Lexington Weather

Lexington, Massachusetts, USA

50°F

10/6/2024 2:55am

Lexington Conditions: Clear
Temperature: 50.4°F / 10.2°C
Dew Point: 44.1°F
Relative Humidity: 79%
Wind: Calm, 10-min avg: Calm, gust: None
Barometer: 30.11 in Steady
Visibility: 10 miles
Rain Today: 0.00 in

Area Forecast Discussion
for Boston / Norton, MA

        
000
FXUS61 KBOX 010716
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
316 AM EDT Tue Oct 1 2024

.SYNOPSIS...
Elongated high pressure over the Canadian Maritimes yields 
mainly dry weather through the work week save for a few isolated
showers today and tomorrow. Temperatures moderate to above 
normal levels by Thursday and especially Friday. An approaching 
cold front may bring a period of scattered showers 
Saturday...but a washout is not expected. Dry and pleasant 
weather should return by Sunday, but a disturbance moving in 
from the west may result in unsettled/wet weather by Monday.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...

Overnight, cloud cover remained less expansive than forecast which 
led to reasonably widespread radiational fog across the CT River 
Valley as well as in typical radiating sites across eastern MA, like 
Taunton and Norwood. Guidance was also keen on a stratus deck 
developing across coastal MA around 05Z this morning, which failed 
to develop in a timely fashion. While we have begun to see some 
signs of this deck approaching the coast, with FEW007-009 cigs 
observed across the Outer Cape and South Shore, it appears guidance 
overestimated dewpoints by several degrees overnight, which
influenced the delay in coastal stratus/fog development this
morning.

Reduced vsbys/cigs remain a possibility through sunrise as we often 
see both drop a bit as boundary layer mixing begins. With that said, 
do anticipate that any LIFR/IFR will lift to MVFR and even VFR 
through the day. East flow thanks to high pressure over the Canadian 
Maritimes looks to keep low clouds pinned up against the Worcester 
Hills, with clouds becoming more scattered across the CT River 
Valley. Onshore flow also looks to generate a few scattered 
sprinkles across the region today, though not expecting substantial 
precipitation from any of these passing showers. 

Temperatures today will be influenced by onshore flow, with most of 
eastern MA and RI struggling to climb into the low/mid 60s. Temps 
will be much warmer on the leeward side of the Worcester hills where 
a reading of 70F cant be ruled out in Hartford to Springfield 
corridor. 

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/...

Elongated high pressure continues to remain anchored in the Canadian 
Maritimes, influencing the synoptic pattern through the near term 
forecast. With generally no change expected to the pattern over the 
next 24 hours, thinking that fog is likely to develop once again 
this evening in the River Valleys, but may perhaps be absent from 
our radiational sites across eastern MA thanks to more expansive 
cloud cover. Light showers remain possible into the first half of 
the overnight hours thanks to continued onshore flow. Lows will be 
bounded by dewpoints, falling back into the low 50s for most. 

Overall, a generally mundane midweek is expected with clouds and 
seasonable temperatures Wednesday as temps warm into the mid 60s for 
most. Shortwave approaches from the west the second half of 
Wednesday bringing showers to upstate NY, but aforementioned high 
pressure does it's job in eating away at the precip shield as 
shortwave moves east before dissipating. The NAM shows this 
effective "poof" of precipitation quite well, with a very low chance 
of spot shower making it into the Berkshires before 00Z
Thursday. 

&&

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

Key Points...

* Dry & very pleasant Thu & esp Fri with highs well into the 70s
* Period of scattered showers possible Sat...but not a washout
* Dry Sun but unsettled/wet weather may arrive by Mon

Details...

Mid level ridging aloft and high pressure at the surface will 
continue to result in mainly dry and very pleasant weather Thu & 
Fri. The higher than normal height fields will also result in above 
normal temps. Highs will mainly be in the lower to middle 70s Thu 
and the middle to upper 70s by Fri. 850T reach around +12C by 
Fri...so it is possible a few spots in the lower CT Valley flirt 
with 80 degrees. Regardless...very nice early October weather is on 
tap to close out the work week. Overnight low temps should mainly be 
in the upper 40s to the middle 50s.

An approaching shortwave/cold front will cross the region on 
Sat...which may bring a period of scattered showers to the region 
but not expecting a washout. High temps Sat will still be a bit 
above normal...mainly in the lower to middle 70s but some upper 60s 
along the immediate coast. Behind the shortwave Sat...brief mid 
level ridging should bring dry weather to close out the weekend on 
Sun with highs mainly in the upper 60s to the lower 70s.

A fairly potent shortwave trough looks to approach the region from 
the west on Mon. Still nearly a week out...but may see low pressure 
develop off the coast in response. Thinking a period of 
unsettled/wet weather may kick off the start of the new work week 
by next Mon.

&&

.AVIATION /07Z TUESDAY THROUGH SATURDAY/...
Forecast Confidence Levels:

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

06Z Update. 

Through 12Z... Low Confidence in Fog/reduced cigs 

Models continue to suggest low stratus and fog will develop
along the coastline and across interior eastern MA but we have
not seen any reduction in vsbys and hardly any lowering ceiling
save for areas where radiational fog has developed. Anticipating
that fog and low stratus will continue to struggle but may
develop rapidly around sunrise. 

Today... Low to moderate confidence 

Generally MVFR from Worcester, east and VFR in the Connecticut
River Valley. Winds from the east will enhance cloud cover for
eastern and coastal terminals. Spotty showers possible but not
expected to impact operations. 

Tonight...Low confidence. 

MVFR with localized IFR possible. Light east to northeast 
winds. 

Wednesday...Moderate Confidence

Morning IFR to MVFR will lift to VFR. Light east/northeast 
winds persist and will continue to support spotty shower 
activity. 

BOS TAF...Low Confidence in TAF. High uncertainty in the
development of low cigs and stratus through 12Z. Generally MVFR
today though pockets of IFR possible. Light showers possible
with no impact to operations expected. Steady NE surface winds.


BDL TAF...Moderate Confidence in TAF, primarily due to
uncertainty if MVFR ceilings develop in the area very late
early this morning. VFR redevelops this afternoon. 

Outlook /Wednesday Night through Saturday/...

Wednesday Night through Friday: VFR. 

Friday Night: Mainly VFR, with local MVFR possible. Slight
chance SHRA.

Saturday: Mainly MVFR, with areas VFR possible. Chance SHRA.

&&

.MARINE...
Forecaster Confidence Levels:

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

Through Wednesday...High confidence. 

Quiet weather conditions today with east to northeast 
winds 15 to 20 knots and seas 3 to 4 foot. Seas and winds remain
below S.C.A throughout the period due to surface high pressure 
over the coastal waters. Marine stratus and patchy fog and a 
passing shower again possible on Tuesday night. Status quo
conditions expected Wednesday. 

Outlook /Wednesday Night through Saturday/... 

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

Friday through Friday Night: Winds less than 25 kt. 

Saturday: Winds less than 25 kt. Seas locally approaching 5 ft.
Chance of rain showers. 

&&

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

&&

$$

SYNOPSIS...Frank/KS
NEAR TERM...KS
SHORT TERM...KS
LONG TERM...Frank
AVIATION...KS
MARINE...Frank/KS