Lexington Weather

Lexington, Massachusetts, USA

54°F

11/10/2025 2:31am

Lexington Conditions: Fog, Overcast
Temperature: 54.0°F / 12.2°C
Dew Point: 52.9°F
Relative Humidity: 96%
Wind: Calm, 10-min avg: Calm, gust: None
Barometer: 29.62 in Falling Slowly
Visibility: ¼ mile
Rain Today: 0.00 in

Southeast Middlesex County, MA - Special Weather Statement
- SEE ALL NEARBY ALERTS -

Area Forecast Discussion
for Boston / Norton, MA

        
000
FXUS61 KBOX 051117
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
617 AM EST Wed Nov 5 2025

.SYNOPSIS...
Dry and seasonably mild conditions today with increasing SW 
winds, then a strong cold front generates fast-moving gusty 
showers and possibly thunderstorms this evening. Behind the 
front strong to damaging wind gusts will develop late this 
evening and overnight gradually diminishing during Thursday. 
High pressure builds into the region Thursday night and moves 
offshore Friday. Weather pattern turns unsettled next weekend as
a series of frontal systems move through, followed by blustery 
and colder weather early next week.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
300 AM Update:

Key Messages: 

* Mostly clear to start. While dry weather prevails, turning
  overcast with canopy of mid-level cloud cover by late morning.

* SWly breezes to around 20-25 mph today. Seasonable temps in
  the 50s, near 60 in some spots.

Details:

Ridge of sfc high pressure is in place over Southern New England 
early this morning, with initially clear skies and a modest SW wind. 
Current temps varied pretty widely but were as low as the low 30s in 
interior Southern New England but in the mid 40s for eastern 
MA/coastal areas where SW winds were around 5-10 mph. To our west, 
infrared satellite was showing considerable midlevel cloud cover 
over central and southern NY associated with midlevel moist 
advection in a belt of fast westerly flow aloft, extending out well 
ahead of an organizing low pressure area over WI. 

Dry weather is expected today, but conditions should trend overcast 
by the mid-morning to noontime period as this midlevel moisture 
advects eastward into our area. This will allow for slow diurnal 
warming. A steadily-tightening southwest pressure gradient will also 
permit increasing southwest breezes, with shallow mixing allowing 
for gusts in the 20-25 mph range as we move into the aftn. Highs in 
the 50s today, but a few areas in CT-RI-SE MA could still see 
temps near 60 degrees.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/...
230 AM Update:

Key Messages: 

* Fast-moving line of gusty showers and embedded thunderstorms 
  capable of isolated/sporadic wind damage between 7 pm to midnight 
  from the Berkshires to the east coast. 

* Drying out after midnight, but with a period of strong to damaging 
  northwest wind gusts in the 55 to 60 mph range for overnight into 
  early Thurs AM. Downed trees and powerlines in scattered instances 
  with this period of northwest winds. 

* Sunny and still windy for Thursday, but gusts to steadily decrease 
  after mid-morning Thursday. Highs in the 40s to mid 50s, though 
  winds will make it feel colder than that.

Details: 

Potent mid/upper level shortwave with associated strengthening 
sfc frontal wave will be moving through the Gt Lakes, northern 
New England and offshore tonight and overnight. Its passage 
through the Northeast will bring a couple of anticipated hazards
to Southern New England: the first being a fast-moving line of 
low- topped convective showers/embedded thunderstorms through 
midnight in lockstep with a strong cold frontal passage, and 
then a period of post-frontal strong to damaging northwest wind 
gusts for the overnight to early Thurs AM hours. 

Model guidance trends from the overnight suite drove wind- 
headline changes. Compared to the last 24-hours worth of 
guidance, the post-frontal northwest wind gusts doesn't look 
quite as robust with slightly-less amplification to the sfc low,
and speeds at the top of the mixed layer being about 5-kt 
lower. Weighing that trend, I only felt sufficiently confident 
enough to convert the standing High Wind Watch over to High Wind
Warnings for the east slopes of the Berkshires and the Cape and
Islands, where post-cold-frontal northwest wind gusts up to 60 
mph are expected. For the rest of Southern New England, the high
wind watch was maintained given the slightly less-robust trend 
from overnight. Later shifts today will need to make a decision 
on the status of the remaining High Wind Watch pending the 
incoming 12z guidance. That still allows for sufficient lead-
time. Without question, some headline will be needed to address 
the strong northwest winds. 

