Lexington Weather

Lexington, Massachusetts, USA

10/17/2021 9:41pm 
  • Lexington Conditions: Partly cloudy
  • Temperature: 52.2°F / 11.2°CColder 0.9°F than last hour.
  • Dew Point: 46.8°FDecreased 0.9°Fsince last hour.
  • Relative Humidity: 82
  • Wind: Calm, 10-min avg: Calm, gust: 2 mph
  • Barometer: 29.68 in Steady
  • Visibility: 10 miles
  • Rain Today: 0.35 in

Area Forecast Discussion
for Boston, MA

FXUS61 KBOX 172340

Area Forecast Discussion
National Weather Service Boston/Norton MA
740 PM EDT Sun Oct 17 2021


Blustery and cool weather continues Monday and Tuesday. Dry 
weather generally persists Wednesday into Thursday with 
unseasonably mild temperatures returning. A cold front may bring
a few brief showers Thursday night and/or Friday, but a washout
is not expected. Behind the cold front; a rather cool airmass 
with below normal temperatures will move into the region for 
next weekend.



735 PM Update:

Isolated diurnally driven showers across the interior were
dissipating early this evening with the loss of daytime heating.
We still can not rule out a brief spot shower or two overnight,
but generally expect dry weather with scattered clouds at times.
Previous forecast captures this well.

Low pressure over Nova Scotia and high pressure centered over the 
Ohio River valley has southern New England beneath a region of deep 
northwest flow. Deep northwest flow pattern will continue to 
advect cooler air over the region tonight. Overnight low 
temperatures will be chilly but seasonable for this time of 
year. We probably won't see any significant radiational cooling
as the elevated wind speeds will likely produce just enough 
mechanical mixing overnight. Additionally some moisture 
streaming in from The Great Lakes region will support areas of 
scattered clouds. Expecting low temperatures in the low-mid 40s
across the interior with temperatures staying a bit warmer 
along the coast in the middle 40s - to the lower 50s.



Short Term 

* Breezy northwest winds Monday
* Seasonable high/low temperatures


Deep northwest flow pattern continues with surface high pressure 
nosing in from the south west tomorrow afternoon. CAA aloft brings 
temperatures at 850 hPa below 0. Thus, diurnal mixing to 850 hPa 
tomorrow afternoon will only support high temperatures in the mid-
upper 50s for much of southern New England. Deep mixing will also 
support another day with west/northwest wind gusts up to 20 knots. 
Steep low-level lapse rates in the afternoon will again support the 
development of diurnal cu/stratocu and possibly an isolated 
instability shower or two.

Monday Night

Little change in the forecast between tonight and Monday night. 
Biggest difference will be attributed to the cooler air mass 
overhead. Low temperatures will fall into the low 40s for many areas 
and perhaps even the upper 30s for the low-lying areas out west. 
Otherwise continue to expect persistent winds out of the northwest 
and mostly clear skies.




* Dry/seasonable Tue but it will be breezy
* Unseasonably mild temps return Wed & Thu with dry weather
* A few showers possible Thu night and/or Fri but not a washout
* Cool/Below normal temps next weekend & watching offshore wave



Upper trough/cold pool aloft begins to lift northeast and move away 
from the region. This should allow more sunshine than Monday and 
temps probably a degree or two higher. Expect high temps Tue 
generally in the 60 to 65 degree range. However, modest northwest 
LLJ coupled with lots of sunshine will result in good mixing. This 
will result in a rather breezy day with NW winds of 20-30 mph and 
perhaps a few gusts up to 35 mph.

Wednesday and Thursday...

High pressure to our south moves off the coast as a cold front 
approaches from the west. This will allow a return SW flow of milder 
temperatures back into southern New England. High temperatures 
should recover back into the upper 60s and lower 70s on Wed. The 
mildest day of the week looks to be Thursday as 850T moderate to 
between +10C and +12C. Highs probably will be able to reach into the 
lower to middle 70s in many locales on Thursday if enough solar 
insolation is realized.

Thursday night and Friday...

An approaching cold front will bring the potential for a few showers 
sometime Thursday night and/or Friday. Timing currently favors the 
greatest risk for some showers Thu night and Fri may end up mainly 
dry. This is certainly subject to change. Regardless, it does not 
look like a washout though as the deeper forcing/moisture will 
remain across northern New England. High probably are mainly in the 
60s on Friday.

Next Weekend...

EPS/GEFS guidance are in good agreement in developing northeast 
trough next weekend with below normal height fields.  It remains to 
be seen exactly how cool temperatures will get next weekend, but 
thinking high temperatures may remain in the 50s for one or both 
days next weekend. Low temps should be down into the 30s/40s 
depending on the amount of cloud cover. As for precipitation 
chances, most of the guidance favors the majority of the weekend 
ending up dry. That being said, an offshore wave of low pressure 
will need to be watched. A few members have it tracking close enough 
to the coast to result in a period of rain. Still to early to say 
much more at this point, but the greatest risk appears to be near 
the southeast New England coast at this point.



