Wednesday, March20, 2019 L-36.com


Marine Weather and Tides
Nahant, MA

Version 3.4
What's New / NOTES
10/6/2018 Colors of tide XTide graphs changed to emphasize that they were upgraded. See next note. Comments welcome.
10/4/2018 I have fixed XTide and updated the harmonic files. There were some name changes so you might have to click EDIT to find the new station name.

Sunrise 6:45AMSunset 6:56PM Wednesday March 20, 2019 5:49 AM EDT (09:49 UTC) Moonrise 6:34PMMoonset 6:53AM Illumination 99% Phase: Full Moon; Moon at 14 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- 419 Am Edt Wed Mar 20 2019
Today..SW winds around 5 kt, becoming S this afternoon. Waves 1 foot or less.
Tonight..S winds 5 to 10 kt. Waves around 2 ft in the evening, then 1 foot or less.
Thu..SE winds 5 to 10 kt with gusts up to 20 kt. Waves around 2 ft.
Thu night..E winds 5 to 10 kt with gusts up to 20 kt. Waves 2 to 3 ft. Patchy fog. Showers. Vsby 1 to 3 nm, decreasing to 1 nm or less after midnight.
Fri..S winds 5 to 10 kt, becoming W 10 to 15 kt with gusts up to 25 kt in the afternoon. Waves 2 to 3 ft. A chance of showers. Patchy fog in the morning with vsby 1 nm or less.
Fri night..W winds 10 to 15 kt, increasing to 15 to 20 kt after midnight. Gusts up to 30 kt. Waves around 2 ft. A chance of showers. A chance of snow showers after midnight with vsby 1 to 3 nm.
Sat..W winds 15 to 20 kt with gusts up to 30 kt. Waves around 2 ft. A chance of snow showers in the morning with vsby 1 to 3 nm.
Sat night..NW winds 10 to 15 kt with gusts up to 25 kt. Waves around 2 ft.
Sun..W winds 10 to 15 kt. Gusts up to 20 kt in the morning. Waves around 2 ft.
Sun night..W winds 5 to 10 kt. Waves 1 foot or less. A chance of showers after midnight. 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 419 Am Edt Wed Mar 20 2019
Synopsis for massachusetts and rhode island coastal waters.. High pres along the southern new england coast this morning slowly drifts seaward to south of the maritimes tonight. Thursday a gale center develops off the mid atlc coast, moving ne along the coast Thu night and then across the ma coastline Fri before possibly intensifying into a storm Fri night along the maine coast. This powerful storm lingers near the maine coast Saturday before finally exiting Sat night. High pressure then builds into the mid atlc waters Sunday. 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 Nahant, MA
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location: 42.44, -70.94     debug


Area Discussion for - Boston, MA
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Fxus61 kbox 200813
afdbox
area forecast discussion
national weather service boston norton ma
413 am edt Wed mar 20 2019

Synopsis
High pressure south of new england will bring dry weather with
moderating temperatures this afternoon. A coastal storm impacts the
region late Thursday into Friday with periods of rain, heavy at
times and strong winds. Strong winds continue into Saturday along
with a shot of cold air, then becoming more seasonable Sunday.

Near term until 6 pm this evening
4 am update ...

1030 mb high pressure just off the southern new england coast
providing dry chilly conditions during the predawn hours this
morning. Most locations are in the 20s.

However WAA pattern in return flow developing already over ny state
into western ct ma in the form of mid level cloudiness.

Unfortunately none of the 00z model guidance is capturing these
clouds. This mid level warm front lifts across the region today.

Thus expect clouds to dim the sunshine from time to time with most
sunshine observed along and near the south coast. Cloud shield will
retreat northward into northern new england this afternoon so
expecting a trend toward more sunshine from south to north this
afternoon.

