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FXUS61 KBOX 250212

Area Forecast Discussion
National Weather Service Taunton MA
1012 PM EDT Sun Sep 24 2017

High pressure covering much of the Eastern USA will bring warm and
dry weather to Southern New England the first part of this week.
Cold front approaches southern New England during Wednesday
afternoon and triggers scattered showers. Cold front slowly moves
through southern New England on Thursday and offshore Thursday
night. Maria will bring swells to the south coast, but the center is
expected to pass well southeast of New England late this week.



As per observations and GOES16 fog product, fog and stratus are
advecting onshore across Cape Cod/Vineyard/Nantucket. There
have been a couple of reports of 1/4 mile vsbys, but most spots
show 2-4 miles at most. There is still a reasonable chance of
widespread dense fog developing by midnight, but not enough to
go to an advisory at this time. We will continue to monitor.

Fog product also shows increasing fog potential all along the
eastern Mass waters with light east to southeast winds in place
to move any fog onshore. With this as well, no observed fog
reports at this time.

Patchy light fog also showing up in a couple of traditional fog
spots, due to radiation fog.

To sum up... fog forecast remains likely and the forecast will
continue in this direction with both advection and radiation fog
in play.

Otherwise, high pressure brings clear skies and light wind. Fari
dry weather overnight with min temps mainly in the low to mid


Strong subtropical ridge remains in control across New Eng with
sunshine and unseasonably warm conditions. However, stratus may
linger through the morning across Cape/Islands. Similar
850/925 mb temps suggest temps close to today with upper 80s to
around 90 interior but cooler along the immediate coast where
sea breezes are likely.

Monday night...
As Maria lifts north across SE US waters, higher PWAT air and
KI values will approach SNE from the east along with increasing
elevated instability. This will lead to a risk of showers across
SE New Eng and have chc PoPs for Cape/Islands. Otherwise, the
guidance is indicating stratus and fog may be more expansive
across SNE as higher dewpoints move in. Low temps will be in the



* Very warm temperatures persist into Wednesday
* Scattered showers Wednesday afternoon through Thursday night
* Maria will bring swells to the south coast but will sharply
  recurve out to sea southeast of New England late in the week

A weakening high pressure ridge should linger across southern
New England Tuesday into the first part of Wednesday. Light flow
will likely mean seabreezes, with lower temperatures along the
immediate coast.

A surface cold front should cross our region Wednesday night
into Thursday. Given the summer-like warmth ahead of this
front, some isolated thunderstorms are not out of the question.
The increasing southwest flow ahead of this cold front might
also be strong enough to tap into some tropical moisture from
Maria. If this moisture is available, it could lead to locally
heavy downpours. Some question as to how quickly this cold front
will move offshore, particularly once it reaches the coastal
plain of RI and southeast MA.

High pressure should build in from the west Friday into
Saturday. Besides a chance of some lingering showers Friday
morning across the Cape and islands, much of this period will be
dry. It will also be noticeably cooler, with below normal
temperatures expected.


Forecaster Confidence Levels...

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

Short Term /through Monday Night/...

Tonight...Fog and low clouds will linger through the night.
Most likely on Cape Cod and Islands, and may spread to parts of
Bristol and Plymouth Counties. Areas of 1/4 mile vsbys or less
expected. VFR elsewhere with patchy fog in the traditional fog

Monday...High confidence. VFR, but areas of IFR stratus and
patchy fog may linger over Cape and Islands into the afternoon.
Uncertain timing of improving conditions over the Cape and

Monday night. Moderate confidence. IFR stratus and patchy fog
may become more expansive across SNE but areal extent

KBOS TAF...High confidence. Seabreeze redevelops by 16z Mon.

KBDL TAF...High confidence in TAF.

Outlook /Tuesday through Friday/...


Tuesday...Mostly VFR except for patchy early morning fog.

Wednesday...Mostly VFR but scattered MVFR ceilings/visibilities
in showers, main during the afternoon.

Wednesday night through Thursday...MVFR ceilings and areas of
IFR ceilings and visibilities in scattered showers and fog.

Friday...Mainly VFR. Lingering MVFR in scattered showers across
the Cape and islands in the morning.


Forecaster Confidence Levels...

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

Short Term /through Monday Night/...High confidence.

Winds will remain light through Mon night with high pressure
over the waters. However, increasing long period south swell
from Hurricane Maria will be moving into the waters with
potential for 7 to 8 ft seas over southern waters Mon/Min night.
SCA for seas will continue. In addition, areas of fog will
result in poor vsbys at times, especially south and east of Cape

Outlook /Tuesday through Friday/...Confidence...High

Relatively light winds are expected through this period. However,
swells from Maria will propagate into the southern coastal waters,
beginning late Sunday night or Monday. Small Craft Advisories will
likely need to be extended due to rough seas for the waters south of
the MA and RI coast for all of this period.

The swells from Maria will likely produce another round of high surf
and dangerous rip currents.

OUTLOOK...Monday night through Friday


Relatively light winds are expected through Friday. However,
swells from Maria will impact the south coastal marine zones,
and Small Craft Advisories will likely be needed due to rough
seas for much of this week.

The swells from Maria will likely produce continuing high surf and
dangerous rip currents, probably lasting most of this week.


Long period swell from Hurricane Maria will be moving north
into the south coastal waters. WNAWave guidance indicating
increasing swell to 7-8 ft with a period of 15 seconds moving
into the south coastal waters Mon into Mon night and up to 9 ft
on Tuesday. This will result in increasing high surf and
dangerous rip currents. High surf advisory will continue and
will extend through Tue, and it is likely the high surf will
continue through the week even as Maria likely recurves out to
sea well southeast of New England.


Record high today was broken at BDL with a temp of 92 degrees.
Record high today was broken at ORH with a temp of 86 degrees.

Two of four climate sites broke max temp records today. Another
chance for record high temps Monday, when records are 85-90.
Records jump up Tuesday to 89-95, while less mixing will lead to
lower max temps. So the chance for new records diminishes
Tuesday. The current record max temps for the three
days...today, Monday, Tuesday...are:

BOS  90/1959  89/1926  95/1881
ORH  85/2010  85/1970  91/1930
BDL  89/1959  90/2007  93/2007
PVD  87/1959  89/1920  89/2007

Also, dew points in the 60s, while high for this time of year,
are not unprecedented. The daily extreme high values for dew
points are still in the low 70s, except for a couple of 68 and
69 values at Worcester.


MA...High Surf Advisory until 6 PM EDT Tuesday for MAZ020-022>024.
RI...High Surf Advisory until 6 PM EDT Tuesday for RIZ006>008.
MARINE...Small Craft Advisory for hazardous seas until 6 PM EDT Tuesday
     for ANZ235-237-254>256.



NWS BOX Office Area Forecast Discussion