1/ Cold Frontal Gusty Showers/Thunder Before Midnight 

Pretty classic strongly-forced, high-shear but very low instability 
convective pre-frontal setting tonight thru midnight. Convective-
permitting models continue to show a broken line or clusters of 
gusty convective elements. Not much instability to really speak of 
with CAPE values around 200 J/kg or less, but model soundings show 
enough CAPE around -10C to support a risk for lightning in some of 
the cells. In addition, Southern New England looks primed for added 
kinematic support placed in the poleward exit region of an 
impressive 120-kt jetstreak at 500 mb, similar to the event which 
happened Monday night. While no two events are truly ever 100 
percent matches, some of the main synoptic features (digging 
shortwave, diffuent flow aloft) also bear some similarities to an 
early-October 2020 high shear low CAPE thunderstorm event as well, 
though that took place more during the later-afternoon hours. 

Timing this threat looks to be around the 7 pm to midnight timeframe 
from the Berkshires eastward to the coast. It's also worth noting 
that these gusty showers/storms are likely to be hauling eastward, 
given 50-55 kt storm motion vectors. It wouldn't entirely shock me 
if we do hear of sporadic wind damage associated with these 
showers/t-storms, before the northwest winds really pick up for 
the overnight. SPC maintains low probabilities for severe 
weather conveyed by a marginal risk of severe weather. 

2/ Strong to Damaging Winds Overnight to Early Thursday

We then get into the strong cold advection period after the cold 
front works its way offshore, which will help to steepen lapse rates 
overnight. Working in concert with 6-8 mb per 6 hr pressure rises, a 
period of strong to damaging winds are still expected. With a 60-65 
kt NW jet at 850 mb over the Berkshires, and then the Cape and 
Islands as the low starts to really amplify towards the wee hours of 
the morning, felt high wind criterion would be most likely to be met 
for those areas, peak gusts for these areas have the potential to 
reach 60 mph. Elsewhere, with 55-60 kt at 850 mb, felt gusts could 
be close enough to advisory level (50 to 55 mph) to wait another 
model cycle before making changes to the Watch. The period of 
strongest gusts also just takes place for a handful of hours, 
before the jet starts to weaken/pull eastward into early 
Thursday morning. 

Thursday itself still ends up being a rather windy day with full sun 
allowing for a continued deepening mixed layer, but northwest wind 
gusts more clock in around 25-40 mph in gusts. Note that daytime 
highs in the mid 40s to low 50s, which will feel even colder given 
the winds, with wind chills around the freezing mark for the higher 
terrain during the day.

&&

.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
Key Messages:

* Initially zonal and progressive pattern becomes increasingly 
  amplified by early next week.

* Multiple chances of precipitation with bouts of drier weather in 
  between.

* Above average temperatures to end the week, potential for 
  significantly cooler conditions early next week.

The theme of the long term forecast will be for the upper air 
pattern to progress from a zonal regime late this week into a more 
meridional and amplified regime early next week. In terms of 
sensible weather impacts, this evolution will lead to a period of 
changeable weather Fri-Sun followed by much cooler conditions early 
next week. 

Expecting a cold night Thursday behind a deepening northern stream 
system. NBM shows rapid clearing and decreasing winds allowing for 
lows to fall below freezing outside of the Cape and Islands. Cool 
spots in the higher terrain may even fall into the mid and lower 20s 
by early Friday morning. Strong return flow behind a quick moving 
area of high pressure warms 850 mb temps from -negative 3-5C Friday 
morning to +5-8C Friday evening. This sharp increase in mid-level 
temperatures will translate 10-15 degree warmer low temps Friday 
night. Continued WAA brings increasing cloud cover and increasing 
POPs later Friday into Saturday. A slow-moving frontal boundary 
serves as the forcing mechanism for periods of rain on Saturday as 
PWATS increase to 1.5-2 STD above climo. Not seeing too much of a 
signal for excessive rainfall amongst the ensembles with the NBM 
showing 24hr precip totals generally below 1". 

