Lexington Weather

Lexington, Massachusetts, USA

84°F

5/27/2026 3:52pm

Lexington Conditions: Partly cloudy
Temperature: 83.8°F / 28.8°C
Dew Point: 61.5°F
Feels Like: 84.4°F
Relative Humidity: 47%
Wind: S 1 mph, 10-min avg: Calm, gust: 2 mph
Barometer: 29.62 in Falling Slowly
Visibility: 10 miles
Rain Today: 0.00 in

Area Forecast Discussion
for Boston / Norton, MA

        
000
FXUS61 KBOX 270730
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
330 AM EDT Wed May 27 2026

.WHAT HAS CHANGED...
No significant changes to the forecast.

&&

.KEY MESSAGES...

- Warm and more humid today with isolated showers and
  thunderstorms possible in the afternoon, mainly across south 
  coast and southeast MA.

- Trending cooler late-week. Scattered showers possible Thursday with
  next period of rain arriving as early as Friday afternoon. 

- Becoming unsettled by the weekend with below normal
  temperatures and shower chances.

&&

.DISCUSSION...
KEY MESSAGE 1...Warm and more humid today with isolated showers and 
thunderstorms possible in the afternoon, mainly across south coast 
and southeast MA.

For today, surface high pressure will be positioned to the south of 
the region while our next system and cold front approach from the 
west. This will advect in more moisture at the surface along with 
weak warm advection bringing up 925mb temperatures a degree or two. 
This will support high temperatures in the mid to upper 80s with 
southwest to westerly winds. Dewpoints rise into the low 60s, making 
it feel a touch humid. 

The added heat and moisture ahead of the approaching front will 
build marginal instability through the day (MLCAPE 200-500 J/kg). 
This is enough to support thunderstorms as long as the cold front 
does not come in too quickly (before instability builds up enough). 
The moisture is fairly limited, especially evident in the mid-levels 
which will favor more isolated to scattered showers or thunderstorms 
this afternoon. 0-6 km bulk shear values range 25-35 kts to support 
organized convection if it develops. However, the weaker mid-level 
lapse rates may act to suppress thunderstorm development and 
longevity.


The 00Z high-resolution guidance has stayed split on potential for 
showers and thunderstorms. The NAMnest/FV3, and RRFS show 
isolated showers and storms developing across the southern 
portion of the region, mainly across the south coast. The ARW 
remains dry. The HRRR is mainly dry, with an isolated shower or 
two. This supports the lower probability (< 30%) for isolated 
showers or thunderstorms in the afternoon. Highest chances for
showers/storms will be in the 2-7 PM timeframe near the south 
coast into southeast MA. The cold front fully pushes through by 
tomorrow night diminishing any lingering showers. 

KEY MESSAGE 2...Trending cooler late-week. Scattered showers 
possible Thursday with next period of rain arriving as early as 
Friday afternoon. 

A cooler post-frontal airmass will be in place Thursday and Friday 
which will bring temperatures closer to normal in the upper 60s near 
the coast and low-mid 70s further inland/valleys. A shortwave trough 
drops southward across the region on Thursday which may bring a 
period of scattered light showers.

Confidence in the upper level pattern decreases Friday, mainly with 
regards to the speed and evolution of a cutoff low that tracks south 
from Canada. The GFS and AI GFS remain the quicker solutions, 
bringing the system in quicker with rain arriving as early as mid-
afternoon Friday. Remaining deterministic guidance has the low and 
accompanying rain arriving in the late Friday night-early Saturday 
AM timeframe. Despite the different timing in the deterministic GFS, 
the GEFS shows the highest probabilities for rain overnight Friday-
Saturday with more moderate values for Friday. There is a little 
more confidence in the widespread rain arriving late Friday night; 
however, a few showers are possible Friday at this time. 

KEY MESSAGE 3...Becoming unsettled by the weekend with below normal 
temperatures and periodic rain chances through early next week.

