Richmond, New Hampshire Weather Forecast Discussion

474
FXUS61 KBOX 051847
AFDBOX
Area Forecast Discussion
National Weather Service Boston/Norton MA
247 PM EDT Fri Sep 5 2025
.SYNOPSIS...
A warm and humid day is on tap for Saturday ahead of an approaching
cold front. This front will bring scattered severe thunderstorms
with localized torrential rainfall Saturday afternoon and evening
across interior southern New England. This activity will weaken some
on approach the Boston to Providence corridor Saturday evening.
However...an anafrontal wave will bring a period of widespread
showers Sunday morning which may linger int the afternoon towards
the coast. Otherwise...much of the work week looks dry and very
pleasant outside the risk for a few brief showers around mid-
week.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
Key Messages:
* Rain this morning will give way to dry conditions this afternoon.
Frontal boundary continues to move from west to east across southern
New England this morning with periods of moderate rainfall. Cannot
rule out a rumble of thunder as well with marginal instability. Rain
moves out early this morning with clearing skies. Isolated warm
advection showers cannot be ruled out this afternoon for areas north
of Route 2 in northern Massachusetts, as the best forcing is across
northern New England. Otherwise, it`s a warm and muggy afternoon, a
blend of sun and clouds. Temperatures reach the low to middle 80s,
the south coast remains less warm with highs in the upper 70s to
80F. Dew points are noticeably higher and range between the low 60s
across interior locations with middle to upper 60s for the coastal
plain. Additionally, have breezy S to SSW winds 10-15 mph and gusts
up to 25 mph.
Dry tonight, increasing low level moisture along the south coast may
lead to areas of fog/stratus. Mild and muggy overnight, lows fall to
the middle and lower 60s.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
Key Messages:
* Dry to begin, strong to severe storms develop Saturday afternoon
  across southern New England interior.
* Cold front is slow to exit and leads to continued rain showers
  overnight through Sunday morning.
Summer heat and humidly stretches into Saturday with highs returning
to the low to middle 80s! Plus, dew points are into the upper 60s to
perhaps as high as 70F. This helps fuel convective storms during the
afternoon as a mid-level trough and cold front approach, leading to
isolated severe thunderstorms across interior New England. SPC does
highlight the area of greatest risk well with the Day 2 Outlook. If
you are planning to spend the day outdoors, remember to be weather
aware!
Early sunshine will help to warm things up as mentioned, also help
to build instability, with 1,500 J/kg of mean CAPE based off of HREF
with values as high as 2,000 units. The wind field is also looking
more impressive with effective shear 35-45 knots and the effective
SRH 100+ units. SREF shows modest probabilities for severe weather
and the low chance for a tornado for areas of interior southern New
England. The fly in the ointment will be timing of the best forcing,
as the best lift arrives mid to late afternoon. Area of risk is
shown well on the Day 2 Outlook from SPC. Storms are likely to fall
apart as the move east and towards the I-95 corridor. Bit of better
news, feel that the I-95 corridor will remain free of rain for much
of the daylight hours. Tonight there was a discussion whether to
upgrade from a Marginal Risk to a Slight Risk but held off due to
lower confidence. That said, there will be a reevaluation on the day
shift, which could lead to an upgrade in category. Primary hazards
are straight-line damaging wind gusts as the DCAPE values are 900-
1,000 J/kg, hail, heavy downpours and a lower risk, as we like to
say, a non-zero chance for a tornado. With PWATs nearing 1.8" with
isolated area of 2.0" localized flash flooding is possible,
especially for urban locations and areas with poor drainage. WPC
expanded a Marginal ERO into much of southern New England for areas
west of I-95. Timing the convection, reviewing the 00z CAMs storms
could fire in eastern NY/western MA as early as 12-2pm with activity
continuing through the evening hours. Given poor mid-level lapse
rates these storms will likely start to fall apart shortly after
sunset. The cold front is slow to exit and leads to showers
overnight into the start of Sunday.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
Key Messages...
* Cooler with showers Sun am, which linger into afternoon on coast
* Mainly dry/pleasant for much of next week...cool nights/mild days
* Offshore low may briefly graze the coast with a few showers Wed
Details...
Sunday...
An anafrontal wave will result in a wet Sunday morning for much of
southern New England given persistent southwest flow aloft. We still
need to sort out the axis of the most significant rain...but there
is often a narrow area that can receive quite the soaking in these
setups. Some elevated instability around too...so there will be an
isolated t-storm risk in the morning especially southeast of I-95.
