Monday, August20, 2018 L-36.com


Marine Weather and Tides
Yarmouth Port, MA

Version 3.4
What's New / NOTES
7/21/2018 Trying to make page Mobile Friendly

Sunrise 5:54AMSunset 7:34PM Monday August 20, 2018 3:00 AM EDT (07:00 UTC) Moonrise 3:44PMMoonset 12:45AM Illumination 64% Phase: Waxing Gibbous; Moon at 9 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
ANZ231 Cape Cod Bay- 116 Am Edt Mon Aug 20 2018
Rest of tonight..NE winds 10 to 15 kt with gusts up to 20 kt. Seas 2 to 3 ft. Patchy fog. A slight chance of showers with patchy drizzle. Vsby 1 to 3 nm.
Mon..NE winds 10 to 15 kt with gusts up to 20 kt. Seas 2 to 4 ft.
Mon night..NE winds 5 to 10 kt. Seas around 2 ft.
Tue..E winds 5 to 10 kt. Seas around 2 ft.
Tue night..SE winds 5 to 10 kt. Seas around 2 ft. A chance of showers.
Wed..S winds 10 to 15 kt with gusts up to 20 kt. Seas 2 to 3 ft. A chance of showers and tstms.
Wed night..W winds 10 to 15 kt. Seas 2 to 3 ft.
Thu..NW winds 5 to 10 kt. Seas 2 to 3 ft.
Thu night..W winds around 5 kt. Seas 1 foot or less.
Fri..N winds around 5 kt. Seas 1 foot or less.
Fri night..SW winds around 5 kt. Seas 1 foot or less. 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 116 Am Edt Mon Aug 20 2018
Synopsis for massachusetts and rhode island coastal waters.. A front will remain stalled south of new england overnight. Weak waves of low pres will move along it, bringing scattered showers and patchy fog, especially across the southern waters along with gusty ne winds up to around 25 kt. High pres will build across the waters from the N through Tue, then retreating ne Tue night. Low pres with its associated fronts will approach the waters from the W on Wed, then head offshore Wed night. Dry high pres will build in from the W on Thu and Fri. 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 Yarmouth Port, MA
   Hourly   EDIT   Help
location: 41.71, -70.29     debug


Area Discussion for - Boston, MA
      (on/off)   Help   NOTE: mouseover dotted underlined text for definition
Fxus61 kbox 200310
afdbox
area forecast discussion
national weather service boston norton ma
1110 pm edt Sun aug 19 2018

Synopsis
High pressure over the maritimes and a stalled front to the
south will combine to bring a northeast flow to southern new
england through Monday night. A cold front will bring showers
and thunderstorms Tuesday night into Wednesday. High pressure
will build over the region Thursday, bringing fair weather and
comfortable humidity through the weekend.

Near term until 6 am Monday morning
1030 pm update...

patchy showers and drizzle was moving onshore across portions of
e mass, especially from kpym southward as seen on latest
observations. Noting bands of showers moving westward off mass
bay, though mostly not reaching the ground from kghg northward
where t TD from 5 to 8 degrees were in place from kbos through
kbvy and kpsm at 02z.

Will see scattered showers and patchy drizzle across eastern
areas with the NE low level wind flow, along with patchy fog
especially across S coastal ri and SE mass through the night.

Elsewhere, conditions were dry with clear to partly cloudy
skies. A few lower clouds may sneak into central areas, as well
as develop across portions of the ct valley after 07z or so as
temps bottom out in the upper 50s to around 60, close to the
dewpoints.

Have updated near term to bring conditions current and
incorporated trends into the remainder of the overnight
forecast.

Previous discussion...

widely scattered showers have developed near CAPE cod and
islands this evening, which are too shallow to easily be
detected by kbox radar. Most of the high-res guidance keeps this
activity across SE ma tonight, although some models try to
bring few showers into boston and providence which seems too
aggressive.

Otherwise clouds will spread inland across most of sne tonight.

Short term 6 am Monday morning through Monday night
High pressure remains in place over the maritimes with a
resulting northeast low level flow over southern new england.

