Lexington Weather

Lexington, Massachusetts, USA

42°F

4/19/2026 6:19pm

Lexington Conditions: Rain, Mist, Overcast
Temperature: 41.5°F / 5.3°C
Dew Point: 39.7°F
Relative Humidity: 93%
Wind: NNW Calm, 10-min avg: 1 mph, gust: 5 mph
Barometer: 29.81 in Rising Slowly
Visibility: 5 miles
Rain Today: 0.08 in

Area Forecast Discussion
for Boston / Norton, MA

        
000
FXUS61 KBOX 140000
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
800 PM EDT Mon Apr 13 2026

.WHAT HAS CHANGED...
No significant changes.

&&

.KEY MESSAGES...

- Summerlike warmth Tue and Wed away from the coast with scattered
  thunderstorms and a low risk of severe weather.

- Backdoor front may bring cooler temperatures Thu-Sat, especially
  in eastern MA, but uncertainty is high in exactly where it ends up.

- More seasonable temperatures early next week.

&&

.DISCUSSION...
KEY MESSAGE 1...Summerlike warmth Tue and Wed away from the coast 
with scattered thunderstorms and a low risk of severe weather. 

Confidence remains high in summerlike warmth Tue and Wed away from 
both coasts as a strong upper level ridge builds over region from 
Gulf. Highs both days should easily reach lower 80s inland while 
onshore flow keeps immediate coastal areas in 50s to around 60. We 
also need to watch a backdoor front lurking close to northeast MA 
which could bring cooler temperatures there as well, perhaps into 
the 40s or lower 50s, but right now it seems like that front 
should stay to the north until sometime Wed night or Thu.

One thing we are monitoring is the potential for severe storms 
during afternoon and evening both Tue and Wed, mainly from 2 PM to 
10 PM. Trough axis near eastern Great Lakes should provide 
sufficient lift to generate scattered showers and thunderstorms to 
our west both days, and some of this activity could survive the trip 
into interior southern New England given warm airmass in place and 
more importantly strong westerly flow aloft.

Tue actually looks to be the more interesting day with greatest 
potential for severe storms roughly along and west of I-91. Guidance 
shows decent instability (1000-1500 J/kg) Tue afternoon along with 
rather impressive mid level lapse rates (6-7 C/km) that we don't see 
too often here and sufficient 0-6km shear of 35-40kt. This may be 
enough to bring storms into southern New England during the 
afternoon and evening with localized wind damage and hail being the 
main threats. Note both 3km NAM and RRFS are fairly aggressive in 
depicting a small line of storms moving SE across interior Tue 
afternoon, though HREF updraft helicities are focused more in 
western New England and lightning probabilities are in that area as 
well. However, CSU machine learning guidance does highlight much of 
interior southern New England with a low severe potential.

Environment still looks favorable for thunderstorms on Wed though 
several of the high-res models don't show much in way of activity. 
CSU and SPC HREF expand the low severe risk into more of southern 
New England, with guidance showing decent instability across more of 
southern New England (focused north and west of I-95 in CT, RI, and 
MA) with continued strong 0-6km shear (40-50kt) and better low level 
moisture (dewpoints into lower 60s). Mid level lapse rates are more 
marginal however (5-6 C/km) but that could be overcome with 
sufficient instability. While overall severe threat remains low (and 
higher to west of New England) we can't rule out a few storms 
capable of producing localized wind damage or hail. 


KEY MESSAGE 2...Backdoor front may bring cooler temperatures Thu-
Sat, especially in eastern MA, but uncertainty is high in exactly 
where is ends up.

Forecast becomes more uncertain later this week as we deal with 
another backdoor front potentially dropping south across New 
England. Details will need to be worked out regarding how far south 
and exactly how quickly the front will be able to push southward.
 
Typically these fronts end up somewhere from central MA into RI, 
with summerlike temperatures continuing to its south (Hartford) and 
much cooler temperatures to the north and east. For now we are 
basing forecast on a model blend which helps iron out some of the 
uncertainty, but getting more into time window for higher resolution 
models will help refine forecast in coming days. Certainly potential 
for big temperature busts this far out in time.


KEY MESSAGE 3...More seasonable temperatures early next week.

A stronger cold front is expected to cross region sometime Sun, 
accompanied by some showers. Much cooler airmass follows behind 
front early next week with temperatures returning to more typical 
levels for mid April, generally in 50s to around 60.

&&

.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
Forecaster Confidence Levels...

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

00z TAF Update: 

Tonight...High Confidence. 

VFR conditions for most. IFR possible for Cape/Island terminals
before clearing to VFR by 04Z. Periods of fog possible for
Cape/Islands 08-12Z. SW winds with gusts diminishing. Gusts 
25-30kts possible through 03Z for Cape/Islands along with LLWS 
due to 020 winds 230/50-60kt.

Tuesday...High confidence overall. Moderate for storm chances.

VFR with S/SW winds and coastal sea breezes 8-12 kts. Scattered
showers and thunderstorms are possible during the afternoon and
evening (20-00Z), especially across interior southern New 
England. Included in TAF as light to moderate showers for 
east/central terminals for now due to lower confidence in 
thunderstorm chances/location. PROB30 included for -TSRA for BDL
because it is further west (greater risk for tstorms). Brief 
MVFR possible in any moderate showers or thunderstorms. Winds
should most likely lean more SW at 10-15 kts, gusts to 22 kts 
in the shower/storm timeframe. Locally higher/erratic gusts in
any thunderstorms. 

KBOS Terminal...High confidence in TAF.

KBDL Terminal...High confidence in TAF.

Outlook /Wednesday through Saturday/...

Wednesday: VFR. Breezy. Chance SHRA, slight chance TSRA.

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

Thursday: VFR. Chance SHRA.

Thursday Night: VFR. Slight chance SHRA.

Friday: VFR. Chance SHRA, slight chance TSRA.

Friday Night: VFR. Slight chance SHRA.

Saturday: Mainly VFR, with local MVFR possible. 

&&

.MARINE...
Forecaster Confidence Levels...

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

High confidence through the end of the week.

Fairly strong low level jet will bring frequent 30kt gusts to the 
waters through the evening with some 35kt gusts likely around Cape 
Cod and Islands. Maintaining current headlines of SCA and Gale 
Warnings as a result.

Winds and seas gradually diminish tonight and especially Tue and Wed 
when local sea breezes are expected near shore. 

The other concern is for areas of fog developing this afternoon and 
persisting early tonight on south coastal waters due to mild SW 
winds over colder ocean waters.

Outlook /Wednesday through Saturday/...

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. Chance of rain showers, slight chance of
thunderstorms. 

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

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

Saturday: Winds less than 25 kt. 

&&

.CLIMATE...
Upcoming record highs:

Tue 4/14
Boston 83 in 2023
Hartford 96 in 2023
Providence 87 in 2023
Worcester 90 in 2023

Wed 4/15
Boston 82 in 1896
Hartford 88 in 1941
Providence 82 in 1938
Worcester 85 in 1941

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...None.
RI...None.
MARINE...Small Craft Advisory until 8 PM EDT this evening for ANZ230-
     236.
     Small Craft Advisory until 11 AM EDT Tuesday for ANZ235-237.
     Small Craft Advisory until 2 AM EDT Tuesday for ANZ250-251.
     Small Craft Advisory until 2 PM EDT Tuesday for ANZ254>256.

&&

$$

DISCUSSION...JWD
AVIATION...Mensch/JWD
MARINE...JWD
CLIMATE...JWD