Friday, January19, 2018 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 7:06AMSunset 4:44PM Friday January 19, 2018 12:51 AM EST (05:51 UTC) Moonrise 9:37AMMoonset 8:18PM Illumination 6% Phase: Waxing Crescent; Moon at 2 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- 1018 Pm Est Thu Jan 18 2018
Overnight..NW winds 5 to 10 kt. Waves 1 foot or less.
Fri..W winds 5 to 10 kt. Waves 1 foot or less.
Fri night..SW winds 5 to 10 kt. Gusts up to 20 kt after midnight. Waves around 2 ft.
Sat..SW winds 10 to 15 kt, becoming W 5 to 10 kt in the afternoon. Gusts up to 20 kt. Waves around 2 ft.
Sat night..W winds 5 to 10 kt. Waves around 2 ft.
Sun..W winds around 5 kt. Waves 1 foot or less.
Sun night..NW winds around 5 kt, becoming N after midnight. Waves 1 foot or less.
Mon..E winds 5 to 10 kt. Waves 1 foot or less. A chance of rain. Vsby 1 to 3 nm.
Mon night..SE winds 5 to 10 kt with gusts up to 20 kt. Waves 2 to 3 ft. Rain. Vsby 1 to 3 nm.
Tue..S winds around 10 kt with gusts up to 20 kt. Waves around 2 ft. Showers.
Tue night..W winds around 10 kt with gusts up to 20 kt. Waves around 2 ft. 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 1018 Pm Est Thu Jan 18 2018
Synopsis for massachusetts and rhode island coastal waters.. Large high pres will build S of the waters through this weekend. Low pres will pass well W of the region late Monday, but its associated front will likely bring periods of rain and gusty southerly winds. 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 190344
afdbox
area forecast discussion
national weather service taunton ma
1044 pm est Thu jan 18 2018

Synopsis
Dry and seasonably cold conditions into Friday, then a warming
trend this weekend with continued dry weather. A storm system
will affect the region sometime late Monday into Tuesday with
mostly rain and coastal wind, but there is a risk of some wintry
mix ice across the interior. Warm weather Tuesday is replaced
by blustery, dry and seasonably cold weather Wednesday and
Thursday.

Near term until 6 am Friday morning
1020 pm update...

still noting low clouds lingering along east coastal areas
including CAPE cod and the islands as intensifying low pres
continues to move offshore. Another area of low clouds will push
across central and northern portions of the ct valley as seen
on goes-16 nighttime microphysics channel as well as hourly
obs. This area is associated with quickly passing h5 short wave
in the fast northern stream flow aloft, then should lift
further into northern new england overnight. Will watch this
closely, as short range models showing this feature pushing a
bit further S than previous forecast runs. Noting NW wind gusts
across the nearshore waters at 15-20 kt.

Overall forecast in pretty good shape but did refresh to bring
near term conditions current. Temps were a couple of degrees
either side of forecast which were adjusted.

Previous discussion...

deamplifying h5 impulse sweeping across the region overnight.

Accompanying ascent with differential vorticity advection and
parent jet streak. Overrunning response but atmosphere rather
void of moisture given precipitable waters up around 0.2
inches. Green's and white's likely to see some snow potentially
extending as far S as the berkshires as flurries. Otherwise
scattered to broken cloud decks while monitoring low-level
stratus lingering along the high terrain and along the outer
cape. With clouds anticipated, leaning away from coldest of
guidance, that being met mav.

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

departing h5 vort MAX with accompanying enhancement to the low-
level wind profile. Mixing out to around h9 through the day,
there's the possibility of some breezy W winds during the
morning, otherwise relaxing through the remainder of the day
beneath a follow-up brief, weak ridge of high pressure. Boundary
layer lapse rates remaining well mixed, beneath a dry inversion,
and anticipating temperatures to warm into the mid and upper 30s,
with snow melt, can't rule out some few to scattered pancake
cumulus.

Friday night...

continued energy and moisture accelerating through the pseudo-
zonal flow, sagging S into the great lakes region. Up against
high pressure over the SE conus, an amplified gradient wind
response with accompanying speed MAX at h925. Warmer, dry air
pushing out of the sw, warming within h9-7 apparent within model
forecast soundings, limitations on mixing down to the surface.

