Gale Warning 31, NWS Boston/Norton, MA

238 
WHUS71 KBOX 050227
MWWBOX

URGENT - MARINE WEATHER MESSAGE
National Weather Service Boston/Norton MA
1027 PM EDT Fri May 4 2018

ANZ254-255-051030-
/O.CON.KBOX.GL.W.0031.180505T0300Z-180505T1100Z/
Coastal waters from Provincetown MA to Chatham MA to Nantucket MA
out 20 nm-
Coastal Waters extending out to 25 nm South of Marthas Vineyard
and Nantucket-
1027 PM EDT Fri May 4 2018

...GALE WARNING REMAINS IN EFFECT UNTIL 7 AM EDT SATURDAY...

* WINDS AND SEAS...Southwest winds 15 to 25 kt with gusts up to 
  35 kt. Seas 6 to 9 feet.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Gale Warning means winds of 34 to 47 knots are imminent or
occurring. Operating a vessel in gale conditions requires
experience and properly equipped vessels. It is highly
recommended that mariners without the proper experience seek safe
harbor prior to the onset of gale conditions.

&&

$$

ANZ232>234-051030-
/O.CON.KBOX.GL.W.0031.180505T0300Z-180505T1100Z/
Nantucket Sound-Vineyard Sound-Buzzards Bay-
1027 PM EDT Fri May 4 2018

...GALE WARNING REMAINS IN EFFECT UNTIL 7 AM EDT SATURDAY...

* WINDS AND SEAS...West winds 10 to 20 kt with gusts up to 35 
  kt. Seas 3 to 5 feet.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Gale Warning means winds of 34 to 47 knots are imminent or
occurring. Operating a vessel in gale conditions requires
experience and properly equipped vessels. It is highly
recommended that mariners without the proper experience seek safe
harbor prior to the onset of gale conditions.

&&

$$

ANZ230-051030-
/O.CON.KBOX.GL.W.0031.180505T0300Z-180505T1100Z/
Boston Harbor-
1027 PM EDT Fri May 4 2018

...GALE WARNING REMAINS IN EFFECT UNTIL 7 AM EDT SATURDAY...

* WINDS AND SEAS...West winds 15 to 20 kt with gusts up to 35 
  kt. Waves Around 2 feet.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Gale Warning means winds of 34 to 47 knots are imminent or
occurring. Operating a vessel in gale conditions requires
experience and properly equipped vessels. It is highly
recommended that mariners without the proper experience seek safe
harbor prior to the onset of gale conditions.

&&

$$

ANZ231-251-051030-
/O.CON.KBOX.GL.W.0031.180505T0300Z-180505T1100Z/
Cape Cod Bay-Massachusetts Bay and Ipswich Bay-
1027 PM EDT Fri May 4 2018

...GALE WARNING REMAINS IN EFFECT UNTIL 7 AM EDT SATURDAY...

* WINDS AND SEAS...West winds 15 to 20 kt with gusts up to 35 kt.
  Seas 3 to 4 feet.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Gale Warning means winds of 34 to 47 knots are imminent or
occurring. Operating a vessel in gale conditions requires
experience and properly equipped vessels. It is highly
recommended that mariners without the proper experience seek safe
harbor prior to the onset of gale conditions.

&&

$$

ANZ250-051030-
/O.CON.KBOX.GL.W.0031.180505T0300Z-180505T1100Z/
Coastal waters east of Ipswich Bay and the Stellwagen Bank
National Marine Sanctuary-
1027 PM EDT Fri May 4 2018

...GALE WARNING REMAINS IN EFFECT UNTIL 7 AM EDT SATURDAY...

* WINDS AND SEAS...Southwest winds 15 to 25 kt with gusts up to 
  35 kt. Seas 3 to 6 feet.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Gale Warning means winds of 34 to 47 knots are imminent or
occurring. Operating a vessel in gale conditions requires
experience and properly equipped vessels. It is highly
recommended that mariners without the proper experience seek safe
harbor prior to the onset of gale conditions.