Low level moisture will diminish through the day as the sun
heats the air, so morning clouds should give way to more Sun in
the afternoon. CAPE cod and southeast mass in general may have
the toughest road to sun. Another shortwave moves overhead and
may generate a light shower or sprinkle mainly along the cape
and islands.

Sea temps around the coast are in the upper 60s and 70s, which
will influence values along the coast, with temps in the lower
70s. Inland temps will be more subject to mixing, with mixing
to 900 mb suggested by the forecast data. Temps at that level
are equiv to 9-10c at 850 mb... So MAX sfc temp potential would
be in the mid to upper 70s. If we were to mix up to 850 mb
directly, slightly warmer temperatures would support MAX sfc
temps around 80f.

Similar air mass Monday night, with dew points a degree or two
lower. Expect min sfc temps roughly 55-65.

Long term Tuesday through Sunday
Highlights...

* strong severe storms possible Tuesday night and Wednesday.

* fair weather Thursday into the weekend with comfortable humidity.

Overview...

large scale pattern features upper trough over northeast
through end of week before we see re-emergence of upper ridge
which begins to establish itself closer to sne by end of
weekend. Aside from brief return of tropical humidity Tuesday
night and Wednesday ahead of cold front, this setup favors near
average temperatures but more importantly brings our first
stretch of more comfortable humidity (dewpoints in 50s and 60s)
later this week and into weekend. It does appear that heat and
humidity may very well return beyond Sunday as upper ridge
becomes more dominant.

Details...

main concern deals with potential for strong or even severe storms
Tuesday night and Wednesday. Localized wind damage flash flooding
are main threats but an isolated short-lived tornado is also
possible.

Low CAPE high shear environment in place ahead of cold front should
be favorable for strong or even severe thunderstorms late Tuesday
night (after midnight) into Wednesday morning. SPC sref shows decent
probabilities of more than 500 j kg of MLCAPE and 0-1km helicity of
more than 100. Tropical airmass returns as GEFS shows precipitable
water values climbing above 2 inches (+2-3 sd) and dewpoints rise
back into 70s. 12z nam GFS support this thinking and show 30-40kt of
0-6km shear collocated with best instability.

Linear convection looks to be favored but typical of these
environments, we also need to be concerned with possibility of an
isolated, short-lived tornado developing along line due to low lcls
and high 0-500m helicity of over 100.

For now, this is something to be aware of which will be refined in
later forecasts.

Front moves offshore around midday Wednesday. Drying and subsidence
behind short wave will bring an end to showers storms by early
Wednesday afternoon. A prolonged stretch of dry and more comfortable
weather follows Thursday and into weekend as high pressure builds
over region.

Aviation 03z Monday through Friday
Forecaster confidence levels...

low - less than 30 percent.

Moderate - 30 to 60 percent.

High - greater than 60 percent.

Short term through Monday night ... Moderate confidence
overnight...

ifr-lifr CIGS MVFR-ifr vsbys mainly from kghg-kewb line eastward
through the remainder of the night, otherwise, areas of MVFR
cigs and some MVFR vsbys in patchy fog across the remainder of e
coastal mass extending into E ri. May see some MVFR CIGS at
times across NE ct and portions of the ct valley, mainly after
08z. Light sct showers patchy drizzle moving onshore mainly near
and S of kghg and especially across CAPE cod and islands.

Monday...

conditions ranging fromVFR northwest to MVFR-ifr CIGS SE mass
to start the day. Expect Sun heating to eat away at the sky
cover, bringingVFR conditions to all areas. Exception to this
could be nantucket and parts of CAPE cod, where 2000-3000 foot
cigs may linger through the day. Northeast gusts to 20 knots
mainly along the coastline.

Monday night...

vfr lingers in the west. MVFR ifr CIGS expands over
eastern central mass and ri northeast ct due to marine flow.

Kbos terminal... Moderate confidence in taf.

MVFR cigs, around 1500 feet, across the airport, though may
lower to ifr after 06z or so. May also see a few showers from
time to time through the night with ifr vsbys in patchy fog.

Conditions improve toVFR around 9-10 am.

Kbdl terminal... High confidence in taf. MainlyVFR. May see
brief MVFR CIGS after 08z through around 9 am or so.

