Lexington, Massachusetts, USA
000
FXUS61 KBOX 081803
AFDBOX
Area Forecast Discussion
National Weather Service Boston/Norton MA
103 PM EST Thu Jan 8 2026
.WHAT HAS CHANGED...
Increased confidence in patchy freezing drizzle/fog that may result
in icy conditions on untreated surfaces tonight into Friday
morning.
&&
.KEY MESSAGES...
- Areas of freezing fog tonight into Friday morning. Light rain
overnight Friday.
- Another round of rain later Saturday into Sunday bringing
mainly a soaking rainfall to southern New England.
- Breezy to gusty west winds Sunday night into Monday.
&&
.DISCUSSION...
KEY MESSAGE 1...Patches of freezing fog tonight into Friday
morning. Light rain overnight Friday.
Surface high pressure moves offshore overnight. Light return flow
allows dew point temperatures to rise into the upper 20s/ lower 30s.
BUFKIT soundings show ideal conditions for fog with an inversion
near the surface along with a saturated layer up to about 1 kft.
Given the surface temperatures are below freezing, patchy freezing
fog is likely late tonight into Friday morning. Thankfully, the
freezing fog threat will quickly diminish after 12z Friday as
surface temperatures warm above freezing. Strengthening southwest
winds aloft result in strong WAA with 850mb temperatures rising
between +4C to +6C Friday afternoon. As a result, it should be a
warmer day with highs climbing into the mid and upper 40s for most
of the region. NBM even shows areas of southern Massachusetts
and Rhode Island touching 50F. Surface warm front moves through
southern New England Friday night into early Saturday morning.
Guidance still shows a broken band of showers with QPF between
0.10 and 0.25 inches, certainly not a washout. Highest totals
will be further to the north across northern New England, with
the parent low pressure system. No p-type issues expected with
this event as temperatures Friday night remain in the low-40s at
the coast and upper 30s across interior locations.
KEY MESSAGE 2...Another round of rain later Saturday into Sunday bringing
mainly a soaking rainfall to southern New England.
By Saturday morning, Friday's system will be exited to the east
along with the bulk of the rain showers. A few showers may linger
along the south coast and Cape/Islands in the morning.
The approaching system will be better synoptic support than Friday's
system, consisting of deep, closed-off mid-level trough coupled with
a southwesterly upper level. Model guidance has been consistent with
showing developing of a secondary surface low offshore that tracks
northeast around Cape/Islands or just offshore. An enhanced SW jet
will help transport above normal moisture into southern New England,
around 230-280 percent of normal. This will set the stage for
another round of rain with more rain expected to fall compared to
the late Friday system. Smaller details such as the exact track of
the surface low and timing are still less certain due to subtle
difference among model guidance. Rain will likely arrive in the
afternoon, late morning at earliest for the south coast. Rain
continues Saturday night, tapering off Sunday morning. Showers may
linger across the south coast and Cape/Islands through the
afternoon. For total rain, ensembles show a likely range of 0.50-1"
with the higher end of that range favored for the south coast,
southeast MA, and Cape/Islands. The axis of higher amounts shifts a
little from run to run owing to the uncertainty in the low track.
Upper percentiles of ensemble guidance show potential for amounts up
to 1.5" for the Cape/Islands.
One thing that will need to be monitored will be temperatures across
the northern parts of the interior Saturday night. A cooler airmass
will be in place behind the morning cold front and warm air aloft
will be pushing in from the south with the precipitation. If
temperatures end up cold enough, this would result in a brief period
of freezing rain at onset Saturday night. There are subtle
differences among the global models on temperatures and we'll have
to wait to get in higher-res guidance. Overall, if it ends up cold
enough this would be fairly isolated and confined to the northern
Berkshires and north Worcester Hills.
KEY MESSAGE 3...Breezy to gusty west winds Sunday night into
Monday.
A cold front moves through later Sunday into Monday. A tightened
pressure gradient behind the exiting low pressure, moderate westerly
LLJ, and some CAA will support gusty west winds Sunday night into
Monday. The set-up isn't favorable for high winds, but is sufficient
to support gusts 25-40 mph with the higher gusts over the higher
terrain.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
Forecaster Confidence Levels...
Low - less than 30 percent.
Moderate - 30 to 60 percent.
High -greater than 60 percent.
18Z TAF update...
Tonight... Moderate Confidence.
IFR/MVFR ceilings, potential for fog or freezing fog with
visibilities lowering 1/2SM to 1SM. South wind less than 5
knots.
Friday... Moderate Confidence (timing of lowering ceilings).
VFR, trending to MVFR by mid afternoon as a warm front
approaches. Showery rain possible around and after 00z.
Friday Night...Moderate Confidence on timing of precipitaiton.
MVFR, potential for isolated IFR. Areas of -SHRA move in from
W-E between 22z-00z winding down between 03-06z Friday night.
KBOS Terminal... Moderate Confidence.
MVFR/IFR developing tonight. West-northwest wind around 10
Potential for dense fog tonight into 15z Friday.
KBDL Terminal... High Confidence.
MVFR/IFR tonight, potential for fog or freezing fog tonight
into Friday morning.
Outlook /Saturday through Tuesday/...
Saturday: Mainly VFR, with local MVFR possible. Chance RA,
chance FZRA.
Saturday Night: Mainly IFR, with areas MVFR possible. RA,
chance FZRA.
Sunday: Mainly VFR, with areas IFR possible. Breezy. Chance RA,
chance FZRA.
Sunday Night: VFR. Windy with local gusts up to 30 kt. Chance
RA, slight chance SN.
Monday: VFR. Windy with local gusts up to 30 kt.
Monday Night through Tuesday: VFR. Breezy.
&&
.MARINE...
Forecaster Confidence Levels...
Low - less than 30 percent.
Moderate - 30 to 60 percent.
High - greater than 60 percent.
Today through Saturday... High Confidence.
A lull over the waters tonight, wind increases from the south
on Friday as a warm front lifts over the region. Gusting between
20 to 25 knots and seas increasing 4 to 6 feet by Friday night.
Small craft conditions for most of the waters except the bays
and harbors 00z to 12z Saturday. Seas calm later Saturday
morning before another system approaches from the S late Sat
into Sat night.
Outlook /Saturday through Tuesday/...
Saturday: Winds less than 25 kt. Seas locally approaching 5 ft.
Chance of rain.
Saturday Night: Winds less than 25 kt. Local rough seas. Rain.
Sunday: Winds less than 25 kt. Areas of rough seas. Rain
likely.
Sunday Night: Strong winds with gusts up to 40 kt. Areas of
rough seas. Chance of rain, slight chance of snow.
Monday: Strong winds with gusts up to 35 kt. Areas of rough
seas.
Monday Night through Tuesday: Low risk for Small Craft Advisory
winds with gusts up to 25 kt. Local rough seas.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...None.
RI...None.
MARINE...Small Craft Advisory until 1 PM EST this afternoon for
ANZ254>256.
&&
$$
DISCUSSION...KP/FT
AVIATION...Mensch/FT
MARINE...FT
Meta data:
ID: 30da4dc4-1e6e-4fdf-bb71-ebba3a81e070
Link:
https://api.weather.gov/products/30da4dc4-1e6e-4fdf-bb71-ebba3a81e070
Index:
https://api.weather.gov/products/types/AFD/locations/BOX