&&

$$

ANZ256-051030-
/O.CON.KBOX.SC.Y.0068.000000T0000Z-180505T2200Z/
Coastal Waters from Montauk NY to Marthas Vineyard extending out
to 20 nm South of Block Island-
1027 PM EDT Fri May 4 2018

...SMALL CRAFT ADVISORY REMAINS IN EFFECT UNTIL 6 PM EDT
SATURDAY...

* WINDS AND SEAS...West winds 15 to 25 kt with gusts up to 30 
  kt. Seas 7 to 10 feet.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Small Craft Advisory means that wind speeds of 25 to 33 knots
are expected to produce hazardous wave conditions to small craft.
Inexperienced mariners, especially those operating smaller
vessels, should avoid navigating in these conditions.

&&

$$

ANZ235-237-051030-
/O.CON.KBOX.SC.Y.0068.000000T0000Z-180505T2200Z/
Rhode Island Sound-Block Island Sound-
1027 PM EDT Fri May 4 2018

...SMALL CRAFT ADVISORY REMAINS IN EFFECT UNTIL 6 PM EDT
SATURDAY...

* WINDS AND SEAS...West winds 15 to 25 kt with gusts up to 30 
  kt. Seas 4 to 7 feet.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Small Craft Advisory means that wind speeds of 25 to 33 knots
are expected to produce hazardous wave conditions to small craft.
Inexperienced mariners, especially those operating smaller
vessels, should avoid navigating in these conditions.

&&

$$

ANZ236-051030-
/O.CON.KBOX.SC.Y.0068.000000T0000Z-180505T1200Z/
Narragansett Bay-
1027 PM EDT Fri May 4 2018

...SMALL CRAFT ADVISORY REMAINS IN EFFECT UNTIL 8 AM EDT
SATURDAY...

* WINDS AND SEAS...West winds 10 to 15 kt with gusts up to 25 
  kt. Waves 3 to 5 feet.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Small Craft Advisory means that wind speeds of 25 to 33 knots
are expected to produce hazardous wave conditions to small craft.
Inexperienced mariners, especially those operating smaller
vessels, should avoid navigating in these conditions.

&&

$$

For the latest updates...please visit our webpage at
www.weather.gov/boston

You can follow us on Facebook at
www.facebook.com/NWSBoston

You can follow us on Twitter at
@NWSBoston

867 
WHUS71 KBOX 050723
MWWBOX

URGENT - MARINE WEATHER MESSAGE
National Weather Service Boston/Norton MA
323 AM EDT Sat May 5 2018

ANZ255-051530-
/O.CAN.KBOX.GL.W.0031.000000T0000Z-180505T1100Z/
/O.EXB.KBOX.SC.Y.0068.000000T0000Z-180506T0300Z/
Coastal Waters extending out to 25 nm South of Marthas Vineyard
and Nantucket-
323 AM EDT Sat May 5 2018

...SMALL CRAFT ADVISORY UNTIL 11 PM EDT THIS EVENING...
...GALE WARNING IS CANCELLED...

The National Weather Service in Boston/Norton has issued a Small
Craft Advisory, which is in effect until 11 PM EDT this evening.
The Gale Warning has been cancelled.

* WINDS AND SEAS...West winds 10 to 20 kt with gusts up to 30 kt.
  Seas 6 to 9 feet.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Small Craft Advisory means that wind speeds of 25 to 33 knots
are expected to produce hazardous wave conditions to small craft.
Inexperienced mariners, especially those operating smaller
vessels, should avoid navigating in these conditions.

&&

$$

ANZ232>234-051200-
/O.CAN.KBOX.GL.W.0031.000000T0000Z-180505T1100Z/
/O.EXA.KBOX.SC.Y.0068.000000T0000Z-180505T1200Z/
Nantucket Sound-Vineyard Sound-Buzzards Bay-
323 AM EDT Sat May 5 2018

...SMALL CRAFT ADVISORY UNTIL 8 AM EDT THIS MORNING...
...GALE WARNING IS CANCELLED...

The National Weather Service in Boston/Norton has issued a Small
Craft Advisory, which is in effect until 8 AM EDT this morning.
The Gale Warning has been cancelled.

* WINDS AND SEAS...West winds 10 to 20 kt with gusts up to 30 kt.
  Seas 2 to 4 feet.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Small Craft Advisory means that wind speeds of 25 to 33 knots
are expected to produce hazardous wave conditions to small craft.
Inexperienced mariners, especially those operating smaller
vessels, should avoid navigating in these conditions.

