Thursday, June22, 2017 L-36.com


Marine Weather and Tides
Groton, MA

Version 3.4
What's New / NOTES
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 5:08AMSunset 8:30PM Thursday June 22, 2017 4:30 PM EDT (20:30 UTC) Moonrise 4:01AMMoonset 6:47PM Illumination 2% Phase: Waning Crescent; Moon at 28 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- 358 Pm Edt Thu Jun 22 2017
Tonight..SW winds 5 to 10 kt. Seas 1 foot or less. A slight chance of showers with isolated tstms after midnight.
Fri..S winds 5 to 10 kt, increasing to 10 to 15 kt with gusts up to 25 kt in the afternoon. Seas around 2 ft.
Fri night..SW winds 10 to 15 kt. Gusts up to 25 kt in the evening. Seas around 2 ft. Patchy fog. A chance of showers and tstms. Some tstms may produce heavy rainfall.
Sat..SW winds 5 to 10 kt. Seas 1 foot or less. Patchy fog. Showers likely with a chance of tstms. Some tstms may produce heavy rainfall. Vsby 1 to 3 nm.
Sat night..W winds around 5 kt. Seas 1 foot or less. A chance of showers.
Sun..W winds 5 to 10 kt. Seas 1 foot or less.
Sun night..W winds around 5 kt. Seas 1 foot or less.
Mon..SW winds 5 to 10 kt. Seas 1 foot or less.
Mon night..SW winds around 5 kt. Seas 1 foot or less. A chance of showers.
Tue..S winds around 5 kt. Seas 1 foot or less. A chance of showers.
Tue night..W winds around 5 kt. Seas 1 foot or less. A chance of showers. Winds and seas higher in and near tstms. 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 358 Pm Edt Thu Jun 22 2017
Synopsis for massachusetts and rhode island coastal waters.. High pressure will slide east of the waters overnight. A warm southwest wind sets up for Friday into the weekend with periods of showers from the remnants of tropical cindy. There will likely be periods of moderate to occasionally heavy rain for Friday into Saturday. A cold front will slowly pass east of the water by Sunday morning. 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 Groton, MA
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location: 42.6, -71.63     debug


Area Discussion for - Boston, MA
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Fxus61 kbox 222001
afdbox
area forecast discussion
national weather service taunton ma
401 pm edt Thu jun 22 2017

Synopsis
Warm frontal passage tonight will result in warm and humid air
on Friday along with the threat of heavy rain associated with
the remnants of cindy. The cold front will stall across new
england Saturday before moving offshore Saturday night.

Seasonably warm and less humid conditions Sunday will be
followed by cooler and somewhat unsettled weather for early next
week.

Near term until 6 am Friday morning
400 pm update...

leftover seabreezes are beginning to push offshore as mixing
continues across the area. Surface warm front is still taking its
time as it is currently located across central pa and nj. This front
will begin to move northward over the next several hours. One thing
to watch is the convection firing across central pa and upstate ny
along and ahead of the warm front. These storms will continue to
develop and move from towards the southeast this evening per mid-
level flow. The bulk of this precip should remain south of the area,
however cannot rule out a few isolated showers.

Tonight...

cloud cover will increase as a warm front will push through the
region tonight. 850 mb WAA will take hold as temps warm overnight
from 13c to 18c. This combined with the overcast skies will keep
temps more mild then previous nights with lows in the mid 60s. This
frontal system will turn the winds to a more southwesterly direction
resulting in an increasing low level moisture and strengthening llj.

Increasing k values combined with showalters dropping to below 0 may
result in a few sct showers. Highest confidence is north of the
pike, which will be on the nose of the llj. The only caveat is that
the upper level ridge will remain over the region which will limit
anything becoming widespread as southern shortwave won't approach
until Friday.

Aside from warm frontal passage and showery activity, the other
focus is on the increasing low level moisture. Dewpoints overnight
will also be on the rise, reaching the upper 60s by daybreak Friday.

