Tuesday, November20, 2018 L-36.com


Marine Weather and Tides
Somerville, 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 6:40AMSunset 4:19PM Tuesday November 20, 2018 8:31 AM EST (13:31 UTC) Moonrise 4:15PMMoonset 4:27AM Illumination 94% Phase: Waxing Gibbous; Moon at 12 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 Am Est Tue Nov 20 2018
.gale watch in effect from late Wednesday night through Thursday afternoon...
Today..NE winds 10 to 15 kt, becoming N 15 to 20 kt this afternoon. Gusts up to 25 kt. Waves 2 to 3 ft. Rain. Vsby 1 to 3 nm.
Tonight..NW winds 10 to 15 kt with gusts up to 20 kt. Waves around 2 ft, except 3 to 5 ft at the outer harbor entrance.
Wed..W winds 10 to 15 kt. Gusts up to 20 kt, increasing to 30 kt in the afternoon. Waves around 2 ft.
Wed night..NW winds 10 to 15 kt with gusts up to 35 kt. Waves around 2 ft. A chance of snow showers. Vsby 1 to 3 nm.
Thu..NW winds 15 to 20 kt with gusts up to 35 kt. Waves around 2 ft.
Thu night..NW winds 15 to 20 kt, diminishing to 10 to 15 kt after midnight. Gusts up to 30 kt. Waves around 2 ft.
Fri..W winds 5 to 10 kt with gusts up to 20 kt. Waves 1 foot or less.
Fri night..SW winds 5 to 10 kt with gusts up to 20 kt. Waves around 2 ft.
Sat..SW winds 5 to 10 kt with gusts up to 20 kt. Waves 1 foot or less.
Sat night..SE winds 5 to 10 kt. Waves 1 foot or less. Rain likely. 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 Am Est Tue Nov 20 2018
Synopsis for massachusetts and rhode island coastal waters.. A low pressure system tracks up along the south coasts of ri and massachusetts this morning and midday. Chance of rain continues this morning through the evening. Arctic high pressure then builds across the region for Wednesday through Saturday. 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 Somerville, MA
   Hourly   EDIT   Help
location: 42.37, -71.07     debug


Area Discussion for - Boston, MA
      (on/off)   Help   NOTE: mouseover dotted underlined text for definition
Fxus61 kbox 201140
afdbox
area forecast discussion
national weather service boston norton ma
640 am est Tue nov 20 2018

Synopsis
A low pressure system today brings accumulating snows mainly
n of the ma-turnpike, impacting the morning commute for some
especially in the higher terrain. Otherwise... Mainly a rain
event is expected for the rest of the region perhaps ending as a
a brief period of snow late this afternoon or early this
evening. An arctic cold front may bring a few snow squalls late
Wednesday into Wednesday evening... Followed by record cold
along with bitterly cold wind chills Wednesday night into
Thursday. Dry weather expected Friday into Saturday afternoon
with moderating temperatures. Periods of unsettled weather
appear to be in the cards at times Saturday night through next
Monday although specific timing is uncertain. Odds favor
precipitation mainly being in the form of rain... But some
ice snow is possible at the onset across the interior.

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

reports of rain turning to snow in the expected locations this
morning. Radar shows the heavies precip band over northeast ma
this morning, with the boston-providence-hartford coridor
remaining all snow. In northern locations the snow will come
down hard enough to create some snow slush covered roads for
lower elevations initially. The majority of snow will occur this
morning when we'll see the best lift, but will have to watch
for a second round of flakes on the back end of the system as it
exits this afternoon evening.

Previous discussion...

a 1012mb low is centered over new jersey this morning associated
with a broad mid level trough digging over the ohio valley. Latest
guidance continues to indicate strengthening of the low downstream
of sne. Rain and snow showers will continue to overspread the region
this morning, increasing in coverage after 4-5 am. Generally still
expecting a rain event for much of the region, with snow likely over
interior northern ma, especially over 1000 ft. This event won't have
a very high impact the likes of which we saw last Thursday given
warmer temperatures and less efficient snowfall production. As the
low crosses the region we do have some good forcing for ascent.