Thus expecting a gradient wind response with strongest winds
potentially in excess of 30 mph along the s-coast, across the
cape and islands. Keep it dry but also mild with the winds. Lows
down in the 20s for most locations.

Long term Saturday through Thursday
340 pm update...

highlights...

* dry and mild this weekend, possibly low 50s Saturday!
* another storm will bring mostly rain and gusty coastal winds
late Mon into Tue with a risk of some interior mixed
precip ice
this weekend...

confluent flow aloft across new england provides dry weather to
the region this weekend. Low pres tracking across southeast
canada combined with high pres over the southeast states yields
a tight westerly pgrad over the area. Warm air just above the
surface with 925 mb temps +2c to +4c. However model soundings
indicate a stout subsidence inversion limiting blyr mixing. Thus
how much warm air aloft mixes down to the surface? Given the
tight westerly pgradient and associated downsloping
winds adiabatic warming looks to be an overachieving temp setup.

Model 2-meter temps and MOS guid continue to trend warmer with
each run. ECMWF mos and GFS mos are the warmest guidance sources
and will lean in this direction. Thus will go warmer than guid
sat with highs in the upper 40s to lower 50s, warmest in the
coastal plain of ri and southeast ma. Although cooler along the
immediate south coast and islands given wsw winds coming off the
chilly near shore waters.

Regarding winds sat, GFS model soundings suggest g35 kt
possible. Pgrad supports a windy so could see a few g40 mph but
gusts 15 to 30 mph more common. Another nice day Sunday however
winds will be much less along with temps not quite as mild,
45-50. Still 10-15 degs above normal. Turning colder Sunday
night as a backdoor front slips across the area as 1037 mb high
builds southeast into ontario and quebec.

Monday Tuesday...

pacific short wave marches across the country with an influx of
gulf and atlantic moisture as it approaches from the southwest
with pwats surging up to +2 sd Tue morning across southern new
england. Fairly robust wind anomalies within this moisture plume
with GEFS ensembles offering +2 sd 850 mb and 925 mb winds.

Ecmwf more amplified than the GFS but the GEFS lends some
support toward the stronger ecmwf. Thus will base this portion
of the forecast toward a ECMWF gefs blend.

Meanwhile, shallow cold air bleeds southward into southern new
england Monday behind the backdoor cold front and 1038 mb high
pressure builds from quebec into maine and new brunswick. This
will provide a cold air damming (cad) setup for especially
northern ma later Monday and possibly lingering into early tue
morning. Thus potential for a period of mixed precip ice across
this region.

Elsewhere expecting a chilly windswept rain Monday night into
tue morning with increasing ese winds off the cool near shore
waters ahead of a strong cold front and possible triple pt low.

Ecmwf and GFS both have 925 mb southerly jet up to 65-70 kt
crossing southern new england tue. In addition, it's aways out
but some of the deterministic guid has mid level lapse rates up
to 6-7c km along and ahead of the frontal boundary. Thus could
be some elevated convection which would enhance the threats of
strong winds aloft reaching the surface and locally heavy rain.

Both ensembles and deterministic guid have 1+ of rainfall
possible. As for temps, possibly another 50+ day especially in
the coastal plain where warm sector has best chance of advancing
but also temps may jump into the 50s behind the front as post
frontal winds scour out any leftover shallow cold air from mon
night Tue morning.

Wednesday Thursday...

post frontal airmass is colder with 850 mb temps around -8c on
both GEFS and ecens ensembles, which is seasonably cool for this
time of year. So expecting highs at or slightly above normal.

Although it will probably feel a bit colder given gusty wnw post
frontal winds. Dry weather expected Wed and thu.

Aviation 04z Friday 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 ... High confidence.

Overnight... MainlyVFR. MVFR CIGS will likely hang close to e
coastal ma, but impact the CAPE and islands with a more N ne
onshore flow. Expect winds to become more northerly towards
daybreak fri. Bkn-ovc MVFR along the slopes of the berkshires.

