Low-level jet remains relatively strong with winds
at 925 hPa/850 hPa around 40 and 50 knots respectively. Model
forecast soundings suggest areas across the interior may decouple
overnight which may halt or at least weaken gusty northwest winds
from this afternoon for a period of time. After midnight however,
strong CAA will result in steepening low-level lapse rates that
should allow some 20 to 30 mph gusts to make it to the surface
across the interior. Closer to the coast, mixing should be more
efficient with warmer surface temps supporting steeper lapse rates.
30 to 35 mph gusts should persist near the coast and especially over
The Cape/Islands overnight. Low temps bottom out in the upper 30s to
low 40s, but the wind chill factor will have it feeling closer to
freezing.

Tomorrow

Dry and sunny tomorrow with near normal high temperatures ranging
from the mid to upper 40s across the interior to the upper 40s to
low 50s over the coastal plain. Northwest flow in a low-level CAA
regime will continue to support efficient mixing in the boundary
layer. Thus, we`ll be dealing with another afternoon of gusty
northwest winds. Model guidance has trended downward a touch with
the strength of the low-level jet with wind speeds at 925 and 850
hPa ranging anywhere from 35 to 40 knots. This should allow for
another afternoon of 30 to 40 mph wind gusts, but it looks as though
we will fall short of any widespread/persistent gusts strong enough
to warrant a wind advisory.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
Highlights:

* Sunny, dry with easing winds for Mon with slightly above
  normal temps.

* Frontal system passing to our north and west on Tue brings another
  round of beneficial wetting rains.

* Cooler and blustery but dry weather for the Wednesday travel day.

* Monitoring a potential storm that could brush Southern New England
  on Thanksgiving and/or Black Friday, but low confidence due to
  large uncertainty. Stay tuned!

Details:

Sunday Night and Monday:

Decreasing WNW winds Sun night with skies trending clear as ridge of
high pressure moves in from the west. Lows in the upper 20s to
the mid 30s. This high pressure ridge then crests over Southern
New England on Monday, leading to a mostly sunny, dry and
seasonably mild day (highs mid to upper 50s). Though we start
off mostly clear for Mon evening, expect increasing cloudiness
in response to an approaching frontal system, bringing lows in
the mid to upper 30s, however dry weather is still expected.

Tuesday:

Ensembles coming into better agreement on lead 500 mb shortwave
disturbance and ~994 mb sfc cyclone moving through the Gt Lakes and
St. Lawrence Valley on Tue. With a rather mild warm sector (850 mb
temps around +6 to +8C) rain showers should break out in earnest
starting Tue morning, progressing through Southern New England
through the daytime hours, before moving offshore for the evening.
Likely due to the progressive nature of the system, most models
suggest rain amounts in the third to half inch range common for
most, with low (< 20%) probs for rain amounts at or over 1". Will
turn blustery behind the cold front with moderately strong cold
advection. With cloud cover for most of the day, reduced highs into
the upper 40s to mid 50s even though thermal profiles would support
warmer. With WNW winds around 10-15 mph behind the front, kept lows
on the milder side in the upper 20s/mid 30s.

Wednesday:

Still under a broad WSW cyclonic flow with a rather chilly low-
level airmass (925 mb temps 0 to -3C). Still looks to be a dry
day with blustery WNW winds, speeds 10-15 mph with gusts 20-25
mph. Mostly sunny conditions should help take the edge off the
colder airmass, with highs in the 40s, with upper 30s in the
higher terrain. All in all, conditions still seem favorable for
holiday travel. Decreasing winds Wed night should lead to a
pretty chilly night, with lows in the 20s for most, though the
Greater Boston area and the Cape/Islands should stay around
freezing.

Thursday / Friday:

Still a low-confidence forecast for the Thanksgiving holiday to
Black Friday period. Considerable disparity exists in potential
outcomes across the models and their ensembles, associated with
Pacific energy coming out of the Rockies and its potential
interaction with an injection of northern-stream energy digging out
of the Canadian Prairies. Compared to its prior run which was
flatter/weaker and a cold and dry out-to-sea passage, the 00z GFS
and its GEFS now show a more robust low pressure passing from the
southern Appalachians to near the 40N/70W benchmark early Fri. The
ECMWF shows more interaction with the northern stream, with the EPS
mean favoring a track through the OH Valley and into the Northeast,
suggesting the potential for a storm that has the potential for some
of it to be wintry in the interior. However EPS member low tracks
still show quite a range with not much clustering, ranging from the
eastern Gt Lakes to the Carolinas. The 12z Canadian GEM favors a
track through the mid-Atlantic coast into coastal Southern New
England, with an interior snow and a snow-to-mainly-rain outcome for
the coastal plain.