We should see things dry out across the interior Sunday
afternoon...but showers may linger into the afternoon along and
southeast of the I-95 corridor. High temps will probably be held in
the middle 60s to the lower 70s given the clouds and rain.
Monday through Friday...
Dry/very pleasant weather is in store for much of the upcoming work
week...outside of an offshore low may briefly graze the coast with a
few showers mid-week. High pressure building in behind the cold
front will for the first half of next week will result in cool
nights and mild days. Low temps will probably be in the 40s to the
lower 50s with highs mainly in the 70-75 degree range. In fact...on
the coast and high terrain may see highs in the upper 60s at times.
This might occur near mid-week when a distant offshore low may
briefly graze the coast with a few showers. We may see a a brief
warm up on Thursday with perhaps highs approaching 80. However...a
cold front will likely bring the return to slightly cooler than
normal temps by Friday.
&&
.AVIATION /19Z FRIDAY THROUGH WEDNESDAY/...
Forecaster Confidence Levels...
Low - less than 30 percent.
Moderate - 30 to 60 percent.
High - greater than 60 percent.
18z TAF Update...
Today... High Confidence. Moderate on timing of improvements to
VFR.
IFR cigs scatter out this morning bemusing VFR for the
afternoon. Breezy, SSW wind 10-15 knots with gusts around 25
knots. A few brief gusts approaching 30 knots are also possible
during the afternoon.
Tonight... High Confidence.
VFR, areas of MVFR-IFR are possible across south coast, Cape
Cod, and the Islands. SW wind 8-12 knots.
Saturday... Moderate Confidence.
VFR, becoming MVFR with afternoon thunderstorms. Area of greatest
risk for strong to severe storms are interior southern New England
terminals. Storms likely develop into a squall line after 19z
and move west. Gusty SSW wind 10-15 knots, gusting 25 knots.
KBOS Terminal...Moderate confidence in TAF.
Likely VFR through the overnight and into tomorrow morning.
Gusty SSW winds, 15-20 knots, gusting to 30 knots. Possible
-SHRA and -TSRA activity after 22z as a line of storms moves
 from west to east.
KBDL Terminal...High confidence in TAF.
Outlook /Sunday through Wednesday/...
Sunday: Mainly VFR, with areas MVFR possible. Breezy. Chance
SHRA, slight chance TSRA.
Sunday Night: VFR. Breezy. Slight chance SHRA.
Monday: VFR. Breezy.
Monday Night: VFR.
Tuesday through Tuesday Night: VFR. Breezy.
Wednesday: Breezy. Slight chance SHRA.
&&
.MARINE...
Forecaster Confidence Levels...
Low - less than 30 percent.
Medium - 30 to 60 percent.
High - greater than 60 percent.
* A Small Craft Advisory is in effect into Saturday evening
Tonight and  Saturday... High Confidence.
SSW for continue tonight and Saturday ahead of a cold front with
gusts between 20 and 30 knots. Strongest of those winds will
be nearshore Saturday afternoon. Seas on the outer waters are
building 4-5 feet and near shore waters are 3-4 feet. A strong
cold front will move across the waters late Saturday into Sunday
morning, rain and thunderstorms are possible.
Outlook /Sunday through Wednesday/...
Sunday: Winds less than 25 kt. Seas locally approaching 5 ft.
Rain showers, isolated thunderstorms. Local visibility 1 to
3 nm.
Sunday Night: Winds less than 25 kt. Areas of seas approaching
5 ft. Chance of rain showers.
Monday: Winds less than 25 kt. Seas locally approaching 5 ft.
Monday Night through Tuesday: Winds less than 25 kt.
Tuesday Night: Winds less than 25 kt. Seas locally approaching
5 ft. Slight chance of rain showers.
Wednesday: Low risk for Small Craft Advisory winds with gusts
up to 25 kt. Areas of seas approaching 5 ft. Chance of rain
showers.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...None.
RI...None.
MARINE...Small Craft Advisory until 7 PM EDT this evening for ANZ230-
     236.
     Small Craft Advisory until 8 PM EDT Saturday for ANZ231>235-
     237-250-251-254>256.
&&
$$
SYNOPSIS...Frank
NEAR TERM...Dooley
SHORT TERM...Dooley
LONG TERM...Frank
AVIATION...FT/Frank
MARINE...FT/Frank

NWS BOX Office Area Forecast Discussion