Old Res Weather

Lexington, Massachusetts, USA

35°F

2/16/2025 7:17pm

Lexington Conditions: Overcast
Temperature: 35.1°F / 1.7°C
Dew Point: 32.4°F
Relative Humidity: 90%
Wind: Calm, 10-min avg: Calm, gust: None
Barometer: 29.00 in Falling Slowly
Visibility: 10 miles
Rain Today: 0.01 in
UV Index: $VPuv None

Southeast Middlesex County, MA - High Wind Warning
- SEE ALL NEARBY ALERTS -

Area Forecast Discussion
for Boston / Norton, MA

        
000
FXUS61 KBOX 151059
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
659 AM EDT Sun Mar 15 2026

.WHAT HAS CHANGED...
No significant changes. High wind watches for RI and eastern MA and 
storm watches for the waters continue. Flood Watches may need to be 
issued today for the potential of flooding of rivers, small streams 
as well as urban and poor drainage areas.

&&

.KEY MESSAGES...

- Mix of sun and clouds with seasonable temperatures today 
  before conditions start to worsen tonight into Monday

- Periods of heavy rain with embedded t-storms Monday, 
  especially Monday night, may lead to some river and small 
  stream flooding. Poor drainage in urban areas could flood as 
  well.

- A period of strong to damaging winds expected across portions
  of SNE Monday night. 

- Mainly dry and trending colder Tue into Wed, then moderating 
  temperatures Thursday and especially Friday.

&&

.DISCUSSION...
KEY MESSAGE 1...Mix of sun and clouds with seasonable temperatures
today before conditions start to worsen tonight into Monday.

Mid-level ridging persists today with surface high pressure as well 
before a warm front brings more unsettled conditions tonight into 
Monday. Strong winds from the day before have diminished 
considerably as ridging has built in overnight. Lighter winds from 
the SE can be expected this afternoon. Seasonable highs in the mid 
40s along with a mix of sun and clouds will be the result today. 
This respite will be short-lived though as a warm front will lift 
north across southern New England. Showers will start to move into 
the region tonight, mostly after midnight, and SE winds will begin 
to strengthen behind the front. Lows tonight will fall mostly in the 
low 30s; upper 20s possible in the higher elevations.

KEY MESSAGE 2...Periods of heavy rain with embedded t-storms 
Monday, especially Monday night, may lead to some river and 
small stream flooding. Poor drainage in urban areas could flood 
as well.

Guidance has continued to show significantly above average PWAT 
values for this time of year associated with this system and is 
supportive of total QPF approaching 2" for much of southern New 
England. Strong southerly flow ahead of a powerful low will kick up 
heading into Monday night, which will help advect in significant 
moisture. PWAT values approaching 1.5" are possible, and with the 
stronger forcing that comes with a strong LLJ, widespread amounts of 
rain to 2" are possible. The NAM has been depicting a fine line 
feature developing in the latest runs, too, and MUCAPE values around 
500 J/kg could lend to isolated t-storms developing. These could 
lead to localized higher rain totals approaching 3"+ (more details 
on possible severe weather in KEY MESSAGE 3). This additional rain 
would also have a greater impact on the above normal stream levels 
we've been seeing with the snowmelt and rain we've seen lately, so 
some streams and rivers could see flooding. Spots of poor drainage 
in urban areas could lead to localized flooding as well.

KEY MESSAGE 3...A period of strong to damaging winds expected 
across portions of SNE Monday night. 

While winds will be ramping up Mon afternoon, the main concern will 
be Mon night as a very impressive and anomalous low level jet 
develops ahead of a strong cold front and lifts across SNE. 3K NAM 
showing 90-100 kt at 925 mb moving up along the SE New Eng coast 03-
06z and exiting Cape Cod by 09z. Up to 80 kt extends back to the I-
95 corridor. The biggest challenge is determining how much of this 
wind will be able to mix down as we will have a low level inversion 
in place with NAM soundings showing a strong inversion over the 
Islands and adjacent waters which complicates the forecast. How mild 
it can get Mon evening as well as a potential fine line of 
convection will be a significant factor to damaging wind potential. 
High confidence that temps will reach the upper 50s with a chance 
temps could get to 60+ away from the immediate south coast. 
Soundings indicate damaging wind potential increases significantly 
if temps get to 60F or higher as inversion would weaken 
considerably. 3K NAM also indicating a fine line of convection along 
the front which seems more than reasonable given the strong low 
level convergence and elevated instability. Any fine line or pre-
frontal convective elements would also increase damaging wind 
potential. It is interesting to note that CSU machine learning probs 
have severe wind probs and 2% tornado probs across SNE but think 
this is more of a reflection of damaging wind potential with the 
fine line as surface based convection is unlikely unless we can get 
temps to 62-63F with dewpoints 60+. At the very least, even if 
cooler temps win out with stronger inversion in place, taking 50 
percent of the LLJ would suggest at least 45-55 mph gusts, with risk 
for 60-70 mph gusts and power outages if the inversion weakens. We 
will continue the high wind watch across RI and eastern MA where 
highest risk for damaging wind gusts, but wait until we get into the 
HREF window before potentially upgrading to warnings. Wind 
advisories will also likely be needed further west across CT and 
portions of central and western MA. 

