Friday, May26, 2017 L-36.com


Marine Weather and Tides
Chelsea, 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 5:11AMSunset 8:11PM Friday May 26, 2017 10:27 PM EDT (02:27 UTC) Moonrise 6:13AMMoonset 9:09PM Illumination 2% Phase: Waxing Crescent; Moon at 1 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
    EDIT      (on/off)   Help
ANZ230 Boston Harbor- 716 Pm Edt Fri May 26 2017
Tonight..N winds 5 to 10 kt. Seas 1 foot or less. Scattered showers this evening.
Sat..N winds 5 to 10 kt...becoming E in the afternoon. Seas 1 foot or less.
Sat night..SE winds 5 to 10 kt...becoming S after midnight. Seas 1 foot or less.
Sun..S winds around 5 kt...becoming se around 5 kt in the afternoon. Seas 1 foot or less.
Sun night..S winds around 5 kt. Seas 1 foot or less.
Mon..SE winds 5 to 10 kt. Seas 1 foot or less. Showers likely. Vsby 1 to 3 nm.
Mon night..E winds around 5 kt. Seas 1 foot or less. Patchy fog. A chance of showers. Vsby 1 to 3 nm.
Tue..SE winds around 5 kt. Seas 1 foot or less. Patchy fog. A chance of showers. Vsby 1 to 3 nm.
Tue night..S winds around 5 kt. Seas 1 foot or less. Patchy fog. A chance of showers. Vsby 1 to 3 nm.
Wed..SW winds 5 to 10 kt with gusts up to 20 kt. Seas 1 foot or less. A chance of showers. Vsby 1 to 3 nm.
Wed night..W winds around 5 kt. Seas 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 716 Pm Edt Fri May 26 2017
Synopsis for massachusetts and rhode island coastal waters.. Low pres will continue to head ne toward nova scotia tonight and behind it high pres will build across the waters. Anticipate quiet weather for the weekend with another frontal system expected to move through Mon and Tue. 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
   Hourly   EDIT   Help
location: 42.37, -71.06     debug


Area Discussion for - Boston, MA
      (on/off)   Help   NOTE: mouseover dotted underlined text for definition
Fxus61 kbox 270210
afdbox
area forecast discussion
national weather service taunton ma
1010 pm edt Fri may 26 2017

Synopsis
Low pressure moves offshore tonight followed by weak high pressure
this weekend which will bring mild days and cool nights. Low
pressure in the great lakes generates a coastal low late Monday
that passes off nantucket on Tuesday. This will bring wet weather
on memorial day. Daytime clouds and scattered showers will pop
up each day Tuesday through Friday.

Near term until 6 am Saturday morning
10 pm update...

comma-head occlusion continues to peel off to the E round which
there is some emphasis of boundary-layer focus of airmasses
brought on by mid-level lobing energy round the backside of the
low. Broken to overcast low cloud decks lingering along with
scattered shower activity. This as cooler air surges rearward
and onshore as discerned via latest radar imagery. Temperatures
dropping towards their respective wet-bulb, it is behind the
cool-frontal surge that patchy fog and drizzle development are
possible, especially over E ma.

But some improvement on the horizon. Heights rising as weak
mid-level ridging builds in from the w. Building high pressure
along with drier air, should see showers dissipate E as we go
through the overnight hours. Winds should relax becoming more
northerly with time. Lows bottoming around the upper 40s to low
50s.

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

weak high pres builds across the region but low level moisture
remains abundant below the inversion which indicates clouds will
dominate with bkn-ovc cloud cover. Mid level shortwave approaches
from the west by late in the day which will also bring increasing
mid level clouds and can't rule out a brief shower toward evening
across ct. Soundings show mixing to about 925 mb with highs mostly
in the 60s with a few lower 70s possible lower ct valley. Seabreezes
expected in the afternoon which may hold temps in the upper 50s
along east coastal ma.

Saturday night...

a brief shower possible from ct to southern ri in the evening as
shortwave passes to the south, otherwise dry weather as weak high
pres remains in control. Mostly cloudy skies persisting. Mins mid
40s to lower 50s.

Long term Sunday through Friday
Big picture...

longwave scale maintains a ridge west trough east pattern for much
of the long term period. Shortwave scale shows a closed low slowly
moving from canada across the great lakes, eventually reaching new
england late in the week. Two jets in place for much of the period.

