Saturday, August24, 2019 L-36.com


Marine Weather and Tides
Chelsea, MA

Version 3.4
NOTICE
7/25/2019 New feature in the Airports section gives a link to 5 minute updates for data reports.
6/2/2019. Many thanks to a user for reporting an error on one of the Edit pages. The switch to PHP 7.2 caused many pages that previously worked to quit working. I fixed many but I still depend on users to report ones I missed. Please report errors HERE or send an email to me at L-36.com. Allen

Sunrise 5:59AMSunset 7:33PM Saturday August 24, 2019 3:56 PM EDT (19:56 UTC) Moonrise 12:00AMMoonset 2:47PM Illumination 32% Phase: Waning Crescent; Moon at 24 days in cycle
NOTE: Some of the data on this page has not been verified and should be used with that in mind. It may and occasionally will, be wrong. The tide reports are by xtide and are NOT FOR NAVIGATION.
Marine Forecasts
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ANZ230 Boston Harbor- 117 Pm Edt Sat Aug 24 2019
This afternoon..NE winds 10 to 15 kt with gusts up to 20 kt. Waves 1 foot or less.
Tonight..NE winds 10 to 15 kt with gusts up to 20 kt. Waves around 2 ft.
Sun..NE winds 15 to 20 kt, diminishing to 10 to 15 kt in the afternoon. Gusts up to 25 kt. Waves around 2 ft.
Sun night..NE winds 10 to 15 kt with gusts up to 20 kt, diminishing to 5 to 10 kt after midnight. Waves around 2 ft.
Mon and Mon night..NE winds 5 to 10 kt. Waves around 2 ft.
Tue..E winds 5 to 10 kt. Waves 1 foot or less, except 2 to 4 ft at the outer harbor entrance.
Wed..E winds around 5 kt. Waves 1 foot or less, except 2 to 4 ft at the outer harbor entrance. A chance of showers. Vsby 1 to 3 nm.
Wed night..E winds around 5 kt. Waves 1 foot or less, except 2 to 4 ft at the outer harbor entrance. A chance of showers. Seas are reported as significant wave height, which is the average of the highest third of the waves. Individual wave heights may be more than twice the significant wave height.
ANZ200 117 Pm Edt Sat Aug 24 2019
Synopsis for massachusetts and rhode island coastal waters.. High pressure over the great lakes will move to the maritimes by tonight. This will bring shifting winds, initially from the north shifting from the northeast and eventually from the east by midweek. A tropical depression may form off the coast of florida early next week. This system may track close enough to effect the coastal waters with elevated seas by mid week. For information on possible hazardous weather beyond the 24-36 hour forecast period, please visit www.weather.gov/boston and follow the current hazards link above the map on the left.


7 Day Forecast for Marine Location Near Chelsea, MA
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location: 42.37, -71.06     debug


Area Discussion for - Boston, MA
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Fxus61 kbox 241917
afdbox
area forecast discussion
national weather service boston norton ma
317 pm edt Sat aug 24 2019

Synopsis
High pressure will bring pleasant, dry conditions today. However
it'll contribute to low clouds and light showers for Sunday,
especially across southeast new england. High pressure lingering
into midweek, seasonable and dry conditions continue. An eye on
the tropics around this time, potential high surf and dangerous
rip currents for the atlantic-exposed shoreline of new england.

Near term until 6 am Sunday morning
2 pm update...

a wicked awesome day. From satellite moisture trapped beneath a
building dry inversion is evident from the flat, cellular cumulus
cloud deck. The mid-level trof axis presently sw-ne over the s-
half of the NE conus, the ridge of high pressure is beginning to
build out of the great lakes round which you can see the leading
edge of low-level drying through me into nh vt. This dry air
will be the main player in the discussion below that'll divide
where the long-fetch E NE will contribute to low clouds and light
showers and where it will not.

As mentioned prior, another element is the ongoing cold advection
within the low levels aiding in the destabilization of the boundary
layer environment. Subsequent mixing with enhancing surface pressure
gradient as the high sulks se, 10 to 15 mph NE winds with gusts up
around 20 mph continue for the E SE shoreline and will likely
persist into evening, lessen across the interior with boundary
layer decoupling.

Highs today into the 70s, slightly cooler along the shores with
onshore flow. Comfortable with dewpoints in the 40s to 50s.

Tonight...

s E low clouds, light showers. N W mainly clear, cooler, light winds
and the threat of patchy dense fog.

