Monday, September25, 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 6:34AMSunset 6:36PM Monday September 25, 2017 11:54 PM EDT (03:54 UTC) Moonrise 11:48AMMoonset 9:58PM Illumination 30% Phase: Waxing Crescent; Moon at 5 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- 923 Pm Edt Mon Sep 25 2017
Overnight..S winds around 5 kt. Waves 1 foot or less. Areas of fog. Vsby 1 nm or less.
Tue..SW winds around 5 kt, becoming se in the afternoon. Waves 1 foot or less. Areas of fog. Vsby 1 to 3 nm.
Tue night..S winds around 5 kt. Waves 1 foot or less. Patchy fog. Vsby 1 nm or less.
Wed..S winds around 5 kt, becoming se in the afternoon. Waves 1 foot or less. Patchy fog. Vsby 1 nm or less.
Wed night..S winds around 5 kt. Waves 1 foot or less. A chance of showers. Vsby 1 nm or less.
Thu..NW winds 5 to 10 kt. Waves 1 foot or less.
Thu night..N winds around 10 kt. Waves around 2 ft.
Fri..N winds 5 to 10 kt. Waves 1 foot or less.
Fri night..N winds around 5 kt. Waves 1 foot or less.
Sat..N winds around 5 kt. Waves 1 foot or less.
Sat night..N winds around 5 kt. Waves 1 foot or less. 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 923 Pm Edt Mon Sep 25 2017
Synopsis for massachusetts and rhode island coastal waters.. Areas of dense fog mainly during the night into mid morning hours will impact the waters through the middle of the week. Southerly swell from hurricane maria will continue to move north into the waters and linger for much of the week. A cold front from canada will cross the waters later Wednesday or early Thursday. 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 260050
afdbox
area forecast discussion
national weather service taunton ma
850 pm edt Mon sep 25 2017

Synopsis
High pressure will remain across the northeast into Wednesday,
with warm and humid conditions. A cold front combined with
moisture from maria may impact the CAPE and islands and
southeast massachusetts late Wednesday night into Thursday.

Behind the front, turning much cooler Thursday night through the
weekend. Hurricane maria will bring dangerous rough surf and
rip currents to the south coast this week, before passing well
southeast of new england late this week.

Near term until 6 am Tuesday morning
***areas of dense fog expected overnight especially across rhode
island and southeast ma***
850 pm update...

we went ahead and issued a dense fog advisory across rhode
island and southeast ma through 8 am Tuesday. Some fog already
developing along the coast. The ncar ensembles and narre-tl
show fairly high probabilities of visibility dropping to one
quarter of a mile overnight into early Tuesday morning. This
seems to make sense given light winds, high dewpoints, and
longer nights now that it is late september. Further northwest,
we are concerned about locally dense fog as well but confidence
was a bit lower so opted to issue a special weather statement
for now and will monitor conditions closely for a possible
upgrade. Low temps should bottom out between 60 and 65 in most
locations.

Short term 6 am Tuesday morning through Tuesday night
Tuesday...

high pressure ridging remains across northern new england. Once
the fog lifts, should see mostly sunny skies away from the s
coast where clouds and patchy fog will linger.

Noting the 12z ggem as an outlier with a band of showers trying
to push toward the S coast Tue afternoon well ahead of
hurricane maria. The remaining short range models remain mainly
dry, though may see a band of scattered showers developing S and
e of nantucket during the day.

Will be another mild and humid day, though temps will be cooler
than today with decent mixing especially away from the coast.

Expect temps to top off in the 80-85 degree range away from the
coast and in the 70s along the shore.

Tuesday night...

models starting to signal some bands of showers out ahead of
maria approaching the southern waters. Still model spread with
this aspect of the forecast, with most keeping mainly dry
conditions. Expect another round of low clouds and fog to
return, though will likely push further inland as winds shift to
light s-se. Lows will be in the lower-mid 60s.

Long term Wednesday through Monday
Highlights...

* very warm and humid Wednesday with low risk of a shower t-storm
* sct showers t-storm possible late Wed night Thu SE new eng
* taste of autumn Thu night into the weekend with much cooler and
less humid weather
models in good agreement on mid level trough moving east from the
great lakes and amplifying over new eng this weekend. This will
effectively be a kicker to push maria out to sea and also bring a
pattern change to more seasonable autumn like weather late in the
week through the weekend. Before the cooler airmass arrives, will
have to watch for potential of some showers t-storms with locally
heavy rain late Wed night into Thu across SE new eng.

Wednesday will be another very warm and humid day ahead of
approaching cold front from the nw. Temps well into the 80s away
from the south coast with dewpoints near 70. Some instability noted
which supports a few showers or an isold t-storm developing but mid
level lapse rates are meager which is a limiting factor.

As maria begins to move eastward well south of new eng Wed night
into thu, a plume of tropical moisture will lift north into the
region and interact with an approaching front moving into new eng.

