Lexington Weather

Lexington, Massachusetts, USA

43°F
11/4/2024 10:13am 
  • Lexington Conditions: Few Clouds
  • Temperature: 43.2°F / 6.2°CWarmer 2.9°F than last hour.
  • Dew Point: 31.5°FIncreased 0.9°Fsince last hour.
  • Relative Humidity: 63%Decreased 5.0% 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 291105
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
705 AM EDT Tue Oct 29 2024

.SYNOPSIS...
Looking at a period of below normal temperatures this morning. 
A warm front today will bring increasing clouds and light 
rainfall to the region. Warming up for Wednesday then near 
record warmth Thursday before a cold front will bring 
temperatures back into the 50s for the weekend. Light rain 
showers are possible Friday with dry and sunny conditions 
returning for the weekend.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
The core of surface high pressure shifts east of the region today 
and winds will turn southerly as a warm front begins to make its way 
north across southern New England. The biggest impact of this front 
today will be an increase in cloudcover starting early, then rain 
chances overspreading the region from west to east in the afternoon 
(western MA/CT) and late evening (eastern MA). Along with forcing 
for ascent from the warm advection, a 30-35 kt LLJ develops 
overhead; these together will act on a 1.25+ inch PWAT plume leading 
to widespread light rain showers as we go into the overnight hours. 
The warm advection will also lead to slightly warmer temperatures 
today compared with yesterday, in the upper 50s.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/...
Tonight rain showers continue, exiting western areas before sunrise 
but may linger into the early morning hours for extreme eastern MA. 
Rainfall amounts are not expected to be significant in the face of 
our abnormally dry stretch, especially for areas further south. The 
highest rainfall amounts (some guidance suggesting as much as a 
quarter inch or more) is more likely in northern MA in closer 
proximity to better forcing. Ensemble guidance indicates a 90%+ 
chance of at least a tenth of an inch of rain in northern MA while 
southern MA and RI is at a 40-50% chance. Winds will be breezy 
overnight, especially over the waters as that LLJ passes overhead. 

Wednesday a few showers linger in the morning but as mid level 
ridging builds back in so does drier air. W/SW winds will advect in 
a much warmer airmass with 850 mb temps climbing from +1C on Tuesday 
to +14C on Wednesday! This translates to a much above average day, 
with highs in the mid 70s.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
Key Points

* Well above normal to record high warmth Thursday

* Elevated fire weather concerns continue with abnormally dry 
  conditions

* Cold front could bring light showers Friday with much colder 
  temperatures by Saturday

Thursday

Despite the flattening upper level ridge on Thursday, 850mb temps 
rise to +12C to +13C on with strong WSW winds. With mostly sunny 
skies in place, High temperatures across the region will sore to 
near record high values in the upper 70s to low 80s. Not out of the 
question that typical warm spots like Bradley and Norwood reach the 
mid 80s. With SSW winds, Thursday could even feature closer to 
summer like dewpoints in the upper 50s to low 60s. However, I think 
guidance may be a bit bullish on dewpoints as mixing will help bring 
more dry air down then current global guidance is indicating. BUFKIT 
soundings show dewpoints dropping from 50F at 925mb to 32F around 
900mb. If temps are able to top 80F, mixing above 900mb becomes more 
likely, pulling down very dry air from aloft. Winds above 900mb look 
to be near 40mph, but its unlikely to see gusts that high mix down 
the surface. Winds in the middle of the boundary layer are closer to 
20mph which is more likely to be observed at the surface. With the 
continued abnormally dry conditions, expect elevated fire weather 
conditions to continue on Thursday.

Friday

A cold front and trailing shortwave crosses the region Friday which 
could bring some scattered showers to the region. Moisutre looks 
limited again with the cold frontal passage and a soaking rain is 
looking is unlikely. Some of the global deterministic guidance even 
pitch a shut out for all of SNE. Any rain that does fall will likely 
be light under a tenth of an inch. Temps do moderate into the low to 
mid 70s with the passage of the first cold front. Winds turn west 
behind the front and remain gusty at 20-30mph. Depending on how the 
precip forecast evolves through the week, elevated fire weather 
conditions would persist with a drier forecast.

Saturday and Sunday.

A secondary cold front and reinforcing shot of cold air bring temps 
back down into the 50s. Upper level ridge and surface high pressure 
build back in, bringing dry conditions and mostly sunny skies. Winds 
quickly die down and become light northerly on Saturday, flipping to 
light SSW again on Sunday.

Early next week:

Forecast confidence breaks down significantly by Monday with large 
phase differences in the global deterministic guidance. The general 
trend however looks to be near normal temperatures and possibly more 
chances at some beneficial rainfall.

&&

.AVIATION /11Z TUESDAY THROUGH SATURDAY/...
Forecast Confidence Levels:

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

12Z update...

Today...High Confidence. 

VFR/MVFR to start, lowering to MVFR during the late afternoon 
and evening ahead of an approaching warm front. South/southeast 
winds 7 to 10 knots.

Tonight...Moderate Confidence. 

MVFR to IFR. -SHRA moves in from west to east after 00z in 
western areas, while the eastern coast 03z. South winds around 
10 knots, may have gusts near 20 knots along the coast. 

Wednesday...High Confidence. 