Transient ridge of higher pressure makes a return again to dry the 
region out briefly Saturday night into Sunday. Attention then turns 
to a deepening and anomalous upper-level longwave trough over the 
eastern CONUS in response to a building upper level ridge over the 
west. Guidance depicts an area of low pressure developing ahead of 
the trough on Sunday followed by a strong cold front later Sunday 
into Monday. We may see our first bonafide shot of colder air Monday 
and Tuesday of next week as guidance has 850s falling to as low as 
minus 10-15C. An early glimpse at forecast temperatures for next 
week shows highs struggling into the lower to mid 40s behind the 
front on Tuesday.

&&

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

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

12z TAF Update: 

Today: High confidence. 

VFR, with increasing mid-high clouds. Wind becoming SW 10-20 kt
in the afternoon, with gusts 25-30 kt developing along the 
south coast and Cape/Islands by late in the day.

Wednesday night: High confidence.

VFR-MVFR cigs with brief scattered showers and possibly an
isolated t-storm during the evening, then clearing overnight.
Wind shift to WNW 03-06z with cold front passage followed by 
strong wind gusts 45-55 kt. 

Thursday: High confidence. 

VFR. Gusty NW winds 30-40 kt early Thurs but decreasing trends
thru the day.

KBOS Terminal... High confidence. 

KBDL Terminal... High confidence.

Outlook /Thursday Night through Sunday/... 

Thursday Night through Friday: VFR. Breezy. 

Friday Night: MVFR/IFR conditions possible. Windy with local
gusts up to 30 kt. RA likely.

Saturday: Mainly VFR, with local MVFR possible. Breezy. Chance
RA.

Saturday Night: VFR. Slight chance RA.

Sunday: Mainly VFR, with local MVFR possible. Breezy. Chance
RA.

&&

.MARINE...
Forecaster Confidence Levels...

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

Key Messages:

* Increasing SW winds today reaching gale force over southern 
  waters toward evening.

* Possible line of gusty showers capable of lightning could
  prompt special marine warnings or marine weather statements
  late this evening.

* Widespread storm force winds overnight to early Thurs after 
  wind shift to W-NW. Gusts 50-60 kt. 

Storm warnings remain in effect for all waters. 

SW winds will be steadily increasing today to around 25 to 30
kt and trending toward gale force SW gusts late in the day
today. Dry weather prevails, although a line of gusty showers
with embedded lightning strikes associated with a strong cold
front later this evening could prompt MWSs/SMWs. 

Windshift to NW late tonight and overnight will bring a period 
of widespread storm-force gusts 50-60 kt into Thurs AM with 
building and rough seas in the 13-16 ft range. A gradual 
decrease in gusts into into the 35-40 kt range by Thurs aftn 
then trending toward 25-30 kt gusts by early evening.

Outlook /Thursday Night through Sunday/... 

Thursday Night: Low risk for Small Craft Advisory winds with
local gusts up to 30 kt. Local rough seas. 

Friday: Low risk for Small Craft Advisory winds with gusts up
to 30 kt. Seas locally approaching 5 ft. 

Friday Night: Strong winds with local gusts up to 30 kt. Areas
of rough seas. Rain likely. 

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

Saturday Night: Winds less than 25 kt. Local rough seas. Slight
chance of rain. 

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

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...High Wind Watch from this evening through Thursday morning for 
     CTZ002>004.
MA...High Wind Watch from this evening through Thursday morning for 
     MAZ003>007-010>021-026.
     High Wind Warning from 7 PM this evening to 8 AM EST Thursday 
     for MAZ002-008-009.
     High Wind Warning from 10 PM this evening to 8 AM EST Thursday 
     for MAZ022>024.
RI...High Wind Watch from this evening through Thursday morning for 
     RIZ001>008.
MARINE...Storm Warning from 10 PM this evening to 7 AM EST Thursday for 
     ANZ230-233>237.
     Storm Warning from 10 PM this evening to 10 AM EST Thursday 
     for ANZ231-232-250-251.
     Storm Warning from 7 PM this evening to 10 AM EST Thursday for 
     ANZ254-255.
     Storm Warning from 7 PM this evening to 7 AM EST Thursday for 
     ANZ256.

&&

$$

SYNOPSIS...Loconto/FT
NEAR TERM...Loconto
SHORT TERM...Loconto
LONG TERM...FT
AVIATION...Loconto/FT
MARINE...Loconto/FT