This will likely set up a pre late Wed night into Thu with area of
showers t-storms with locally heavy rainfall but low confidence on
location of the heavy rainfall axis and if it extends west into new
eng. Consensus of the deterministic guidance keeps it mostly
offshore, but ECMWF and several GEFS members bring some heavy rain
to SE new eng. Still uncertainty so will maintain pops of previous
forecast and continue to monitor.

Behind the cold front, much cooler airmass will move into new eng
thu night and last through the weekend as mid level trough amplifies
over new eng. Mainly dry weather, but may see some diurnal showers
on Sat under the cold pool aloft with 500 mb temps -22c. Temps
mostly in the 60s Fri into Sun with lows in the 40s. Coolest day
likely on Sat with moderating temps Sun into Mon as the trough
axis moves east and heights rise.

Aviation 01z Tuesday through Saturday
Forecaster confidence levels...

low - less than 30 percent.

Moderate - 30 to 60 percent.

High - greater than 60 percent.

Short term through Tuesday night ...

tonight... Moderate confidence. Widespread ifr lifr conditions
appearing likely in areas of fog some of which will be locally
dense especially across rhode island and southeast ma.

Tuesday... Moderate to high confidence.

MainlyVFR. Areas of ifr-lifr early across CAPE cod and the
islands due to fog, with some improvement to MVFR by around
midday. Light s-se winds.

Tuesday night... Moderate confidence.

Vfr to start, then MVFR-ifr conditions moving in again. Lifr
conditions possible across CAPE cod and the islands.

Kbos taf... Moderate confidence in taf.

Kbdl taf... Moderate confidence in taf.

Outlook Wednesday through Saturday ... High confidence.

Wednesday... Areas of ifr lifr stratus and fog near the south
coast early, otherwiseVFR. Low risk of a few afternoon showers
or an isold t-storm.

Wednesday night into Thursday... MainlyVFR, but areas of
stratus and fog possible near the south coast Wed night into
early thu. In addition, scattered showers t-storms may impact
the CAPE islands and SE ma late Wed night into Thu morning with
lower conditions.

Friday and Saturday... MainlyVFR. Patchy MVFR CIGS and low risk of
showers sat.

Marine
Forecaster confidence levels...

low - less than 30 percent.

Moderate - 30 to 60 percent.

High - greater than 60 percent.

Short term through Tuesday night ... High confidence.

***dense fog a concern into mid morning Tuesday***
main concern is dense fog overnight into Tuesday morning
resulting in visibility being reduced to one quarter of a mile
or less at times. Should see the fog burn off later Tuesday
morning. Light e-ne winds will continue through Tuesday as high
pressure remains near and north of the waters. As this slowly
shifts offshore, winds will remain light but become s-se Tuesday
night.

Increasing long period south swells from hurricane maria will
continue to push across the southern waters, with the potential
for 5 to 7 foot seas tonight increasing to 7 to 10 feet late
Tuesday and Tuesday night. SCA for hazardous seas will continue,
and have extended to vineyard sound and buzzards bay mainly
near the entrances where 5 foot seas will move in.

Areas of fog will result in poor visibility at times,
especially south and east of CAPE cod and into nantucket and
vineyard sounds where visibility may lower to below 1 2 mile.

Outlook Wednesday through Saturday ... High confidence.

Wednesday... Light winds but large southerly swell will impact
the southern waters. Reduced vsbys in fog Wed morning.

Wednesday night into Thursday night... Light winds Wed night
shifting to north Thu afternoon. Increasing N winds Thu night
with gusts 25- 30 kt possible. Large southerly swell continuing.

Some heavy rain possible over waters south and east of cape
cod. In addition areas of dense fog may be an issue.

Friday into Saturday... Diminishing northerly wind. Seas
gradually subsiding and may drop below 5 ft Fri night.

Tides coastal flooding
Long periods swells continue to propagate north from distant
hurricane maria across the southern coastal waters. Wna
wavewatch guidance continues to slowly increase the swells,
reaching up to 7 to 10 feet on the southern outer waters on
Wednesday. Increasing high surf and dangerous rip currents are
expected with these high swells.

We have once again extended the high surf advisory for the
south facing beaches for mass and ri through Wednesday. The high
surf is likely to continue through the remainder of the week
even as maria will likely recurve out to sea well southeast of
new england.

Climate
So far, the high temp has reached 91 degrees at kbdl, setting
the record high for today's date. Record report has been sent,
but will be updated once final high has been reached. Also, the
high at korh reached 85 degrees at 338 pm, tying the record high
to today's day. The MAX so far at kpvd remains at 84 degrees.

Records jump up Tuesday to 89-95 degrees. However, low level mixing
lowers, which leads to lower MAX temps on Tuesday. At this point,
the highs at our 4 climate sites are well below the records for
9 26, mainly in the lower-mid 80s away from the coast, and around 80
at bos and pvd.

Box watches warnings advisories
Ct... None.

Ma... Dense fog advisory until 8 am edt Tuesday for maz013-016>024.

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

Ri... Dense fog advisory until 8 am edt Tuesday for riz001>008.