Otherwise mostly clear skies. W-nw winds prevail.

Friday...

vfr. Brief period of breezy W winds as sct-bkn high clouds
erode. Few-sct around 3500 ft possible during at times around
midday.

Friday night...

vfr. W winds on the increase towards Saturday morning. Mainly a
gradient wind with the potential of sustained values up to 25
kts, gusts up to 30 kts.

Kbos terminal... High confidence in taf.

Kbdl terminal... High confidence in taf.

Outlook Saturday through Tuesday ...

Saturday:VFR. Windy with gusts to 30 kt.

Saturday night:VFR. Breezy.

Sunday through Sunday night:VFR.

Monday: MVFR ifr conditions possible. Chance ra, chance sn,
fzra likely.

Monday night: mainly MVFR, with areas ifr possible. Breezy. Ra,
fzra likely, sn likely.

Tuesday: mainly MVFR, with local ifr possible. Breezy. Shra.

Marine
Forecaster confidence levels...

low - less than 30 percent.

Moderate - 30 to 60 percent.

High - greater than 60 percent.

Short term through Friday night ... High confidence.

1030 pm update...

small craft advisories remain in effect over the open waters e
and S of CAPE cod and the southern outer waters. Winds gusting
to around 20 kt there with seas remaining around 5 ft.

Seas will hold at around 5 ft through the night, then should
subside briefly on Friday. Continued W winds through Friday.

Greater concern is on the Friday night into Saturday morning
period with increasing sustained winds potentially up to 25 kts,
gusts up to 30 kts. Small craft headlines may need to be
renewed. There is also a low risk of low end gales.

Outlook Saturday through Tuesday ...

Saturday: low risk for gale force winds with gusts up to 35 kt.

Areas of rough seas.

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

Sunday: winds less than 25 kt. Seas locally approaching 5 ft.

Sunday night: winds less than 25 kt.

Monday: winds less than 25 kt. Seas locally approaching 5 ft.

Chance of rain.

Monday night: low risk for small craft advisory winds with
gusts up to 30 kt. Local rough seas. Rain likely.

Tuesday: moderate risk for small craft advisory winds with
gusts up to 30 kt. Rough seas up to 9 ft. Rain showers.

Hydrology
A flood warning remains in effect for the connecticut river at
middle haddam, where ice jams are causing river fluctuations.

For details on specific area rivers, including observed and
forecast river stages, please visit the advanced hydrologic
prediction service (ahps) graphs on our website.

Box watches warnings advisories
Ct... None.

Ma... None.

Ri... None.

Marine... Small craft advisory for hazardous seas until 6 am est Friday
for anz254>256.

Synopsis... Nocera sipprell
near term... Evt gaf
short term... Sipprell
long term... Nocera
aviation... Nocera evt gaf
marine... Nocera evt gaf
hydrology... 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 mi52 min 25°F 1013.2 hPa (+0.4)
44013 - BOSTON 16 NM East of Boston, MA 22 mi62 min NW 16 G 19 29°F 41°F3 ft1012.9 hPa (+0.5)
44029 - Buoy A0102 - Mass. Bay/Stellwagen 28 mi108 min 14 G 16 28°F 39°F3 ft1012.3 hPa
FOXR1 - 8454000 - Providence, RI 43 mi52 min NNW 8 G 15 24°F 34°F1014.2 hPa (+0.0)
PVDR1 44 mi52 min WNW 8 G 13 24°F 1014.8 hPa (+0.0)15°F
FRVM3 - 8447386 - Fall River, MA 46 mi52 min 25°F 34°F1015.1 hPa (+0.5)
BLTM3 - 8447387 - Borden Flats Light at Fall River, MA 46 mi52 min NW 8 G 9.9 25°F 1014.1 hPa (+0.6)
FRXM3 47 mi52 min 26°F 17°F
IOSN3 - Isle of Shoals, NH 47 mi52 min WNW 13 G 15 26°F 1012.8 hPa (+0.3)20°F
CPTR1 - 8452944 - Conimicut Light, RI 48 mi52 min WNW 12 G 14 24°F 34°F1014.6 hPa (+0.0)
BGXN3 - Great Bay Reserve, NH 49 mi67 min Calm 14°F 1014 hPa13°F

