Lexington, Massachusetts, USA
000
FXUS61 KBOX 060705
AFDBOX
Area Forecast Discussion
National Weather Service Boston/Norton MA
305 AM EDT Sat Jun 6 2026
.WHAT HAS CHANGED...
No significant forecast changes.
&&
.KEY MESSAGES...
- Another hot, summerlike day with increasing humidity.
Thunderstorms arrive late this afternoon into tonight, a few
of which could become strong to severe. Sunday turns cooler
with scattered showers, but not a washout.
- Seasonable temperatures Monday, followed by another stretch of
summerlike heat and building humidity. No notable storms next
week, though a front may bring a period of showers and
thunderstorms mid to late week.
&&
.DISCUSSION...
KEY MESSAGE 1...Another hot, summerlike day with increasing
humidity. Thunderstorms arrive late this afternoon into tonight, a
few of which could become strong to severe. Sunday turns cooler with
scattered showers, but not a washout.
There were no notable changes to the near and short-term forecast.
Given a well-mixed boundary layer reaching 850-800 mb, highs should
climb well into the upper 80s to lower 90s, remaining well above
normal for early June, when average highs are typically in the lower
70s. Dewpoints rise into the upper 50s to lower 60s today, leading
to a somewhat muggier feel, though conditions should not feel
excessively humid. For those heading to the beaches, there is a
moderate risk for rip currents Saturday along east-facing beaches of
Cape Cod, ocean-facing beaches of Nantucket and Marthas Vineyard,
and south-facing beaches from Point Judith, RI to Westport, MA.
Always check with lifeguards regarding local rip current conditions.
Confidence remains consistent that most, if not all, daylight hours
remain dry, though a brief afternoon shower cannot be ruled out
north and west of the I-495 corridor, likely associated with a
prefrontal trough. Increasing heat and humidity will lead to a
moderately unstable atmosphere, with CAPE values between 500-1000
J/kg, though some guidance suggests locally higher values
approaching 1500 J/kg. This should support convective initiation by
late afternoon, roughly 5-6PM. Activity may persist after sunset,
supported by frontal forcing, modest mid-level lapse rates near 6.5
C/km, and increasing deep-layer shear, before weakening and shifting
offshore by around midnight. DCAPE values are modest as well,
approaching 800 J/kg, while 0-6 km bulk shear increases to around 30-
40 kt. Given this setup, a Slight Risk for severe thunderstorms
continues for much of interior southern New England, with the
primary threats being strong to damaging straight-line winds and
locally heavy downpours as PWAT values climb to around 1.8 inches.
Sunday morning, subsidence behind the front allows for drier, albeit
humid, conditions with a mix of clouds and sunshine. By afternoon, a
more defined mid-level trough and associated shortwave energy move
across southern New England, though recent guidance has trended the
surface low farther north into the Gulf of Maine. As a result,
rainfall appears more showery and less widespread, with the greatest
concentration of showers, general thunder, and perhaps small hail
mainly across eastern portions of southern New England, though the
overall severe threat appears limited. Cooler air arrives more
gradually, which may allow highs to still reach the upper 70s to
lower 80s before northeast flow develops later in the evening.
KEY MESSAGE 2...Seasonable temperatures Monday, followed by another
stretch of summerlike heat and building humidity. No notable storms
next week, though a front may bring a period of showers and
thunderstorms mid to late week.
Sundays mid-level trough exits east of New England by early Monday
morning as an amplified ridge shifts toward the eastern third of the
CONUS. The trough eventually evolves into a cutoff mid-level low
over the Canadian Maritimes, helping to slow eastward progression of
the ridge and supporting another stretch of summerlike temperatures
across southern New England. Monday will likely be the coolest day
of next week due to north-northeast flow aloft draining a cooler
airmass southward into the region. Forecast soundings Monday
afternoon depict a well-mixed atmosphere with the boundary layer
extending to around 850 mb and temperatures at that level ranging
from +8C to +12C. Naturally, the farther east, the cooler
temperatures will be, with Cape Cod, the Islands, Boston, and the
eastern coastal plain largely remaining in the 70s, while the
Connecticut River Valley reaches the lower to middle 80s. Through
much of next week, an anomalous ridge extending north toward Hudson
Bay in Canada favors mainly dry and increasingly hot conditions. 850
mb temperatures rise to around +15C Tuesday, then increase to around
+18C Wednesday through Friday. This should support highs in the
middle 80s to near 90 Tuesday, followed by upper 80s to lower 90s
through much of the remainder of the week. The first half of next
week should feature relatively comfortable dewpoints in the 50s.