The northern jet sweeps around the closed low from western canada
across the northeast usa. The southern jet swings from baja into the
southern plains and southeast usa. The two streams interact over
the ohio valley and mid atlantic early next week.

Model mass fields are similar through Tuesday... The GFS and ecmwf
are similar through Thursday. GFS and ECMWF moisture and thermal
fields are similar during the same period while showing differences
in detail. This brings increased confidence in the overall pattern
through much of next week, although lingering uncertainty regarding
timing of individual shortwaves in the flow.

Details...

Sunday...

high pressure is in control Sunday with subsidence and light wind
flow. Moisture fields show an area of higher rh below 800 mb and
suggests a cloud Sun mix with the fair weather. Temperatures in the
mixed layer are equiv to 5-8c, suggesting MAX temps upper 60s to mid
70s. Sea breezes along the coast will hold temps there in the 60s.

Fair skies linger early in the night, but the next approaching
shortwave supports increasing clouds... Expect this overnight. Dew
points will be roughly 45-50 which with light flow and initial fair
skies should allow temps to reach the lower 50s and possibly the mid
40s.

Monday-Tuesday...

interaction between the northern and southern streams leads to a 120-
knot jet over the ohio valley which races east ahead of northern
stream shortwave during Monday. This crosses the surface cold front
and generates a triple-point low as it crosses the mid atlantic
coast. This in turn spins up a weak southerly low level jet that
aims for SRN new england during the afternoon evening. Precipitable
water values reach 1.0-1.2 inches which is above normal but not
excessive.

Model consensus slows some slowing of the onset of measurable
pcpn in southern new england. The GFS holds off on measurable
until after 12z Monday while the ggem and ECMWF bring it to the
ct valley by 12z and possibly a little farther. We opted to slow
pcpn onset to a compromise time with chance pops to the ct
valley around 09z and to worcester and the ri hills 12z... Then
to most of eastern ma by 14z.

We will bring likely pops to the western sections for late
morning early afternoon and for eastern sections for the afternoon.

Stability parameters are somewhat favorable for convection, with
totals around 50 while surface LI values will be near zero. We will
include scattered to isolated tstms Monday afternoon evening.

The coastal low passes offshore Tuesday morning. Expect leftover
showers diminishing Tuesday morning, then expanding again as another
shortwave moves through.

Wednesday through Friday...

upper low slowly sweeps across eastern canada during the period,
with shortwaves moving through the flow across new england. Cold
pool advection aloft will destabilize the airmass and support
scattered daytime showers, especially in areas north of the mass
pike. Temperatures in the mixed layer will support MAX temps upper
60s to mid 70s each day. Fair skies and dew points in the 50s will
support mins in the 50s each night... Possibly cooling to mid 40s to
low 50s late in the week.

Aviation 02z Saturday through Wednesday
Forecaster confidence levels...

low - less than 30 percent.

Moderate - 30 to 60 percent.

High - greater than 60 percent.

Short term through Saturday night ... Moderate confidence.

2z update...

tonight...

MVFR CIGS mainly with low risk ifr, while an improving trend
from the W with low-endVFR cigs. Lowest conditions across E ma
with the threat of dz fg as winds have turned NE onshore. Should
see improving conditions W to E overnight, diminishing winds
becoming northerly. Shra activity concluding.

Saturday and Saturday night...

mix ofVFR MVFR cigs. Seabreezes developing late morning into
the afternoon. Low risk for a brief shower late Sat sat evening
south of the mass pike.

Kbos taf... Ne flow persisting as a cool front has pushed onshore.

Should see NE winds diminish towards midnight becoming more n
overnight. The brief period of ifr should be just that, the rest
of the overnight period MVFR.

Kbdl taf... Bkn low-endVFR CIGS persisting. N flow.

Outlook Sunday through Wednesday ... Moderate confidence.

Sunday...

vfr. Light S wind becoming onshore on the mass east coast by
midday.

Monday...

vfr at first, lowering to MVFR in the afternoon and ifr lifr at
night. SE winds less than 20 kts. Ra shra developing during the
morning and midday, with potential sct tsra in the afternoon into
evening. Areas of fog at night.

Tuesday-Wednesday...

ifr Tuesday morning, improving toVFR Tuesday afternoon through
Wednesday. Sct shra, mostly during the daytime. Light E wind
Tuesday becoming S in the afternoon, then W SW Wednesday. Speeds
less than 15 kts.

Marine
Forecaster confidence levels...

low - less than 30 percent.

