Lexington, Massachusetts, USA
000
FXUS61 KBOX 041532
AFDBOX
Area Forecast Discussion
National Weather Service Boston/Norton MA
1132 AM EDT Sat Apr 4 2026
.WHAT HAS CHANGED...
No significant changes; forecast remains on track.
&&
.KEY MESSAGES...
- After mild weather Friday, another backdoor front brings a
return to chilly weather Saturday afternoon, especially
eastern MA.
- Showers Sat night and Sunday, milder with highs in the upper
50s and lower 60s.
- Could see a few rain/snow showers Monday night/ Tuesday
morning,but otherwise expecting cooler temperatures and dry
weather for a good portion of next week.
- Second half of next week looks mainly dry with temperatures on
the rise.
&&
.DISCUSSION...
KEY MESSAGE 1...After mild weather Friday, another backdoor
front brings a return to chilly weather Saturday afternoon.
Mild during the predawn hours of Saturday across SNE, with
prefrontal airmass and dew pts in the upper 40s and lower 50s
across the region. This moist airmass (by early April
standards), courtesy of a modest low level prefrontal southwest
jet, is the culprit for the low clouds, fog and spotty drizzle
along the south coast. As a cold front approaches from the NW,
surface winds over SNE will veer to the WNW toward daybreak,
shunting this low level moisture offshore and giving way to
clearing/improving conditions along the south coast toward
sunrise.
As northern stream jet energy streams across the maritimes this
morning, its corresponding surface boundary will traverse
across SNE in the form of a backdoor front, from east to west.
Hence, warmest part of the day will be this morning, along with
sunshine thru high clouds, warming temps through the 50s and
60s. Then followed by a noticeable temperature drop this
afternoon from east to west, as winds shift from the north into
the east with the FROPA. This wind shift will be abrupt, with
gusts up to 30 mph from the ENE! This cold air is evident by a
pocket of -2C temps at 925 mb advecting down the coast of ME &
NH this morning, then into NE MA this afternoon. This chilly
airmass will be enhanced by streaming across ocean temps in the
low to mid 40s. At the surface, this will translate to a very
large temp difference across SNE this afternoon, with highs well
into the 60s across western MA/CT, while temps fall into the
upper 30s and lower 40s across eastern MA, including Boston and
Cape Cod.
KEY MESSAGE 2...Showers Saturday night into Sunday, but turning
mild Sunday, with highs in the upper 50s and lower 60s.
Saturday night...1035 mb surface high over the maritimes,
combined with the backdoor front south of New England lifting
north as warm front, will set the stage for overrunning precip
in the form of spotty light rain/drizzle. Chilly with lows in
the 30s, then temps rising overnight into the 40s as warm sector
approaches from the south. Given the easterly upslope flow up,
the eastern slopes of the Berks may experience temps at or below
freezing. Hence, some spotty light freezing drizzle can't be
completely ruled out. However, given marginal temps and confined
to elevation AOA 500 ft, little if any impact expected.
Sunday...low pressure over the Great Lakes exits into Ontario,
with its trailing cold front sweeping across SNE. Modest jet
dynamics coupled with an ample moisture plume (PWATs 1.2-1.4
inches) will support widespread showers Sunday. Although, given
how progressive this system is, expecting modest rainfall totals
on the order of 0.2 to 0.4 tenths of an inch, which is
supported by both deterministic and ensemble datasets. Hence,
beneficial rains but flooding is not expected. Despite the
widespread showers, its a mild airmass with dew pts in the 50s.
Therefore, not a chilly day with strong low level WAA providing
highs in the upper 50s to lower 60s. It will become breezy over
RI and eastern MA given the strengthening southwest jet.
KEY MESSAGE 3...Could see a few rain/snow showers Monday night/
Tuesday morning, but otherwise expecting cooler temperatures
and dry weather for a good portion of next week.
Both ensemble and deterministic guidance continue to be in good
agreement that an upper-level trough pushes across the Great
Lakes and into New England next week, leading to mostly dry
weather but cooler temperatures. Ensemble guidance is indicating
850mb temperatures could get to below -5C and 500mb
temperatures below - 30C Tuesday as a shortwave moves through,
which would support snow showers developing and mixing in with
rain showers. Given that surface temperatures will remain at
least in the mid 40s, not expecting any road or travel impacts.
Otherwise, dry weather with high temps mainly in the middle 40s
to the lower 50s and overnight temperatures ranging from the mid
20s to mid 30s through Wednesday night.
KEY MESSAGE 4...Second half of next week looks mainly dry with
temperatures on the rise.
A large high pressure system moves into the Mid-Atlantic region
by the second half of next week, bringing predominantly
southwesterly flow back to southern New England. The warmer
airmass advecting into the region will allow temperatures to
recover back into the 50s, likely the 60s, by the end of the
week. Expecting conditions to remain mostly dry.
&&
.AVIATION /14Z SATURDAY THROUGH WEDNESDAY/...
Forecaster Confidence Levels...