This may result in a round of fog and stratus especially across the
south coast as ocean temperatures are still in the low 60s.

Short term 6 am Friday morning through Friday night
Friday into Friday night...

active weather pattern for tomorrow as southern new england remains
in the warm sector for this period. Warm and muggy to start the day
as temperatures will quickly rise into the mid to upper 80s. If
breaks of Sun can occur, then a few spots may be in the low 90s,
especially across the ct and merrimack valleys. Continuous
southwesterly flow will keep both clouds and tropical moisture
around Friday night. Overnight lows will remain mild, dropping into
the upper 60s to low 70s. This may result in another round of fog
and stratus with the highest confidence across the south coast once
again. May need to watch for a possible dense fog advisory as
surface dewpoints will be in the 70s.

Biggest focus is on precipitation potential for this time period.

Increasing moisture will begin to pool into the area with pwat
values increasing to above 2 inches by Friday evening overnight.

This gulf moisture will eventually be tapped into the tropical
moisture from cindy which will push pwat near 3 std above normal. In
fact, moisture flux values at 850 mb during this timeframe is
nearing 4 std above normal. Thus within any heavy shower, the
potential for flooding rains is possible.

Through this period, an upper level trough over the great lakes will
begin to approach from the west. A few weak waves will move along
the flow as the ridge begins to push eastward. Southwesterly flow
aloft will remain overhead as a few isolated showers move into
southern new england from the mid-atlantic. Believe these showers
will maintain themselves as they ride along a theta-e boundary and
increasing llj. Best timing will be during the morning hours. Models
continue to indicate a dry slot moving aloft as 700 mb rh values dry
up and k values decrease. Thus the remainder of the day could be on
the dry side, however, cannot rule out a few hit or miss showers
developing since we are in the warm sector. The risk for thunder
continues to be a possibility as surface CAPE will be near 1000
j kg. Not expecting anything severe as lapse rates are quiet poor,
less than 5.5 c km.

A merger between the upper level system and leftovers from cindy
will approach the area late Friday night. Slow moving cold front
will be the focus on heavy rainfall development as higher pwats and
moisture transport moves into southern new england. Concerned that
models are underdoing the potential rain set-up for Friday night
into Saturday morning as mass fields would indicate widespread heavy
rainfall. One possibility is that our moisture could get robbed by
the surface low associated with cindy's remnants. Something to watch
in the upcoming forecasts. Right now have trended the forecast
towards the ec and canadian which highlights the heavy rainfall
potential across southern new england.

Long term Saturday through Thursday
Highlights...

* scattered showers and isolated t-storms sat, especially in the
morning
* seasonably warm and less humid on Sunday
* unsettled pattern for early next week, cooler with showers possible
overview...

longwave trough evolving over the great lakes region continues to be
the main feature for the extended forecast. A series of weak
shortwaves move through the flow as the trough gradually moves
towards new england early next week. This will bring a somewhat
unsettled pattern into the middle of next week with cooler temps
trending near or below normal.

Details...

Saturday...

cold front stalled out across southern new england for at least a
portion of the day, while remnant low and shortwave from cindy
trek near or south of our area. 12z NAM 12z ECMWF indicate drier
air pushing into our area during the afternoon while front
makes an eastward push towards the southern new england
coastline. Meanwhile the 09z SREF and 12z GFS gfs ensemble mean
are more pessimistic, keeping some of the deeper moisture and
associated precip chances lingering over southern new england
into the afternoon.

During at least the morning hours, a plume of tropical moisture is
in place with precipitable water values of 1.5 to 2+ inches, highest
east of the stalled front. The shortwave will likely bring showers
with the chance for thunderstorms, especially eastern ma and south
of the mass pike. Brief locally heavy rainfall is possible.

For this forecast package will include likely pops Saturday morning
except chance north central western ma, then chance pops continuing
into Saturday afternoon due to uncertainty of arrival time of drier
airmass. Could still see developing sunshine at Saturday afternoon,
especially over the interior.