&&

$$

ANZ230-051100-
/O.CON.KBOX.GL.W.0031.000000T0000Z-180505T1100Z/
Boston Harbor-
323 AM EDT Sat May 5 2018

...GALE WARNING REMAINS UNTIL 7 AM EDT THIS MORNING...

* WINDS AND SEAS...West winds 15 to 20 kt with gusts up to 40 kt.
  Waves Around 2 feet.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Gale Warning means winds of 34 to 47 knots are imminent or
occurring. Operating a vessel in gale conditions requires
experience and properly equipped vessels. It is highly
recommended that mariners without the proper experience seek safe
harbor prior to the onset of gale conditions.

&&

$$

ANZ231-251-051100-
/O.CON.KBOX.GL.W.0031.000000T0000Z-180505T1100Z/
Cape Cod Bay-Massachusetts Bay and Ipswich Bay-
323 AM EDT Sat May 5 2018

...GALE WARNING REMAINS UNTIL 7 AM EDT THIS MORNING...

* WINDS AND SEAS...West winds 15 to 20 kt with gusts up to 35 kt.
  Seas 2 to 4 feet.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Gale Warning means winds of 34 to 47 knots are imminent or
occurring. Operating a vessel in gale conditions requires
experience and properly equipped vessels. It is highly
recommended that mariners without the proper experience seek safe
harbor prior to the onset of gale conditions.

&&

$$

ANZ250-254-051100-
/O.CON.KBOX.GL.W.0031.000000T0000Z-180505T1100Z/
Coastal waters east of Ipswich Bay and the Stellwagen Bank
National Marine Sanctuary-
Coastal waters from Provincetown MA to Chatham MA to Nantucket MA
out 20 nm-
323 AM EDT Sat May 5 2018

...GALE WARNING REMAINS UNTIL 7 AM EDT THIS MORNING...

* WINDS AND SEAS...West winds 15 to 20 kt with gusts up to 35 kt.
  Seas 4 to 7 feet.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Gale Warning means winds of 34 to 47 knots are imminent or
occurring. Operating a vessel in gale conditions requires
experience and properly equipped vessels. It is highly
recommended that mariners without the proper experience seek safe
harbor prior to the onset of gale conditions.

&&

$$

ANZ256-051530-
/O.EXT.KBOX.SC.Y.0068.000000T0000Z-180506T0300Z/
Coastal Waters from Montauk NY to Marthas Vineyard extending out
to 20 nm South of Block Island-
323 AM EDT Sat May 5 2018

...SMALL CRAFT ADVISORY UNTIL 11 PM EDT THIS EVENING...

* WINDS AND SEAS...West winds 10 to 20 kt with gusts up to 30 kt.
  Seas 6 to 9 feet.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Small Craft Advisory means that wind speeds of 25 to 33 knots
are expected to produce hazardous wave conditions to small craft.
Inexperienced mariners, especially those operating smaller
vessels, should avoid navigating in these conditions.

&&

$$

ANZ235-237-051530-
/O.EXT.KBOX.SC.Y.0068.000000T0000Z-180506T0000Z/
Rhode Island Sound-Block Island Sound-
323 AM EDT Sat May 5 2018

...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING...

* WINDS AND SEAS...West winds 10 to 15 kt with gusts up to 25 kt.
  Seas 4 to 7 feet.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Small Craft Advisory means that wind speeds of 25 to 33 knots
are expected to produce hazardous wave conditions to small craft.
Inexperienced mariners, especially those operating smaller
vessels, should avoid navigating in these conditions.

&&

$$

ANZ236-051200-
/O.CON.KBOX.SC.Y.0068.000000T0000Z-180505T1200Z/
Narragansett Bay-
323 AM EDT Sat May 5 2018

...SMALL CRAFT ADVISORY UNTIL 8 AM EDT THIS MORNING...

* WINDS AND SEAS...West winds 10 to 15 kt with gusts up to 25 kt.
  Waves 2 to 4 feet.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Small Craft Advisory means that wind speeds of 25 to 33 knots
are expected to produce hazardous wave conditions to small craft.
Inexperienced mariners, especially those operating smaller
vessels, should avoid navigating in these conditions.

