Lexington Weather

Lexington, Massachusetts, USA

46°F

4/19/2026 6:59am

Lexington Conditions: Mist, Overcast
Temperature: 45.9°F / 7.7°C
Dew Point: 44.4°F
Relative Humidity: 95%
Wind: Calm, 10-min avg: Calm, gust: None
Barometer: 29.77 in Steady
Visibility: 3 miles
Rain Today: 0.00 in

Area Forecast Discussion
for Boston / Norton, MA

        
000
FXUS61 KBOX 190846
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
446 AM EDT Sun Apr 19 2026

.WHAT HAS CHANGED...
Wind gusts associated with the cold front will likely bring small 
craft advisory conditions across the northern waters as well. 
Confidence continuing to increase in the chance for scattered 
showers and increased cloud cover associated with a weak low 
pressure Monday.

&&

.KEY MESSAGES...

- Strong cold front brings a round of widespread showers today. 
  Leaves colder temperatures and drier conditions in its wake.

- Cooler than normal Monday. Generally dry weather expected in  
  the morning, then increased cloud cover and the chance for 
  spotty showers moves in during the afternoon.

- Seasonable temperatures Wednesday, then another cold front
  arrives.

&&

.DISCUSSION...
KEY MESSAGE 1...Strong cold front brings a round of widespread 
showers today. Leaves colder temperatures and drier conditions in 
its wake.

A strong cold front today will bring a round of widespread showers. 
This front is part of a strong upper level trough that will continue 
shifting east from the Great Lakes today into Monday. Ahead of this 
front and trough, PWAT values this morning ahead of the front are 
elevated, reaching 1.4". This is part of a moisture plume that will 
help set the stage for the widespread rain today. Given these higher 
values, moderate to heavy rainfall rates are a possibility. The 
progressive nature of these incoming showers with the front should 
keep any flash flooding threat at bay, however, localized rainfall 
totals of around an inch cannot be ruled out in any convective 
showers that develop. MUCAPE around 500 J/kg this afternoon is 
indicative of some marginal instability that could lead to some
embedded thunderstorms/convective showers.

Colder and drier air is left in the front's wake, reinforced by 
breezy W to NW winds starting this afternoon. Gusts to 30 MPH are a 
possibility post-front, particularly towards the Cape and Islands. 
Elsewhere, gusts to 25 MPH can be expected. Showers may be mixed 
with some snow in the higher elevations of western MA as this colder 
airmass takes hold, but any accumulations more than a coating at 
most are not expected at this time. Lows tonight will likely fall to 
the upper 20s, while more urban areas, the Cape and Islands, and the 
CT Valley can expect lows in the mid to upper 30s.

KEY MESSAGE 2...Cooler than normal Monday. Generally dry weather 
expected in the morning, then increased cloud cover and the chance 
for spotty showers moves in during the afternoon.

The upper level trough settles overhead Monday, and with it, an 
unseasonably cold airmass moves in. 925 mb temperatures fall below 
0C during the day, then further to -5C heading into the overnight 
hours. Breezy W to NW winds continue, and highs may not climb out of 
the upper 40s and low 50s. Winds will start to diminish as high 
pressure approaches from the west, and lows Monday night may fall 
into the 20s for much of southern New England, aside from the 
coastal areas where 30s can be expected. Even with approaching high 
pressure, guidance has continued to indicate a weak low pressure 
moving into the region Monday that would bring increased clouds and 
scattered showers. Across different guidance suites, high res and 
global scale models have continued to trend towards scattered 
showers popping up in the afternoon hours. Some spatial and temporal 
discrepancies do still exist, but latest trends indicate the chance 
for these showers starting out in the interior by the late 
morning/early afternoon hours, then moving east through the day. 
Showers would then be expected out in eastern MA by the late 
afternoon/evening hours if this trend holds. Outside of system, 
incoming high pressure should keep the region dry for much of the 
start of the week. 

KEY MESSAGE 3...Seasonable temperatures Wednesday, then another
cold front arrives.