Forecast highs continue to be a challenge, especially south of the
pike where showers may hold temps down. Will go with continuity
here, highs mostly in the 70s to near 80 but low to mid 80s
northeast ma. However if we clear out in the afternoon the highs
could be several degrees higher.

Saturday night drier air moves into southern new england in earnest,
with pwats plummeting to 0.75 inch. A dry night is forecast.

Shortwave energy mainly crossing thru northern new england, may
brush our area but only anticipating some clouds at best with this
feature.

Sunday...

quite dry airmass in place. Mid level shortwave moving into our area
should mainly bring diurnal clouds, can't rule out a brief shower or
two across the interior. Seasonable temps in the upper 70s and lower
80s with low humidity as dewpoints will be in the 50s.

Monday into Wednesday...

unsettled weather pattern anticipated for the first half of the next
workweek, as trough over the great lakes region gradually shifts
eastward towards southern new england. Series of short waves
rotating thru the base of the trough will bring chances for showers
and some afternoon evening thunderstorms at times. Monday looks to
have low moisture, so will limit pops to slight chance low chance
pops. Otherwise, being several days out, still have low confidence
on timing. Temps averaging near or a bit below seasonable normals.

Aviation 20z Thursday through Tuesday
Forecaster confidence levels...

low - less than 30 percent.

Moderate - 30 to 60 percent.

High - greater than 60 percent.

Short term through Friday night ...

before 00z... High confidence.VFR.

Tonight... Moderate confidence. CIGS becoming sct to bkn
lowering towards 4-6 kft with scattered shra moving in, the
better chance of which will be north of the pike with a low risk
tsra. Increasing S winds with the threat of MVFR ifr vsbys
along the S coast from stratus and fog.

Friday... Moderate confidence. Ifr MVFR stratus and fog across
the south coast should improve toVFR during the day. Much of
the region will remainVFR with hit or miss showers. Heavy
downpours possible with the potential for iso thunder. Stratus
will fill back in late afternoon ESP across CAPE and islands.

Gusty southwesterly winds during the day with gusts near 25 kts.

Friday night... Moderate confidence.VFR conditions north of the
pike through the night, with MVFR ifr south of the pike in
another round of stratus and fog. Better chance for showers and
iso thunder during the overnight hours. Heavy rainfall could
limit vsbys.

Kbos terminal... Seabreeze dissipating early afternoon.

OtherwiseVFR for the entire TAF period. Gusty SW winds near
25kts Friday afternoon.

Kbdl terminal... High confidence.VFR throughout. Gusty SW winds
near 25kts during Friday afternoon.

Outlook Saturday through Tuesday ...

Saturday... Moderate confidence.

MVFR and localized ifr in sct showers and isold t-storms, especially
south of the pike. During the afternoon improvement to mainlyVFR
north of the pike.

Saturday night and Sunday... High confidence. MainlyVFR.

Monday... High confidence.

MainlyVFR CIGS with a few showers possible in the interior.

Tuesday... Moderate confidence.

MainlyVFR CIGS with some scattered showers isolated t-storms
possible.

Marine
Forecaster confidence levels...

low - less than 30 percent.

Moderate - 30 to 60 percent.

High - greater than 60 percent.

Short term through Friday night ...

southerly winds overnight as warm front passes. Wind will
increase into Friday with sustained winds 10 to 15 kts and
gusts up to 25 kts. This will push seas 5 to 6 feet and will
continue with the sca. With a cold front sweeping down from the
n as the remnants of TS cindy advect N from the s, will likely
see the return of mist fog conditions resulting in low
visibility down to a quarter mile or less at times.

Outlook Saturday through Tuesday ...

Saturday... Moderate confidence.

Some gusty W SW winds early sat, possibly near SCA thresholds in the
morning, should be diminishing in the afternoon. Seas up to 5-6 ft
over the south coastal waters.

Sunday and Monday... High confidence.

Winds should generally remain below small craft advisory thresholds
through the period. Lingering 5 ft seas over the south coastal
waters will subside Sun night.

