Lexington Weather

Lexington, Massachusetts, USA

47°F

4/12/2026 9:40pm

Lexington Conditions: Overcast
Temperature: 46.6°F / 8.1°C
Dew Point: 35.1°F
Relative Humidity: 64%
Wind: Calm, 10-min avg: Calm, gust: 3 mph
Barometer: 30.31 in Steady
Visibility: 10 miles
Rain Today: 0.00 in

Area Forecast Discussion
for Boston / Norton, MA

        
000
FXUS61 KBOX 121140
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
740 AM EDT Sun Apr 12 2026

.WHAT HAS CHANGED...
Small Craft Advisories and Gale Watches issued for our coastal
waters late tonight and Monday. Confidence continues to increase 
in well above normal summer-like warmth for much of the work
week, at least away from the immediate coast.

&&

.KEY MESSAGES...

- Dry weather today with highs in the 50s to near 60, but cooler
  upper 40s to lower 50s on parts of the immediate coast. A few
  showers tonight, mainly across northern MA. Gusty southerly  
  winds develop toward daybreak Mon.

- Summer-like warmth much of the work week with highs in the 70s
  and 80s at least away from the immediate coast. A few showers
  and thunderstorms are possible at times, but dry weather
  dominates. 

&&

.DISCUSSION...
KEY MESSAGE 1...Dry weather today with highs in the 50s to near
60, but cooler upper 40s to lower 50s on parts of the immediate 
coast. A few showers tonight, mainly across northern MA. Gusty 
southerly winds develop toward daybreak Mon.

Large high pressure gradually shifts east of the region today.
This will result in seasonable/pleasant weather to close out 
the weekend...But with much less wind than yesterday. Plenty of 
sunshine is also expected this morning...but we should see mid-
high level cloudiness increase and thicken this afternoon out 
ahead of an approaching shortwave. High temperatures today will 
mainly be in the 50s to perhaps near 60 in spots...but cooler 
upper 40s to the lower 50s are expected along parts of the 
immediate coast with sea breezes.

A warm front and associated shortwave energy crosses the region 
tonight. The deeper moisture and stronger forcing will be 
located to our north across northern New England where the bulk 
of the showers will reside. Nonetheless...a few showers are 
expected tonight mainly across northern MA closer to the better 
forcing. Any rainfall amounts though should be rather light. Low
temperatures will be in the 40s...but many locations will rise 
to around 50+ toward daybreak Mon as warm advection increases. 
In fact...a 45 to 55+ knot southwest LLJ will result in gusty 
southwest winds developing toward daybreak. 

KEY MESSAGE 2...Summer-like warmth much of the work week with
highs in the 70s and 80s at least away from the immediate coast. 
A few showers and thunderstorms are possible at times, but dry 
weather dominates.

All of our model guidance continues to support well above normal 
temperatures for most of the work week. On Monday...strong warm 
advection aloft/southwest LLJ will result in a lot of clouds, 
gusty southwest winds and the risk for a few showers at times. 
High temps will mainly be in the 60s to the lower 70s...but 
cooler along the south coast given gusty southwest winds. 

The real warmth looks to arrive Tue and continue for the rest of
the work week. A strong upper level ridge over the Gulf of 
Mexico will result in well above normal height fields across the
region. This should yield high temps in the 70s and 80s for the
rest of the work week...At least away from the immediate coast.
We will have to watch for a backdoor cold front lurking to our 
north. Most of the guidance keeps it generally north of us 
during the work week except for areas near the eastern MA 
coast...where temps could be noticeably cooler for a day or two 
than the rest of the region. We also should mention that 
sometimes these backdoor cold fronts end up further south than 
the global guidance suggests...so this will be one potential fly
in the ointment. Again right now thinking outside the immediate
coast...odds favor summerlike warmth for the rest of the week. 
But given our climatology...still a bit cautious until we get 
into more of the high resolution CAMs which handle these 
situations better.

While much of the upcoming week will be dry...there will be the
risk for a few showers/t-storms at times. Westerly flow aloft 
coupled with an anomalous airmass in place will result in this 
potential especially during the afternoon/evening hours. That 
being said...timing of any shortwaves in westerly flow aloft is 
often difficult. Just something to keep in mind. FWIW...the CSU 
machine learning probs do even has some low severe probs across 
the region on Tue.

&&

.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
Forecaster Confidence Levels...

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

High confidence.

Mainly VFR conditions continue today through Monday. A few
showers tonight mainly across northern MA may result in briefly 
lower/localized conditions. We also should see MVFR-IFR
conditions in low clouds and fog patches develop near the south 
coast during the day Monday as high dewpoint air begins to work 
over the relatively cold ocean. 

Light and variable winds early this morning become S at 6-12 kt
this afternoon, but with localized sea breezes developing along 
parts of the immediate coast. SW winds will increase very late 
tonight and especially Monday with gusts of 20 to 30 kt
expected, strongest of which will be near the south coast. In
fact, we may see southwest wind gusts near 35 knots in the
vicinity of KFMH given pattern recognition. 

KBOS Terminal... High confidence in TAF. Sea breeze should
develop by 14z this morning. 

KBDL Terminal... High confidence in TAF.

Outlook /Monday Night through Thursday/...

Monday Night: VFR. Breezy. 

Tuesday through Tuesday Night: VFR. Breezy. Scattered SHRA.

Wednesday through Wednesday Night: VFR. Chance SHRA, slight
chance TSRA.

Thursday: VFR. Chance SHRA.

&&

.MARINE...
Forecaster Confidence Levels...

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

Today through Monday...High confidence.

Winds/seas will remain below Small Craft Advisory thresholds 
today. However, a strengthening LLJ very late tonight and
especially Monday will result in SW wind gusts of 25 to 30+ kt
over all the waters and potentially some nearshore 35 kt gusts 
in the climatologically favorable locations in this setup near 
Buzzards/Cape Cod Bays as well as Block Island and Nantucket 
sounds. Therefore, we opted to issue a Gale Watch for those
waters on Monday. Lastly, will need to watch for the development 
of fog across the southern waters on Monday as high dewpoint air
advects northward over the relatively cold ocean.

Outlook /Monday Night through Thursday/...

Monday Night: Low risk for Small Craft Advisory winds with
gusts up to 30 kt. Areas of rough seas. Slight chance of rain
showers. 

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

Tuesday Night: Winds less than 25 kt. Seas locally approaching
5 ft. Isolated rain showers. 

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

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

Thursday: Winds less than 25 kt. Areas of seas approaching
5 ft. Slight chance of rain showers.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...None.
RI...None.
MARINE...Small Craft Advisory from 2 AM to 8 PM EDT Monday for ANZ230-
     236.
     Gale Watch from Monday morning through Monday afternoon for 
     ANZ231>234.
     Small Craft Advisory from 2 AM Monday to 5 AM EDT Tuesday for 
     ANZ235-237.
     Small Craft Advisory from 10 PM this evening to 2 AM EDT 
     Tuesday for ANZ250-251.
     Small Craft Advisory from 2 AM Monday to 8 AM EDT Tuesday for 
     ANZ254>256.

&&

$$

DISCUSSION...Frank
AVIATION...Belk/Frank
MARINE...Frank