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 270546
AFDBOX

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

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

&&

.KEY MESSAGES...

- Warm and humid on Wednesday with isolated to scattered showers
  and thunderstorms possible Wednesday afternoon

- Trending cooler for the end of the week with chance of 
  showers Thu.

- Below normal temperatures this weekend into early next week
  with unsettled conditions.

&&

.DISCUSSION...
KEY MESSAGE 1...Warm and humid on Wednesday with isolated to 
scattered showers and thunderstorms possible Wednesday afternoon

An area of surface high pressure positioned to the south will 
continue to support southwest flow and low-level WAA into southern 
New England on Wednesday. 925 hPa temps rise to 20-22C which will 
support surface temperatures in the mid to upper 80sF on Wednesday 
afternoon. Dewpoints increase as well to the low 60s. This will 
support some diurnal instability with the latest suite of high 
resolution model forecasts suggesting 400-800 J/kg of SBCAPE. 
0-6km shear is modest but sufficient between 30-35 knots to 
support organized convection as a moisture starved cold front 
pushes through the region Wednesday evening. Mid-level dry air 
and weak mid-level lapse rates will be the limiting factors for 
thunderstorm development, but enough ingredients are in place to
warrant some risk.

The latest 12Z HREF members depict considerable spread across each 
of it's 5 non time-lagged members. NAMNest and FV3 members support 
some isolated shower/thunderstorms near the south coast while the 
ARW, NSSL-WRF, and HRRR keep things mostly dry. Leaned on a blend of 
guidance to place a 20-25 percent chance of showers or storms over 
CT, RI, and southeast MA between 2 and 6PM tomorrow. The cold front 
then ushers out any remaining showers and cloud cover to support a 
quiet/dry Wednesday night.  

KEY MESSAGE 2...Trending cooler for the end of the week with chance 
of showers Thu.

Cooler temps Thu and Fri in the post frontal airmass, but near 
seasonable with highs upper 60s near the eastern MA coast to low-mid 
70s further inland. Northern stream shortwave drops south across the 
region Thu with increasing moisture which may lead to scattered 
showers developing in the afternoon, especially across eastern half 
New Eng. Then on Friday there are timing differences with cutoff low 
moving south from eastern Canada. GFS is the quickest among the 
deterministic guidance and brings increasing risk of shower from the 
north during the afternoon while ECMWF and GGEM and slower. GEFS 
ensemble probs of 0.1" QPF suggest a drier/slower solution for Fri 
as weak shortwave ridging develops between the 2 systems so leaned 
toward NBM PoPs which keeps it mainly dry Fri. Then increasing 
shower chances during Fri night as the cutoff low approaches. 

KEY MESSAGE 3...Below normal temperatures this weekend into early 
next week with unsettled conditions.

Timing differences continue with arrival of anomalous cutoff low 
which will impact sensible weather Sat. Consensus of the guidance 
favors the cutoff low and accompanying cold pool aloft dropping 
south across New Eng during Sat which should be the cooler and 
wetter of the weekend days. Expect at least scattered showers Sat 
with highs in the 60s with some improvement Sunday. However, the 
overall pattern features a blocking pattern into early next with 
upper trough persisting across the NE. Multiple shortwave passages 
are anticipated which will bring the risk for showers at times early 
next week with temps averaging a bit below normal, but a washout is 
not expected.

&&

.AVIATION /06Z 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 through Sunday: VFR. Breezy. 

&&

.MARINE...
Forecaster Confidence Levels...

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

Tonight and Tomorrow

Southwest winds associated with high pressure to the south will 
persist over the coastal waters through tomorrow night. Winds stay 
at modest speeds around 10-15 knots with some gusts to 20 knots 
possible. Seas remain manageable and sub-SCY level with 
significant wave heights between 1-3 feet. 

Tomorrow Night

A moisture-starved cold front moves over the coastal waters tomorrow 
night. This may be accompanied by a few showers and possibly a 
thunderstorm near the south coast. Winds shift to the northwest 
behind the front around 10 knots.

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. Slight chance of rain showers. 

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

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

Saturday Night: Low risk for Small Craft Advisory winds with
gusts up to 25 kt. Areas of seas approaching 5 ft. Slight
chance of rain showers. 

Sunday: Winds less than 25 kt. Areas of seas approaching 5 ft. 

&&

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

&&

$$

DISCUSSION...KJC/RM
AVIATION...Mensch
MARINE...KJC/RM