Lexington Weather

Lexington, Massachusetts, USA

43°F
11/4/2024 10:19am 
  • Lexington Conditions: Mostly cloudy
  • Temperature: 43.2°F / 6.2°CWarmer 2.6°F than last hour.
  • Dew Point: 31.8°FIncreased 1.2°Fsince last hour.
  • Relative Humidity: 64%Decreased 3.0% since last hour.
  • Wind: Calm, 10-min avg: Calm, gust: None
  • Barometer: 30.53 in Steady
  • Visibility: 10 miles
  • 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 040459
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
1159 PM EST Sun Nov 3 2024

.SYNOPSIS...
High pressure will continue to govern our weather pattern this 
weekend bringing dry weather and cooler than normal temperatures. 
Above normal temperatures expected Tuesday and Wednesday with windy 
conditions. A cold front moves through by Thursday with a few 
showers/sprinkles possible Wednesday night. Cooler, but still 
slightly above normal temperatures Thursday and Friday.

&&

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
10 PM Update:

No major changes made to the forecast overnight. Some of the
HREF members indicate a low chance for showers or snow showers 
in the high terrain early tomorrow morning. If any rain or snow 
does fall, it will be very light, likely not accumulating more 
then a trace. 

Previous discussion.

Center of strong 1034 mb high pressure area was located near Ottawa 
ON this afternoon, bringing continued dry weather and light 
northerly to northeast winds. Temperatures were seasonable in the 
mid 40s to lower 50s under mostly clear skies, although there was 
still some continued stratocumulus over the South Shore, Cape and 
Islands. 

High pressure will continue to move southeast into interior Southern 
New England tonight. With clear skies, light winds and a very dry 
airmass favoring optimal radiational cooling, strong falls in hourly 
temps are expected after sundown. Though we will see an increasing 
coverage of high clouds from west to east tonight, it shouldn't 
permit strong cooling overnight. Looking at a chilly night with lows 
in the upper teens to lower 20s in northwest MA, the low to mid 20s 
around eastern CT, around I-495 in eastern MA, with mid 30s for the 
cities, Cape and Islands.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
415 PM Update:

Monday: 

High pressure moves off the coast early on Mon, which will allow for 
a southeast to southerly flow to return to the region. Unlike the 
past several days where sunny skies have predominated, Mon looks to 
feature filtered sun at best with a canopy of mid to high clouds, 
although most areas should trend toward overcast by sundown. The 
modest southerly winds will also bring an increase in dewpoint temps 
back into the 30s to low 40s from north to south. Highs in the lower 
to mid 50s. 

Monday Night: 

A warm front will be passing to our north on Mon evening. While the 
best chance for rain passes well to our north Mon night, it will 
bring overcast skies along with southerly winds around 10 mph. 925-
850 mb temps also steadily warm to around +8 to +10C in the face of 
strong warm advection. This is a scenario where low temperatures 
occur early in the night (in the lower to mid 40s), then rise into 
the upper 40s to the lower 50s.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
Tuesday and Wednesday: 

Tuesday, the upper level ridge axis shifts east of the region. 
Ridging weakens in response to an approaching shortwave trough to 
the west. A low level jet begins to shift into southern New England 
later in the day. With some mixing this will transport down breezier 
SW winds with gusts 20-30 mph in the afternoon. With a weak wave or 
two in the flow, ensemble guidance shows marginal moisture in the 
mid-levels. This will bring additional cloud cover and limit mixing 
heights to some extent. Weak warm air advection overnight into early 
Tuesday brings in warmer 850mb temperatures. This will support highs 
rising back into the 60s with even a shot at 70 in some spots. There 
is some uncertainty in the dewpoints. NBM has values in the mid-
upper 50s, but given a dry surface, values may trend slightly drier. 
Made some minor adjustments to dewpoints, mainly for MA (except SE 
MA). The low level jet positions across southern New England 
overnight into Wednesday morning. This should continue gusty winds 
over the waters bleeding into the Cape and Islands with elevated 
winds elsewhere overnight.

Similar conditions for Wednesday with breezy conditions. This is 
looking like another day of above normal temperatures, with highs 
potentially even a degree or two warmer than Tuesday. The GFS trends 
a bit warmer than the ECMWF for highs likely owing to better mixing. 
If it ends up better mixed and drier, combined with SW flow this 
would give some locations a shot at approaching some 
records...again. Highs will range in the upper 60s to low 70s, 
potentially mid 70s in some locations. 