We're positioned under the left front quadrant of a 120 kt upper jet
and have a h5 vort MAX moving overhead. However, given the marginal
temperature profile, much of the best forcing is below the dendritic
growth zone. Both the best omega and an area of strong h85
frontogenesis will simply be too low in the atmosphere to take
advantage of the -10 to -20 temps for most efficient snowfall
production. Additionally, snowfall amounts have been pulled back a
bit given a downward trend in the hi-res guidance QPF through 00z.

Previously mentioned probabilities of 1" hr rates in some hi-res
guidance were all but zeroed out in the latest runs, and this event
shouldn't feature high snowfall rates given the previously mentioned
factors. All told we're likely see a dusting to 1" north of the ma
pike with 1-2" in lower elevations and 2-4" in higher elevations
with locally higher amounts. There remains potential for some
locations to briefly switch to snow on the back end as precip is
departing and colder air wraps around from behind. If this happens,
not expecting much in the way of accumulation. Hazardous travel for
the morning commute will be possible over northwest ma, especially
in the higher terrain of the worcester hills and berkshires. Any
snow showers could reduce visibility on the road.

Short term 6 pm this evening through 6 am Wednesday
When the strengthening low moves out we're in for a big cool down as
winds turn out of the northwest and funnel cold canadian air over
sne. Winds will be brisk and gusty as a h925 LLJ moves over us and
which will be able to mix down with the help of good CAA giving
gusts to 20 mph, higher over the CAPE and islands. This will make
our already cold lows in the 20s (teens at highest elevations) feel
even colder.

Long term Wednesday through Monday
Highlights...

* arctic cold front may bring a few snow squalls late Wed wed eve
* record cold & bitterly cold wind chills Wed night thanksgiving
* dry with moderating temps Fri and especially Saturday afternoon
* unsettled at times Sat night-mon with periods of rain favored but
some ice snow possible at the onset mainly across the interior
details...

Wednesday...

an arctic cold front will be crossing the region late Wednesday
afternoon and evening. Appears to be enough southwest flow ahead of
this cold front to allow highs to recover into the upper 30s to the
lower 40s in many locations. As the arctic front crosses the
region... We will have to watch for a few localized snow squalls. The
guidance indicates decent low level convergence... Along with enough
0-2 km moisture steep lapse rates to allow the potential development
of a few locally heavy snow squalls. Areal coverage remains
uncertain and some areas may remain completely dry or just see a few
flurries. However... The potential exists for localized heavy brief
heavy snow squalls poor visibility and rapidly falling temps which
could impact travel. We will have to watch this very closely given
it is one of the busiest travel days of the year.

Wednesday night and thanksgiving...

all the guidance continues to advertise an extremely anomalous
bitterly cold airmass for this time of year... Wednesday night into
thanksgiving. In fact... Both the GEFS naefs show the extreme nature
of this bitter cold falling outside the cfsr climatology in terms of
850 mb temperatures. Basically that means that these models have
never forecasted an airmass that cold at 850 mb based on reanalysis.

850t are expected to fall to between -20c and -24c... Which will
result in bitterly cold temperatures. Low temperatures should
plunge into the single digits across portions of the interior with
lower to middle teens on the coastal plain. Highs on thanksgiving
will remain in the middle to upper teens across portions of the
interior high terrain to between 20 and 25 on the coastal plain.

This will be accompanied by northwest wind gusts of 30 to 40 mph
resulting in bitter cold wind chills of 0 to 10 below zero
thanksgiving morning for much of the region!
while dry weather is expected for thanksgiving for the vast majority
of the region... Some ocean effect snow showers are likely for the
mid and outer-cape into thanksgiving night. While there is some low
level dry air which will be a limiting factor... The 850 to sst
differential is extreme with a greater than 30c differential!
certainly the potential for one half to two inches of snow in this
region... Given the extreme nature of this airmass especially as
winds begin to turn more nnw.