However, by late week, dewpoints rise into the 60s, leading to a
more humid airmass. While outside the forecast period, there is a
signal for heat to continue into next weekend, reflected in CPC
outlooks depicting a Slight Risk (20 to 40% probability) for extreme
heat across portions of the Northeast. In terms of precipitation,
there does not appear to be anything appreciable on the horizon
through much of next week. However, a frontal passage late in the
week may bring a period of showers and thunderstorms as heat and
humidity continue to build.
&&
.AVIATION /07Z SATURDAY THROUGH WEDNESDAY/...
Forecaster Confidence Levels...
Low - less than 30 percent.
Moderate - 30 to 60 percent.
High - greater than 60 percent.
06Z TAF Update:
Today...High confidence.
VFR, though the risk for isolated to scattered TSRA increases after
20Z from KORH westward. A few storms may become strong, with gusty
winds and localized turbulence the primary aviation hazards. Greater
storm coverage becomes more likely after 00Z farther east. Winds
become SW and increase to around 10-12 kt with gusts of 20-25 kt.
Tonight...Moderate confidence.
VFR outside of scattered thunderstorms, which may briefly reduce
flight categories to IFR in heavy rainfall and lower visibility.
Initially scattered convection may consolidate into a broken line of
storms moving eastward into the ORH/BED/BOS/PVD corridor between 00-
03Z before shifting offshore. A few storms could remain strong early
with localized gusty winds, though general weakening trends are
favored overnight. Brief clearing develops between 04-08Z from north
to south as the front moves offshore. SW winds around 10 kt shift to
W/WNW at 5-10 kt.
Sunday...Moderate confidence.
VFR, though SHRA/TS develops as early as 16Z Sunday across the
MA/VT/NH border region and progresses south/southeast through the
afternoon. Best chances appear from ORH eastward to the Cape and
Islands, with lower coverage farther west. Coverage should
diminishes roughly after 21Z. Winds become NW around 10-13 kt before
turning NE late in the day.
KBOS...High confidence in TAF, though moderate confidence in wind
timing.
VFR through 00Z Sunday. ENE winds become SW around 16-17Z. TSRA
possible after 23Z.
KBDL...High confidence in TAF.
VFR, with SW winds gusting to 20-25 kt after 17Z. TSRA possible
after 22Z.
Outlook /Sunday Night through Wednesday/...
Sunday Night: VFR. Breezy. Slight chance SHRA.
Monday: VFR. Breezy.
Monday Night: VFR.
Tuesday: VFR. Breezy.
Tuesday Night: VFR.
Wednesday: VFR. Breezy. Slight chance SHRA.
&&
.MARINE...
Forecaster Confidence Levels...
Low - less than 30 percent.
Moderate - 30 to 60 percent.
High - greater than 60 percent.
Saturday and Sunday...High confidence.
Small Craft Advisories have been expanded for Saturday afternoon
through Saturday night across the southern waters, eastern waters,
and Cape Cod Bay for a combination of SW wind gusts up to 25 kt and
building seas of 4-6 ft.
There is also a risk for thunderstorms capable of frequent
lightning, heavy downpours, and localized strong wind gusts, mainly
after 7 PM across both the southern and eastern waters.
Another round of scattered showers and thunderstorms develops Sunday
afternoon. There could be a period Sunday late afternoon into the
evening where portions of the eastern waters experience northerly to
northeast wind gusts approaching 25 kt, which may prompt an
extension of Small Craft Advisories into Sunday night. For now,
advisories remain in effect through Sunday afternoon.
Outlook /Sunday Night through Wednesday/...
Sunday Night: Low risk for Small Craft Advisory winds with
gusts up to 25 kt. Seas up to 5 ft. Chance of rain showers.
Monday: Low risk for Small Craft Advisory winds with gusts up
to 25 kt. Seas up to 5 ft.
Monday Night: Winds less than 25 kt. Seas locally approaching
5 ft.
Tuesday through Wednesday: Winds less than 25 kt.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...Air Quality Alert from 11 AM this morning to 11 PM EDT this
evening for MAZ013-016>024.
RI...Air Quality Alert from 11 AM this morning to 11 PM EDT this
evening for RIZ001>008.
MARINE...Small Craft Advisory from 2 PM this afternoon to 11 PM EDT
this evening for ANZ231-250.
Small Craft Advisory from 2 PM this afternoon to 8 AM EDT
Sunday for ANZ232>235-237.
Small Craft Advisory from 2 PM this afternoon to 2 AM EDT
Monday for ANZ254>256.
&&
$$
DISCUSSION...Dooley
AVIATION...Dooley
MARINE...Dooley
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