NWS Forecast Discussion
000
FXUS61 KBOX 280744
AFDBOX
Area Forecast Discussion
National Weather Service Boston/Norton MA
344 AM EDT Sun Apr 28 2024
.SYNOPSIS...
Warm but unsettled conditions today with a few chances of
widely scattered showers through early Monday. Mainly dry and
warm temperatures on tap for Monday, except it`s considerably
cooler along portions of the immediate coast. A backdoor cold
front will bring cooler temperatures Tuesday and Wednesday
before it warms up again by late in the week. The greatest risk
for a period of showers will be later Tuesday into Wednesday.
Next period of unsettled weather arrives around Saturday.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Numerous showers across southern New England into northern New York
early this morning, in northern New York there is enough instability
for rumbles of thunder. These showers are associated with a warm
front that is slowly making its way across the northeast states.
Would not be shocked if a couple make it to western Massachusetts or
northwestern Connecticut. Otherwise, showers east of the CT River
will diminish shortly after sunrise.
Surface high pressure which gave us wonderful conditions over the
past couple of days is shifting south along with surface pressure
falls. Today features more clouds than sunshine. WAA increases PWATs
across southern New England, well above an inch in most cases.
Aloft, mid-level ridge with pulses of energy provides enough lift to
keep the clouds about and a few hit-and-miss showers. An isolated
rumble of thunder is not out of the question for areas furtherest
north and west where a some breaks in the clouds may allow for a few
hundreds units of CAPE. Window for these showers are between 22z and
03z, does look to be more sct`d in nature. Will say there are some
discrepancies in the CAMs this morning, most notably the ARW, which
shows more widespread light to moderate rains with potential for
embedded thunder into southern Connecticut.
Given higher PWATs, higher humidity is on tap today, dewpoints are
increasing through the 40s and 50s. This is most noticeable since the
previous two days have featured dewpoints in the 20s and 30s. Highs
this afternoon climb into the upper 60s and lower 70s away from the
coast. Perhaps a few mid 70s in the mid CT River Valley. The coastal
plain, areas south of Boston to Providence area in the mid 60s. The
immediate south coast will be the coolest do to the onshore winds,
from the southwest, keep temperatures in the mid 50s to 60
degrees.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/...
A mild night ahead, many locations are in the lower and mid 50s, at
the coast temperatures are slightly cooler in the upper 40s and low
50s. Deep southwest flow and overcast sky cover helps maintain these
temperatures. Any lingering showers exit the region between 03z and
06z. Do think there will be areas of coastal fog that develops, many
VSBY guidance show potential of widespread fog and/or low stratus. A
wind shift to the north-northwest around dawn should help to advect
lower dewpoints, this should help to cut down on the duration of the
fog. That said, a later shift in the wind could prolong the fog
across southeast Massachusetts and Rhode Island.
Clouds to start Monday, mid-level ridging is nearly over New England
by afternoon should promote cloud cover to gradually thin. Otherwise
a warm afternoon away from the coast. While coastal towns are in the
upper 50s and lower 60s, just a few miles inland temperatures
quickly climb into the 70s! Further inland, mid and upper 70s are a
good possibility. In fact, NBM has 20-30 percent probabilities of
80F across the lower CT River Valley, Springfield to Hartford. What
will be tricky, how far inland does the sea breeze make it. If the
guidance shows the sea breeze to be a bit strong it could mean the
forecast highs will need to be lowered. In addition, if clouds
remain stubborn and don`t thin out enough, it could lead to cooler
temperatures as well. Something to keep in mind heading into
Monday.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
Key Points...
* Periodic rain chances through the week, first late Tue/Wed then
again on Friday.
* After a warm start to the week temps cool Tue/Wed before warming
back up late week.
Details...
Tuesday and Wednesday...
Tuesday a weak surface low pressure moves into SNE and this in
conjunction with the high to the north will push a backdoor cold
front through the region taking those 70s we enjoyed on Monday out
of the forecast for two days. Highs will be limited to the 60s
(inland) and 50s (along the coast) each day. A mid level shortwave
moves out of the Great Lakes Tuesday night bringing a round of light
rain to the region overnight into Wednesday. The best forcing from
divergence at 300 mb and upslope orographics will place the bullsey
for the largest rainfall totals over northern/central MA and areas
further to our north and west.
