Sunday, April23, 2017 L-36.com


Marine Weather and Tides
Harwich Port, MA

Version 3.4
What's New / NOTES
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.
3/12/2015 - Added section for Gulf current for users in the GMZ marine zones.
This was requested by a user. If you have requests, please let me know.

Sunrise 5:45AMSunset 7:32PM Sunday April 23, 2017 1:37 AM EDT (05:37 UTC) Moonrise 4:21AMMoonset 4:14PM Illumination 9% Phase: Waning Crescent; Moon at 27 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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ANZ232 Nantucket Sound- 1023 Pm Edt Sat Apr 22 2017
Overnight..N winds 5 to 10 kt with gusts up to 20 kt. Seas 2 to 3 ft. Patchy fog. A slight chance of rain. Vsby 1 to 3 nm.
Sun..N winds 5 to 10 kt...becoming E in the afternoon. Seas 2 to 3 ft.
Sun night..SW winds 5 to 10 kt. Seas 2 to 3 ft.
Mon..S winds around 5 kt. Seas around 2 ft.
Mon night..E winds 5 to 10 kt...increasing to 10 to 15 kt with gusts up to 25 kt after midnight. Seas 2 to 3 ft. Patchy fog. A chance of rain. Vsby 1 to 3 nm.
Tue..E winds 15 to 20 kt with gusts up to 25 kt. Seas 2 to 4 ft. Patchy fog. Rain likely. Vsby 1 to 3 nm.
Tue night..E winds 15 to 20 kt with gusts up to 25 kt. Seas 2 to 4 ft. Patchy fog. Rain. Vsby 1 to 3 nm.
Wed..SE winds 15 to 20 kt with gusts up to 25 kt. Seas 2 to 4 ft. Patchy fog. Rain likely. Vsby 1 to 3 nm.
Wed night..SW winds 5 to 10 kt. Seas 2 to 3 ft. Patchy fog. A chance of rain. Vsby 1 to 3 nm.
Thu..SW winds 10 to 15 kt with gusts up to 20 kt. Seas 2 to 3 ft. Patchy fog. Vsby 1 to 3 nm.
Thu night..SW winds 10 to 15 kt with gusts up to 20 kt. Seas 2 to 3 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 1023 Pm Edt Sat Apr 22 2017
Synopsis for massachusetts and rhode island coastal waters.. Weak low pressure over georges bank this evening will move out to sea tonight. Weak high pres builds across the area Sun and Mon. On Tue...a late season coastal storm could wrap rain and strong northeast winds across the waters into Wed. A cold front will then cross the waters late in the day Thu. 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 Harwich Port, MA
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location: 41.57, -70.05     debug


Area Discussion for - Boston, MA
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Fxus61 kbox 230158
afdbox
area forecast discussion
national weather service taunton ma
958 pm edt Sat apr 22 2017

Synopsis
Low pressure moves out to sea tonight with high pressure
building into new england late tonight through Monday. As high
pressure ridge noses across central and northern new england,
low pressure will slowly move NE along the SE and mid atlantic
coast. This will bring a prolonged period of wet weather from
Monday night through Wednesday night, along with gusty easterly
winds. There looks to be a short dry spell sometime early
Thursday. However a cold front will move across late Thursday
bringing some scattered showers and possible an isolated
thunderstorm well inland. Another period of showers is possible
into early next weekend.

Near term /until 6 am Sunday morning/
10 pm update...

cold front/wind shift line now thru the ct river valley with nw
winds at baf/bdl/hfd. This boundary will continue moving east as
mid level trough over ny state streams eastward overnight.

Surface obs show back edge of cloud shield across central
portions of ny/pa and moving steadliy east. Thus improving
trends overnight setting the stage for a fabulous day Sunday
with abundant sunshine, light winds and temps in the 60s (50s
along the immediate coast)!
previous discussion...

area of rain will gradually push south and move off the coast
late this afternoon and evening as forcing for ascent moves
offshore and some mid level drying comes in from the north.

Lingering light rain possible this evening along the south coast
and especially the islands. Otherwise a dry night with clearing
developing from west to east late tonight as mid level
shortwave moves to the east and high pres builds in from the
west. Low temps will settle into the mid 30s to around 40
degrees.