While the background pattern is one which lends itself to
storminess, given the range in possible outcomes and ensembles not
exactly breaking the tie on what is still a Day 6 forecast, there is
still too much uncertainty to favor any solution at this point. All
outcomes, including a cold and dry pass out-to-sea or a significant
storm are still on the table. Will continue to monitor trends in the
models, take a probabilistic approach and make finer adjustments
once the global models/ensembles show more congruence. For now, kept
PoPs in the higher end of Chance range for both days. The other
aspect to keep in mind is that, provided we see a storm track
favoring prolonged onshore flow, sea surface temperatures are still
in the 50s and that maritime air could also significantly dictate
durations of rain vs snow. Something we`ll be continuing to monitor,
so keep abreast with the latest forecasts/changes as we move through
the next few days.

&&

.AVIATION /11Z SATURDAY THROUGH WEDNESDAY/...
Forecast Confidence Levels:

Low - less than 30 percent.
Moderate - 30 to 60 percent.
High - greater than 60 percent.

12Z TAF Update:


Today: Moderate confidence.

MVFR ceilings/perhaps IFR at times near the coast, with periods
of rain thru the morning hrs. Rain and lower ceilings could
linger into the aftn for eastern airports before trending all
VFR later in the day. By late morning to the afternoon, expect
a rapid increase in NW winds and gusts, peaking later in the day
around 25-35 kt in gusts. Gusts could get near 40 kt near the
interior high terrain.

Tonight: High confidence.

SCT-OVC VFR ceilings. Gusty NW winds around 25-35 kt.

Sunday: High confidence.

VFR. Gusty NW winds 25-35 kt continue into the morning hours,
although NW gusts should ease to around 20-25 kt thru the aftn.

KBOS Terminal...Moderate confidence in TAF. MVFR ceilings with
4-6 SM rain will continue into the early aftn; Rain gradually
pulls away into the rest of the aftn with gradual improvement
toward VFR. Gusty NW winds develop around 16-18z, with gusts
around 35 kt which continue into the evening.

KBDL Terminal...Moderate confidence in TAF. Rain pulls away by
late morning, but NW winds then increase and become gusty,
around 25-35 kt, which continue into the evening.

Outlook /Sunday Night through Wednesday/...

Sunday Night through Monday: VFR. Breezy.

Monday Night: Mainly VFR, with local MVFR possible. Chance RA.

Tuesday: MVFR/IFR conditions possible. Breezy. RA likely.

Tuesday Night through Wednesday: VFR. Breezy.

&&

.MARINE...
Forecaster Confidence Levels:

Low - less than 30 percent.
Medium - 30 to 60 percent.
High - greater than 60 percent.

Today through Tomorrow

* Gale Warning in Effect through Sunday morning

Area of low-pressure over The Gulf of  Maine will support gale
force northwest wind gusts for today, tonight, and the first
half of tomorrow. Gale force gusts should begin to wane Sunday
afternoon as low-pressure slowly exits east over The Canadian
Maritimes. Offshore flow will limit seas close to the coast to
the 4 to 5 foot range, but the outer marine zones will see
higher seas with significant wave heights in the 5 to 8 foot
range.


Outlook /Sunday Night through Wednesday/...

Sunday Night: Moderate risk for Small Craft Advisory winds with
areas of gusts up to 30 kt. Areas of rough seas.

Monday: Winds less than 25 kt. Local rough seas.

Monday Night: Winds less than 25 kt. Chance of rain.

Tuesday: Low risk for Small Craft Advisory winds with gusts up
to 25 kt. Seas locally approaching 5 ft. Rain likely.

Tuesday Night: Moderate risk for Small Craft Advisory winds
with gusts up to 30 kt. Areas of rough seas. Chance of rain.

Wednesday: Moderate risk for Small Craft Advisory winds with
gusts up to 25 kt. Rough seas up to 9 ft.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...None.
RI...None.
MARINE...Gale Warning from 11 AM this morning to 4 AM EST Sunday for
     ANZ230-236.
     Gale Warning from 11 AM this morning to 1 PM EST Sunday for
     ANZ231>235-237-250-251-254>256.

&&

$$

SYNOPSIS...Loconto/RM
NEAR TERM...RM
SHORT TERM...RM
LONG TERM...Loconto
AVIATION...Loconto/RM
MARINE...Loconto/RM