Friday and Saturday...

anomalous trough moves east of the region as upper level ridging
builds in from the west. The result will be dry weather but with
moderating temperatures... Especially by Saturday afternoon. Highs
on Friday will still be well below normal... In the upper 20s to
lower 30s but an improvement over thanksgiving along with much less
wind. By Saturday... Many locations should see high temperatures
recover well into the 40s.

Saturday night through Monday...

vigorous upper level energy dives into the southern plains and then
lifts northeast. The response will be continued rising height
fields into southern new england and milder temperatures. This
upper level energy will also send a couple waves of low pressure
into our region... Resulting in periods of unsettled weather. Timing
is uncertain... But ptype favors rain giving milder air moving into
the region. However... A bit of snow ice is certainly possible at
the onset depending on how much low level cold air remains in place.

Aviation 12z Tuesday through Saturday
Forecaster confidence levels...

low - less than 30 percent.

Moderate - 30 to 60 percent.

High - greater than 60 percent.

Short term through tonight ... High confidence.

Today... Ifr and lifr at all TAF sites this morning in rain and
snow. Most TAF sites will see rain, generally south of a line
from bdl- orh- bvy, with sn to the north. We'll see improvement
to MVFRVFR from south to north, between 21z and 6z. Winds n-ne
become NW by 0z.

Tuesday night...

winds shifting NW as conditions improve towardsVFR. Winds will
be gusty out of the NW up to 25 kts, especially along coastal
sites.

Kbos terminal... Moderate confidence, mainly due to
uncertainty in timing of lower categories precipitation.

Mainly ra through the day but could see a brief change to sn or
a rn sn mix as the precip exits.

Kbdl terminal...

moderate confidence, mainly due to timing of lower
categories precipitation. Ra or a non-accumulating ra sn mix
through the morning, becoming all rain towards midday. Could see
an hour or two of snow at precip exits in the afternoon but
confidence is low. Mostly ifr, improving MVFR toVFR late
Tuesday into Tuesday evening. N winds throughout shifting nw
late.

Outlook Wednesday through Saturday ...

Wednesday: mainlyVFR, with local ifr possible. Windy with
gusts to 35 kt. Chance shsn.

Wednesday night: mainlyVFR, with local ifr possible. Windy
with gusts to 35 kt. Slight chance shsn.

Thanksgiving day:VFR. Strong winds with local gusts to 40 kt.

Thursday night:VFR. Windy with gusts to 35 kt.

Friday through Friday night:VFR. Breezy.

Saturday: mainlyVFR, with local MVFR possible. Breezy. Slight
chance shra, slight chance fzra.

Marine
Forecaster confidence levels...

low - less than 30 percent.

Moderate - 30 to 60 percent.

High - greater than 60 percent.

Short term through tonight ... High confidence.

Storm center passing over the CAPE cod canal around 18z today.

Will see increasing E NE winds out ahead especially over the e
waters, S SW for the S waters. Behind the storm center, winds
turning nw, remaining blustery. Throughout, gusts up around 25
kts possible. Can't rule out near gale force gusts. Small craft
headlines in effect for the later-half of today and tonight
as seas build up around 5 to 7 feet on the outer
waters.

Outlook Wednesday through Saturday ...

Wednesday: low risk for gale force winds with gusts up to
35 kt. Seas up to 5 ft. Local visibility 1 to 3 nm.

Wednesday night: moderate risk for gale force winds with gusts
up to 40 kt. Rough seas up to 10 ft. Slight chance of snow
showers. Arctic sea smoke possible. Visibility 1 to 3 nm.

Thanksgiving day: moderate risk for gale force winds with gusts
up to 40 kt. Rough seas up to 11 ft. Chance of snow showers.

Arctic sea smoke possible. Visibility 1 to 3 nm.

Thursday night: low risk for gale force winds with gusts up to
40 kt. Areas of rough seas. Slight chance of snow showers.

Areas of visibility 1 to 3 nm.