&&

$$

For the latest updates...please visit our webpage at
www.weather.gov/boston

You can follow us on Facebook at
www.facebook.com/NWSBoston

You can follow us on Twitter at
@NWSBoston

432 
WHUS71 KBOX 051036
MWWBOX

URGENT - MARINE WEATHER MESSAGE
National Weather Service Boston/Norton MA
636 AM EDT Sat May 5 2018

ANZ230-051500-
/O.CAN.KBOX.GL.W.0031.000000T0000Z-180505T1100Z/
/O.EXB.KBOX.SC.Y.0068.000000T0000Z-180505T1500Z/
Boston Harbor-
636 AM EDT Sat May 5 2018

...SMALL CRAFT ADVISORY IN EFFECT UNTIL 11 AM EDT THIS MORNING...
...GALE WARNING IS CANCELLED...

The National Weather Service in Boston/Norton has issued a Small
Craft Advisory, which is in effect until 11 AM EDT this morning.
The Gale Warning has been cancelled.

* WINDS AND SEAS...West winds 10 to 15 kt with gusts up to 30 
  kt. Waves Around 2 feet.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Small Craft Advisory means that wind speeds of 25 to 33 knots
are expected to produce hazardous wave conditions to small craft.
Inexperienced mariners, especially those operating smaller
vessels, should avoid navigating in these conditions.

&&

$$

ANZ231-251-051500-
/O.CAN.KBOX.GL.W.0031.000000T0000Z-180505T1100Z/
/O.EXB.KBOX.SC.Y.0068.000000T0000Z-180505T1500Z/
Cape Cod Bay-Massachusetts Bay and Ipswich Bay-
636 AM EDT Sat May 5 2018

...SMALL CRAFT ADVISORY IN EFFECT UNTIL 11 AM EDT THIS MORNING...
...GALE WARNING IS CANCELLED...

The National Weather Service in Boston/Norton has issued a Small
Craft Advisory, which is in effect until 11 AM EDT this morning.
The Gale Warning has been cancelled.

* WINDS AND SEAS...West winds 10 to 15 kt with gusts up to 30 
  kt. Seas 2 to 3 feet.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Small Craft Advisory means that wind speeds of 25 to 33 knots
are expected to produce hazardous wave conditions to small craft.
Inexperienced mariners, especially those operating smaller
vessels, should avoid navigating in these conditions.

&&

$$

ANZ250-051500-
/O.CAN.KBOX.GL.W.0031.000000T0000Z-180505T1100Z/
/O.EXB.KBOX.SC.Y.0068.000000T0000Z-180505T1500Z/
Coastal waters east of Ipswich Bay and the Stellwagen Bank
National Marine Sanctuary-
636 AM EDT Sat May 5 2018

...SMALL CRAFT ADVISORY IN EFFECT UNTIL 11 AM EDT THIS MORNING...
...GALE WARNING IS CANCELLED...

The National Weather Service in Boston/Norton has issued a Small
Craft Advisory, which is in effect until 11 AM EDT this morning.
The Gale Warning has been cancelled.

* WINDS AND SEAS...West winds 10 to 20 kt with gusts up to 30 
  kt. Seas 3 to 5 feet.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Small Craft Advisory means that wind speeds of 25 to 33 knots
are expected to produce hazardous wave conditions to small craft.
Inexperienced mariners, especially those operating smaller
vessels, should avoid navigating in these conditions.

&&

$$

ANZ254-051845-
/O.CAN.KBOX.GL.W.0031.000000T0000Z-180505T1100Z/
/O.EXA.KBOX.SC.Y.0068.000000T0000Z-180506T0000Z/
Coastal waters from Provincetown MA to Chatham MA to Nantucket MA
out 20 nm-
636 AM EDT Sat May 5 2018

...SMALL CRAFT ADVISORY IN EFFECT UNTIL 8 PM EDT THIS EVENING...
...GALE WARNING IS CANCELLED...

The National Weather Service in Boston/Norton has issued a Small
Craft Advisory, which is in effect until 8 PM EDT this evening.
The Gale Warning has been cancelled.

