Old Res Weather

Lexington, Massachusetts, USA

35°F

2/16/2025 7:17pm

Lexington Conditions: Light snow, 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: 1½ miles
Rain Today: 0.01 in
UV Index: $VPuv None

Area Forecast Discussion
for Boston / Norton, MA

        
000
FXUS61 KBOX 221643
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
1143 AM EST Thu Jan 22 2026

.WHAT HAS CHANGED...
As of 1142 AM, confidence continues to increase on arctic air
arriving Fri night into Sat followed by a high impact winter 
storm Sunday into Monday. Headlines being worked on for the
early afternoon update.

&&

.KEY MESSAGES...

- Lingering rain/snow mix through sunrise with another 0.5 inches of 
snow possible in the Worcester Hills.

- Temperatures surge above normal today with gusty winds 25-35
  mph. An arctic front moving through Friday brings another
  round of gusty winds 30-40 mph.

- Arctic front arrives Friday night with dangerous cold and wind 
chills expected this weekend and into next week.

- A late- weekend coastal storm will bring impactful snow to
  Southern New England Sunday into Monday.

&&

.DISCUSSION...
Key Message 1...Lingering rain/snow mix through sunrise with 
another 0.5 inches of snow possible in the Worcester Hills.

A wide swath of precipitation across most of southern New England 
will move offshore around sunrise. While temperatures are already on 
the rise, and the coastal plain above freezing, the remaining snow 
will be confined to the interior higher terrain areas. Expecting up 
to another 0.5 inches across the Worcester Hills.

Key Message 2...Temperatures surge above normal today with 
gusty winds 25-35 mph. An arctic front moving through Friday 
brings another round of gusty winds 30-40 mph.

Continued southwesterly flow and warm air advection helps warm 850 
mb temperatures to -2C to -5C and 925 mb temperatures to -2C to +2C 
this morning. This will allow surface temperatures to surge above 
normal... afternoon highs in the upper 30s in the higher terrain to 
low to mid 40s in the coastal plain. The pressure gradient begins to 
tighten as another low pressure system move through the Great Lakes 
and high pressure stalls over the Atlantic Ocean. Winds will pick up 
during the afternoon hours as the land rapidly warms... expecting 
gusts to increase to 25-35mph through this afternoon before calming 
for the overnight period.

Expecting an arctic front to drop through southern New England by 
Friday afternoon, rapidly increasing gusts to 30-40 mph with it's 
passage.

Key Message 3...Arctic front arrives Friday night with dangerous 
cold and wind chills expected this weekend and into next week.  

The post frontal airmass Friday night into Saturday will be truly 
arctic with the coldest air we've experienced in quite some time. 
This intrusion of cold air will feature 850 mb temps as cold as -25 
to -30C, several standard deviations below normal for late January. 
This cold advection will result in a windy and frigid morning, the 
coldest of the forecast period on Saturday. Low temps drop into the 
single digits for most, and below zero in the Berkshires and 
Worcester Hills. This is dangerous cold, especially when combined 
with the gusty winds as a result of good mixing of a LLJ overhead. 
Wind gusts 30-40 mph will make it feel like -15 to -25 in the 
Berkshires where an Extreme Cold Watch has been issued. Elsewhere, a 
Cold Weather Advisory will likely be needed for "feels like" temps 
of -5 to -15F Saturday morning. Even in the afternoon highs will 
only reach the single digits in the high terrain and mid teens 
elsewhere. Temps only slightly moderate going into the second half 
of the weekend. The Saturday morning period will also bring a high 
risk of moderate freezing spray, and potentially heavy freezing 
spray which would be a hazard for any crafts out on the waters. 

Key Message 4...A late- weekend coastal storm will bring impactful 
snow to Southern New England Sunday into Monday. 

