NWS Forecast Area Discussion - New England Area

851
FXUS61 KBOX 190815
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
415 AM EDT Sat Oct 19 2019

.SYNOPSIS...
High pressure will build across the region this weekend
bringing dry and seasonable fall-like weather. The remnants of
Nestor may track close enough to the region to bring a period of
light rain late Sunday into Sunday night. Weak high pressure
and dry weather follows Monday. Strong low pressure across the
Great Lakes with another low well south of Nantucket will likely
bring showers and gusty onshore winds Tuesday into Wednesday.
Another high will shift east to the mid Atlantic coast late
Wednesday through Friday, bringing dry conditions and seasonable
temperatures.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
4 AM Update...

Chilly morning across the region with 1020 mb high over NY and PA
continuing to advect cool/dry air into the area. Where winds have
decoupled temps have dipped into the 30s. However many locations
still holding onto a light WNW west wind and has kept temps in the
40s. However winds will continue to diminish thru sunrise so
expecting many more locations to dip into the 30s. Thus will
continue with the Frost Advisory for northern CT into RI and
interior southeast MA.

After a chilly start abundant sunshine will help temps to rise thru
the 40s and 50s this afternoon. Model soundings indicate blyr
deepening to just above 900 mb with temps at this level around +4C.
This will support highs from the upper 50s to lower 60s. It will
feel even milder given full sunshine and light WNW winds.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/...
4 AM update ...

Tonight ...

Another chilly/frosty night ahead with high pressure over the area
providing mostly clear skies and light winds. This combined with a
dry atmosphere will support another night with lows in the 30s,
upper 20s in the some of the typically colder spots.  Given this
cold setup derived mins tonight from the coldest MOS guidance.

Will likely need Frost/Freeze headlines but need to see how cold
temps get before sunrise this morning to see where frost/freeze
occurred which will result to the end of the growing season.

Sunday ...

Another chilly start to the day but morning sunshine will help
temperatures recover. However clouds will be on the increase during
the afternoon as moisture from the remnants of Nestor approach from
the southwest. The global guidance (GFS, EC and UKMET) is less
amplified and suppressed while the Hi Res guidance is more amplified
and farther north with Nestor rain shield. Perhaps the Hi Res
guidance is generating too much diabatic heating and resulting in
more downstream ridging yielding a track closer to the coast. After
collaboration with WPC the recommendation is to follow a non-NAM
solution for this time period. Given still 48-60 hrs out in model
time followed a model blend here given the uncertainty. Not
expecting a washout here but the risk for some light rain late in
the day is possible.

Highs will be 55-60 along with light winds so very pleasant for late
October.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...

Highlights...

* Rain will linger Sunday night into early Monday, mainly south
  of the Mass Pike
* High pressure brings dry conditions Monday
* A cold front will swing east, bringing showers Tuesday into
  Wednesday, with locally gusty winds on Wednesday
* Another high approaches with dry and seasonable conditions
  late next week

Details...

Sunday night and Monday...

Most of the 00Z model suite keeps the remnants of TS Nestor
well S of the region as high pres ridge builds across northern
New England. Increasing E-SE winds will keep good inflow of low
level moisture in place, so will see an area of rain continuing
mainly from the Mass Pike southward Sunday evening then, as the
remnant low shifts further S, should see precip begin to push
off the S coast overnight Sunday night. The rain may linger into
sunrise Monday across portions of the lower Cape and the
islands.

While what`s left of Nestor lingers well E of the mid Atlc
coast, high pressure to the N will keep conditions dry across
the region on Monday. Some scattered clouds will linger along
the coast on light E- NE winds, with mainly sunny skies are
forecast inland. May see wind gusts up to around 15-20 mph along
the S coast closest to the remnant low well offshore. Expect
temps to top off in the upper 50s to near 60 along the immediate
E coast, ranging to the mid 60s across the CT valley.

Tuesday and Wednesday...

