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: 10 miles
Rain Today: 0.01 in
UV Index: $VPuv None

Area Forecast Discussion
for Boston / Norton, MA

        
000
FXUS61 KBOX 251126
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
626 AM EST Sun Jan 25 2026

.WHAT HAS CHANGED...
- Trended snowfall totals higher for northeast MA, central MA
  high terrain, and the Berkshires.

&&

.KEY MESSAGES...

- Major winter storm will bring intense, heavy snow to Southern
  New England Sunday into Monday. Heavy snowfall with 1-2"+ inch
  per hour snow rates Sunday afternoon and evening, making for
  dangerous travel conditions.

- Abnormally cold and mostly dry with a low probability of
  another storm off the coast next weekend.

&&

.DISCUSSION...
KEY MESSAGE...Major winter storm will bring intense, heavy snow to 
Southern New England Sunday into Monday. Heavy snowfall with 1-2"+ 
inch per hour snow rates is expected Sunday afternoon and evening, 
making for dangerous travel conditions.

A major winter storm arrives in western southern New England 9AM-
11AM and 11AM-1PM in the east and lasts into Monday. Expecting 
snowfall rates of 1"-2+" per hour to start soon after storm onset, 
leading to dangerous travel conditions in the afternoon/evening and 
into the overnight period. Storm total snowfall expected to be in 
the 12"-18" range across the majority of southern New England, with 
8"-12" expected on the Cape, Islands, and immediate southern coast. 
The higher elevations and northeastern MA will likely see 18"-20", 
including Boston.

A widespread winter storm moves out of the Deep South/Midwest and 
into the Mid-Atlantic/New England region Sunday. Guidance has 
narrowed in on an 850mb closed low tracking over southern New 
England, bringing PWATs 0.75"-1.0" (200%-300% of normal) and very 
strong frontogenesis. Model guidance is indicating large, negative 
omega values within a deep dendritic growth zone leading to the 
development of large snowflakes. Also expecting a coastal front to 
push into the north and eastern portions of southern New England 
Sunday evening leading to a sharper gradient dividing the arctic 
airmass from Canada and slightly warmer air being funneled in off 
the ocean. There will likely be development of heavier snow bands on 
the northwest side of the strongest frontogenesis. Given this is a 
meso-/micro- scale feature, there is high uncertainty in where 
exactly the banding will set up, but thinking somewhere between 
Plymouth and Worcester at this time.

The high PWATs, strong frontogenesis, and coastal front combined 
with the arctic airmass indicates this event will be quite the 
efficient snow maker, with intense snowfall rates of 1"-2+" per
hour likely over several hours into late Sunday night. Guidance
is also indicating gusty winds arriving Sunday night, 
especially over the southern waters, Cape and Islands. HREF 
blizzard probs remain around 20%-30%, so low confidence in long-
duration blizzard conditions. However, can't rule out periods of
short-lived white-out conditions.

As the storm advances into Sunday evening, expecting a shot of warm 
air to mix in aloft and lead to temperatures warming closer to 32F. 
This will likely allow sleet to mix into the snow, lowering snow 
ratios and creating a wetter snow that will reduce totals. The GFS 
and NAM bring the warmer temperatures further inland into the south 
shore, but currently favoring a mix of the ECMWF, Canadian, and NBM 
which keep the warm layer confined to the immediate southern 
coastline, Cape, and Islands.

By early Monday morning, a dry slot pushes into southern New 
England, cutting the available moisture for snow growth and leading 
to the development of smaller snowflakes. This will dramatically 
lower snowfall rates through the morning, eventually tapering off to 
light flurries. Prolonged northeasterly flow on Monday will allow 
for ocean enhanced snow flurries to linger across the northeastern 
coastal plain, including Boston, into Monday afternoon.

Key Message 2...Abnormally cold and mostly dry with a low 
probability of another storm off the coast next weekend.