Mid-level trof exiting, amplifying into a closed low. High in tow,
surface pressure gradient tightens thereby enhancing long-fetch ne
flow especially over E SE coastal ma and ri. Having cooled within
low-levels below a dry-subsidence inversion down to h8-7, moisture
collects and coalesces around h95 within a destabilized boundary
layer. Convergent low-level wind elements included, low cloud and
light shower threats encompass areas around and southeast of cape
ann to mid-coastal ct.

Meanwhile N w, partial to mostly clear, likely radiational cooling,
boundary layer decoupling and light winds. Expect dense fog within
interior valleys.

Tricky low temperature forecast along the forecast wind cloud edge.

Preference to consensus near-term high-res guidance but some wiggle
room. Even as far back as the berkshires there's the possibility of
lingering surface-h8 moisture (evident in present cumulus field).

And given the cooling profile there's the possibility of low cloud
development, especially along the N e-facing slopes where moisture
would pool. Yet evidence of drying in the column. Rap builds SW a
significant h85 dry wedge (presently inching S into N me) that'll
mix into the aforementioned low level cool boundary layer profile.

Could be stubborn clouds along the high terrain but clear within the
valleys N W while low clouds prevail SE with the NE long-fetch. A
bunch of near-term updates likely.

Short term 6 am Sunday morning through Sunday night
2 pm update...

Sunday...

low clouds, showers linger S e. Looking pleasant N w. As noted in
the tonight discussion, following low-level h925-85 thetae dry air
advection. Continued h8-7 dry-subsidence inversion beneath which the
profile remains cool, destabilized, daytime heating plus convergent
elements of h925-85 winds, broken to overcast low clouds and light
shower chances are likely to continue over SE new england whereas
more scattered to broken cloud decks and dry prevail NW ma and ct.

Showers mainly during the morning, thinking daytime heating and
boundary layer mixing should limit the deep-layer moisture profile
with some dry-air contamination. Continued preference to consensus
of near-term high-res guidance. Another tricky high-temperature
forecast dependent on cloud shield edge. Should see blustery ne
winds for all locations, strongest of course along the coast.

Sunday night...

low clouds linger, however shower chances diminish. Mid to upper
level high nudging S round which h925-85 dry air advection should
finally sweep through all new england, the accompanying subsidence
inversion deepening down to the surface through the atmospheric
column. Moisture continuing to pool beneath through which NE long-
fetch flow prevails, low clouds seem likely over SE new england
whereas over mostly clear NW ma and ct it's another night of
radiational cooling and patchy dense fog within the valleys. Once
again a tricky low-temperature forecast given the uncertainty as to
the cloud-shield edge. Mild se, cooler nw.

Long term Monday through Saturday
4 am update...

highlights...

* cooler than normal temperatures early next week especially
across eastern massachusetts into rhode island
* onshore winds will bring spotty light rain or showers at
times into mid week
* temperatures return to near normal levels around mid week,
becoming warmer than normal by Friday
* another chance for showers late Wednesday through Thursday
details...

Monday through Tuesday...

the center of the large high to the N will slowly cross southern
quebec into the maritimes by early Sunday night. With the long
easterly fetch around the e-w elongated high, will see temps
below seasonal levels both Monday and Tuesday with the coolest
temps along the immediate E coast where readings may not break
70 on Sunday and possibly even Monday.

The long fetch will also allow low level moisture to continue
to increase, so have kept slight chc pops across E mass into ri
through part of Monday before the winds diminish as the center
of the high tries to shift a bit further s. Chances for spotty
showers and possibly even some drizzle return on Tuesday.

Further inland, skies should be partly to mostly sunny.

The easterly winds may become gusty as the pressure gradient
increases around the southern section of the high from Monday
into Tuesday. May see gusts up to 20 to as high as 30 mph,
highest across CAPE cod and the islands.

Wednesday through Friday...

as the large high slowly exits to the western atlc, another
cold front begins to approach later wed, but will tend to stall
across E ny state as the potential tropical system passes well
se of nantucket around the late Wed night or Thu timeframe.

Light e-se winds should eventually shift to SE or even S as the
front approaches, but this will depend upon the timing of the
passing tropical system.

Will also see marginal instability as the front approaches, so
can not rule out isolated thunderstorms mainly from late wed
through thu. By thu, highs will reach up to the lower-mid 80s,
which will also assist in any developing convection. As the
potential tropical system exits to the western atlc, showers
should push offshore, but some question on the timing of this
front as model solution spread increases. At this point, have
kept slight chance pops going into Friday as yet another front
may approach in the fast flow aloft.

Aviation 19z Saturday through Thursday
Forecaster confidence levels...

low - less than 30 percent.