Thursday through Saturday...
Mid level ridging then builds in for the latter half of the week
leading to a warming airmass (highs back into the 70s!) and dry
weather. The trend in the guidance over the last 24 hours has been
to slow the advancement of our next disturbance, now looking more
likely to bring unsettled weather for sometime over the weekend but
as early as Friday night. GEFS ensemble guidance is more excited
about the possibility of measurable rain Friday night than the EPS;
for now sticking with a blend and low POPs.
&&
.AVIATION /08Z SUNDAY THROUGH THURSDAY/...
Forecast Confidence Levels:
Low - less than 30 percent.
Moderate - 30 to 60 percent.
High - greater than 60 percent.
06z TAF Update...
Through 12z... High confidence.
VFR/MVFR, becoming widespread MVFR with isolated IFR within
areas of scattered light rain showers. Winds are south-southwest
5 to 10 knots, locally higher gusts to 20 knots near the coast.
Today... High confidence.
MVFR/IFR conditions early in the morning. Improving cigs after
16z, trending VFR some time after 18z/20z. Lower cigs may linger
later into the afternoon for terminals on Cape Cod & Islands
into the late afternoon. Winds are southwest 8 to 12 knots.
Tonight... Moderate confidence.
Generally VFR away from the Cape and Islands where patchy fog
will develop. Winds are southwest to start, transitioning to
the west-northwest across the interior by daybreak.
Monday... Moderate confidence.
VFR, mid-level clouds across western terminals 050-070k ft.
Northerly winds for most, but do expect a sea breeze for
eastern Massachusetts, east-northeast winds along the north and
south shore of Boston. Sea breeze may be strong enough to reach
KPVD with a east-northeast wind.
KBOS TAF...High confidence in TAF. Scattered showers possible
between 08Z and 12Z. MVFR develops behind diminishing showers
for the better part of the morning. VFR at times later this
afternoon, before returning to MVFR/IFR overnight.
KBDL TAF...High confidence in TAF. Scattered showers through
09z, becoming MVFR shortly after. VFR conditions later this
afternoon along with a low chance of a brief afternoon shower.
Trending back to MVFR tonight.
Outlook /Monday Night through Thursday/...
Monday Night: Mainly VFR, with areas MVFR possible. Slight
chance RA.
Tuesday: Mainly MVFR, with areas VFR possible. Chance RA.
Tuesday Night: Mainly MVFR, with local IFR possible. Chance RA.
Wednesday: Mainly VFR, with local IFR possible. Chance RA.
Wednesday Night: Mainly VFR, with local MVFR possible.
Thursday: VFR.
&&
.MARINE...
Forecaster Confidence Levels:
Low - less than 30 percent.
Medium - 30 to 60 percent.
High - greater than 60 percent.
Through Monday... High confidence.
Generally tranquil boating conditions expected through Sunday
outside of a few rounds of widely scattered showers overnight
tonight and tomorrow evening. Onshore breeze across the eastern
waters will subside quickly this evening giving way to primarily
south/southwest winds for Sunday. Some patchy fog possible
Sunday night into early Monday morning. Dry conditions with mix
of clouds Monday afternoon along with northerly winds 10 to 15
knots. Seas mainly 3ft or less all waters.
Outlook /Monday Night through Thursday/...
Monday Night: Winds less than 25 kt. Slight chance of rain.
Tuesday through Wednesday: Winds less than 25 kt. Chance of
rain.
Wednesday Night through Thursday: Winds less than 25 kt.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...None.
RI...None.
MARINE...None.
&&
$$
SYNOPSIS...BW/Dooley
NEAR TERM...Dooley
SHORT TERM...Dooley
LONG TERM...BW
AVIATION...BW/Dooley
MARINE...BW/Dooley
NWS BOX Office Area Forecast Discussion
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