Low - less than 30 percent.
Moderate - 30 to 60 percent.
High - greater than 60 percent.
15z TAF Update:
Today: High confidence in TAF/trends but moderate on timing.
SCT-OVC VFR ceilings (low-VFR/MVFR range eastern MA/RI) as
backdoor cold front now moving thru eastern MA brings a gusty
windshift to ENE thru 20z toward the Berkshires. Gradual
deterioration in ceilings likely into the remainder of the
afternoon; ceilings could drop into MVFR range as soon as 20z
from BOS/Cape airports to ORH/PVD, then continue to spread
westward to BDL/Berkshires thru 00z. NE/E winds around 12-15 kt
with gusts 20-23 kt, though trending E/ESE at BDL and PVD late.
Tonight: High confidence in TAF/trends but moderate on timing
any showers.
MVFR to LIFR ceilings with E/ESE winds around 10-15 kt. Though
there could be patchy intervals of drizzle, scattered showers
develop ENE as backdoor front from today lifts northward as a
warm front. Uncertain on exact timing but best chance probably
not sooner than 03z continuing to about 10-11z. Winds to then
turn from E/ESE 10-15 kt with occasional gusts 20-25 kt to SE-S
around 10 kt.
Sunday: Moderate confidence.
IFR/patchy LIFR early, but should trend toward IFR-MVFR cloud
bases by mid-morning to noontime. Possible mist and drizzle
ahead of cold front, which brings widespread rain showers
approx. 17-23z from west to east. A low chance for a rumble or
two of thunder but think SHRA predominates much of the time. SW
winds around 10-15 kt (upwards of 20 kt with gusts 25-28 kt Cape
and Islands), shifting to W/WNW and decreasing to under 10 kt
speeds upon frontal passage.
Sunday Night: High confidence.
Mainly VFR, possible VFR/MVFR ceilings western high terrain. NW
winds increase to 10-15 kt with gusts 25 kt.
KBOS Terminal...High confidence in TAF/trends but moderate on
timing. E winds around 15-20 kt with area of SCT VFR/MVFR
ceilings lingers most of today; deteriorating to MVFR ceilings
as soon as 20z, continuing to trend to MVFR-IFR ceilings this
evening as winds become ESE. Psbl SHRA 05-10z Sun.
KBDL Terminal...High confidence. VFR with north winds, trending
easterly late in the day with arrival of MVFR ceilings. Ceilings
continue to lower to MVFR/IFR range early tonight. Psbl SHRA
03-08z Sun.
Outlook /Sunday Night through Wednesday/...
Sunday Night: VFR. Breezy.
Monday: Breezy.
Monday Night: Slight chance SHSN.
Tuesday: Breezy. Chance SHRA, chance SHSN.
Tuesday Night: Breezy.
Wednesday:
&&
.MARINE...
Forecaster Confidence Levels...
Low - less than 30 percent.
Moderate - 30 to 60 percent.
High - greater than 60 percent.
High confidence.
Given NE/E gusts are currently in very solid SCA to near-gale-
force range with the immediate passage of the backdoor front,
and that SWly gusts for Sunday look to be more in the SCA range
with strongly- inverted profiles, have hoisted SCAs for all
waters starting now through 00z Monday (thus, gale watches on
southern waters converted to SCAs).
Expect gusts to be strongest thru Saturday afternoon at around
25-30 kt (occasional gusts to 35 kt possible), then settle in
around 25-30 kt range. Seas remain in the 3-5 ft range thru
tonight, then increase more markedly as southerly winds increase
the fetch, building offshore to nearly 10 ft on southern
waters. Winds Sunday night to shift to NW at sub-SCA levels
briefly, but could gust to around SCA ranges late overnight
Monday.
Low chance at mist/fog overnight, but better chance for rain
showers late Sunday afternoon to early Sunday evening.
Outlook /Sunday Night through Wednesday/...
Sunday Night: Winds less than 25 kt. Areas of rough seas.
Chance of rain showers.
Monday: Winds less than 25 kt. Local rough seas.
Monday Night: Winds less than 25 kt. Seas locally approaching
5 ft.
Tuesday: Winds less than 25 kt. Chance of rain showers, chance
of snow showers.
Tuesday Night: Winds less than 25 kt. Seas locally approaching
5 ft.
Wednesday: Winds less than 25 kt. Areas of seas approaching
5 ft.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...None.
RI...None.
MARINE...Gale Watch from Sunday morning through Sunday afternoon for
ANZ231>235-237-254>256.
Small Craft Advisory until 1 PM EDT this afternoon for
ANZ254>256.
&&
$$
DISCUSSION...McMinn/Nocera
AVIATION...Loconto/McMinn/FT
MARINE...Loconto
Meta data:
ID: b97bf707-adc2-4434-8838-3c78357e07d9
Link:
https://api.weather.gov/products/b97bf707-adc2-4434-8838-3c78357e07d9
Index:
https://api.weather.gov/products/types/AFD/locations/BOX