Moderate - 30 to 60 percent.

High - greater than 60 percent.

Short term through Sunday night ... Moderate confidence.

18z update...

rest of today...

vfr. Sct-bkn 030-050. Interior N NE winds around 10 kts, E se
coast 10 to 15 kts with gusts up to 20 to 25 kts.

Tonight...

e SE ma and ri, CIGS lowering to MVFR around midnight into early
morning Sunday, vcsh as sct -shra forecast. Persistent 10 to 15
kt N NE winds. N W ma and ri there's the possibility of sct-bkn
ifr CIGS across the high terrain with breezy E NE winds around
10 kts, but few-sct within the valleys along with light winds
allowing ifr fg. Higher confidence ifr fg within sheltered
valleys in NW ma. Hold MVFR at 020 throughout tafs.

Sunday...

conditions lift and improve toVFR across NW new england with sct
low-endVFR cigs. E NE winds around 10 kts. Sct-bkn MVFR continues
along with morning -shra across SE new england with E NE 10 to
15 kts with gusts around 20 kts.

Sunday night...

few-sct across the interior with light winds, the threat of ifr
fg once again. Sct-bkn MVFR continues across SE new england with
breezy E NE winds 10 to 15 kts.

Kbos terminal...

hold at 020 in TAF with MVFR impact the terminal closer to early
Sunday morning.

Kbdl terminal...

confident in taf. No impacts.

Outlook Monday through Thursday ... Moderate confidence.

Monday through Tuesday:VFR. Breezy.

Tuesday night: mainlyVFR, with local ifr possible. Slight
chance shra, patchy br.

Wednesday: mainlyVFR, with areas MVFR possible. Slight 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 night ... High confidence.

3 pm update...

long-fetch E NE winds the height of which will occur on Sunday
with gusts up to 30 kts and seas building up around 5 feet. This
as high pressure builds out of the N with low pressure lingering
s. A downward trend Sunday night into Monday as high pressure
wins out and builds across the region. Small craft advisories in
effect for a majority of the waters, especially S se, beginning
early Sunday morning.

Scattered light showers at times, developing late tonight and
continuing into early Sunday.

Outlook Monday through Thursday ... Moderate confidence.

Monday: low risk for small craft advisory winds with gusts up
to 25 kt. Seas up to 5 ft. Slight chance of rain showers.

Monday night: winds less than 25 kt. Seas up to 5 ft.

Tuesday through Tuesday night: winds less than 25 kt. Seas up
to 5 ft. Slight chance of rain showers.

Wednesday: winds less than 25 kt. Seas up to 5 ft. Slight
chance of rain showers, isolated thunderstorms.

Box watches warnings advisories
Ct... None.

Ma... None.

Ri... None.

Marine... Small craft advisory from 8 am to 8 pm edt Sunday for
anz232>234.

Small craft advisory from 10 am to 6 pm edt Sunday for anz231-
236.

Small craft advisory from 10 am to 8 pm edt Sunday for anz235-
237.

Small craft advisory from 6 am Sunday to 6 am edt Monday for
anz250-254>256.

Synopsis... Sipprell evt
near term... Sipprell
short term... Sipprell
long term... Evt
aviation... Sipprell evt
marine... Wtb evt


Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
BHBM3 - 8443970 - Boston, MA 1 mi62 min 68°F 1022.5 hPa
44013 - BOSTON 16 NM East of Boston, MA 22 mi66 min 65°F 66°F3 ft1021.3 hPa (+0.7)
44029 - Buoy A0102 - Mass. Bay/Stellwagen 28 mi112 min NE 12 G 14 66°F 66°F3 ft1021.9 hPa
FOXR1 - 8454000 - Providence, RI 43 mi62 min E 9.9 G 15 73°F 71°F1021.3 hPa
PVDR1 44 mi62 min NE 7 G 11 77°F 1021.7 hPa54°F
BLTM3 - 8447387 - Borden Flats Light at Fall River, MA 46 mi62 min NE 12 G 16 75°F 1021.5 hPa
FRVM3 - 8447386 - Fall River, MA 46 mi62 min 75°F 78°F1021.9 hPa
FRXM3 47 mi62 min 73°F 56°F
IOSN3 - Isle of Shoals, NH 47 mi56 min ENE 8 G 8.9 66°F 1021.9 hPa (+0.6)57°F
CPTR1 - 8452944 - Conimicut Light, RI 48 mi62 min NE 9.9 G 13 73°F 74°F1021.5 hPa
BGXN3 - Great Bay Reserve, NH 49 mi71 min ESE 2.9 71°F 1022 hPa58°F