Wind History for Providence, RI
(wind in knots)    EDIT      (on/off)   Help
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
11
PM
12
AM
Last
24hr
N8
G11
NW7
G11
N10
G13
N5
G12
N10
N8
G11
NE3
G6
NE6
N5
G8
NW4
N6
N9
G15
NE9
G17
NE7
G13
NE12
G15
N12
G16
N9
G13
N5
G8
NW5
G11
NW6
NW10
G13
NW10
G13
NW8
G14
NW8
G15
1 day
ago
S5
SE4
SE6
SE3
SE4
NE4
NE4
NE3
NE4
NE3
NE4
NE4
G8
NE5
NE7
NE6
N6
NE4
NE5
E4
N5
N7
G10
N4
G8
N8
G11
N9
2 days
ago
NE4
G9
NE4
G7
E5
E1
G4
E1
SE2
S5
S5
S6
S4
S7
S9
S9
S6
S7
S8
G11
S4
S3
S3
S5

Airport Reports
    EDIT      (on/off)   Help   Click EDIT to display multiple airports
AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Boston, Logan International Airport, MA2 mi58 minW 1110.00 miA Few Clouds25°F16°F69%1014.1 hPa
East Milton, MA11 mi56 minWNW 9 mi19°F14°F81%1014.5 hPa
Norwood, Norwood Memorial Airport, MA14 mi59 minW 610.00 miFair25°F15°F66%1014.4 hPa
Bedford, Hanscom Field, MA14 mi56 minWSW 310.00 miFair20°F14°F78%1015.5 hPa
Beverly, Beverly Municipal Airport, MA16 mi59 minW 310.00 miFair21°F15°F78%1013.4 hPa

Wind History from BOS (wind in knots)
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
11
PM
12
AM
Last 24hrNW10W9W10W12W11W5W6NW11W4NW7NW8W10NW11NW12
G19
NW11
G19
NW11NW9NW9
G19
NW11NW9W9W11W10W11
1 day agoS5S3S5SE5SE4E3NE3NE4E4NE5NE4N6N6N8N5N6N6N6NW7N6NW7NW8NW9NW8
2 days agoNW9N7NW5NW6N5N3NE4NE5CalmCalmSE4S3SE4SE4SE4SE3SE4SE6SE4SE5SE6S6S6S5

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 -- 12:37 AM EST     9.14 feet High Tide
Fri -- 06:31 AM EST     0.79 feet Low Tide
Fri -- 07:08 AM EST     Sunrise
Fri -- 08:36 AM EST     Moonrise
Fri -- 12:42 PM EST     10.16 feet High Tide
Fri -- 04:41 PM EST     Sunset
Fri -- 07:01 PM EST     -0.11 feet Low Tide
Fri -- 07:18 PM EST     Moonset
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
8.99.18.16.44.42.4112.34.26.38.49.810.19.17.352.70.7-0.10.62.34.36.4

Tide / Current Tables for Boston Harbor, Massachusetts Current
   EDIT      (on/off)   Help   One Week of Data
Boston Harbor
Click for Map
Fri -- 12:01 AM EST     -0.00 knots Slack
Fri -- 04:02 AM EST     -1.02 knots Max Ebb
Fri -- 06:33 AM EST     0.00 knots Slack
Fri -- 07:08 AM EST     Sunrise
Fri -- 08:36 AM EST     Moonrise
Fri -- 08:40 AM EST     1.15 knots Max Flood
Fri -- 12:10 PM EST     -0.00 knots Slack
Fri -- 03:37 PM EST     -1.12 knots Max Ebb
Fri -- 04:41 PM EST     Sunset
Fri -- 06:56 PM EST     0.00 knots Slack
Fri -- 07:18 PM EST     Moonset
Fri -- 09:03 PM EST     1.20 knots Max Flood
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
0-0.5-0.8-1-1-1-0.50.41.11.11.10.80.1-0.5-0.9-1.1-1.1-1.1-0.80.10.91.21.11

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 (0,6,7,8)
      (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.