Return flow low level WAA yields ssw winds today and milder temps
than yesterday with highs this afternoon from the upper 40s to lower
50s, with a few mid 50s possible across the interior. Coolest
readings near the south shore given ssw winds off the chilly ocean
waters. Leaned toward the milder ec MOS guidance.

Expecting ssw winds 5 to 15 mph but could have some gusts up to 20
mph per model soundings.

Short term 6 pm this evening through 6 pm Thursday
4 am update ...

tonight ...

ridge axis remains across the region supporting dry weather and
light winds. Mid and high clouds arrive second half of the night.

However mostly clear skies, light winds and dry airmass over the
region will support radiational cooling. Not as cold as previous
nights but still chilly. Thus leaned toward the colder MOS temps
with lows 25-30, except low to mid 30s in the urban areas.

Thursday ...

dry weather to start the day along with some early morning sunshine
thru mid high clouds. Increasing clouds during the day as oh trough
advects eastward toward the mid atlc coast. As trough amplifies
downstream upstream short wave riding develops over southern new
england. This likely delays onset of rain until late in the day
across western ma ct and possibly not until sunset across ri and
eastern ma. Thus much of Thu should be dry especially over ri and
eastern ma. Despite the clouds highs will climb to 45-50 Thu along
with an increasing ese wind.

Long term Thursday night through Tuesday
* highlights ...

- widespread rain, embedded heavy showers, thunder Thursday night
- wet snows, becoming blustery Friday night into Saturday
- mild, dry conditions Sunday
- wintry weather potential early next week, turning colder
- late week high pressure, return mild
overview and model preferences...

with both the 19.12z and 20.00z model guidance updates,
operational and ensemble forecast solutions seem to be better
converging on the late week double trof, and resulting coastal
low pres for late week. The mention of a double trof is
intentional, as the recent trend, now that the arctic wave from
manitoba is being better sampled somewhat, no looks to remain
unphased with the modified pacific energy currently caught just
downstream of a pac NW rex block. As such, the leading wave
fails to tilt fast enough to enhance offshore cyclogenesis in
the mid-atlantic. Also, after this wave moves out, the secondary
arctic wave acts as a pivot to draw the low more due N or even
slightly W of N rather than E of new england for a final track.

This favors a warmer solution, with the mid lvl low wave passing
far enough inland that there will be little to stop the surge
of higher theta-e air toward new england. It is the arctic wave
that ultimately settles across new england into the weekend and
while some modest ridging follows, the mean longwave trof will
allow a reinforcing arctic wave to dig toward the NE conus
through mid next week. With both operational and some ensemble
guidance coming more in-line, feel that a consensus blend will
work as a baseline.

Details...

thu night into early fri...

mid-atlantic low pres will be sliding up the coast, mainly due
n given the current track solutions. There is a link to
subtropical moisture with pwats reaching 1.00-1.50inches (around
2 std deviations). The track favors a mainly warm solution
throughout, and bufkit soundings are supportive of this. With
the high pwats and a moderate llj, expect a risk for pockets of
heavier ra. As previous forecaster noted as leading sfc low
makes its closest pass and mid lvl warming peaks mid lvl lapse
rates reach 6.0-7.0c km highlighting upper lvl instability. This
could enhance localized ra rates. Therefore, will need to watch
for overnight localized urban poor drainage flooding. Also
noted, area rivers streams are generally running near seasonal
normals, and with final QPF totals ranging 0.5-1.5 inches, this
may not be enough to exceed flooding, but something to watch,
especially if heavy rain is observed over flashier basins. Bulk
of the precip ends with morning dry slot fri. For more on the
coastal flood risk, see the coastal flood section below.

Late Fri into sat...

low pres shifts toward the bay of fundy and continues to deepen
through the 980s. As 1020+ high pres approaches, the
combination of tightening pres gradient and pres rises will lead
to increasing w-nw flow. These winds are likely to peak sat
thanks to CAA allowing deep mixing beyond h85. Low risk for wind
advisory criteria, particularly late Fri night into early
daytime sat. Otherwise, lingering moisture could allow for
upslope sn in the berkshires and worcester hills late Fri before
the sounding becomes fully dry.