A weak shortwave moves through Wednesday evening; however, most 
guidance has leaned on the drier side with lacking upper level 
support. Can't rule out lower coverage/isolated showers or sprinkles 
early evening. 

Thursday and onward: 

A weak cold front moves through by Thursday. Flow aloft stays zonal 
with W/WNW flow. This will bring in a cooler airmass than the last 
few days; however, still a bit above normal overall. Highs range in 
the 60s. 

Ensemble guidance indicates another system dropping south from 
Canada across northern Maine. Still fuzzy in the details such as 
timing, but it there is a consensus that it will be lacking 
moisture. 

For the weekend, ensemble guidance shows a general consensus with an 
upper low exiting the Intermountain west and a weak ridge settled 
just south of southern New England. Ensemble means lift it across 
the Great Lakes while bringing a plume of elevated moisture with it. 
Plenty of uncertainty this far out, but we'll keep monitoring it for 
a chance at rainfall to the region.

&&

.AVIATION /04Z MONDAY THROUGH FRIDAY/...
Forecast Confidence Levels:

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

06Z TAF Update:

Rest of Tonight: High confidence. 

VFR. Calm or light and variable winds.

Monday: High confidence. 

VFR. Mainly light winds starting east, then turning south in the
afternoon. Winds less then 10 knots.  

Monday Night: Moderate confidence. 

VFR becoming MVFR after 03z. Winds begin to pick up from the
south at 5-10 knots inland, and 10-15 knots near the waters.

Tuesday: Moderate Confidence

MVFR in the morning, turning VFR in the afternoon. MVFR may
linger into Monday evening across the Cape and Islands. SW 
winds at around 10-15 knots, gusting to 20 knots.

KBOS TAF...High confidence in TAF. 

VFR today with winds turning to the east in the morning, then 
to the south in the afternoon. MVFR CIGS move in tonight.

KBDL TAF...High confidence in TAF. 

VFR with light easterly winds this morning, turning south in the
afternoon. MVFR CIGS likely tonight. 

Outlook /Monday Night through Thursday/

Tuesday: Mainly VFR, with local MVFR possible. Breezy. 

Tuesday Night through Wednesday Night: Mainly VFR, with areas
MVFR possible. Breezy. Slight chance RA.

Thursday through Thursday Night: Mainly VFR, with areas MVFR
possible. Slight chance RA.

Friday: Breezy. Slight chance RA.

&&

.MARINE...
Forecaster Confidence Levels:

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

Tranquil marine weather conditions are expected through Monday
under strong high pressure. Light northeast winds tonight become
SE to S on Monday with speeds around 5-10 kt. Seas 3 ft or less
on all waters. Dry weather is expected.

For Monday night...southerly winds increase to around 10-15 kt
with gusts to 20 kt. Dry weather still expected.

Outlook /Tuesday through Friday/...

Tuesday: Low risk for Small Craft Advisory winds with gusts up
to 25 kt. Areas of seas approaching 5 ft. 

Tuesday Night: Moderate risk for Small Craft Advisory winds
with gusts up to 30 kt. Seas up to 5 ft. Slight chance of rain.

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

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

Thursday through Thursday Night: Winds less than 25 kt. Chance
of rain. 

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

&&

.FIRE WEATHER...
415 PM Update:

The protracted stretch of dry weather will continue to lead to 
elevated concerns for wildfire development until we can get a 
substantial wetting rain event. Relative humidities should range 
around 30 percent today with light north winds.

With a lack of significant rain expected over the next several days, 
Special Weather Statements are likely to be needed through next week 
coinciding with periods where winds are on the light side. 
Consideration will be given toward red flag headlines to highlight a 
greater threat for wildfire development and spread when and where 
there are sufficiently strong enough winds. Tuesday and Wednesday 
could meet that criterion pending wind speeds, but those decisions 
will be coordinated beforehand with our state fire weather
partners.

&&

.CLIMATE...
Previous Record highs for Wednesday, November 6th
 
Boston: 76F set in 2022 
Hartford: 76F set in 2022 
Providence: 75F set in 2022 
Worcester: 72F set in 2022

&&

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

&&

$$

SYNOPSIS...Loconto/Mensch
NEAR TERM...Loconto/KP
SHORT TERM...Loconto
LONG TERM...Mensch
AVIATION...Loconto/Mensch/KP
MARINE...Loconto/Mensch
FIRE WEATHER...Loconto/Mensch
CLIMATE...
      

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