Lexington Weather

Lexington, Massachusetts, USA

49°F

10/6/2024 4:06am

Lexington Conditions: Clear
Temperature: 49.3°F / 9.6°C
Dew Point: 44.1°F
Relative Humidity: 82%
Wind: Calm, 10-min avg: Calm, gust: None
Barometer: 30.10 in Steady
Visibility: 10 miles
Rain Today: 0.00 in

Area Forecast Discussion
for Boston / Norton, MA

        
000
FXUS61 KBOX 301741
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
141 PM EDT Mon Sep 30 2024

.SYNOPSIS...
High pressure continues to provide dry conditions to the region for 
the start of the work week. Low chance for a shower mid-week, 
followed by continued dry conditions as high pressure will bring a 
return to dry and seasonable weather later in the week.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
7am update...

Satellite and surface obs show some fairly widespread low
elevation and valley fog out there this morning. We should see
that continue to mix out over the next several hours and should
be gone by 10am. 

Previous Discussion...

Patchy radiation fog that formed overnight should burn off shortly 
after 8 am this morning, but skies wont stay clear for long. Another 
thick deck of high cirrus clouds begins to move in later this 
morning as the once stalled closed low breaks down and moves just 
offshore to the south.  With high pressure to the north, winds turn 
NE again today. With onshore flow, overcast skies, and 850 temps 
dropping to +7C, trended high temps cooler than the NBM into the 
upper 60s to low 70s for today.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
Onshore flow continues overnight. With high-level cirrus and 
some easterly surface flow, radiation fog should be much more 
localized. There could be another marine stratus deck that forms
overnight. With less than ideal radiational cooling conditions,
overnight lows should stay in the low to mid-50s vs. the mid to
upper 40s.

More of the same weather on Tuesday as the surface and upper-level 
pattern hardly change. Low to mid-level stratus should burn off
by the afternoon, but skies remain mostly cloudy with the high 
cirrus deck remaining overhead. Winds increase to 10-15 mph 
from the ENE as the pressure gradient tightens slightly. High 
temps moderate back down to the low to mid-60s, except in the CT
river valley where upper 60s to low 70s are possible.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
Highlights...

* Mostly dry & pleasant weather continues through the end of the 
  week. 

* First chance of rain showers comes late Wednesday but chance of 
  rain has steadily been decreasing over the last 48 hours and most 
  locations likely stay dry. 

*  Next chance of rain arrives on Saturday.  

Details...

Good news for those with outdoor activities planned on Wednesday as 
the trend over the last 48-72 hours with our mid week frontal system 
has been slower and drier, to the point that most in southern New 
England likely won't see any rain at all. The high pressure ridge 
overhead, extending from Nova Scotia, will remain strong enough to 
keep Helene's remnants removed to the south and the Great Lakes 
trough confined to northern New England. The best shot of seeing any 
rain Wednesday night will be in far northwest MA in closer proximity 
to said dynamics. By the latter half of the week mid level heights 
will begin to rise as surface high pressure builds in further, 
keeping the forecast dry. This also means temps will be quite a bit 
warmer Thu/Fri as previously cool onshore flow becomes southwest and 
the building 850 me ridge takes the airmass at 850 mb from +6C on 
Wednesday to +12C by Thu/Fri. High temperatures will increase from 
the 60s Wednesday to the mid to upper 70s on Thu/Fri. 

Looking ahead at next weekend guidance is in pretty good agreement 
that another shortwave swings through on Saturday bringing a cooler 
and wetter forecast for the first half of the weekend followed 
by a drier Sunday. Of course, timing of this feature can change 
as we get closer to the weekend so check back as we get more 
information and the forecast is adjusted accordingly.

&&

.AVIATION /18Z MONDAY THROUGH FRIDAY/...
Forecast Confidence Levels:

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

Today...High confidence. 

VFR after the fog burns off with light winds at 5-10 knots from
the ENE. MVFR stratus deck may hang over the Cape and Islands
through the rest of the afternoon.

Tonight...Moderate confidence. 

Should be less fog around with a thick high cirrus deck
overhead, however, guidance is hinting at another MVFR stratus
deck forming over Eastern MA and RI. DZ possible going into
morning hours over SE MA, RI, Cape/Islands.

Tomorrow...Moderate confidence.

MVFR stratus deck should lift and break up by mid morning with
VFR conditions by the afternoon, except towards Cape/Islands,
where MVFR should persist. The only uncertainty is that wind 
pick up to 10-15 knots out of the east, which may keep the low 
to mid level cloud deck around.


BOS TAF...Moderate Confidence in TAF.

VFR. Winds turn ENE today at 5-10 knots. Lower ceilings develop
after 00z tonight, resulting in MVFR ceilings. IFR possible, 
but have low confidence at this time, so it was left out of the 
TAF.

BDL TAF...High Confidence in TAF. VFR.


Outlook /Tuesday Night through Friday/...

Tuesday Night: Mainly VFR, with local MVFR possible. 

Wednesday through Friday: VFR.

&&

.MARINE...
Forecaster Confidence Levels:

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

Through Tuesday...High confidence. 

Tranquil boating conditions today have light ENE winds at 5-10 knots 
and gusts of 15 knots in the southern waters.  Seas today remain 1-3 
feet.  Winds increase out of the east on Tuesday, gusting up to 20 
knots, especially in the southern waters. Seas increase to 3-4
feet.

Outlook /Tuesday Night through Friday/... 

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

Thursday Night: Winds less than 25 kt. Seas locally approaching
5 ft. 

Friday: Winds less than 25 kt.

&&

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

&&

$$

SYNOPSIS...BW/KP
NEAR TERM...KP
SHORT TERM...KP
LONG TERM...BW
AVIATION...BW/Hrencecin/KP
MARINE...Belk/BW/KP