* WINDS AND SEAS...West winds 10 to 15 kt with gusts up to 25 
  kt. Seas 3 to 6 feet.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Small Craft Advisory means that wind speeds of 25 to 33 knots
are expected to produce hazardous wave conditions to small craft.
Inexperienced mariners, especially those operating smaller
vessels, should avoid navigating in these conditions.

&&

$$

ANZ232>234-051500-
/O.EXT.KBOX.SC.Y.0068.000000T0000Z-180505T1500Z/
Nantucket Sound-Vineyard Sound-Buzzards Bay-
636 AM EDT Sat May 5 2018

...SMALL CRAFT ADVISORY NOW IN EFFECT UNTIL 11 AM EDT THIS
MORNING...

* WINDS AND SEAS...West winds 10 to 15 kt with gusts up to 25 
  kt. Seas 2 to 4 feet.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Small Craft Advisory means that wind speeds of 25 to 33 knots
are expected to produce hazardous wave conditions to small craft.
Inexperienced mariners, especially those operating smaller
vessels, should avoid navigating in these conditions.

&&

$$

ANZ236-051400-
/O.EXT.KBOX.SC.Y.0068.000000T0000Z-180505T1400Z/
Narragansett Bay-
636 AM EDT Sat May 5 2018

...SMALL CRAFT ADVISORY NOW IN EFFECT UNTIL 10 AM EDT THIS
MORNING...

* WINDS AND SEAS...West winds around 10 kt with gusts up to 25 
  kt. Waves 1 to 3 feet.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Small Craft Advisory means that wind speeds of 25 to 33 knots
are expected to produce hazardous wave conditions to small craft.
Inexperienced mariners, especially those operating smaller
vessels, should avoid navigating in these conditions.

&&

$$

ANZ255-256-051845-
/O.CON.KBOX.SC.Y.0068.000000T0000Z-180506T0300Z/
Coastal Waters extending out to 25 nm South of Marthas Vineyard
and Nantucket-
Coastal Waters from Montauk NY to Marthas Vineyard extending out
to 20 nm South of Block Island-
636 AM EDT Sat May 5 2018

...SMALL CRAFT ADVISORY REMAINS IN EFFECT UNTIL 11 PM EDT THIS
EVENING...

* WINDS AND SEAS...Southwest winds 10 to 15 kt with gusts up to 
  25 kt. Seas 5 to 8 feet.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Small Craft Advisory means that wind speeds of 25 to 33 knots
are expected to produce hazardous wave conditions to small craft.
Inexperienced mariners, especially those operating smaller
vessels, should avoid navigating in these conditions.

&&

$$

ANZ235-237-051845-
/O.CON.KBOX.SC.Y.0068.000000T0000Z-180506T0000Z/
Rhode Island Sound-Block Island Sound-
636 AM EDT Sat May 5 2018

...SMALL CRAFT ADVISORY REMAINS IN EFFECT UNTIL 8 PM EDT THIS
EVENING...

* WINDS AND SEAS...West winds 10 to 15 kt with gusts up to 20 
  kt. Seas 3 to 6 feet.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Small Craft Advisory means that wind speeds of 25 to 33 knots
are expected to produce hazardous wave conditions to small craft.
Inexperienced mariners, especially those operating smaller
vessels, should avoid navigating in these conditions.

&&

$$

For the latest updates...please visit our webpage at
www.weather.gov/boston

You can follow us on Facebook at
www.facebook.com/NWSBoston

You can follow us on Twitter at
@NWSBoston

Area Forecast Discussion
National Weather Service Boston/Norton MA
318 PM EDT Fri May 4 2018

.SYNOPSIS...
A cold front sweeps across Southern New England tonight with
showers and a couple of thunderstorms ahead of it. Strong west
to northwest winds follow the front. High pressure builds over
the region Saturday bringing fair dry seasonable weather. A
weather system lifts out of the Gulf of Mexico Saturday night
bringing rain on Sunday.  Monday into Tuesday, cool, dry, still
breezy with N/W winds. Wednesday into Thursday, heat and
humidity rebounding ahead of a sweeping cold front Friday with a
chance of wet weather.