Wind History for Providence, RI
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Boston, Logan International Airport, MA2 mi2 hrsENE 1510.00 miPartly Cloudy71°F55°F59%1022 hPa
East Milton, MA11 mi2 hrsENE 11 G 19 mi69°F55°F61%1022.8 hPa
Norwood, Norwood Memorial Airport, MA14 mi63 minNE 1110.00 miFair74°F55°F52%1021.9 hPa
Laurence G Hanscom Field Airport, MA14 mi2 hrsno data10.00 miMostly Cloudy77°F53°F43%1022.6 hPa
Beverly, Beverly Municipal Airport, MA16 mi63 minENE 710.00 miPartly Cloudy72°F55°F57%1021.6 hPa

Link to 5 minute data for KBOS

Wind History from BOS (wind in knots)
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Last 24hrN10NW8NW8N8N10N10N10--NW10----NW10--NW11NW9NW7--N6NE10E12E13E14E15E14
1 day agoW13
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2 days agoS13S10S9S15
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G18

Tide / Current Tables for Charles River Dam, Charles River, Massachusetts
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Charles River Dam
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Sat -- 12:02 AM EDT     1.17 feet Low Tide
Sat -- 06:00 AM EDT     Sunrise
Sat -- 06:14 AM EDT     8.57 feet High Tide
Sat -- 12:18 PM EDT     1.52 feet Low Tide
Sat -- 02:47 PM EDT     Moonset
Sat -- 06:32 PM EDT     9.60 feet High Tide
Sat -- 07:31 PM EDT     Sunset
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.

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1.21.73.24.96.47.88.58.37.15.53.82.41.61.83.35.16.88.49.49.58.56.84.93.1

Tide / Current Tables for Boston Harbor, Massachusetts Current
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Boston Harbor
Click for Map
Sat -- 12:09 AM EDT     0.00 knots Slack
Sat -- 02:09 AM EDT     1.12 knots Max Flood
Sat -- 05:42 AM EDT     -0.00 knots Slack
Sat -- 06:00 AM EDT     Sunrise
Sat -- 08:43 AM EDT     -0.94 knots Max Ebb
Sat -- 12:25 PM EDT     0.00 knots Slack
Sat -- 02:32 PM EDT     1.23 knots Max Flood
Sat -- 02:46 PM EDT     Moonset
Sat -- 06:06 PM EDT     -0.00 knots Slack
Sat -- 07:31 PM EDT     Sunset
Sat -- 09:20 PM EDT     -1.09 knots Max Ebb
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.

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-0.10.71.110.90.5-0.2-0.7-0.9-0.9-0.8-0.7-0.30.51.11.210.70.1-0.6-0.9-1.1-1.1-1

Weather Map and Satellite Images
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GOES Local Image of    EDIT
NOTE: East coast views moved to GEOS-16. They are experimental and not well supported by NOAA so they may not be correct so be warned. This change required redoing a large amount of the GOES code. If the image you are expecting is not showing, please let me know. You may need to use the EDIT function to update your location.
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Wind Forecast for Boston, MA (15,3,4,5)
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Ground Weather Radar Station Boston, MA
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Disclaimer:
The information on this web site has not been checked for accuracy. It is for entertainment purposes only and should be independently verified before using for any other reason. There are five sources. 1) Documents and manuals from a variety of sources. These have not been checked for accuracy and in many cases have not even been read by anyone associated with L-36.com. I have no idea of they are useful or accurate, I leave that to the reader. 2) Articles others have written and submitted. If you have questions on these, please contact the author. 3) Articles that represent my personal opinions. These are intended to promote thought and for entertainment. These are not intended to be fact, they are my opinions. 4) Small programs that generate result presented on a web page. Like any computer program, these may and in some cases do have errors. Almost all of these also make simplifying assumptions so they are not totally accurate even if there are no errors. Please verify all results. 5) Weather information is from numerious of sources and is presented automatically. It is not checked for accuracy either by anyone at L-36.com or by the source which is typically the US Government. See the NOAA web site for their disclaimer. Finally, tide and current data on this site is from 2007 and 2008 data bases, which may contain even older data. Changes in harbors due to building or dredging change tides and currents and for that reason many of the locations presented are no longer supported by newer data bases. For example, there is very little tidal current data in newer data bases so current data is likely wrong to some extent. This data is NOT FOR NAVIGATION. See the XTide disclaimer for details. In addition, tide and current are influenced by storms, river flow, and other factors beyond the ability of any predictive program.