Lexington Weather

Lexington, Massachusetts, USA

38°F

4/25/2024 8:53am

Lexington Conditions: Clear
Temperature: 37.6°F / 3.1°C
Dew Point: 15.4°F
Relative Humidity: 40%
Wind: Calm, 10-min avg: Calm, gust: None
Barometer: 30.30 in Rising Slowly
Visibility: 10 miles
Rain Today: 0.00 in

Southeast Middlesex County, MA - Freeze Watch
- SEE ALL NEARBY ALERTS -

Area Forecast Discussion
for Boston / Norton, MA

        
000
FXUS61 KBOX 210447
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
1247 AM EDT Sun Apr 21 2024

.SYNOPSIS...

A ridge of high pressure will result in dry weather Sunday 
through Tuesday with mild days and cool nights, along with 
elevated fire weather potential. Unsettled, wet and cool on 
Wednesday. Turning drier late in the week.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...

915 PM Update...

* Clearing overnight with lows in the 30s to lower 40s 
* Areas of frost toward daybreak in normally coolest locales

The last of the showers were now confined to the Cape/Islands 
along the advancing cold front. There was even a few rumbles of 
thunder/graupel with this activity earlier near the south coast.
But this activity will exit the Cape/Islands in the next hour 
or so. As the wind shifts behind the front...the remaining low 
clouds/fog across the Cape/Islands will scour out over the next 
few hours.

Otherwise...a much drier west to northwest flow of air follows 
behind the cold front overnight. A brief surge of WNW 20-25 mph 
immediately behind the front will not last too long. The drier 
airmass followed by diminishing wind overnight will allow for 
overnight low temps near 30 across the normally coolest 
locations of western MA. The rest of the region should see 
overnight lows mainly between 35 and 40 with lower 40s in the 
Urban Heat Island of Boston and Nantucket. Patches of frost may 
also develop toward daybreak in some of the normally coolest 
low-lying locations.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM MONDAY/...

High pressure starts to build across southern New England
through Sunday night, providing dry weather. Expecting a period
of clouds Sunday afternoon and evening as a weak trough passes
by. This weak trough will also help generate gusty afternoon
west winds. Near to slightly below normal temperatures.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...

Highlights

* Very seasonable weather next week with daily high/low temps
  close to the climatological normal

* Rainy on Wednesday

Monday through Saturday

No anomalous or impactful weather is expected in the extended 
forecast for southern New England next week. The week begins 
with the region largely dominated by high pressure building in 
from the west. This should support a sunny/dry start to the week
with highs in the upper 50s/low 60s and lows in the upper 
30s/low 40s. The only active period of weather this week will be
on Wednesday when a modest short-wave disturbance aloft 
traverses over the region. Southerly flow ahead of this feature 
will increase the moisture over southern New England allowing 
for widespread stratiform precipitation during the day 
Wednesday. With neither forcing nor moisture forecast to reach 
impressive levels, the total rainfall accumulation with this 
system is expected to be modest with amounts likely between 0.1 
and 0.25 inches. As the associated surface cold front pushes 
through the region behind this system Wednesday night, we'll be 
left with a dry but cooler air mass on Thursday which should 
feature temperatures only slightly below normal. High pressure 
then builds over The Northeast to end the week with more dry, 
quiet, and seasonable conditions.

&&

.AVIATION /06Z SUNDAY THROUGH THURSDAY/...

Forecast Confidence Levels:

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

06z TAF Update...

Today...High Confidence.

VFR with just an increase in mid level cloudiness today. W winds
10 to 15 knots with gusts into the lower 20 knots at times this
afternoon in some locations. 

Tonight and Monday...High Confidence.

VFR conditions continue tonight and Monday. WNW winds generally
5-10 knots. Some risk that a weak sea breeze will develop late
Monday afternoon along portions of the eastern MA coast...but
that is still uncertain at this time.

KBOS TAF...High Confidence in TAF. 

KBDL TAF...High Confidence in TAF. 

Outlook /Monday Night through Thursday/... 

Monday Night: VFR. 

Tuesday: VFR. Windy with local gusts up to 30 kt. 

Tuesday Night: VFR. Windy with gusts up to 35 kt. Slight chance
SHRA.

Wednesday: Mainly VFR, with local IFR possible. Breezy. Chance
SHRA.

Wednesday Night: VFR. Breezy. Chance SHRA.

Thursday: VFR. Breezy.

&&

.MARINE...

Forecaster Confidence Levels:

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

Through Sunday Night...High Confidence.

A relatively weak pressure gradient should keep winds and seas 
generally below Small Craft Advisory thresholds through Sunday
night. However, good mixing on westerly flow Sunday may yield a
few afternoon nearshore wind gusts of 20-25 knots creating some
chop. 

Outlook /Monday Night through Thursday/... 

Monday through Monday Night: Winds less than 25 kt. 

Tuesday: Low risk for Small Craft Advisory winds with areas of
gusts up to 30 kt. 

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

Wednesday: Moderate risk for Small Craft Advisory winds with
gusts up to 25 kt. Seas up to 5 ft. Chance of rain showers. 

Wednesday Night: Moderate risk for Small Craft Advisory winds
with gusts up to 25 kt. Seas up to 5 ft. Slight chance of rain
showers. 

Thursday: Moderate risk for Small Craft Advisory winds with
gusts up to 25 kt. Seas up to 5 ft.

&&

.FIRE WEATHER...
Sunday...

Dry westerly flow in pre-greenup should allow for elevated fire 
weather concerns on Sunday. The airmass will mix deeply and 
allow for a large temp/dewpoint spread. Highs should reach the 
upper 50s to near 60 with dewpoints dropping into the lower to 
middle 20s. This should result in minimum afternoon relative 
humidities between 20 and 30 percent. The deep mixing should 
also produce some 20 to 25 mph wind gusts with perhaps a few 
locales approaching 30 mph briefly. However, the rainfall today
was wetting for most locations. Will continue to monitor this
potential overnight.

&&

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

&&

$$

SYNOPSIS...Belk/RM
NEAR TERM...Frank
SHORT TERM...Belk
LONG TERM...RM
AVIATION...Frank/RM
MARINE...Belk/RM
FIRE WEATHER...Belk