Friday: low risk for small craft advisory winds with gusts up
to 25 kt. Seas locally approaching 5 ft. Local visibility 1 to
3 nm.

Friday night: low risk for small craft advisory winds with
gusts up to 25 kt.

Saturday: winds less than 25 kt. Slight chance of rain showers.

Climate
With the potential of the coldest air of the season moving into
the region around thanksgiving, here are the record temperatures
for november 22nd and the holiday of thanksgiving.

November 22nd
location record low record minimum high
boston... ... ... .9 (1879) 24 (1880)
hartford... ... .14 (1969) 27 (1978)
providence... ..16 (1987) 30 (2008)
worcester... ... 11 (1987) 24 (2008)
thanksgiving
location record low record minimum high
boston... ... ... 11 (nov 27, 1873) 24 (nov 28, 1901)
hartford... ... .12 (nov 28, 2002) 27 (nov 23, 1989)
providence... ..14 (nov 23, 1972) 30 (nov 28, 1996)
worcester... ... .9 (nov 23, 1989) 22 (nov 23, 1989)

Box watches warnings advisories
Ct... None.

Ma... Winter weather advisory until 5 pm est this afternoon for
maz002>004-008-009-026.

Ri... None.

Marine... Gale watch from Wednesday evening through Thursday evening for
anz231>234-251.

Small craft advisory from 4 pm this afternoon to 4 am est
Wednesday for anz232>234.

Gale watch from late Wednesday night through Thursday
afternoon for anz230-236.

Small craft advisory from 1 pm this afternoon to 1 am est
Wednesday for anz231-251.

Gale watch from Wednesday afternoon through Thursday evening
for anz235-237-250-254>256.

Small craft advisory from 4 pm this afternoon to 6 am est
Wednesday for anz235-237.

Small craft advisory from 10 am this morning to 6 am est
Wednesday for anz250.

Small craft advisory from 1 pm this afternoon to 6 am est
Wednesday for anz254>256.

Synopsis... Frank bw
near term... Bw
short term... Bw
long term... Frank
aviation... Frank bw
marine... Frank bw
climate...



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 mi32 min 37°F 1012.4 hPa (-1.1)
44013 - BOSTON 16 NM East of Boston, MA 22 mi42 min NNE 12 G 12 43°F 51°F2 ft1012 hPa (-0.6)42°F
44029 - Buoy A0102 - Mass. Bay/Stellwagen 29 mi88 min NE 16 G 19 42°F 48°F2 ft1011.2 hPa
FOXR1 - 8454000 - Providence, RI 43 mi32 min NE 5.1 G 9.9 39°F 49°F1011.1 hPa (-1.2)
PVDR1 44 mi32 min N 6 G 9.9 39°F 1011.7 hPa (-1.1)39°F
FRVM3 - 8447386 - Fall River, MA 46 mi32 min 41°F 50°F1011.7 hPa (-1.1)
BLTM3 - 8447387 - Borden Flats Light at Fall River, MA 46 mi32 min NE 5.1 G 7 42°F 1011.5 hPa (-1.1)
FRXM3 47 mi32 min 41°F 40°F
CPTR1 - 8452944 - Conimicut Light, RI 47 mi32 min N 8 G 8.9 39°F 48°F1011.6 hPa (-1.0)
IOSN3 - Isle of Shoals, NH 48 mi32 min NE 21 G 23 38°F 1012.6 hPa (-0.6)36°F
BGXN3 - Great Bay Reserve, NH 49 mi47 min NNE 1.9 33°F 33°F

Wind History for Providence, RI
(wind in knots)    EDIT      (on/off)   Help
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
1
AM
2
AM
3
AM
4
AM
5
AM
6
AM
7
AM
Last
24hr
S2
SE1
N4
E1
E2
E4
NE8
N4
G10
NE4
NE3
NE2
NE3
NE4
NE6
NE7
G10
NE9
NE7
NE4
G7
NE8
E6
NE5
NE6
NE4
NE9
G12
1 day
ago
N4
G9
N6
G9
N4
G8
N3
SE1
SE2
S2
S6
S4
G7
W4
G7
NW4
W1
G4
W2
SW3
S2
E1
E1
E4
E2
E3
NE3
NE2
E4
NE1
G4
2 days
ago
W4
G9
W6
G11
W8
G11
NW10
G14
NW12
G19
NW16
G22
NW10
G17
NW9
NW4
G8
W5
W4
G11
W4
G8
W3
G6
W3
W2
NW3
G6
NW5
G8
W3
NW5
G9
NW8
G11
NW6
W3
NW5
N5
G9

