Old Res Weather

Lexington, Massachusetts, USA

35°F

2/16/2025 7:17pm

Lexington Conditions: Clear
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 080409
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
1109 PM EST Sat Mar 7 2026

.WHAT HAS CHANGED...

No significant changes. Becoming more confident in springtime
warmth, especially Tuesday, along with the potential for minor 
river flooding within the next 7 days.

&&

.KEY MESSAGES...

- A brief round of showers, and perhaps a rumble of thunder, 
  late tonight into very early Sunday morning.

- Above normal temperatures next week. Trending more unsettled
  mid to late week with a round or two of precipitation
  possible.

- Expecting significant snowmelt over the coming week. Minor
  river flooding possible.

&&

.DISCUSSION...

KEY MESSAGE 1...A brief round of showers, and perhaps a rumble
of thunder, late tonight into very early Sunday morning.

Southern New England remains on the cool side of a warm front
tonight, until a cold front passes by late Sunday. This gives 
our region a brief period of time within the warm sector of a 
low pressure moving east across northern New England Sunday.

Areas of fog and patchy drizzle finally ended for a time this  
afternoon, but are likely to return later tonight. With dew
points expected to remain above freezing through Sunday, we're
looking at continued snow melt during this time. 

Expecting a round of rainfall ahead of a pair of fronts starting 
late this evening before winding down from west to east during 
the day Sunday. It could be late afternoon before this rainfall 
finally clears the Cape and islands. While it's not impossible 
for there to be a few rumbles of thunder given the observed 
convection farther to our west, thinking the time of day and 
year does not favor thunderstorms across southern New England 
and left them out of this forecast.

KEY MESSAGE 2...Above normal temperatures next week. Trending
more unsettled mid to late week with a round or two of
precipitation possible. Minor river flooding possible.

A thermal ridge is expected to build in further from the south
next week bringing light S/SW winds. In response, 850mb
temperatures rise to 10-15C through the week, supporting above
normal temperatures. Highs will likely rise into the upper 50s 
and 60s Monday through Thursday for many spots. Tuesday will
likely be the warmest day with highs in the 60s with a some
interior/valley areas potentially approaching 70. This runs
round 20-25 degrees above normal. Immediate coastal areas will
run a bit cooler, especially along the immediate south coast 
and the Cape and Islands given the onshore southerly component 
flow. Those mentioned areas will more likely stay in the 40s and
50s. Some guidance continues to hint at the potential for a 
backdoor front later Wednesday which could bring down
temperatures, at least in northeast MA. Highs will depend on 
how far south this front extends. 

The pattern trends more unsettled Wednesday onward with the
passage of a few shortwave troughs bringing a few rounds of
precipitation through late week. There is still uncertainty in
the timing/coverage of showers on Wednesday. Thursday's wave 
will be more organized with a stronger cold front accompanying 
it. This will support more widespread precipitation later 
Thursday, likely rain to start, with potential snow mixing in 
for the higher terrain as the front works through. 

KEY MESSAGE 3...Expecting significant snowmelt over the coming
week. Minor river flooding possible.

The extended period of warmer conditions does raise concern for
rises in rivers/streams from the quicker melting of snowpack. 
Ensemble guidance indicates rising river/stream levels through 
the week. Ensembles show some locations, particularly on the CT 
and Merrimack Rivers, reaching at least action stage, if not 
minor flood stage within the next week. By late next week,
ensemble guidance indicates 40-60% probabilities for CT river 
locations to exceed minor flood stage and low probabilities (< 
15%) for moderate flood stage.

For some rivers across RI and eastern MA (e.g. Taunton River at
Bridgewater), snowmelt could lead to potential minor flooding as
early as Monday or Tuesday. We will also need to watch some of
the smaller rivers, such as the Pawcatuck River at Westerly, the
Assabet River at Maynard and the Shawsheen River at Wilmington
for possible flooding later next week.

&&

.AVIATION /04Z SUNDAY THROUGH THURSDAY/...

Forecaster Confidence Levels...

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

06z TAF Update...

Today...High confidence in trends with moderate confidence in 
timing. 

Any lingering scattered showers should come to an end by early-mid 
morning. Otherwise...widespread IFR/LIFR conditions very early this 
morning will gradually improve today...but this will be a slow 
process. We do expect most locations northwest of I-95 to improve to 
VFR by mid afternoon as drier air works into the region.
Meanwhile...IFR-LIFR conditions will persist near the south 
coast and especially the Cape & Islands where fog and areas of 
drizzle may linger into the afternoon. SW winds will shift to 
the W and diminish to 6-12 knots later this morning and 
afternoon. LLWS should also subside this morning as the core of
the LLJ departs...but it will still flirt with the Cape and 
Islands into the afternoon.

Tonight and Monday...High confidence. 

Any lingering IFR/LIFR conditions near the Cape/Islands this evening 
should scour out toward or shortly after after midnight. 
Otherwise...mainly VFR tonight and Monday. Calm/light SW winds 
tonight. Winds on Mon will be from the S-SW at 7 to 15 knots.

KBOS Terminal...High confidence in trends and moderate
confidence in timing.

KBDL Terminal...High confidence in trends and moderate
confidence in timing.

Outlook /Monday night through Thursday/...

Monday Night through Tuesday: VFR. 

Tuesday Night: 

Wednesday: Breezy. Chance RA.

Wednesday Night: Windy with local gusts up to 30 kt. Chance RA.

Thursday: Windy with gusts up to 30 kt. Chance RA, SN likely.

&&

.MARINE...

Forecaster Confidence Levels...

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

Today through Sunday Night...High confidence. 

Lingering rough seas across the outer waters through this
weekend. In addition, a period of southwest wind gusts of 20 to
30 knots tonight into Sunday morning for most of our waters. 
Therefore, Small Craft Advisories continue for most souther New
England Waters.

Lastly, areas of fog and poor visibility will be an issue for 
mariners this entire weekend, especially near the south coast.

Outlook /Monday through Thursday/...

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

Tuesday through Tuesday Night: Winds less than 25 kt. 

Wednesday: Winds less than 25 kt. Seas locally approaching
5 ft. Slight chance of rain. 

Wednesday Night: Strong winds with gusts up to 30 kt. Seas up
to 5 ft. Chance of rain. 

Thursday: Strong winds with gusts up to 35 kt. Rough seas up to
11 ft. Chance of rain.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...None.
RI...None.
MARINE...Small Craft Advisory until 10 AM EST Sunday for ANZ231-234.
     Small Craft Advisory until 7 PM EST Sunday for ANZ232-233.
     Small Craft Advisory until 11 PM EST Sunday for ANZ235-237.
     Small Craft Advisory until 10 PM EST Sunday for ANZ250.
     Small Craft Advisory until 1 PM EST Sunday for ANZ251.
     Small Craft Advisory until 7 AM EST Monday for ANZ254>256.

&&

$$

DISCUSSION...Belk/McMinn/Mensch
AVIATION...Frank
MARINE...Belk/Mensch