Sunday, September24, 2017 L-36.com


Marine Weather and Tides
Chelsea, MA

Version 3.4
What's New / NOTES
6/25/2017 - NOAA is having a major issue that impact the 7 day forecast load times. Many users are reporting problems. The issue has been reported.
5/23/2017 - Worked with NOAA again to speed up the 7 day forecast load times. Thanks to them for being responsive.
5/19/2016 - There were issues with the 3 day airport observation history. I switched to another data source. Let me know if you see any issues with the data feeds.

Sunrise 6:33AMSunset 6:38PM Sunday September 24, 2017 2:36 AM EDT (06:36 UTC) Moonrise 10:50AMMoonset 9:22PM Illumination 13% Phase: Waxing Crescent; Moon at 4 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- 116 Am Edt Sun Sep 24 2017
Rest of tonight..Light and variable winds. Waves 1 foot or less. Areas of fog. Vsby 1 nm or less.
Sun..N winds around 5 kt, becoming E in the afternoon. Waves 1 foot or less. Areas of fog. Vsby 1 nm or less.
Sun night..S winds around 5 kt, becoming sw after midnight. Waves 1 foot or less.
Mon..E winds around 5 kt. Waves 1 foot or less.
Mon night..SE winds around 5 kt, becoming S around 5 kt after midnight. Waves 1 foot or less. Patchy fog. Vsby 1 to 3 nm.
Tue..SE winds around 5 kt. Waves 1 foot or less. Patchy fog. Vsby 1 to 3 nm.
Tue night..S winds around 5 kt. Waves 1 foot or less.
Wed..S winds around 5 kt. Waves 1 foot or less.
Wed night..S winds around 5 kt. Waves 1 foot or less. A chance of showers.
Thu..SW winds around 5 kt. Waves 1 foot or less. A chance of showers.
Thu night..NW winds 5 to 10 kt. Waves 1 foot or less. 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 116 Am Edt Sun Sep 24 2017
Synopsis for massachusetts and rhode island coastal waters.. Locally dense fog extends from cape ann to narragansett bay. This will linger through Sunday morning. High pressure will bring dry weather to the waters Sunday through at least Tuesday. Hurricane maria will slowly lift north to a location off the north carolina coast by the middle of next week. It will generate southerly swell particularly across our southern outer waters during the first half of next week. Mariners should Monitor the latest forecasts from the national hurricane center at www.nhc.noaa.gov. 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 240544
afdbox
area forecast discussion
national weather service taunton ma
144 am edt Sun sep 24 2017

Synopsis
High pressure, both at the surface and aloft, will extend from the
eastern great lakes to new england overnight through early next
week. It will bring unseasonably warm weather to the region
into the middle of next week. Maria is expected to pass
southeast of new england late in the week with strongest winds
well offshore.

Near term until 6 am this morning
1130 pm update...

will be adding dense fog advisory to CAPE cod and islands
including block island. Considered plymouth county, but
satellite trends show thinning of the stratus, so suspect the
fog will thin shortly.

Previous discussion...

fog over much of eastern massachusetts, with the GOES 16 fog
product defining this area quite well. This same product shows
some weakening of the stratus over the gulf of maine, but
continued expansion over land and especially south of boston.

This fog should move into eastern ri in the next 1-2 hours. Also
signs of potential development in the ct valley and quabbin
area, as well as a few other spots, which would be expected
under these conditions.

Otherwise surface map shows high pressure over the eastern usa
with a light nne flow over southern new england. This will
continue overnight and provide an environment favorable for fog
expansion. Most observed visibilities are around 1 2 mile or
higher, a little higher than we'd like to see for a dense fog
advisory. The exceptions toward the lower are logan airport and
marshfield which report 1 4 mile and less than 1 4 mile,
respectively. We will hold off on a headline at this time but
re-evaluate before midnight.

Evening temperatures in the 60s and dew points in the mid 50s to
mid 60s. With fair skies and light wind, expect a min
temperature range in the mid 50s to lower 60s.