&&

.NEAR TERM /THROUGH TONIGHT/...

Low pressure over Ontario will pass well north of New England
tonight. This low is supported by a sharp shortwave and a
150-knot upper jet. Already, strong pressure rises are noted
over Michigan which will tighten the pressure gradient and
generate strong winds trailing the low and its cold front.
The cold front was moving across Southern Ontario and Ohio
during the afternoon.

HREF guidance shows CAPE building in eastern NY late afternoon
in an area where satellite shows mostly clear skies and building
cumulus. A pre-frontal surface trough is projected in this area.
Expect developing thunderstorms west of New England that will
move northeast and enter our western areas. But the airmass
remains stable east of the CT River. So any storms coming out of
the Berkshires and Litchfield Hills will enter a hostile
environment and quickly weaken. Because of this, we expect any
thunderstorms to weaken to showers as they move east.

The cold front moves through Southern New England after midnight
with winds shifting from the west northwest overnight. At this
point, those developing strong winds over the Great Lakes will
sweep across our area. At that same time, a 40-50 knot low level
jet will move overhead, and in the cold advection behind the
front it will be possible to bring those winds to the surface in
gusts. This is more easily done in the hills, which will be
closer to the strong winds aloft. We are continuing the Wind
Advisory for central and western Massachusetts. Expect the winds
to diminish by morning.

&&

.SHORT TERM /SATURDAY THROUGH SATURDAY NIGHT/...

Saturday...

High pressure over the region brings fair dry sunny weather.
Lingering northwest winds early will diminish during the
morning. Temps at 850 mb will be 6-9C, supporting highs in the
low to mid 70s with upper 60s in the hills. Winds turn from the
southwest in the afternoon, an onshore wind along the South
Coast. Temps there will top out in the 60s.

Saturday night...

Southern stream upper trough will dig over the Appalachians and
turn the upper flow from the southwest along the coast. Upper
jet supporting the flow will also favor developing low pressure
along the coast, then moving up the coast toward our area.

Expect increasing clouds overnight. Model consensus brings a
chance of rain to our area after 2-6 AM. Will show chance pops
and min temps mostly in the 50s.

&&

.LONG TERM /SUNDAY THROUGH FRIDAY/...
*/ Highlights...

 - Monday into Tuesday, continued breezy W winds, dry, cool
 - Wednesday into Thursday, heat / humidity rebound, light winds
 - Wet weather anticipated for Friday ahead of a sweeping cold front

*/ Overview...

Along the transitional zone.

Saturday...
 - Pleasant, nice Saturday, still a bit breezy with N/W winds
Diminishing winds during the day as gradient relaxes. Otherwise a
very nice day with dry weather given subsidence behind departing
shortwave. Some high clouds expected but there should be plenty of
sunshine. 850 mb temps 7-8C which supports highs in the low and mid
70s, cooler along the immediate south coast and Cape/Islands as
winds turn SW.

 With deeper H5 trof dips over the N/NE
Pacific, exacerbation in ridge-trof W-E CONUS pattern. This as mean
polar low lingers over Baffin Bay / Davis Straight. The mean trend
emphasized within ensembles, some wiggles in-between. But take-away
is persistent Pacific flow into CONUS. H85 positive-temperature
anomalies, rising heights, especially W CONUS, whereas NE Canada /
Greenland on the colder side of envelope beneath polar low. NE CONUS
beneath preferred H5 troughing, within a transitional zone, Spring-
time ebb and flow pattern. Pacific energy quickly racing through the
general pattern, Atlantic wide-open, heat and humidity build prior
to H5 trof / cold frontal passages along which precipitation chances
increase, followed by near- to below-seasonable conditions. Pattern
repeats as associated Canadian highs shift E allowing return S flow.
Our touch of Summer only brief, Spring is here to stay. Forecast
targets of opportunity below.

*/ Discussion...

Weekend...

S-stream impulse beneath RRQ upper-level jet as a N-stream vortmax
rounds through prevailing H5 trof. Leaning pull back of a S-stream
weak wave low along an offshore stalled frontal boundary as a cold
front sweeps in from N/W. Sunday a squeeze-play. N/S streams
sweeping, neighboring but not phasing, subsiding air in-between,
someone's going to be a winner pulling out a dry weekend
overall. Tough to nail down SW-NE region of drier weather.
Likely PoPs for S/E coastal areas.