Some showers are a possibility once again heading into Wednesday as 
another shortwave approaches, but more seasonable temperatures make 
a return as the trough from early in the week exits. 925 mb 
temperatures recover to around 5C, supporting more seasonable highs 
in the upper 50s/low 60s. NW flow makes a return towards 
Thursday/Friday in the wake of another front passing through 
sometime late Wednesday, and high pressure builds back in as ridging 
approaches, which should keep the region dry. Discrepancies 
regarding the placement of the edge of the trough over northern 
New England and parts of eastern Canada may also affect how far 
east the warmer temperatures aloft make it for the second half 
of the week. These would likely, in turn, affect highs later in 
the week. High pressure returns going into Friday as a ridge 
approaches, but guidance is hinting at another approaching 
disturbance in the Great Lakes region towards the end of the 
week that could bring increased rain chances.

&&

.AVIATION /08Z SUNDAY THROUGH THURSDAY/...
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. 

IFR/LIFR CIGS will continue through the early morning today
along with areas of fog, especially over the Cape and Islands.
Winds SE/S 5-10 knots.

Sunday...Moderate Confidence.

IFR/LIFR through the early morning hours with areas of mist or 
drizzle. Locally dense fog possible across Cape Cod and Islands 
through mid-morning. Cold front brings widespread RA from west 
to east, 12z-15z, SW winds around 10 knots, becoming W/NW and 
increasing to 10-15 knots with gusts 20-30 knots post-frontal 
passage. Highest gusts possible over Cape and Island terminals.

Sunday Night...High Confidence.

VFR. Diminishing wind gusts. W wind 5-10 knots. 

Monday...High Confidence.

VFR. Scattered SHRA possible, but VFR conditions expected to
continue. W winds sustained up to 10 kt shifting more NW later 
in the day.

KBOS Terminal... Moderate Confidence in TAF. IFR with periods 
of LIFR expected through this morning. Cigs down to 100 ft and 
visbys to 1/4SM cannot be ruled out, but confidence is lower at 
this time based on surrounding obs. Pockets of DZ also through 
early this morning. RA arrives 14z-16z, LLWS possible ahead of 
the cold front too. Wind shifts to the W/NW by 18z-20z with 
gusts 20-25 knots. Becoming VFR overnight.

KBDL Terminal... Moderate Confidence in TAF. Periods of IFR
visbys possible this morning; included in form of TEMPO.

Outlook /Monday Night through Thursday/...

Monday Night: VFR. Breezy. 

Tuesday: VFR. 

Tuesday Night: Mainly VFR, with local MVFR possible. Slight
chance SHRA.

Wednesday: Mainly VFR, with areas MVFR possible. 

Wednesday Night through Thursday: VFR.

&&

.MARINE...
Forecaster Confidence Levels...

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

Through Sunday Night: High Confidence.

Strong cold front today brings SCA conditions and rain, seas 
3-5 feet, and W-NW gust up to 30 knots for most of the waters 
this evening into early Monday morning. Winds shift NW and ease 
following this frontal passage late tonight. Winds shift W over 
the southern waters and more S over the eastern/northern waters 
Monday and fall to 10-15 knots. Seas also fall to 2-3 ft.

Outlook /Monday Night through Thursday/...

Monday Night: Winds less than 25 kt. Slight chance of rain
showers. 

Tuesday: Winds less than 25 kt. 

Tuesday Night: Winds less than 25 kt. Slight chance of 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. Seas locally
approaching 5 ft. 

Thursday: Winds less than 25 kt.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...None.
RI...None.
MARINE...Small Craft Advisory from 4 PM this afternoon to 8 PM EDT this 
     evening for ANZ230>232-250-251.
     Small Craft Advisory from 11 AM this morning to 6 PM EDT this 
     evening for ANZ235-237.
     Small Craft Advisory from 11 AM this morning to 11 PM EDT this 
     evening for ANZ254>256.

&&

$$

DISCUSSION...Hrencecin
AVIATION...Hrencecin
MARINE...Hrencecin