Short term 6 am this morning through 6 pm Monday
Tonight...

winds diminish tonight, which with clear skies will allow
temperatures to cool to dew point. We trended toward the MOS values
for min temp, which was a couple of degrees lower than the standard
guidance. Radiation fog possible in the interior, and marine
fog stratus is possible along the CAPE islands south coast.

Sunday...

**record high temperatures expected**
high pressure over the region, both at the surface and aloft,
will mean sunshine and hot temperatures away from the coast.

Heights at 500 mb are forecast at or above 590 dm, and 850
temps are forecast at 18-20c. 925 mb temps are forecast to
reach +24c. Expecting highs reaching the lower 90s in the ct
river valley, which would be a record... See climate section at
the end of this forecast discussion. Expecting upper 80s
elsewhere in interior southern new england. Light winds under
the high pressure will allow daytime sea breezes, which will
keep temps much cooler along the shoreline... .Only 70s to near
80.

The one big exception to the above will be CAPE cod and the
islands, which are likely to begin the day with cloud cover and
areas of fog, which may linger through a big chunk of the
morning, before becoming partly sunny. Expecting highs on the
cape and islands to range from the upper 60s on nantucket to
the mid 70s on the upper cape.

With dewpoint temperatures only in the lower to mid 60s, the
heat indices are forecast to reach 90 to 94, just shy of heat
advisory criteria - although that criteria requires it to last
for two days. Will need to keep an eye on this.

Sunday night...

expecting mostly clear skies. Could see marine stratus again
late at night over the CAPE and islands. Patchy fog possible
late in some interior areas. Lows in the 60s.

Swells from hurricane maria will be reaching south coastal
areas, so a high surf advisory remains posted for those areas.

Long term Monday night through Saturday
Highlights...

* summer warmth expected to the middle of next week
* maria expected to sharply recurve out to sea southeast of new
england late next week
no major surprises in the 23 12z guidance. Still expecting an
anomalous mid level ridge to hover over our region through the
middle of next week, although it should weaken with time after
Tuesday. The strength of this ridge will be crucial in delaying the
northward progress of maria towards our region.

High pressure with dry weather expected Monday and Tuesday.

Temperatures should be 10-15 degrees above normal Monday, but not
quite as much Tuesday or Wednesday. A few interior spots may reach
90 degrees Monday. Seabreezes should develop along both coasts,
lowering daytime MAX temperatures there.

A potential weak low level front just south of our region, may be
enough to trigger a few showers Tuesday night into Wednesday. A
greater risk for showers should be ahead of a cold front sweeping
through our region Wednesday night into Thursday morning. This
cold front and a potent mid level trough are expected to be the
final kickers which steers maria out to sea well to our south.

Drier weather should prevail next Friday into Saturday, although
cannot dismiss the possibility of some stray showers given the
proximity of a mid level trough. The bigger change will be the
temperatures, which should snap back to near normal levels during
this time.

The primary impact on our region from maria will likely be another
prolonged period of high surf and dangerous rip currents, mainly
along ocean-exposed south coast beaches. For several days, maria
tracks near a great circle route in our direction and hence we will
likely see significant long period swells from the S or SE propagate
into our coastal waters most of next week. The slow northward speed
of maria for the next several days may enhance the swell activity
during this period.

Aviation 06z Sunday through Thursday
Forecaster confidence levels...

low - less than 30 percent.

Moderate - 30 to 60 percent.

High - greater than 60 percent.

Short term through Monday ...

early morning... Moderate confidence, mainly due to timing.

Ifr lifr CIGS vsbys in fog in southeast mass and parts of ri.

Satellite trends show signs of the fog shifting south toward
the south coast, but in general we expect the fog to linger
overnight and then thin toward morning. Fog has not shown itself
in the ct valley despite a favorable environment for fog
formation. We will continue to monitor and expect at least
patchy fog toward morning.

Today... High confidence.

Any remaining fog will burn off in the morning. The last
patches, likely on the CAPE and islands, should dissipate by
11 am to noon.

Vfr through the day with light wind inland and developing sea
breezes late morning to early afternoon.

Tonight... Moderate to high confidence.

Vfr most areas, however, could see marine ifr developing again
on CAPE cod and the islands. Patchy areas of fog may develop
late over portions of the interior, such as the ct valley.