Overall benign weather is expected to follow this weekend's 
snowstorm. Dry, cold NW flow persists through at least the start of 
next weekend keeping precipitation out of the forecast for the most 
part while temperatures remain well below normal each day. Normal 
highs/lows for late January are in the mid 30s and low 20s 
respectively; we are forecasting highs in the teens and 20s with 
lows in the single digits thanks to an anomalously cold airmass 
overhead. A few shortwaves rounding the broader trough could bring 
some flurries off and on but on the whole things look dry. We'll 
continue to monitor a potential storm off the coast toward next 
weekend but odds are still favorable that it would pass harmlessly 
offshore.

&&

.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 and Tonight: High Confidence.

VFR through this morning. NNE winds 5-10kts through the 
morning, with gusts picking up 25-35kts this evening. Light snow
begins in western New England 13z-15z and 15z-17z farther east,
bringing a rapid drop to IFR conditions. Expecting heavy snow 
to arrive within 1-3 hours of onset with widespread LIFR 
conditions later Sunday afternoon and the first part of Sunday 
night. Snowfall rates of 1-3" per hour are likely. Snow lessens 
in intensity overnight into Monday but there should be a change 
to rain for a time on the Islands and possibly Cape Cod, with 
some sleet possible along the South Coast.

Snowfall totals by Monday morning should range from 8-12" along
the South Coast, Cape Cod, and Islands to 12-18" elsewhere, 
with 18-20" possible in the higher elevations and northeastern 
coast, including BOS. Much of this will fall from later Sunday 
afternoon through midnight Monday.

Monday: High Confidence in treads. Moderate Confidence in 
timing.

Snow begins to lighten up Monday morning. Prolonged 
northeasterly flow brings ocean enhanced snow to the 
northeastern coastal plain, including Boston, through midday. 
Winds shift to north westerlies Monday afternoon and flurries 
finally move offshore.

KBOS Terminal...High Confidence in TAF. 

KBDL Terminal...High Confidence in TAF. 

Outlook /Monday Night through Thursday/...

Monday Night: Mainly VFR, with local MVFR possible. Windy with
areas of gusts up to 30 kt. Chance SN.

Tuesday through Wednesday: VFR. Breezy. 

Wednesday Night: VFR. 

Thursday: VFR. Breezy.

&&

.MARINE...
Forecaster Confidence Levels...

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

High confidence through early next week.

NE winds later today 20-35 kt gusting 30-40 kt by tonight ahead
of the coastal low pressure system heading up the coast. Snow 
arrives by early afternoon and quickly becomes heavy at times, 
before changing to rain or sleet on most of south coastal waters
Sunday night. Seas increase to 8-10 ft tonight, increasing to 
as high as 13 ft on the outer waters Monday. 

Outlook /Monday Night through Thursday/...

Monday Night: Strong winds with gusts up to 40 kt. Rough seas
up to 14 ft. Chance of snow. Local visibility 1 to 3 nm.

Tuesday: Moderate risk for Small Craft Advisory winds with
gusts up to 30 kt. Rough seas up to 14 ft. 

Tuesday Night: Moderate risk for Small Craft Advisory winds
with areas of gusts up to 30 kt. Areas of rough seas. Chance of
freezing spray, slight chance of snow. 

Wednesday: Winds less than 25 kt. Seas up to 5 ft. Chance of
freezing spray. 

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

Thursday: Winds less than 25 kt. Chance of freezing spray,
slight chance of snow.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...Winter Storm Warning until 8 PM EST Monday for CTZ002>004.
MA...Winter Storm Warning until 8 PM EST Monday for MAZ002>024-026.
RI...Winter Storm Warning until 8 PM EST Monday for RIZ001>008.
MARINE...Gale Warning from 10 PM this evening to 5 AM EST Monday for 
     ANZ230-236.
     Gale Warning from 10 PM this evening to 6 AM EST Monday for 
     ANZ231.
     Gale Warning from 7 PM this evening to 6 AM EST Monday for 
     ANZ232>234.
     Gale Warning from 6 PM this evening to 6 AM EST Monday for 
     ANZ235-237.
     Gale Warning from 10 PM this evening to 7 AM EST Monday for 
     ANZ250-251.
     Gale Warning from 7 PM this evening to 7 AM EST Monday for 
     ANZ254.
     Gale Warning from 4 PM this afternoon to 7 AM EST Monday for 
     ANZ255-256.

&&

$$

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