H85 temps drop to nearly 12c below normal with the strong caa,
so even with enhanced mixing, highs Sat will likely struggle to
reach the 40s. Early am wind chills in the single digits are
likely given the peak winds at that time and ambient temps in
the teens to low 20s.

Sun and mon...

mid lvl height rises. Anticipate weakening sfc pres gradient as
high pres slides S with moderating temperatures back toward
seasonal normals. Reinforcing arctic cold frontal passage
possible by mon, but the strongest CAA lags. However there is a
tap of S CONUS moisture which could bring about some shra or
even isolates shsn if the bulk of the precipitation shield is
anafrontal.

Tue and wed...

trend toward colder than normal conditions as secondary arctic
wave and cold advection follows the cold frontal passage.

Aviation 08z Wednesday through Sunday
Forecaster confidence levels...

low - less than 30 percent.

Moderate - 30 to 60 percent.

High - greater than 60 percent.

Short term through Thursday ... High confidence.

06z update ...

today ...

vfr clouds with CIGS bkn060-070 developing from west to east
then retreating northward this afternoon. Light and variable
winds will become ssw 5-15 kt. Dry weather prevails. Local
seabreeze possible eastern ma coast this afternoon.

Tonight ...

vfr, dry weather and light ssw winds.

Thursday ...

vfr and dry to start the day with MVFR arriving in the afternoon
across western ma ct along with increasing chances of light
rain. Increasing ese winds.

Kbos terminal... High confidence in taf. Low probability of a
seabreeze 14-18z then becoming ssw 10-15g20kt.

Kbdl terminal... High confidence in taf.

Outlook Thursday night through Sunday ...

Thursday night: mainly ifr, with local MVFR possible. Breezy.

Shra, slight chance tsra, patchy fg.

Friday: mainlyVFR, with local ifr possible. Breezy. Chance
shra.

Friday night: MVFR ifr conditions possible. Windy with gusts up
to 35 kt. Chance shsn, chance shra.

Saturday into Saturday night:VFR. Windy with areas of gusts up
to 30 kt.

Sunday:VFR. Breezy.

Marine
Forecaster confidence levels...

low - less than 30 percent.

Moderate - 30 to 60 percent.

High - greater than 60 percent.

Short term through Thursday ... High confidence.

4 am update ...

today ... Light and variable winds becoming ssw winds 5 to 15 kt,
possibly up to 20 kt near shore. Dry weather and good vsby.

Tonight ... 1030 mb high moves offshore with winds becoming ese. Dry
weather and good vsby continues.

Thursday ... High pressure slow to depart seaward with low pres
rapidly developing off the mid atlc coast. Dry weather and good vsby
with rain entering ri waters toward sunset.

Outlook Thursday night through Sunday ...

Thursday night into Friday: low risk for small craft advisory
winds with gusts up to 25 kt. Rough seas up to 11 ft. Chance of
rain showers, patchy fog. Local visibility 1 to 3 nm.

Friday night into Saturday: moderate risk for gale force winds
with gusts up to 35 kt. Rough seas up to 12 ft.

Saturday night into Sunday: moderate risk for small craft
advisory winds with gusts up to 25 kt. Local rough seas.

Tides coastal flooding
Even though the current model runs promote a weaker low pres and
inside runner, there is a period of onshore flow and surge
development through the overnight hours Thu night. Peak surge
looks to occur around the timing of low tide early Fri morning
per latest ensembles, however, lingingering surge could lead to
low minor coastal flooding with the astronomical high tide mid
day fri, which is 11.7 ft at boston. Still some time to monitor
timing, but feel this will be the tide most likely to yield any
coastal impacts.