Tuesday... Moderate confidence. There is a chance that winds and seas
may increase to small craft advisory thresholds.

Tides coastal flooding
Astronomical tides are rather high this weekend during the night time
cycles. Boston has a 12.4 ft high tide around midnight Sat night and
12.2 ft just after midnight Sun night. Fortunately, offshore winds
are forecast with minimal or no surge so do not anticipate any
issues.

Box watches warnings advisories
Ct... None.

Ma... None.

Ri... None.

Marine... Small craft advisory from 8 pm Friday to 8 am edt Saturday for
anz231>235-237.

Small craft advisory from 2 pm Friday to 8 am edt Saturday for
anz250-254>256.

Synopsis... Dunten nmb
near term... Dunten
short term... Dunten
long term... Nmb
aviation... Dunten nmb
marine... Dunten nmb
tides coastal flooding... Staff


Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
BHBM3 - 8443970 - Boston, MA 35 mi42 min 81°F 1010.9 hPa
BGXN3 - Great Bay Reserve, NH 53 mi105 min W 2.9 82°F 1013 hPa59°F
44013 - BOSTON 16 NM East of Boston, MA 55 mi40 min SE 7.8 G 9.7 65°F 59°F1 ft1012.3 hPa (-1.4)

Wind History for Providence, RI
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Fitchburg, Fitchburg Municipal Airport, MA8 mi98 minWNW 810.00 miFair83°F52°F34%1012.9 hPa
Nashua - Boire Field Airport, NH14 mi34 minW 7 G 1710.00 miA Few Clouds82°F52°F35%1013.2 hPa
Bedford, Hanscom Field, MA20 mi94 minWNW 910.00 miFair82°F50°F33%1013.2 hPa
Jaffrey Airport-Silver Ranch, NH24 mi38 minVar 6 G 1410.00 miFair78°F50°F37%1014.1 hPa

Wind History from FIT (wind in knots)
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Last 24hrNW14NW13
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W8W3NE3CalmN5NW4N5CalmCalm--CalmCalmCalmNW6W7W7--W12W8
G14
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1 day agoSW10
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SW6W10W6W5W5N3CalmCalmCalmSE3CalmCalmCalmCalmCalmSW8W5W13
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2 days agoS14
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S10SE3SE4CalmS4SW4SW5SW7S6SE3SE4--S7W6SW10W9S14
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Tide / Current Tables for Riverside, Merrimack River, Massachusetts
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Riverside
Click for Map
Thu -- 03:59 AM EDT     Moonrise
Thu -- 05:06 AM EDT     Sunrise
Thu -- 07:17 AM EDT     -0.31 feet Low Tide
Thu -- 11:55 AM EDT     6.12 feet High Tide
Thu -- 06:45 PM EDT     Moonset
Thu -- 07:28 PM EDT     -0.12 feet Low Tide
Thu -- 08:26 PM EDT     Sunset
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
6.86.25.23.82.41.10.1-0.30.11.63.85.66.15.85.142.71.50.5-0.10.11.53.96.1

Tide / Current Tables for Amelia Earhart Dam, Mystic River, Boston Harbor, Massachusetts
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Amelia Earhart Dam
Click for Map
Thu -- 04:00 AM EDT     Moonrise
Thu -- 04:02 AM EDT     -1.04 feet Low Tide
Thu -- 05:07 AM EDT     Sunrise
Thu -- 10:11 AM EDT     10.45 feet High Tide
Thu -- 04:17 PM EDT     -0.43 feet Low Tide
Thu -- 06:44 PM EDT     Moonset
Thu -- 08:25 PM EDT     Sunset
Thu -- 10:28 PM EDT     12.09 feet High Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
7.95.22.3-0-1-0.21.94.47.19.410.4108.46.13.41-0.40.12.14.87.710.411.911.9

Weather Map and Satellite Images
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Weather Map
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IR Satellite Image from GEOS
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GOES Local Image of Northeast    EDIT
Geos

Wind Forecast for Boston, MA (16,3,4,5)
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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.