While the remnant low continues to spin well SE of Nantucket on
Tuesday, another strong low works NE across the Great Lakes. An
associated cold front will wrap around that low, and will
capture the lingering moisture from the remnant low offshore.
Models have been in rather good agreement with these features,
along with the influx of deep layer moisture ahead and with the
approaching front Tue night and Wed. GEFS ensemble PWAT plume
signaling 2-3 SD above normal, with forecasted QPF on the order
of 0.5 to 0.8 inches of rain from late Tue afternoon through Tue
night away from the SE coast.

Increasing wind gusts will also push into coastal areas late
Tue night into Wednesday as the cold front approaches. May see
gusts up to 20-25 kt along the S coast, with higher winds across
the southern coastal waters. Some timing issues noted on the
model members with the frontal passage on Wed, leaned toward the
somewhat slower GGEM/EC solution, pushing the front offshore by
around midday. Winds will shift to W and may see gusts inland
up to around 20-25 mph as well.

Thursday and Friday...

High pressure will set up S of the region at the end of next
week, centered across the central Appalachians on Thu, then
passing S of New England Thu night/Fri. Will see dry and
seasonable temperatures both days. Highs will be in the upper
50s to mid 60s with lows Thu night in the upper 30s to mid 40s,
except the upper 40s to around 50 along the immediate coast.


&&

.AVIATION /08Z SATURDAY THROUGH WEDNESDAY/...
Forecaster Confidence Levels...

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

Short Term /through Sunday/...

06Z update ... High confidence thru Sunday morning then lowering
Sun PM regarding how far north rain shield and MVFR conditions
from remnants of Nestor track.

Today ... VFR, dry and light WNW winds.

Tonight ... VFR and dry conditions continue but light NW winds
late today become light and variable tonight.

Sunday ... VFR, dry weather and light winds to start the day but
then rain shield from remnants of Nestor approach CT late in the
day.

KBOS Terminal...High confidence in TAF.

KBDL Terminal...High confidence in TAF.

Outlook /Sunday Night through Wednesday/...High confidence.

Sunday Night: Mainly VFR, with local IFR possible. Breezy.
Slight chance RA, patchy BR.

Monday: VFR. Breezy.

Monday Night: Mainly VFR, with local MVFR possible.

Tuesday: MVFR/IFR conditions possible. Breezy. SHRA likely.

Tuesday Night: Mainly IFR, with local MVFR possible. Breezy.
SHRA likely, patchy BR.

Wednesday: VFR. Breezy. Chance SHRA.

&&

.MARINE...
Forecaster Confidence Levels...

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

Short Term /through Sunday/...

Today ... 1020 mb high pressure over NY and PA slowly builds east
into New England providing light WNW winds, subsiding seas, dry
weather and good vsby. High confidence.

Tonight ... more tranquil weather as high pressure crest over the
area.  High confidence.

Sunday ... High pressure off the New England coast in the morning
then watching remnants of Nestor emerging off the Carolina coast.
This system should track well south of 40N/70W benchmark.
Moderate confidence given some uncertainty how far north
remnants of Nestor track.

Outlook /Sunday Night through Wednesday/...Moderate confidence.

Sunday Night: Low risk for Small Craft Advisory winds with
gusts up to 25 kt. Chance of rain.

Monday: Winds less than 25 kt. Local rough seas.

Monday Night: Winds less than 25 kt. Areas of rough seas.
Slight chance of rain showers.

Tuesday: Winds less than 25 kt. Rough seas up to 9 ft. Chance
of rain showers.

Tuesday Night: Winds less than 25 kt. Rough seas up to 8 ft.
Rain showers likely, patchy fog. Areas of visibility 1 to 3 nm.

Wednesday: Low risk for Small Craft Advisory winds with gusts
up to 30 kt. Areas of rough seas. Chance of rain showers.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...Frost Advisory until 8 AM EDT this morning for CTZ002>004.
MA...Frost Advisory until 8 AM EDT this morning for MAZ017-018.
RI...Frost Advisory until 8 AM EDT this morning for RIZ001-003.
MARINE...None.

&&

$$
SYNOPSIS...Nocera/EVT
NEAR TERM...Nocera
SHORT TERM...Nocera
LONG TERM...EVT
AVIATION...Nocera/EVT
MARINE...Nocera/EVT

NWS BOX Office Area Forecast Discussion