Short term /6 am Sunday morning through Sunday night/
Sunday...

high pres in control will bring sunshine, light winds and
seasonably mild temps. Seabreezes are likely along the coast
during the afternoon. Highs will range from the upper 50s along
the immediate coast to the upper 60s in the ct valley.

Sunday night...

high pres remains in control. Clear skies and light winds
although some increase in high clouds from the south is
expected overnight. Good radiational cooling with lows ranging
from mid 30s to lower 40s.

Long term /Monday through Saturday/
Overview...

development of h5 cutoff low pres off the carolinas early next
week will slowly progress northward up the eastern seaboard
while high pres ridge noses w-sw across central new england
through around Wed night. Will likely see periods of precip and
gusty onshore winds. Further west, noting digging h5 long wave
trough moving slowly SE out of the eastern rockies into the
plains states. This will develop a responding downstream SW flow
as ridging builds over western quebec into eastern ontario by
late next week. This should help to lift the east coast cutoff
low, but timing is in question.

The upper ridging over eastern canada looks to be short lived
as the midwest upper trough shifts slowly eastward late next
week. Southern stream ridge builds off the carolinas/florida
coast, so SW flow aloft should remain in place. Model solution
spread increases late next week into next weekend as to where
the approaching front may push, or stall in the upper flow if
the E coast ridging up the eastern seaboard.

Details...

Monday...

high pressure near or just off the S coast early Monday will
slip offshore. This ridge may be just strong enough to keep dry
conditions across most of the region, with dewpts mainly in the
upper 30s to lower 40s. However, developing low pressure of the
se u.S. Coast. Winds will start to shift to e-se along s
coastal areas during the day as the leading edge of precip tries
to shift n. Only kept slight chance pops into the immediate s
coast and islands toward daybreak. Daytime highs will be close
to seasonal normals.

Monday night through Wednesday night...

with slow movement of low pressure along eastern seaboard as its
associated mid level system cuts off from the southern stream
flow. Along with increasing easterly flow thanks to ridging over
the maritimes, will see prolonged period of precipitation across
the region. This, along with long fetch moisture plume working
up the coast, with pwats up to 1.4 to 1.6 inches Tue night into
wed. So, expect to see periods of moderate rainfall especially
during the late Tuesday into Wednesday timeframe. The onshore
flow will also help with higher amounts across E mass into ri.

Expected QPF amounts range from 0.75 to 1 inch across central
and western areas, and 1.25 to 1.5 inches further e. Will not
help with the slow movement of the low up the eastern seaboard.

With this expected rainfall, went along with guidance and have
cat pops for central and E areas. Kept high lkly for now across
the w.

Will also see persistent onshore E flow beginning Monday night
thru Wednesday. This, along with building easterly swells as
well as astronomical high tides, will have to monitor potential
for possible coastal issues during this timeframe. Details are
in the tides section below.

Thursday through Saturday... Low confidence.

As the weakening h5 low shifts NE to the maritimes by early
thu, may see a brief respite to the wet conditions early
Thursday. However, upper level pattern remains progressive.

Noting h5 heights slowly fall as another cold front approaches.

Big question during this timeframe is how far E will the front
move as h5 ridge builds off the SE u.S. Coast.

May see some showers move into N central and W mass by midday or
early afternoon thu. Some decent instability also along this
front, so can not rule out an isolated thunderstorm.

Models showing a wide variance of solutions for late next week
into next weekend. What's left of the front may stall somewhere
across the region. For now, have carried mainly dry conditions
on fri, but may see another low moving along the remnants of the
front toward the region Fri night/sat. Tough call as the 12z
ecmwf indicating some possible briefly heavy showers as a weak
wave of low pres moves across. Way too early to lock in on this
timing.

Aviation /02z Sunday through Thursday/
Forecaster confidence levels...

low - less than 30 percent.

Moderate - 30 to 60 percent.

High - greater than 60 percent.

Short term /through Sunday night/...

10 pm update...

cold front/wind shift line now into western ma/ct with CIGS and
vsbys improving toVFR. This trend continues sweeping eastward
overnight into ri and eastern ma. Earlier discussion below.

======================================================================
through tonight... Moderate confidence. MVFR/ifr along and E of
fit- orh- pvd withVFR CIGS to the west, improving toVFR late
tonight with clearing from west to east. However, areas of ifr
persisting over cape/islands.

Sunday... High confidence.