Week ahead...

Monday through Thursday, influential Canadian high pressure train.
One after the other. H85 temperatures certainly cooler, around +6C.
Highs skirting by generally N/E, winds generally light, anticipate
onshore E/NE flow, pronounced more so on Wednesday into Thursday as
heat / humidity builds across the NE CONUS W interior ahead of the
Friday cold front. Havoc on 2m temperatures, likely stout gradients
from E-coastal MA to roughly 10-20 miles inland. Not so much the
case Monday and Tuesday, decent N/W flow, cold air advection, well-
mixed on up to H8, mix down faster winds, drier air, going to keep
sea-breezes, if any, confined to the immediate shore.

Friday...

Sweeping Pacific shortwave, attendant H5 trof, deamplifying beneath
mid-level warming, rising heights immediately W. Timing crucial as
to whether convection can develop in advance. Forecast uncertainty.
Maintain chance PoPs.

&&

.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
Forecaster Confidence Levels...

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

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

Tonight...

Mainly VFR. Dry much of the time, but with scattered showers
that could briefly bring 2000 foot cigs and/or 5 mile vsbys. So
brief MVFR possible in showers.

Thunderstorms approaching from New York could survive briefly as
they enter western Mass and western CT, but should diminish by
the time they cross the Connecticut River.

A cold front approaches during the night. Gusty southwest winds
are expected ahead of the front. Winds then shift from the
northwest behind the front, with potential for gusts of 35-40
knots. These winds should diminish by sunrise.

Saturday...

High pressure builds over the region. VFR with diminishing
northwest winds, turning from the southwest late in the day.

Saturday night...

High pressure retreats. A coastal weather system develops near
the Carolinas and moves up the coast. VFR before midnight.
Chance of MVFR vsbys in light rain after midnight.

KBOS Terminal... Moderate confidence in TAF tonight, then High
confidence in TAF Saturday. East winds have been tougher to
dislodge than expected, but should turn from the southwest at
some point this evening. Southwest winds through midnight with
gusts 25-30 knots, also a few leftover showers from Western MA.
Winds turn from northwest after midnight behind a cold front,
with gusts 30-40 knots possible. Diminishing wind Saturday.

KBDL Terminal...Moderate confidence in TAF tonight, then high
confidence in TAF Saturday. Possible thunderstorm moving in
from the west during the late afternoon/evening. Thunderstorms
will be weakening, and so they may be just showers by the time
they reach the terminal. Gusty southwest winds the first part of
the night, until a cold front moves through and winds turn from
the northwest with gusts 30-40 knots. Winds diminish by Saturday
morning.

Outlook /Sunday through Wednesday/...

Sunday: VFR. Chance SHRA.

Sunday Night: VFR. Slight chance SHRA.

Monday: VFR. Breezy.

Monday Night through Tuesday: VFR.

&&

.MARINE...
Forecaster Confidence Levels...

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

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

Southwest winds 25-30 knots early tonight with a few light
showers possible. A cold front swings through after midnight,
when winds turn from the northwest. Wind gusts to 40 knots
possible on the eastern waters for a few hours after midnight.
This builds rough seas on the outer waters and the RI waters.

A gale warning has been issued for the eastern waters for the
period after the cold front moves through. Small craft advisory
continues for the remaining waters.

High pressure builds over the waters Saturday, bringing
diminishing wind and seas. A coastal system developing near the
Carolinas will spread rain up the coast late Saturday night.
But winds will remain below 25 knots and seas less than 5 feet.

/Sunday through Tuesday/...

Sunday: SHRA through mid-morning, winds less than 25 kt. Chance
of rain showers.

Sunday Night: Winds less than 25 kt. Seas locally approaching
5 ft. Slight chance of rain showers.

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

Monday Night: Winds less than 25 kt. Areas of seas approaching
5 ft.