Moderate - 30 to 60 percent.

High - greater than 60 percent.

Short term through Saturday night ... High confidence.

10 pm update... .

Tonight...

have modified headlines to account for hazardous seas which
persist on the outer waters and S sounds of ri and block island.

With high pressure building in from the w, should see mainly n
winds which will be light allowing seas to diminish further into
the Saturday morning timeframe.

Saturday...

winds becoming E SE with speeds below 15 kt. Seas will subside
below 5 ft over southern waters.

Saturday night...

quiet weather with light winds and seas below sca.

Outlook Sunday through Wednesday ... Moderate confidence.

Winds less than 20 knots and seas less than 5 feet through the
period. Showers and isolated tstms Monday, showers and fog Monday
night and early Tuesday.

Tides coastal flooding
Still observing a 0.5 to 1 ft surge along both coasts which
estofs and etss guidance is underestimating. Surge expected to
diminish to around 0.2 to 0.5 ft at the time of high tide later
tonight as winds and swell diminish. High tides this evening are
quite high (boston 12.41 feet around 1230 am, providence 6.45
feet around 930 pm), even with minimal wave action, total water
level above 12.5 ft in boston typically produces very minor
inundation for the notorious low-lying locations (i.E, morrissey
boulevard in boston). In addition, minor inundation possible
along the south coast if surge still around 0.5 ft. We will
issue a coastal flood statement to address these concerns.

Box watches warnings advisories
Ct... None.

Ma... None.

Ri... None.

Marine... Small craft advisory for hazardous seas until 10 am edt
Saturday for anz235-237.

Small craft advisory for hazardous seas until 6 am edt
Saturday for anz250.

Small craft advisory for hazardous seas until noon edt
Saturday for anz254>256.

Synopsis... Wtb kjc
near term... Wtb kjc sipprell
short term... Kjc
long term... Wtb
aviation... Wtb kjc sipprell
marine... Wtb kjc sipprell
tides coastal flooding... WFO box staff


Weather Reporting Stations
   EDIT       (on/off)   Help   NOTE: Click on distance to see the station location on a map
Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
BHBM3 - 8443970 - Boston, MA 1 mi39 min 53°F 54°F1006.1 hPa
44013 - BOSTON 16 NM East of Boston, MA 22 mi37 min N 3.9 G 3.9 52°F 53°F5 ft1005.4 hPa (+2.3)
44029 - Buoy A0102 - Mass. Bay/Stellwagen 28 mi83 min WNW 1.9 G 1.9 50°F 49°F3 ft1004.7 hPa
FOXR1 - 8454000 - Providence, RI 43 mi39 min NW 4.1 G 7 1005.2 hPa
PVDR1 44 mi39 min WSW 6 G 7 59°F 1005.6 hPa58°F
FRVM3 - 8447386 - Fall River, MA 46 mi39 min 58°F 57°F1006.3 hPa
BLTM3 - 8447387 - Borden Flats Light at Fall River, MA 46 mi39 min SW 8 G 8 58°F 1005 hPa
FRXM3 47 mi39 min 58°F 56°F
IOSN3 - Isle of Shoals, NH 47 mi27 min N 8.9 G 11 53°F 1006 hPa (+2.7)48°F
CPTR1 - 8452944 - Conimicut Light, RI 48 mi39 min S 4.1 G 5.1 57°F 57°F1006.1 hPa
BGXN3 - Great Bay Reserve, NH 49 mi102 min Calm 54°F 1006 hPa52°F

Wind History for Providence, RI
(wind in knots)    EDIT      (on/off)   Help
11
PM
12
AM
1
AM
2
AM
3
AM
4
AM
5
AM
6
AM
7
AM
8
AM
9
AM
10
AM
11
AM
12
PM
1
PM
2
PM
3
PM
4
PM
5
PM
6
PM
7
PM
8
PM
9
PM
10
PM
Last
24hr
E3
G10
NE4
G10
N9
G14
NE6
G12
NE5
G12
E1
G5
NE3
G7
E2
G6
NE7
G10
NE7
G13
N8
G13
N9
G16
N11
G15
N7
G13
N8
G12
NW5
NW5
G9
NW2
G5
NW4
NW4
NW3
NW4
NW1
NW4
G8
1 day
ago
E5
E5
E4
G7
E8
E7
G10
E7
E6
E9
E7
G10
E7
G10
E9
G14
E7
G11
E8
G12
E7
G12
E7
G10
E3
G8
E3
G7
NE4
G9
E4
G9
E3
G9
E2
G6
E3
G7
NE3
G9
NE3
G7
2 days
ago
S8
G12
S7
S2
S4
S5
SE3
E2
SE4
NE4
E5
SE7
E5
E6
G12
E5
G10
SE8
G11
SE5
G9
SE9
G12
SE7
G10
SE7
G10
SE9
SE9
G12
E7
E5
G9
E7