KEY MESSAGE 4...Mainly dry and trending much colder Tue into
Wed, then moderating temperatures Thursday and especially
Friday. 

We will be in the post-frontal airmass on Tue with colder and much 
drier air advecting in from the west in the cold advection pattern. 
It will also be blustery with soundings showing a well mixed 
boundary layer supporting west gusts to 25-35 mph at times. The cold 
will peak Tue night into Wed as 850 mb temps drop to -15 to -18C 
around 12z Wed. Lows Tue night will drop into the teens and low 20s 
with Wed highs in the 30s. Winds will remain gusty into Tue evening 
then diminish late Tue night and Wed as high pres builds into the 
region. Temps then moderate Thu into Fri with temps getting back 
into the upper 40s and lower 50s for Fri. Looks mainly dry through 
the end of the week with chance of showers sometime Fri night or Sat 
as a frontal system approaches.

&&

.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
Forecaster Confidence Levels...

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

12Z update...

Today...High Confidence

VFR. Winds becoming E/SE between 5 and 10 knots after 15Z.

Sunday Night...High Confidence

Deteriorating conditions Sunday night into Monday as a warm front 
lifts north over the region. MVFR/IFR ceilings and visibility 
developing after 06Z as light to moderate rain overspreads southern 
New England.

Monday...High Confidence

Mostly IFR with RA overspreading the region. Winds increasing
and shifting more S through the day. Gusts to 35 kt possible
heading into the evening hours. Some isolated TSRA cannot be
ruled out, particularly in CT and RI. However, it does remain
possible outside of those areas as well.

KBOS Terminal...High confidence.

KBDL Terminal...High confidence

Outlook /Monday Night through Thursday/...

Monday Night: Mainly MVFR, with areas IFR possible. Strong
winds with gusts up to 50 kt. RA, patchy BR.

Tuesday: VFR. Windy with gusts up to 35 kt. 

Tuesday Night through Wednesday: VFR. Breezy. 

Wednesday Night through Thursday: VFR.

&&

.MARINE...
Forecaster Confidence Levels...

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

Through Monday Night

Seas calm to 1-3 ft through the day today as high pressure settles 
overhead. Winds today over the waters shift more to the SE into the 
afternoon but remain around 10-15 kt, occasionally gusting to 20 kt 
over the southern waters. Winds ramp back up tonight into Monday as 
a powerful low pressure system approaches from the west. Seas 
increase considerably headed into Monday night, reaching up to 15 ft 
and even close to 20 ft in the southern waters by 06z Tuesday. Seas 
7-10 ft will be more common in the eastern waters. Winds will likely 
approach storm conditions Monday night.

Outlook /Monday Night through Thursday/...

Monday Night: Low risk for storm force winds with gusts up to
50 kt. Rough seas up to 19 ft. Rain, areas fog, slight chance
of thunderstorms. Local visibility 1 nm or less.

Tuesday: Strong winds with gusts up to 30 kt. Rough seas up to
15 ft. 

Tuesday Night: Moderate risk for Small Craft Advisory winds
with local gusts up to 30 kt. Rough seas up to 12 ft. 

Wednesday: Winds less than 25 kt. Seas up to 5 ft. 

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

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...High Wind Watch from Monday afternoon through late Monday 
     night for MAZ005>007-013>024.
RI...High Wind Watch from Monday afternoon through late Monday 
     night for RIZ001>008.
MARINE...Storm Watch from Monday afternoon through Tuesday morning for 
     ANZ230>237-250-251-254>256.

&&

$$

DISCUSSION...KJC/Hrencecin
AVIATION...BW/Hrencecin
MARINE...Hrencecin