VFR. Breezy SW winds. SHRA chances early morning on east coast
terminals before exiting east. 

KBOS TAF...High Confidence in TAF.

KBDL TAF...High Confidence in TAF.

Outlook / Wednesday Night through Friday/

Wednesday Night through Thursday: VFR. Breezy. 

Thursday Night through Friday: VFR. Breezy. Chance SHRA.

Friday Night through Saturday: VFR. Breezy.

&&

.MARINE...
Forecaster Confidence Levels:

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

Through Tuesday...High confidence.

Today: 

High pressure then remains over the waters with winds less than
25 kts and waves 2-4 ft. 

Tonight: 

Small Craft conditions develop tonight in the outer waters. 
Winds increase with gusts 20-30 kts and waves 4-6 ft.

Wednesday:

Small craft conditions come to an end through the day. SW winds
15-20 kt. 

Outlook /Wednesday Night through Saturday/...

Wednesday Night through Thursday: Winds less than 25 kt. Areas
of seas approaching 5 ft. 

Thursday Night: Moderate risk for Small Craft Advisory winds
with gusts up to 25 kt. Local rough seas. Slight chance of rain
showers. 

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

Friday Night: Low risk for Small Craft Advisory winds with
gusts up to 25 kt. Local rough seas. Slight chance of rain
showers. 

Saturday: Winds less than 25 kt. Local rough seas.

&&

.FIRE WEATHER...
* SPS for Elevated Fire Weather Concerns Continues Today

State Fire Weather Partners requested the continuation of a 
Special Weather Statement for elevated fire weather concerns today.
There are numerous active brush fires are burning across 
southern New England. 

Cooler temperatures continue for today with highs in the 50s to
near 60F in the lower Connecticut River Valley. Dewpoints 
increased slightly, raising the minimum values of relative 
humidity between 45 percent and 65 percent for this afternoon. 
Wind direction are south/southeast 10 to 15 mph with gusts 20 to
25 mph.

&&

.CLIMATE...
Maximum Record High Temperatures: October, 30th

BOS: 78F (1918)
ORH: 78F (1946)
PVD: 79F (1946)
BDL: 83F (1946)

Maximum Record High Temperatures: October, 31st

BOS: 81F (1946) 
ORH: 79F (1946) 
PVD: 83F (1946) 
BDL: 82F (1946)

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...None.
RI...None.
MARINE...Small Craft Advisory from 8 PM this evening to 8 AM EDT 
     Wednesday for ANZ235-237.
     Small Craft Advisory from midnight tonight to 5 PM EDT 
     Wednesday for ANZ250-254.
     Small Craft Advisory from 8 PM this evening to 2 PM EDT 
     Wednesday for ANZ255-256.

&&

$$

SYNOPSIS...BW/KP
NEAR TERM...BW
SHORT TERM...BW
LONG TERM...KP
AVIATION...BW/KP
MARINE...BW/KP
FIRE WEATHER...BW/KP
CLIMATE...Dooley
      

Other recent Area Forecast Discussions

Mon Nov 4, 6:14am EST

Mon Nov 4, 2:36am EST

Sun Nov 3, 11:59pm EST

Sun Nov 3, 9:53pm EST

Sun Nov 3, 6:52pm EST

Sun Nov 3, 4:18pm EST

Sun Nov 3, 1:20pm EST

Sun Nov 3, 10:36am EST

Sun Nov 3, 6:00am EST

Sun Nov 3, 2:12am EST

Sat Nov 2, 9:33pm EDT

Sat Nov 2, 7:40pm EDT

Sat Nov 2, 3:42pm EDT

Sat Nov 2, 1:49pm EDT

Sat Nov 2, 11:15am EDT

Sat Nov 2, 6:52am EDT

Sat Nov 2, 3:27am EDT

Fri Nov 1, 9:40pm EDT

Fri Nov 1, 7:25pm EDT

Fri Nov 1, 3:22pm EDT

Fri Nov 1, 1:32pm EDT

Fri Nov 1, 9:20am EDT

Fri Nov 1, 6:53am EDT

Fri Nov 1, 2:54am EDT

Thu Oct 31, 9:38pm EDT

Thu Oct 31, 7:21pm EDT

Thu Oct 31, 3:09pm EDT

Thu Oct 31, 1:16pm EDT

Thu Oct 31, 8:58am EDT

Thu Oct 31, 6:47am EDT

Thu Oct 31, 2:40am EDT

Wed Oct 30, 9:25pm EDT

Wed Oct 30, 7:22pm EDT

Wed Oct 30, 3:50pm EDT

Wed Oct 30, 3:21pm EDT

Wed Oct 30, 1:30pm EDT

Wed Oct 30, 9:42am EDT

Wed Oct 30, 7:14am EDT

Wed Oct 30, 2:11am EDT

Tue Oct 29, 9:51pm EDT

Tue Oct 29, 7:32pm EDT

Tue Oct 29, 3:38pm EDT

Tue Oct 29, 1:59pm EDT

Tue Oct 29, 10:54am EDT

Tue Oct 29, 3:04am EDT

Tue Oct 29, 1:31am EDT

Mon Oct 28, 9:29pm EDT

Mon Oct 28, 7:30pm EDT

Mon Oct 28, 3:49pm EDT

Mon Oct 28, 2:08pm EDT