Monday... High confidence.

Patches of ifr in fog to start the morning, but otherwiseVFR
through the day. Light wind, with sea breezes again developing.

Kbos taf... Moderate-high confidence. Patches of fog in all
directions around the airport, but not at the field. Low to
moderate chance of brief MVFR vsbys in fog early, but otherwise
we expectVFR conditions through the day. Light wind will turn
into an northeast sea breeze around 14z, then a southeast
seabreeze 18-19z. The sea breeze should diminish 22-24z.

Kbdl taf... High confidence in taf. Patchy MVFR vsbys in fog are
possible early, but otherwise expectVFR through the forecast
period with light wind.

Outlook Monday night through Thursday ... Confidence... High.

Monday night and Tuesday...VFR expected.

Tuesday night... MostlyVFR except MVFR in patchy stratus fog
some interior valleys and near the south coast.

Wednesday... GenerallyVFR except MVFR ceilings visibilities
possible in scattered late day showers and patchy late night early
morning stratus fog.

Thursday... GenerallyVFR, with MVFR in scattered showers during
the morning.

Marine
Forecaster confidence levels...

low - less than 30 percent.

Moderate - 30 to 60 percent.

High - greater than 60 percent.

Tonight... Moderate confidence.

Leftover swell was diminishing along the east coast of ma.

Low clouds and fog will continue along the southern and
southeast coasts tonight with poor visibilities. Winds will
diminish to less than 15 knots, but seas will linger at 5-6 feet
on the southern outer waters.

Sunday... Moderate confidence.

High pressure building over the region will bring light wind,
with sea breezes developing at the shoreline. Poor vsbys in fog
early, slowly improving by late morning or early afternoon over
the southeastern waters. Seas of 5-6 feet will linger on the
southern outer waters. A south swell sent north from maria will
start showing itself in our southern waters late Sunday, with
3-4 feet swell heights in the afternoon.

Sunday night... High confidence.

Seas build to 5 to 7 feet over the southern outer waters, mainly
due to swells from distant hurricane maria. High surf conditions
will exist on area beaches along the south coast. Patchy areas
of fog.

Outlook Monday night through Thursday ... 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.

Tides coastal flooding
High surf advisories will expired along the east coast of ma
this evening, but they will remain in effect through Monday
along the south coast. Swells from maria will likely increase
the surf and associated rip current risk across our ocean-
exposed south coast starting late Sunday and continuing through
the week. This will be true even though maria may eventually
recurves out to sea well southeast of new england.

Climate
Best chance for record high temps will be Sunday and 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 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

Box watches warnings advisories
Ct... None.

Ma... Dense fog advisory until 9 am edt this morning for maz022>024.

High surf advisory until 6 pm edt Monday for maz020-022>024.

Ri... Dense fog advisory until 9 am edt this morning for riz008.

High surf advisory until 6 pm edt Monday for riz006>008.

Marine... Small craft advisory from 2 am to 6 pm edt Monday for anz235-
237.

Small craft advisory until 6 pm edt Monday for anz254>256.

Synopsis... Belk gaf
near term... Wtb belk gaf
short term... Gaf
long term... Belk
aviation... Wtb belk
marine... Wtb belk gaf
tides coastal flooding...

climate...



Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
BHBM3 - 8443970 - Boston, MA 1 mi67 min 65°F 1015.7 hPa
44013 - BOSTON 16 NM East of Boston, MA 22 mi107 min W 1.9 G 3.9 59°F 61°F3 ft1016.5 hPa (-0.6)
44029 - Buoy A0102 - Mass. Bay/Stellwagen 28 mi93 min SW 3.9 G 3.9 59°F 60°F3 ft1015.9 hPa
FOXR1 - 8454000 - Providence, RI 43 mi67 min NNW 1.9 G 2.9 66°F 66°F1016.5 hPa
PVDR1 44 mi67 min N 1.9 G 2.9 65°F 1016.4 hPa64°F
FRVM3 - 8447386 - Fall River, MA 46 mi67 min 62°F 67°F1017.4 hPa
BLTM3 - 8447387 - Borden Flats Light at Fall River, MA 46 mi67 min NE 1.9 G 2.9 63°F 1016 hPa
FRXM3 47 mi67 min 62°F 61°F
IOSN3 - Isle of Shoals, NH 47 mi37 min WSW 8 G 8 64°F 1016.2 hPa (-0.6)62°F
CPTR1 - 8452944 - Conimicut Light, RI 48 mi67 min N 1.9 G 1.9 64°F 67°F1016.6 hPa
BGXN3 - Great Bay Reserve, NH 49 mi112 min Calm 57°F 1017 hPa57°F