Airport Reports
    EDIT      (on/off)   Help   Click EDIT to display multiple airports
AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Boston, Logan International Airport, MA2 mi33 minE 46.00 miFog/Mist53°F53°F100%1006.3 hPa
East Milton, MA11 mi31 minENE 8 mi51°F50°F96%1007 hPa
Norwood, Norwood Memorial Airport, MA14 mi34 minNE 710.00 miOvercast55°F52°F90%1006.1 hPa
Bedford, Hanscom Field, MA14 mi91 minNE 106.00 miDrizzle Fog/Mist55°F52°F90%1006.1 hPa
Beverly, Beverly Municipal Airport, MA16 mi34 minN 010.00 miOvercast55°F53°F93%1005.5 hPa

Wind History from BOS (wind in knots)
11
PM
12
AM
1
AM
2
AM
3
AM
4
AM
5
AM
6
AM
7
AM
8
AM
9
AM
10
AM
11
AM
12
PM
1
PM
2
PM
3
PM
4
PM
5
PM
6
PM
7
PM
8
PM
9
PM
10
PM
Last 24hrNE13N15N12N9N6N17
G23
N11N9N10N11N9N11NW10NW13NW10--W13W10
G18
W8W9W9E9NE6E4
1 day agoNE3N3E3NE4CalmNE7E9E10NE11NE13NE13E14E19
G24
NE17
G25
NE18NE15--NE17NE15NE15
G22
NE14
G18
NE16NE13NE16
G20
2 days agoS6S5S5S5S6S3SE3SE4E4E4NE6E5NE5NE5E6E4E6E7E9E7E8E7E5SE4

Tide / Current Tables for Charlestown Bridge, Charles River, Massachusetts
   EDIT   RT Ports Option   Weekend mode (on/off)   (on/off)   Help   One Week of Data
Charlestown Bridge
Click for Map
Fri -- 05:13 AM EDT     Sunrise
Fri -- 06:12 AM EDT     -1.98 feet Low Tide
Fri -- 06:14 AM EDT     Moonrise
Fri -- 12:24 PM EDT     11.02 feet High Tide
Fri -- 06:27 PM EDT     -0.93 feet Low Tide
Fri -- 08:09 PM EDT     Sunset
Fri -- 09:08 PM EDT     Moonset
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
12.311.18.75.62.3-0.5-1.9-1.30.83.76.79.410.910.79.26.73.81.1-0.7-0.61.34.27.310.2

Tide / Current Tables for Boston Harbor, Massachusetts Current
   EDIT      (on/off)   Help   One Week of Data
Boston Harbor
Click for Map
Fri -- 02:58 AM EDT     -1.52 knots Max Ebb
Fri -- 05:12 AM EDT     Sunrise
Fri -- 06:07 AM EDT     0.00 knots Slack
Fri -- 06:13 AM EDT     Moonrise
Fri -- 08:42 AM EDT     1.49 knots Max Flood
Fri -- 11:54 AM EDT     -0.00 knots Slack
Fri -- 03:18 PM EDT     -1.38 knots Max Ebb
Fri -- 06:25 PM EDT     0.00 knots Slack
Fri -- 08:09 PM EDT     Sunset
Fri -- 08:53 PM EDT     1.55 knots Max Flood
Fri -- 09:08 PM EDT     Moonset
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
-0.5-1.1-1.4-1.5-1.4-1.1-0.111.41.51.30.8-0.1-0.8-1.2-1.4-1.3-1.1-0.50.71.41.51.51.1

Weather Map and Satellite Images
       (on/off)   Help
Weather Map
wmap_A
IR Satellite Image from GEOS
east_satellite

GOES Local Image of Northeast    EDIT
Geos

Wind Forecast for Boston, MA (22,6,7,8)
      (on/off)   Help

Ground Weather Radar Station Boston, MA
   (on/off)   Help
weather_mapweather_map weather_map

Ad by Google

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.