Outlook Tuesday through Friday ...

Tuesday: mainlyVFR, with areas MVFR possible.

Tuesday night: mainlyVFR, with areas ifr possible. Chance
shra, tsra likely, patchy br.

Wednesday: mainlyVFR, with local MVFR possible. Windy with
local gusts to 30 kt. Chance shra, chance tsra, patchy br.

Wednesday night through Friday:VFR.

Marine
Forecaster confidence levels...

low - less than 30 percent.

Moderate - 30 to 60 percent.

High - greater than 60 percent.

Short term through Monday night ... High confidence.

Ne winds through the period. Wind gusts near 25 knots slowly
diminish tonight but 5-6 foot seas linger on the outer waters. A
combination of wind and seas will keep small craft advisory in
effect overnight mainly across the outer waters through Monday,
then, then areal coverage slowly diminishes Monday night.

Spotty light showers sprinkles are possible overnight into
Monday morning, but coverage will be very limited. Mainly good
visibility.

Outlook Tuesday through Friday ...

Tuesday: winds less than 25 kt. Areas of seas approaching 5 ft.

Tuesday night: winds less than 25 kt. Areas of seas approaching
5 ft. Chance of rain showers, chance of thunderstorms, patchy
fog.

Wednesday: low risk for small craft advisory winds with gusts
up to 25 kt. Local rough seas. Chance of rain showers, chance
of thunderstorms, patchy fog.

Wednesday night: winds less than 25 kt. Local rough seas.

Thursday: winds less than 25 kt. Areas of seas approaching
5 ft.

Thursday night through Friday: winds less than 25 kt.

Box watches warnings advisories
Ct... None.

Ma... None.

Ri... None.

Marine... Small craft advisory until 10 pm edt Monday for anz250-256.

Small craft advisory until midnight edt tonight for anz251.

Small craft advisory until 6 am edt Tuesday for anz254-255.

Synopsis... Wtb jwd
near term... Evt jwd
short term... Wtb
long term... Jwd
aviation... Wtb evt jwd
marine... Wtb evt jwd


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
44090 9 mi30 min 66°F2 ft
WAXM3 - Waquoit Bay Reserve, MA 15 mi75 min 1.9 68°F 1018 hPa67°F
44020 - NANTUCKET SOUND 15 mi20 min NE 16 G 19 69°F 1017.1 hPa67°F
BZBM3 - 8447930 - Woods Hole, MA 24 mi30 min 66°F 76°F1017.8 hPa
NTKM3 - 8449130 - Nantucket Island, MA 31 mi36 min NE 8.9 G 12 67°F 75°F1017.1 hPa
44018 - SE Cape Cod 30NM East of Nantucket, MA 35 mi70 min NE 12 G 16 66°F 5 ft1018.5 hPa (+0.0)65°F
BUZM3 - Buzzards Bay, MA 45 mi60 min NE 19 G 21 68°F 1018 hPa (-0.3)
FRVM3 - 8447386 - Fall River, MA 46 mi36 min 67°F 79°F1019.1 hPa
BLTM3 - 8447387 - Borden Flats Light at Fall River, MA 47 mi30 min NNE 9.9 G 14 67°F 1018.5 hPa
FRXM3 47 mi30 min 67°F 66°F
44013 - BOSTON 16 NM East of Boston, MA 48 mi70 min NNE 12 G 14 67°F 68°F4 ft1018.6 hPa (+0.4)65°F

Wind History for Nantucket Island, MA
(wind in knots)    EDIT      (on/off)   Help
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
1
AM
2
AM
Last
24hr
NE12
G17
NE14
G19
NE12
G19
NE13
G17
NE14
G18
NE12
G17
NE11
G16
NE12
G19
NE14
G20
NE14
G19
NE12
G18
NE11
G18
N10
G18
N13
G21
NE10
G17
NE12
G18
NE12
G18
NE8
G15
N11
G15
NE8
G14
NE10
G17
NE7
G11
NE9
G13
NE10
G14
1 day
ago
S6
G12
S7
G10
SW8
G12
SW6
G10
SW5
G10
SW9
G17
SW9
G15
SW7
G15
SW9
G14
SW7
G16
SW8
G13
SW9
G14
W7
G13
W9
G13
SW5
G9
SW5
G10
NW4
G7
N2
NE5
NE3
G6
NE3
NE10
G15
NE13
G19
NE14
G18
2 days
ago
--
SE1
E4
SE5
SE4
SW4
G10
SW3
G10
SW6
G11
W6
G10
SW5
G11
SW7
G10
S6
SW8
G13
SW6
G10
S5
G11
SW5
G8
SW5
G9
SW6
G10
SW7
G10
S6
G9
S6
G11
S6
G11