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

00z TAF Update:

Tonight...High confidence. VFR. W/NW wind 5-10 kt. 

Monday...High confidence. VFR with broken cigs 5-6k ft 
developing. Spot shower possible. NW gusts to 20-25 kt.

Monday Night...High confidence.
VFR. Northwest gusts 15-20 knots

KBOS Terminal...High confidence in trends.

KBDL Terminal...High confidence in trends.

Outlook /Tuesday through Friday/...

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

Wednesday through Thursday: VFR. Breezy. 

Thursday Night: Mainly MVFR, with areas VFR possible. Breezy.
Chance SHRA.

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



Forecaster Confidence Levels.

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


Northwest flow pattern will support gusty winds over the marine 
waters into early next week. As a result SCY remains in effect 
through tomorrow afternoon. By Monday night, a low-level jet moving 
over the coastal waters will bring increasing wind speeds with gusts 
over the southern waters approaching 30 knots. Gale watch is in 
effect for Tuesday as gusts may to rise to 34 knots by Tuesday 

Seas generally range from 1-3 feet in the 
near-shore zones and 4-5 feet for the outer waters.

Outlook /Tuesday through Friday/...

Tuesday: Moderate risk for Small Craft Advisory winds with
gusts up to 30 kt. Seas up to 5 ft. 

Tuesday Night: Moderate risk for Small Craft Advisory winds
with gusts up to 30 kt. Local rough seas. 

Wednesday: Low risk for Small Craft Advisory winds with gusts
up to 25 kt. Seas locally approaching 5 ft. 

Wednesday Night: Winds less than 25 kt. 

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

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

Friday: Moderate risk for Small Craft Advisory winds with gusts
up to 30 kt. Local rough seas. Slight chance of rain showers.


MARINE...Gale Watch from Tuesday morning through Tuesday evening for 
     Small Craft Advisory until 2 PM EDT Monday for ANZ255-256.



Other recent Area Forecast Discussions

Sun Oct 17, 4:11pm

Sun Oct 17, 3:24pm

Sun Oct 17, 1:06pm

Sun Oct 17, 12:45pm

Sun Oct 17, 9:39am

Sun Oct 17, 7:22am

Sun Oct 17, 3:35am

Sun Oct 17, 1:51am

Sat Oct 16, 10:18pm

Sat Oct 16, 7:55pm

Sat Oct 16, 3:51pm

Sat Oct 16, 3:18pm

Sat Oct 16, 1:30pm

Sat Oct 16, 12:51pm

Sat Oct 16, 9:32am

Sat Oct 16, 7:28am

Sat Oct 16, 3:49am

Sat Oct 16, 1:57am

Fri Oct 15, 9:33pm

Fri Oct 15, 7:56pm

Fri Oct 15, 3:47pm

Fri Oct 15, 3:11pm

Fri Oct 15, 10:00am

Fri Oct 15, 7:19am

Fri Oct 15, 3:48am

Fri Oct 15, 1:55am

Thu Oct 14, 10:07pm

Thu Oct 14, 7:54pm

Thu Oct 14, 3:43pm

Thu Oct 14, 3:27pm

Thu Oct 14, 10:02am

Thu Oct 14, 7:11am

Thu Oct 14, 3:37am

Thu Oct 14, 1:44am

Wed Oct 13, 10:07pm

Wed Oct 13, 8:08pm

Wed Oct 13, 4:12pm

Wed Oct 13, 3:28pm

Wed Oct 13, 1:59pm

Wed Oct 13, 10:24am

Wed Oct 13, 7:18am

Wed Oct 13, 3:34am

Wed Oct 13, 1:37am

Tue Oct 12, 10:10pm

Tue Oct 12, 7:49pm

Tue Oct 12, 3:44pm

Tue Oct 12, 1:58pm

Tue Oct 12, 10:00am

Tue Oct 12, 7:12am

Tue Oct 12, 3:29am

Tue Oct 12, 1:45am

Mon Oct 11, 9:52pm

Mon Oct 11, 7:44pm

Mon Oct 11, 3:36pm

Mon Oct 11, 3:02pm

Mon Oct 11, 10:03am

Mon Oct 11, 7:22am

Mon Oct 11, 4:30am

Mon Oct 11, 1:48am

Sun Oct 10, 11:12pm

Meta data:

ID: 4657f459-4511-4e88-8a00-e4c9c0078d0a
Link: https://api.weather.gov/products/4657f459-4511-4e88-8a00-e4c9c0078d0a