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

Area Forecast Discussion
for Boston / Norton, MA

        
000
FXUS61 KBOX 301127
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
727 AM EDT Thu Apr 30 2026

.WHAT HAS CHANGED...

No significant changes to the forecast. 

&&

.KEY MESSAGES...

- Scattered showers wind down from west to east this
  afternoon...but a brief spot shower or two remains possible
  into this evening. Sunshine returns on Fri.

- Cooler and mainly dry this weekend with a coastal storm passing 
  well offshore.

- Warmer albeit unsettled conditions return next week.

&&

.DISCUSSION...

KEY MESSAGE 1...Scattered showers wind down from west to east
this afternoon...but a brief spot shower or two remains 
possible into early this evening. Sunshine returns on Fri.

Shortwave and associated low pressure will continue to result in
scattered showers this morning. This activity will dissipate
from west to east this afternoon as deeper moisture/forcing
exits this region. Otherwise...upper trough may result in a
brief spot shower or two into this evening but overall most of
the afternoon and evening hours will be dry. Highs generally
between 55 and 60 today. Lows tonight mainly in the upper 30s
and lower 40s with perhaps some localized patchy fog very late
tonight in the typically prone locations. 

Plenty of sunshine returns for Friday with pleasant high
temperatures mainly in the lower to middle 60s.

KEY MESSAGE 2...Cooler and mainly dry this weekend with a coastal 
storm passing well offshore.

Amplified pattern over the weekend should feature a building ridge 
of high pressure over central Canada which traps a closed 532 
decimeter upper low over southern Ontario. There are still slight 
differences among global guidance in the exact location and strength 
of the ridge over Canada. The ECMWF shows a more southern solution 
and thus a bit more in the way of shower activity later Saturday 
afternoon. On the whole, southern New England should be far 
enough removed from coldest air aloft to keep us mostly dry, 
especially given W/NW flow, but pattern certainly favors diurnal
clouds and perhaps a few afternoon sprinkles over weekend.

Guidance continues to show a fairly weak low that may bring a few 
showers or perhaps a period of light rain to the southern coast and 
the Cape/Islands Saturday night into Sunday morning. Recent trends 
still paint a weak unamplified picture with the majority of the EPS 
and GEFS ensembles showing a further offshore track. 

KEY MESSAGE 3... Warmer albeit unsettled conditions return next 
week.

Pattern relaxes a bit early next week as closed low lifts farther 
north, but we remain under broad cyclonic flow aloft. Eventually 
longer range guidance shows closed low setting up near upper Great 
Lakes, putting us in SW flow aloft. This could end up bringing more 
moisture and warmer air into region by Tuesday/Wednesday as weak 
front approaches resulting in scattered showers. Ensemble guidance 
shows 850 mb temp anomalies climbing to +10F above climo Tuesday and 
Wednesday of next week.

&&

.AVIATION /12Z THURSDAY THROUGH MONDAY/...

Forecaster Confidence Levels...

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

12z TAF Update...High confidence.

IFR conditions dominate into early afternoon with scattered
showers. Gradual improvement during the afternoon from west to
east. MVFR conditions may linger into this evening near the 
coast...but generally expect improvement to VFR conditions 
tonight. We will have to watch for some very localized fog 
patches overnight...but nothing widespread. VFR conditions on 
Friday. Light and variable winds become light NW tonight. WNW
around 10 knots on Fri. 

KBOS Terminal...Moderate confidence in TAF. Main uncertainty is
the when IFR conditions improve to MVFR levels sometime during
the afternoon. 

KBDL Terminal...High confidence in TAF.

Outlook /Friday Night through Monday/...

Friday Night: VFR. 

Saturday through Saturday Night: VFR. Chance RA.

Sunday: VFR. Breezy. Slight chance RA.

Sunday Night: VFR. 

Monday: VFR. Breezy.

&&

.MARINE...
Forecaster Confidence Levels...

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

High confidence through the end of the week.

Pressure gradient between slow-moving low pressure SE of the 40/70 
benchmark and high pressure over the Canadian Maritimes keeps E/NE 
winds in play through the end of the week. 

Main issue will be the long fetch of NE winds resulting in rough 
seas of 5 to 8 feet on outer waters through Thu where SCA remains 
posted. Areas of fog will persist through tonight along with 
showers.

Outlook /Friday Night through Monday/...

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

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

Saturday Night through Sunday: Winds less than 25 kt. Seas
locally approaching 5 ft. Chance of rain. 

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

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

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...None.
RI...None.
MARINE...Small Craft Advisory until 8 AM EDT Friday for ANZ250.
     Small Craft Advisory until 8 PM EDT Friday for ANZ254>256.

&&

$$

DISCUSSION...Frank/FT
AVIATION...Frank
MARINE...FT