Turning our attention to the thing everyone wants to hear 
about...are we getting a snow storm? Bottom line up front: it's 
looking good. Confidence continues to increase that indeed we'll be 
dealing with a moderate to high impact winter storm on Sunday and 
Sunday night, perhaps lingering into Monday. Just how quickly it 
exits remains more uncertain. Guidance has not made any big jumps 
with the 00z run, continuing to indicate a good chance of much or 
all of SNE to see 6+ inches of snow. That being said, we are still 
over 3 days out from the onset of this system in New England and 
that's an eternity in winter weather guidance world. As we've 
emphasized over the last 48 hours, track of the low is key and many 
solutions remain on the table. For what it's worth, the 00z EPS 
ensemble guidance notably contracted the envelope of member low 
locations (bunched around the favorable 70/40 benchmark). Even so it 
remains best to approach this storm probabilistically, and the NBM 
probability of over 6 inches of snow has gone up; now 60-70% in 
northwest MA and over 90% in southeast MA. Probabilities of a foot 
of snow or more 30-40% and 60-70% respectively. However, keep in 
mind this a computer model probability that can and will still 
change based on future trends. The ingredients are there for a 
significant snow with a plume of subtropical moisture, a very cold 
antecedent airmass, and strong forcing potential (tbd if it falls 
within the DGZ for maximum fluffiness/snowfall rates etc, all 
details we won't know until we get closer). The progressiveness of 
this system is also still in question, but the heaviest snow at the 
moment looks to be during the afternoon through early overnight 
hours Sunday with lighter snow continuing well into Monday. One 
fortunate aspect of this storm is that it doesn't look to bring very 
strong/damaging winds with it (though it will be gusty over the 
waters). Finally, any snow that falls isn't going anywhere fast 
because the cold sticks around next week.

&&

.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
Forecaster Confidence Levels...

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

18Z TAFs: High confidence.

VFR. SW winds gust to 25kt through late afternoon, then diminish
to 5-15kt tonight. W/SW winds Fri increase during the morning
with 20-30kt gusts, then shift to NW later in the day with
25-35kt gusts into Fri night.

KBOS Terminal...High Confidence in TAF. 

KBDL Terminal...High Confidence in TAF.

Outlook /Friday Night through Monday/...

Friday Night: VFR. Windy with gusts up to 30 kt. 

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

Saturday Night: VFR. Breezy. Slight chance SN.

Sunday: MVFR/IFR conditions possible. Breezy. SN.

Sunday Night: Mainly IFR, with areas MVFR possible. Windy with
local gusts up to 30 kt. SN likely.

Monday: Mainly VFR, with areas IFR possible. Breezy. Chance SN.

&&

.MARINE...
Forecaster Confidence Levels...

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

Today through Friday...

Southwesterly winds increase this morning to above 25 knots across 
the outer waters and persist through this evening. Expecting a 
period of calmer winds overnight tonight before ramping up again to 
near Gales on Friday with the passage of an arctic front. Seas begin 
to build today to 5-8 feet across the outer waters and 3-5 feet 
across the inner waters.

Outlook /Friday Night through Monday/...

Friday Night: Strong winds with gusts up to 35 kt. Areas of
rough seas. Freezing spray, slight chance of snow. 

Saturday: Moderate risk for Small Craft Advisory winds with
gusts up to 30 kt. Areas of rough seas. Freezing spray. 

Saturday Night: Winds less than 25 kt. Areas of seas
approaching 5 ft. Slight chance of snow. 

Sunday: Low risk for Small Craft Advisory winds with gusts up
to 30 kt. Seas locally approaching 5 ft. Snow, chance of
freezing spray. Visibility 1 nm or less.

Sunday Night: Strong winds with gusts up to 35 kt. Seas up to
5 ft. Snow, chance of freezing spray. Visibility 1 nm or less.

Monday: Moderate risk for Small Craft Advisory winds with gusts
up to 30 kt. Seas up to 5 ft. Chance of snow, chance of
freezing spray. Local visibility 1 nm or less.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...Extreme Cold Watch from Friday evening through Saturday 
     afternoon for MAZ002-008-009.
RI...None.
MARINE...Small Craft Advisory from 7 PM Friday to 7 AM EST Saturday for 
     ANZ230-236.
     Gale Watch from Friday afternoon through Saturday morning for 
     ANZ231>235-237-250-251-254>256.
     Small Craft Advisory until 1 PM EST Friday for ANZ232-233-235-
     237-250-254>256.

&&

$$

DISCUSSION...BW/McMinn
AVIATION...JWD
MARINE...BW/McMinn