Vfr, except MVFR/ifr stratus lingering over outer cape/islands
in the morning. Seabreezes developing.

Sunday night... High confidence.VFR.

Kbos taf... High confidence in trends, moderate confidence in
timing. Seabreeze developing 15-16z sun.

Kbdl taf... High confidence in trends, moderate confidence in
timing.

Outlook /Monday through Thursday/...

Monday... Moderate confidence.

Should remainVFR through this timeframe. Will see mid to high
clouds increase from s-n during the day. Light S winds early
will back to E during the day. Patchy -ra may move into s
coastal areas toward evening.

Monday night through Wednesday night... Low to moderate
confidence.

Expect CIGS to lower to MVFR-ifr with areas of -ra/ra. Patchy
fog develops Mon night and Tue morning and again Tue night/early
wed morning with low t/td spreads. May see lifr cigs/vsbys at
times during both nighttime periods. Expect E winds to increase,
gusting to around 25 kt tue, then become e-se Tue night. Low
chance for 30 kt gusts at times. Winds shift to S on Wed and
diminish.

May see ifr cigs/vsbys return in low clouds and patchy fog wed
night, but may improve from w-e after midnight as drier air may
work in.

Thursday... Moderate confidence.

Should be mainlyVFR. May see local MVFR conditions across
central and western terminals in sct showers. Low risk of
isolated afternoon tsra.

Marine
Forecaster confidence levels...

low - less than 30 percent.

Moderate - 30 to 60 percent.

High - greater than 60 percent.

Short term /through Sunday night/... High confidence.

Tonight and Sunday...

some northerly gusts to 20 kt over the eastern waters this
evening, otherwise diminishing winds later tonight and
especially Sunday as high pressure gradually builds over the
waters. Winds becoming onshore around 10 kt Sun afternoon as
seabreezes develop. Lingering swell on the eastern waters will
lead to SCA seas which will gradually subside during Sunday.

Sunday night...

mainly southerly winds 15 kt or less as high pres gradually
moves offshore. Some gusts to 20 kt possible over NE ma waters
where seas may build to 5 ft.

Outlook /Monday through Thursday/...

Monday... High confidence.

Expect winds and seas below small craft criteria. Light s-se
winds back to E during the afternoon.

Monday night through Wednesday night... Moderate confidence.

Coastal low slowly pushes NE during this timeframe. Will see
easterly winds in place for most of the period. Small craft
headlines will likely be needed Tue through Wed at least.

Sustained winds of 15-20 kt with gusts up to 30 kt likely. Long
easterly swells will develop especially Tue through Wed as
average seas up to 6-10 kt on the outer waters.

Winds shift to s-se and diminish during Wed as the low moves
across or just W of the waters, but will take time for the seas
to subside.

Thursday... Moderate confidence.

W winds shift to SW during the day but remain below small craft
criteria. May see gusts up to 20 kt Thu night. Leftover high
swells of 6-9 ft will only slowly subside so headlines may
continue.

Tides/coastal flooding
Continue to see potential of an easterly wind flow beginning
late Monday through around midday Wednesday. Could see sustained
winds up to 15 to 20 mph with gusts up to around 30 mph, but the
question is whether the higher winds above the surface will mix
down due to low level inversion. Looks like there could be a
chance for the stronger winds to mix down around the late
Tuesday into Wednesday timeframe, as the h925 jet of 30-35 kt
moves across.

Here are the times of heights of the high tide for boston
harbor...

10.9 feet / Monday 10:33 pm
10.9 feet / Tuesday 10:59 am
11.5 feet / Tuesday 11:20 pm
11.2 feet / Wednesday 11:50 am
with a surge of up to 1 foot brought about by onshore flow,
particularly at the time of the Tuesday night high tide, there
could be some splashover issues along vulnerable E ma roadways.

Have continued to mention this potential in the hazardous
weather outlook.

Box watches/warnings/advisories
Ct... None.

Ma... None.

Ri... None.

Marine... Small craft advisory for hazardous seas until 6 pm edt Sunday
for anz250-254.

Small craft advisory for hazardous seas until 2 pm edt Sunday
for anz251-255.

Synopsis... Kjc/evt
near term... Kjc/nocera/evt
short term... Kjc
long term... Evt
aviation... Kjc/nocera/evt
marine... Kjc/evt
tides/coastal flooding...



Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
44020 - NANTUCKET SOUND 12 mi47 min 46°F3 ft1014.4 hPa (+1.0)
NTKM3 - 8449130 - Nantucket Island, MA 20 mi49 min N 12 G 19 43°F 50°F1014.9 hPa
44090 24 mi63 min 44°F3 ft
WAXM3 - Waquoit Bay Reserve, MA 25 mi112 min 5.1 42°F 40°F
BZBM3 - 8447930 - Woods Hole, MA 33 mi49 min 43°F 47°F1014.9 hPa
44018 - SE Cape Cod 30NM East of Nantucket, MA 42 mi47 min N 16 G 19 41°F 43°F6 ft1013.9 hPa (+0.7)38°F

Wind History for Nantucket Island, MA
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Last
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SE12
G15
SE8
G12
SE4
G7
N7
N6
G9
N9
G13
NE8
G13
N6
G11
N8
G12
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G22
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E11
E8
G12
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G16
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E14
G19
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G20
E14
G17
E14
G21
E15
G19
E14
G19
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G23
E14
G20
E15
G25
E13
G20
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G22
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G19
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SE12
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G19
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S7
G11
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G13
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G10
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SW4
G7
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G9
SW4
--
NE2
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E4
N4
NE5
G8
NE6
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G11
NE7
G10
NE11
NE11
G14
E11
G14
E12
G17
E12
G17

Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Chatham, Chatham Municipal Airport, MA10 mi45 minN 710.00 miOvercast42°F39°F89%1015.1 hPa
Hyannis, Barnstable Municipal-Boardman Airport, MA14 mi41 minN 1010.00 miOvercast43°F39°F86%1014.1 hPa
Nantucket, Nantucket Memorial Airport, MA21 mi44 minN 1210.00 miOvercast43°F37°F82%1014.6 hPa

Wind History from CQX (wind in knots)
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Last 24hr6E53N5N5N8NE7NE655N554NW7
G16
N8
G15
NW12
G21
N7
G18
N7N10
G15
66N75N7
1 day agoE8E9E8E9E10
G20
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G22
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E11
G20
E10E10E9E10
G19
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E9E10E8E11
G16
E7E8SE8
2 days agoS8S9
G14
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G15
S7S6
G16
S5S5S5CalmSE4E544SE4E4E3NE5NE6NE7E9E9E8E9E9

Tide / Current Tables for Monomoy Point, Cape Cod, Massachusetts
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Monomoy Point
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Sun -- 03:41 AM EDT     0.28 feet Low Tide
Sun -- 04:21 AM EDT     Moonrise
Sun -- 05:47 AM EDT     Sunrise
Sun -- 10:00 AM EDT     3.88 feet High Tide
Sun -- 04:07 PM EDT     0.05 feet Low Tide
Sun -- 04:14 PM EDT     Moonset
Sun -- 07:29 PM EDT     Sunset
Sun -- 10:29 PM EDT     3.97 feet High Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
2.71.91.10.40.30.71.42.233.63.93.632.21.30.50.10.30.91.72.63.43.93.9

Tide / Current Tables for Pollock Rip Channel, Massachusetts Current
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Pollock Rip Channel
Click for Map
Sun -- 01:13 AM EDT     0.00 knots Slack
Sun -- 04:21 AM EDT     Moonrise
Sun -- 04:35 AM EDT     1.90 knots Max Flood
Sun -- 05:47 AM EDT     Sunrise
Sun -- 07:40 AM EDT     -0.00 knots Slack
Sun -- 10:21 AM EDT     -1.78 knots Max Ebb
Sun -- 01:29 PM EDT     0.00 knots Slack
Sun -- 04:14 PM EDT     Moonset
Sun -- 04:55 PM EDT     2.10 knots Max Flood
Sun -- 07:29 PM EDT     Sunset
Sun -- 08:07 PM EDT     -0.00 knots Slack
Sun -- 10:48 PM EDT     -1.88 knots Max Ebb
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
-1-0.20.71.51.81.91.50.7-0.4-1.3-1.7-1.7-1.2-0.50.51.41.92.11.91.20.1-1-1.7-1.9

Weather Map and Satellite Images
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Weather Map
wmap_A
IR Satellite Image from GEOS
east_satellite

GOES Local Image of Northeast    EDIT
Geos

Wind Forecast for Boston, MA (1,6,7,8)
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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.