Climate
Average first occurrence of 70 degree high temperatures (since
records began as early as 1872)
boston... ... .April 8th
hartford... ..April 1
providence... April 8th
worcester... .April 11th
average first occurrence of 70 degree daily average temperatures
daily average temperatures = (high + low) 2 (since records
began as early as 1872)
boston... ... .May 27th
hartford... ..May 10th
providence... May 20th
worcester... .May 29th

Box watches warnings advisories
Ct... None.

Ma... None.

Ri... None.

Marine... None.

Synopsis... Nocera doody
near term... Nocera
short term... Nocera
long term... Nocera doody
aviation... Nocera doody
marine... Nocera doody
tides coastal flooding...

climate... Staff


Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
BHBM3 - 8443970 - Boston, MA 8 mi32 min 35°F 1029.6 hPa
44013 - BOSTON 16 NM East of Boston, MA 17 mi60 min W 7.8 G 9.7 37°F 38°F1 ft1029.1 hPa (+0.0)24°F
44029 - Buoy A0102 - Mass. Bay/Stellwagen 21 mi106 min N 1.9 G 3.9 36°F 38°F1 ft1028.4 hPa
IOSN3 - Isle of Shoals, NH 40 mi50 min N 5.1 G 5.1 33°F 1028.8 hPa (-0.6)21°F
BGXN3 - Great Bay Reserve, NH 43 mi65 min Calm 20°F 1030 hPa15°F
44018 - SE Cape Cod 30NM East of Nantucket, MA 45 mi60 min W 3.9 G 5.8 36°F 1 ft1029.5 hPa (+0.0)27°F
44098 - Jeffrey's Ledge, NH (160) 48 mi72 min 39°F1 ft

Wind History for Providence, RI
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Boston, Logan International Airport, MA6 mi56 minW 410.00 miA Few Clouds35°F16°F46%1029.4 hPa
Beverly, Beverly Municipal Airport, MA10 mi57 minWNW 310.00 miFair21°F17°F85%1028.7 hPa
East Milton, MA18 mi54 minWNW 7 mi27°F16°F63%1029.7 hPa
Laurence G Hanscom Field Airport, MA19 mi54 minN 010.00 miFair21°F17°F85%1030.6 hPa
Norwood, Norwood Memorial Airport, MA21 mi57 minN 010.00 miFair23°F17°F78%1029.5 hPa
Lawrence Municipal Airport, MA22 mi56 minN 010.00 miFair22°F16°F78%1029.8 hPa

Wind History from BOS (wind in knots)
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Last 24hrNW7W9W10W9NW11W10NW7
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1 day agoSW9W8W12NW8NW10W10NW11
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2 days agoW13
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W10NW12W10NW7W7W6

Tide / Current Tables for Lynn, Lynn Harbor, Massachusetts
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Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.


Tide / Current Tables for Boston Harbor, Massachusetts Current
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Boston Harbor
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Wed -- 02:42 AM EDT     -1.41 knots Max Ebb
Wed -- 05:06 AM EDT     0.00 knots Slack
Wed -- 06:47 AM EDT     Sunrise
Wed -- 06:52 AM EDT     Moonset
Wed -- 08:16 AM EDT     1.43 knots Max Flood
Wed -- 10:58 AM EDT     -0.00 knots Slack
Wed -- 03:00 PM EDT     -1.51 knots Max Ebb
Wed -- 05:31 PM EDT     0.00 knots Slack
Wed -- 06:34 PM EDT     Moonrise
Wed -- 06:55 PM EDT     Sunset
Wed -- 08:44 PM EDT     1.54 knots Max Flood
Wed -- 09:43 PM EDT     Full Moon
Wed -- 11:30 PM EDT     -0.00 knots Slack
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.

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-0.8-1.2-1.4-1.4-1.1-0.10.91.31.41.30.8-0-0.7-1.2-1.4-1.5-1.3-0.60.51.21.51.51.20.4

Weather Map and Satellite Images
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GOES Local Image of Northeast    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 (5,6,7,8)
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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.