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

Marine... Small craft advisory for hazardous seas from 6 am Tuesday to 6
am edt Wednesday for anz233-234.

Small craft advisory for hazardous seas until 6 am edt
Wednesday for anz235-237-254>256.

Synopsis... Kjc evt
near term... Frank
short term... Evt
long term... Kjc
aviation... Frank kjc evt
marine... Frank kjc evt
tides coastal flooding... Staff
climate... Staff


Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
BHBM3 - 8443970 - Boston, MA 1 mi54 min 66°F 1017 hPa (+0.0)
44013 - BOSTON 16 NM East of Boston, MA 22 mi64 min ESE 3.9 G 3.9 63°F 63°F2 ft1017.9 hPa (+0.5)
44029 - Buoy A0102 - Mass. Bay/Stellwagen 28 mi110 min SSE 7.8 G 9.7 64°F 64°F2 ft1017.6 hPa
FOXR1 - 8454000 - Providence, RI 43 mi54 min S 1.9 G 2.9 69°F 68°F1017.5 hPa (+0.0)
PVDR1 44 mi54 min ENE 1.9 G 2.9 69°F 1017.4 hPa (+0.0)69°F
FRVM3 - 8447386 - Fall River, MA 46 mi54 min 69°F 68°F1018.2 hPa (+0.0)
BLTM3 - 8447387 - Borden Flats Light at Fall River, MA 46 mi54 min NE 4.1 G 4.1 69°F 1016.7 hPa (+0.0)
FRXM3 47 mi54 min 69°F 68°F
IOSN3 - Isle of Shoals, NH 47 mi54 min S 8.9 G 9.9 65°F 1017.7 hPa (+0.0)65°F
CPTR1 - 8452944 - Conimicut Light, RI 48 mi54 min S 1.9 G 1.9 68°F 70°F1017.5 hPa (+0.0)
BGXN3 - Great Bay Reserve, NH 49 mi69 min Calm 62°F 1018 hPa61°F

Wind History for Providence, RI
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Boston, Logan International Airport, MA2 mi60 minN 010.00 miFair66°F64°F96%1018 hPa
East Milton, MA11 mi2 hrsESE 7 mi67°F64°F93%1019.1 hPa
Norwood, Norwood Memorial Airport, MA14 mi61 minN 010.00 miFair65°F64°F97%1017.6 hPa
Bedford, Hanscom Field, MA14 mi2 hrsN 010.00 miFair67°F62°F84%1018.7 hPa
Beverly, Beverly Municipal Airport, MA16 mi61 minSE 50.75 miFog/Mist66°F66°F100%1017.4 hPa

Wind History from BOS (wind in knots)
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Last 24hrSE5S4CalmCalmCalmCalmN3CalmE3SE3Calm4E7E7E8E9E9E7E8E9E5N4NE4Calm
1 day agoCalmCalmCalmCalmCalmCalmCalmCalmNW4NW3NE3E4E4SE5SE6SE7E5E5NE3NE4CalmCalmCalmSE4
2 days agoN16N15
G24
N14N14N15N12N12N9N11N11N9N12NE9E8E11E11E7E6SE6CalmNE3S4S3Calm

Tide / Current Tables for Charlestown Bridge, Charles River, Massachusetts
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Charlestown Bridge
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Mon -- 03:21 AM EDT     9.47 feet High Tide
Mon -- 06:35 AM EDT     Sunrise
Mon -- 09:23 AM EDT     1.02 feet Low Tide
Mon -- 11:47 AM EDT     Moonrise
Mon -- 03:36 PM EDT     9.85 feet High Tide
Mon -- 06:35 PM EDT     Sunset
Mon -- 09:55 PM EDT     0.72 feet Low Tide
Mon -- 09:58 PM EDT     Moonset
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
4.26.48.39.49.28.16.34.32.41.11.32.64.46.48.39.69.88.87.15.131.30.71.5

Tide / Current Tables for Boston Harbor, Massachusetts Current
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Boston Harbor
Click for Map
Mon -- 12:28 AM EDT     1.07 knots Max Flood
Mon -- 02:59 AM EDT     -0.00 knots Slack
Mon -- 06:34 AM EDT     Sunrise
Mon -- 07:29 AM EDT     -1.04 knots Max Ebb
Mon -- 09:29 AM EDT     0.00 knots Slack
Mon -- 11:47 AM EDT     Moonrise
Mon -- 12:45 PM EDT     1.07 knots Max Flood
Mon -- 03:19 PM EDT     -0.00 knots Slack
Mon -- 06:35 PM EDT     Sunset
Mon -- 07:58 PM EDT     -1.14 knots Max Ebb
Mon -- 09:58 PM EDT     Moonset
Mon -- 10:03 PM EDT     0.00 knots Slack
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
110.6-0-0.4-0.7-0.9-1-1-0.50.5111.10.80.2-0.3-0.7-0.9-1.1-1.1-0.9-0.10.7

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

GOES Local Image of Northeast    EDIT
Geos

Wind Forecast for Boston, MA (23,6,7,8)
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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.