Airport Reports
    EDIT      (on/off)   Help   Click EDIT to display multiple airports
AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Boston, Logan International Airport, MA2 mi38 minN 112.00 miLight Rain Fog/Mist38°F35°F89%1012.6 hPa
East Milton, MA11 mi36 minNNE 10 G 16 mi35°F35°F100%1012.5 hPa
Norwood, Norwood Memorial Airport, MA14 mi39 minN 56.00 miLight Rain Fog/Mist39°F37°F93%1012.3 hPa
Laurence G Hanscom Field Airport, MA14 mi36 minNNE 72.00 miLight Snow Fog/Mist34°F30°F89%1013.9 hPa
Beverly, Beverly Municipal Airport, MA17 mi39 minNNW 65.00 miLight Rain Fog/Mist36°F33°F89%1012.7 hPa

Wind History from BOS (wind in knots)
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
1
AM
2
AM
3
AM
4
AM
5
AM
6
AM
7
AM
8
AM
Last 24hrNW4N5NW5NW6NW6W5NW5NW6NW4N4N5N6N4N6N6N6N4N5N5N7N8N10N10N11
1 day agoN6N5W4--E4E5E5SE6S6SE7S6SW5SW6SW5CalmN3CalmCalmN4--N3N7N6N6
2 days agoSW12SW11W12
G18
W11
G14
W13
G20
W13W14
G20
W10
G18
W8
G16
W11
G18
W11W10W10W16
G26
W12
G18
W7W10W7W8W9W7N9N8N8

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
Tue -- 02:29 AM EST     0.78 feet Low Tide
Tue -- 03:27 AM EST     Moonset
Tue -- 06:41 AM EST     Sunrise
Tue -- 08:45 AM EST     10.00 feet High Tide
Tue -- 02:59 PM EST     0.45 feet Low Tide
Tue -- 03:15 PM EST     Moonrise
Tue -- 04:18 PM EST     Sunset
Tue -- 09:09 PM EST     9.58 feet High Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.

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
11
pm
4.32.3112.23.968.19.6109.17.55.43.11.20.41.12.74.76.98.79.69.27.8

Tide / Current Tables for Boston Harbor, Massachusetts Current
   EDIT      (on/off)   Help   One Week of Data
Boston Harbor
Click for Map
Tue -- 12:18 AM EST     -1.18 knots Max Ebb
Tue -- 02:28 AM EST     0.00 knots Slack
Tue -- 03:27 AM EST     Moonset
Tue -- 05:41 AM EST     1.23 knots Max Flood
Tue -- 06:40 AM EST     Sunrise
Tue -- 08:20 AM EST     -0.00 knots Slack
Tue -- 12:39 PM EST     -1.26 knots Max Ebb
Tue -- 02:55 PM EST     0.00 knots Slack
Tue -- 03:14 PM EST     Moonrise
Tue -- 04:17 PM EST     Sunset
Tue -- 06:02 PM EST     1.20 knots Max Flood
Tue -- 08:40 PM EST     -0.00 knots Slack
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.

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
11
pm
-1.2-1.1-0.50.51.11.21.20.90.2-0.4-0.8-1.1-1.2-1.2-0.90.10.91.21.21.10.5-0.2-0.7-1

Weather Map and Satellite Images
       (on/off)   HelpWeather Map
wmap_A
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.
Link to Loop

Other links: Northern Pacific     Contential US     Full GOES-East
Wind Forecast for Boston, MA (8,2,3,4)
      (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.