Airport Reports
    EDIT      (on/off)   Help   Click EDIT to display multiple airports
AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Hyannis, Barnstable Municipal-Boardman Airport, MA2 mi64 minNE 62.00 miLight Rain Fog/Mist67°F66°F100%1017.4 hPa
Otis Air National Guard Base, MA13 mi65 minNNE 103.00 miFog/Mist64°F64°F100%1018.3 hPa
Chatham, Chatham Municipal Airport, MA16 mi68 minNE 92.00 miFog/Mist66°F64°F96%1017.8 hPa
Provincetown Municipal Airport, MA21 mi64 minNE 710.00 miOvercast66°F64°F93%1018.4 hPa

Wind History from HYA (wind in knots)
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
1
AM
2
AM
Last 24hrNE10NE8NE11
G17
NE9NE10NE13
G17
NE11NE12
G17
NE16
G21
NE11
G18
NE12
G21
NE13
G18
NE12
G21
N10N11
G18
N8N9N8N7N9NE9
G16
NE8NE7NE6
1 day agoSW14
G18
SW12
G19
S10S8SW8SW13SW13
G20
SW12SW12SW15SW9
G18
SW12SW17SW15SW14NW7N6NW3CalmN4NE9NE12
G18
NE13
G18
NE11
G17
2 days agoCalmCalmCalmCalmNE3CalmE4S6S65S55S7SW8S11SW12S9SW10SW13SW12SW12
G18
SW11
G19
SW11S10

Tide / Current Tables for Barnstable Harbor, Beach Point, Massachusetts
   EDIT   RT Ports Option   Weekend mode (on/off)   (on/off)   Help   One Week of Data
Barnstable Harbor
Click for Map
Mon -- 12:45 AM EDT     Moonset
Mon -- 01:43 AM EDT     1.02 feet Low Tide
Mon -- 05:54 AM EDT     Sunrise
Mon -- 07:40 AM EDT     8.61 feet High Tide
Mon -- 01:54 PM EDT     1.63 feet Low Tide
Mon -- 03:43 PM EDT     Moonrise
Mon -- 07:33 PM EDT     Sunset
Mon -- 07:58 PM EDT     9.55 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
2.61.31.11.83.15.17.18.48.686.85.33.52.11.62.23.55.37.499.59.18.16.5

Tide / Current Tables for Cape Cod Canal, Massachusetts Current
   EDIT      (on/off)   Help   One Week of Data
Cape Cod Canal
Click for Map
Mon -- 12:47 AM EDT     Moonset
Mon -- 02:26 AM EDT     3.73 knots Max Flood
Mon -- 05:45 AM EDT     -0.18 knots Slack
Mon -- 05:55 AM EDT     Sunrise
Mon -- 08:25 AM EDT     -3.82 knots Max Ebb
Mon -- 11:39 AM EDT     0.17 knots Slack
Mon -- 02:51 PM EDT     3.57 knots Max Flood
Mon -- 03:44 PM EDT     Moonrise
Mon -- 06:03 PM EDT     -0.18 knots Slack
Mon -- 07:34 PM EDT     Sunset
Mon -- 08:52 PM EDT     -3.99 knots Max Ebb
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
2.43.33.73.73.32.4-1.4-3.1-3.8-3.7-3.2-2.11.52.93.43.63.42.70.7-2.8-3.8-4-3.7-2.9

Weather Map and Satellite Images
       (on/off)   HelpWeather Map
wmap_A
GOES Local Image of    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 (3,6,7,8)
      (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.