Lexington, Massachusetts, USA
000
FXUS61 KBOX 140622
AFDBOX
Area Forecast Discussion
National Weather Service Boston/Norton MA
222 AM EDT Tue Apr 14 2026
.WHAT HAS CHANGED...
No significant changes, the forecast remains on track.
&&
.KEY MESSAGES...
- Summerlike warmth Today and Wednesday away from the coast, with
scattered late day/early evening thunderstorms and a low risk of
severe weather.
- Backdoor front may bring cooler temperatures Thu-Sat, especially
in eastern MA, but uncertainty is high in exactly where it ends up.
- More seasonable temperatures early next week.
&&
.DISCUSSION...
KEY MESSAGE 1...Summerlike warmth Today and Wednesday away from the
coast, with scattered thunderstorms & a low risk of severe weather.
Confidence remains high in summerlike warmth Today and Wednesday
away from both coasts, as strong subtropical ridge builds over the
region from the Gulf. All hi res guid has highs both days easily
reaching the upper 70s to lower 80s inland (+18C to +20C at 925
mph). Any early morning fog will burn off rapidly. Meanwhile, a weak
pressure gradient supports cooling seabreezes for the immediate
coastal areas, with temps dropping into the 50s to around 60.
However, locations such as Boston and eastern MA, late morning/early
afternoon seabreeze may give way to a warmer wind shift to the SSW
after 18z/19z, as low level southwest jet traverses the region. This
would yield a late day high temp, after 4/5pm.
We continue to monitor the potential for severe storms during late
afternoon and evening both Tue and Wed, mainly 2 PM to 10 PM
(highest probs 4-8pm). Low amplitude s/wvs moving through the
westerly flow, only yielding weak forcing for ascent, which is
evident by the lack of height falls from each of these s/wvs.
However, modest mixed layer CAPE up to 1000 j/kg, modest mid level
lapse rates around 6.5C/KM and 0-6km shear up to 45 kt, providing
sufficient instability and shear to compensate for the lack of
strong forcing. This is reflective by hi res guid offering 2-5km
updraft helocity tracks into western-central MA/CT, along with
highest probabilities of lightning. Convection will weaken as it
traverses eastward into RI and eastern MA. Not expecting a
widespread severe weather, but can't rule out a few isolates storms
that approach severe in western-central CT/MA. Given the shear and
instability, along with steep low level lapse rates, strong to
damaging winds will be the main threat.
As previous forecaster noted, atmosphere still looks favorable for
thunderstorms on Wed, although the high-res models don't show much
in way of activity. Severe risk is lower on CSU and SPC HREF with
axis shifted farther south into CT/RI and south of the Mass Pike.
While overall severe threat remains low, we can't rule out a few
storms capable of producing localized wind damage or hail.
KEY MESSAGE 2...Backdoor front may bring cooler temperatures Thu-
Sat, especially in eastern MA, but uncertainty is high in exactly
where is ends up.
Temp forecast becomes more uncertain later this week, as short wave
energy riding up and over the top of the subtropical ridge, may be
strong enough to lower heights and have a backdoor front enter SNE,
especially northeast MA. However, at this time range, low
predictability regarding the amplitude of individual short waves
and attending surface boundaries/backdoor fronts. Thus, certainly
potential for big temperature busts this far out in time.
Showers and thunderstorms could be more widespread Friday, as multi
model guidance suggest a more robust mid level short wave moving
across the Northeast into New England.
KEY MESSAGE 3...More seasonable temperatures early next week.
As expected, difficult to sustain temps 20+ degs warmer than normal
in April, thus good multi model agreement (especially at this time
range) that a strong cold front is expected to cross region sometime
Sun, accompanied by some showers, that could spill into early
Monday. Much cooler airmass follows behind front early next week,
with temperatures returning to more typical levels for mid April,
generally in 50s to around 60.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
Forecaster Confidence Levels...
Low - less than 30 percent.
Moderate - 30 to 60 percent.
High - greater than 60 percent.
06z TAF Update:
Tuesday...High Confidence overall, moderate on exact timing and
southeast extent of T-storms.
VFR with S/SW winds and coastal sea breezes 8-12 kts. Sea breezes
likely shift to SSW after 18z/19z. Scattered showers and
thunderstorms are possible during the afternoon and evening (20-
00Z), especially across interior southern New England. Lower
confidence in thunderstorm chances into RI and eastern MA. Brief
MVFR possible in any moderate showers or thunderstorms. Winds should
most likely lean more SW at 10-15 kts, gusts to 22 kts in the
shower/storm timeframe. Locally higher/erratic gusts in any
thunderstorms.
Tuesday night...high confidence in trends, lower on exact timing of
details.
Any evening scattered showers/t-storms dissipate by 02z/03z. Mainly
VFR and dry thereafter. Although, we will have to watch IFR
conditions just offshore, northeast of KBOS.
Wednesday...high confidence on trends, lower on exact timing of
details.
Mainly VFR and dry in the morning, then isolated to scattered
afternoon/evening showers/T-storms. Backdoor front may come onshore
into northeast MA, including KBOS and possibly accompanied by
IFR/LIFR conditions in low clouds/fog.
KBOS Terminal...High confidence in TAF. Early seabreeze develops
14z/15z, then likely shifts to the S after 18z/19z. Showers possibly
21z-02z. Probability of lightning too low to include in the TAF.
KBDL Terminal...High confidence in TAF. Brief -TSRA possible 19z-
00z.
Outlook /Wednesday Night through Saturday/...
Wednesday Night through Thursday: VFR. Chance SHRA, slight
chance TSRA.
Thursday Night through Friday Night: VFR. Chance SHRA.
Saturday: Mainly VFR, with local MVFR possible.
&&
.MARINE...
Forecaster Confidence Levels...
Low - less than 30 percent.
Moderate - 30 to 60 percent.
High - greater than 60 percent.
220 AM update...
High confidence through the end of the week, except across the
northern MA waters, where uncertainty is high regarding the timing
and position of backdoor front Wednesday through the end of the
week.
SCA remains in effect for leftover rough seas. Weak pressure
gradient will support subsiding seas along with developing
seabreezes near shore beginning late Tue morning. Only other issues
will be late night/early morning fog and possible late day/evening
brief isolated shower/thunderstorm.
Outlook /Wednesday Night through Saturday/...
Wednesday Night: Winds less than 25 kt. Seas locally
approaching 5 ft. Chance of rain showers, slight chance of
thunderstorms.
Thursday through Thursday Night: Winds less than 25 kt. Seas
locally approaching 5 ft. Slight chance of rain showers.
Friday: Winds less than 25 kt. Seas locally approaching 5 ft.
Chance of rain showers.
Friday Night: Winds less than 25 kt. Slight chance of rain
showers.
Saturday: Winds less than 25 kt.
&&
.CLIMATE...
Upcoming record highs:
Tue 4/14
Boston 83 in 2023
Hartford 96 in 2023
Providence 87 in 2023
Worcester 90 in 2023
Wed 4/15
Boston 82 in 1896
Hartford 88 in 1941
Providence 82 in 1938
Worcester 85 in 1941
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...None.
RI...None.
MARINE...Small Craft Advisory until 11 AM EDT this morning for ANZ235-
237.
Small Craft Advisory until 2 PM EDT this afternoon for
ANZ254>256.
&&
$$
DISCUSSION...Nocera
AVIATION...Nocera
MARINE...Nocera
CLIMATE...Nocera
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