Wind History for Providence, RI
(wind in knots)    EDIT      (on/off)   Help
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NE14
G21
NE13
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NE8
G18
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G15
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NE9
G16
NE8
G14
NE11
G15
NE12
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NE7
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NE9
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NE18
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NE14
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G22
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NE17
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G27
NE14
G23
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G22
NE11
G25
NE15
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NE14
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NE12
G21
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G24
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G26
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G23
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G31
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G32
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NE20
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Boston, Logan International Airport, MA2 mi43 minN 010.00 miA Few Clouds62°F61°F96%1016.5 hPa
East Milton, MA11 mi41 minWNW 6 mi67°F59°F76%1017.4 hPa
Norwood, Norwood Memorial Airport, MA14 mi44 minN 00.75 miFog/Mist57°F55°F96%1016.4 hPa
Bedford, Hanscom Field, MA14 mi41 minN 010.00 miFair60°F57°F90%1017.5 hPa
Beverly, Beverly Municipal Airport, MA16 mi44 minN 08.00 miFair59°F57°F96%1015.9 hPa

Wind History from BOS (wind in knots)
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Last 24hrN14N15N12N12N9N11N11N9N12NE9E8E11E11E7E6SE6CalmNE3S4S3CalmCalmCalmCalm
1 day agoN21
G30
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G30
N18
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N20
G30
N21
G26
N19
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N22
G28
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N16N15
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2 days agoN18
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G34
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--NE21
G33
NE20N18
G24
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G21
N14N11N15NE17
G25
NE18
G26
N19
G27
NE25
G30
N21
G32

Tide / Current Tables for Charlestown Bridge, Charles River, Massachusetts
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Charlestown Bridge
Click for Map
Sun -- 02:36 AM EDT     9.94 feet High Tide
Sun -- 06:34 AM EDT     Sunrise
Sun -- 08:39 AM EDT     0.54 feet Low Tide
Sun -- 10:50 AM EDT     Moonrise
Sun -- 02:51 PM EDT     10.19 feet High Tide
Sun -- 06:37 PM EDT     Sunset
Sun -- 09:08 PM EDT     0.31 feet Low Tide
Sun -- 09:22 PM EDT     Moonset
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
68.39.79.88.874.82.60.90.61.83.65.889.710.29.47.85.63.31.30.30.82.3

Tide / Current Tables for Boston Harbor, Massachusetts Current
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Boston Harbor
Click for Map
Sun -- 02:12 AM EDT     -0.00 knots Slack
Sun -- 06:33 AM EDT     Sunrise
Sun -- 06:35 AM EDT     -1.15 knots Max Ebb
Sun -- 08:41 AM EDT     0.00 knots Slack
Sun -- 10:49 AM EDT     Moonrise
Sun -- 11:57 AM EDT     1.17 knots Max Flood
Sun -- 02:33 PM EDT     -0.00 knots Slack
Sun -- 06:37 PM EDT     Sunset
Sun -- 07:04 PM EDT     -1.22 knots Max Ebb
Sun -- 09:13 PM EDT     0.00 knots Slack
Sun -- 09:21 PM EDT     Moonset
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
1.10.80.1-0.4-0.8-1-1.1-1.1-0.60.311.11.210.4-0.2-0.7-1-1.1-1.2-1-0.20.61

Weather Map and Satellite Images
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Weather Map
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IR Satellite Image from GEOS
east_satellite

GOES Local Image of Northeast    EDIT
Geos

Wind Forecast for Boston, MA (2,6,7,8)
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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.