Previously noted, there are timing differences for the cutoff low 
amongst guidance that will dictate the timeframe of the greater 
shower/rain chances over the weekend. A quicker arrival of the 
system could taper off the more widespread showers Saturday 
afternoon. Regardless of the timing, Saturday will be unsettled with 
at least scattered showers for the first half of the day if not a 
large portion of the day. Sunday will be the drier day. The cutoff 
low will bring in a cold pool aloft southward into the region 
favoring below normal temperatures for Saturday in the 60s and 
closer to seasonable for Sunday. The pattern stays fairly steady 
through early next week due to a blocky pattern aloft. This will 
keep a troughy pattern over the region keeping temperatures 
seasonably cool. A few embedded shortwaves move through the flow 
bringing a period or two of scattered showers with a greater chance 
on Monday. 

&&

.AVIATION /07Z WEDNESDAY THROUGH SUNDAY/...
Forecaster Confidence Levels...

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

06Z TAF Update:

Through 12Z...High Confidence. Low for fog/stratus for Cape 
terminals. 

VFR. SW wind 5-10 kt. Some fog/low stratus possible at
Cape/Island terminals toward daybreak with IFR conditions
possible. 

Today...High Confidence. Low-moderate (ceilings Cape terminals). 

Mainly VFR. IFR stratus/fog at ACK with LIFR possible.
Confidence lower in the AM. Greater risk for stratus/fog in the
afternoon. Stratus may expand across other portions of Cape Cod
by late morning and through the afternoon. Low risk for 
afternoon SHRA/TSRA mainly over CT, RI, and Cape/Islands 
terminals with highest chances after 21Z. Confidence is not 
high enough to include PROB30 group in TAF, especially given the
isolated nature of any showers/storms. SW-W winds 10-15 kts with
gusts 20-25 kts, Winds shift to NW after 21Z, eventually making
the shift to NW for the south coast by 03Z. 

Wednesday Night... High Confidence.

Winds shift NW/N behind the cold front. This will push out any 
fog/low stratus over The Islands terminals. VFR elsewhere with 
north/northwest wind 5-10 knots. 

KBOS...High confidence in TAF.
Low chance (< 25%) of an isolated shower or storm after 21Z. 
Greater risk more likely to be south of BOS around the south 
coast.

KBDL...High confidence in TAF.

Outlook /Thursday through Sunday/...

Thursday: VFR. Breezy. Chance SHRA.

Thursday Night: VFR. 

Friday: VFR. Chance SHRA.

Friday Night through Saturday: Mainly VFR, with local MVFR
possible. Breezy. Chance SHRA.

Saturday Night: VFR. Breezy. Slight chance SHRA.

Sunday: VFR. Breezy. 

&&

.MARINE...
Forecaster Confidence Levels...

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

Today:

Southwest winds associated with high pressure to the south will 
persist over the coastal waters today around 10-15 kts with a 
few gusts up to 25 kts possible. Seas remain sub- SCA level 
with significant wave heights between 1-3 feet. 

This evening-Tonight: 

Cold front pushes through the waters shifting winds to the NW in
the evening (after 6 PM). This may be accompanied by a few 
showers and possibly a thunderstorm near the south coast. Winds
NW around 10 kts and seas 1-3 feet. 

Outlook /Thursday through Sunday/...

Thursday: Winds less than 25 kt. Chance of rain showers. 

Thursday Night: Winds less than 25 kt. 

Friday: Winds less than 25 kt. Seas locally approaching 5 ft.
Slight chance of rain showers. 

Friday Night: Winds less than 25 kt. Areas of seas approaching
5 ft. Chance of rain showers. 

Saturday: Moderate risk for Small Craft Advisory winds with
gusts up to 25 kt. Seas up to 5 ft. Chance of rain showers. 

Saturday Night: Low risk for Small Craft Advisory winds with
gusts up to 25 kt. Areas of rough seas. Slight chance of rain
showers. 

Sunday: Winds less than 25 kt. Seas up to 5 ft. 

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...None.
RI...None.
MARINE...None.

&&

$$

DISCUSSION...Mensch
AVIATION...Mensch
MARINE...Mensch