Tuesday: Winds less than 25 kt. Seas locally approaching 5 ft.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...Wind Advisory from 11 PM this evening to 7 AM EDT Saturday for
     MAZ002>004-008>012-026.
RI...None.
MARINE...Gale Warning from 11 PM this evening to 7 AM EDT Saturday for
     ANZ230>234-250-251-254-255.
     Small Craft Advisory until 8 AM EDT Saturday for ANZ236.
     Small Craft Advisory until 6 PM EDT Saturday for ANZ235-237-
     256.

&&

SYNOPSIS...WTB/Sipprell
NEAR TERM...WTB
SHORT TERM...WTB
LONG TERM...Sipprell
AVIATION...WTB/Sipprell
MARINE...WTB/Sipprell

Hazardous Weather Outlook
National Weather Service Boston/Norton MA
407 AM EDT Fri May 4 2018

MAZ002>004-008>012-026-050815-
Western Franklin MA-Eastern Franklin MA-Northern Worcester MA-
Western Hampshire MA-Western Hampden MA-Eastern Hampshire MA-
Eastern Hampden MA-Southern Worcester MA-Northern Middlesex MA-
407 AM EDT Fri May 4 2018

...WIND ADVISORY FROM 11 PM THIS EVENING TO 7 AM EDT SATURDAY...

This Hazardous Weather Outlook is for Western and Central
Massachusetts.

.DAY ONE...Today and Tonight.

Please listen to NOAA Weather Radio or go to weather.gov on the
Internet for more information about the following hazards.

   Wind Advisory

There is the risk for a line of strong to severe thunderstorms late
afternoon into early evening, especially across N/W areas of MA and
CT. Strong to damaging winds along with heavy rain and localized
urban, poor-drainage flooding are possible with any storms.

.DAYS TWO THROUGH SEVEN...Saturday through Thursday.

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

Weather spotters are encouraged to report significant weather
conditions according to Standard Operating Procedures.

CTZ002>004-MAZ005>007-013>024-RIZ001>008-050815-
Hartford CT-Tolland CT-Windham CT-Central Middlesex MA-
Western Essex MA-Eastern Essex MA-Western Norfolk MA-
Southeast Middlesex MA-Suffolk MA-Eastern Norfolk MA-
Northern Bristol MA-Western Plymouth MA-Eastern Plymouth MA-
Southern Bristol MA-Southern Plymouth MA-Barnstable MA-Dukes MA-
Nantucket MA-Northwest Providence RI-Southeast Providence RI-
Western Kent RI-Eastern Kent RI-Bristol RI-Washington RI-Newport RI-
Block Island RI-
407 AM EDT Fri May 4 2018

This Hazardous Weather Outlook is for northern Connecticut, eastern
Massachusetts, northeastern Massachusetts, southeastern
Massachusetts, and Rhode Island.

.DAY ONE...Today and Tonight.

There is the risk for a line of strong to severe thunderstorms late
afternoon into early evening, especially across N/W areas of MA and
CT. Strong to damaging winds along with heavy rain and localized
urban, poor-drainage flooding are possible with any storms.

.DAYS TWO THROUGH SEVEN...Saturday through Thursday.

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

Weather spotters are encouraged to report significant weather
conditions according to Standard Operating Procedures.

ANZ230>237-250-251-254>256-050815-
Boston Harbor-Cape Cod Bay-Nantucket Sound-Vineyard Sound-
Buzzards Bay-Rhode Island Sound-Narragansett Bay-Block Island Sound-
Coastal waters east of Ipswich Bay and the Stellwagen Bank National
Marine Sanctuary-Massachusetts Bay and Ipswich Bay-
Coastal waters from Provincetown MA to Chatham MA to Nantucket MA
out 20 nm-
Coastal Waters extending out to 25 nm South of Marthas Vineyard and
Nantucket-
Coastal Waters from Montauk NY to Marthas Vineyard extending out to
20 nm South of Block Island-
407 AM EDT Fri May 4 2018

This Hazardous Weather Outlook is for Massachusetts and Rhode
Island coastal waters.

.DAY ONE...Today and Tonight.

There is a low risk of gales briefly tonight behind a sweeping cold
front.

.DAYS TWO THROUGH SEVEN...Saturday through Thursday.

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

Weather spotters are encouraged to report significant weather
conditions according to Standard Operating Procedures.

For the latest updates, please visit our webpage at
www.weather.gov/boston

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