Tuesday, August22, 2017 L-36.com


Marine Weather and Tides
North Eastham, 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 5:56AMSunset 7:30PM Tuesday August 22, 2017 8:47 PM EDT (00:47 UTC) Moonrise 6:44AMMoonset 8:11PM Illumination 1% Phase: New Moon; 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
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ANZ231 Cape Cod Bay- 717 Pm Edt Tue Aug 22 2017
.small craft advisory in effect through Wednesday morning...
Tonight..SW winds 10 to 15 kt with gusts up to 30 kt. Seas 3 to 5 ft. Patchy fog after midnight. A slight chance of showers with isolated tstms after midnight. Some tstms may produce gusty winds, heavy rainfall, and frequent lightning after midnight.
Wed..SW winds 10 to 15 kt with gusts up to 25 kt, diminishing to 5 to 10 kt in the afternoon. Seas 2 to 4 ft. Patchy fog. A chance of showers.
Wed night..W winds around 5 kt. Seas 1 foot or less.
Thu..NW winds around 5 kt, becoming ne in the afternoon. Seas 1 foot or less.
Thu night..S winds around 5 kt, becoming nw after midnight. Seas 1 foot or less.
Fri..N winds 5 to 10 kt. Seas 1 foot or less.
Fri night..E winds 5 to 10 kt, becoming nw after midnight. Seas 1 foot or less.
Sat..N winds 5 to 10 kt. Seas 1 foot or less.
Sat night..SW winds around 5 kt. Seas 1 foot or less.
Sun..NE winds 5 to 10 kt. Seas 1 foot or less.
Sun night..NE winds 5 to 10 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 717 Pm Edt Tue Aug 22 2017
Synopsis for massachusetts and rhode island coastal waters.. High pres will continue to move east of the waters today. This will be followed by a cold front that will cross the waters on Wed. Large high pres will then build in from the west Thu and remain in control through the weekend. 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 North Eastham CDP, MA
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location: 41.92, -70.03     debug


Area Discussion for - Boston, MA
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Fxus61 kbox 222321
afdbox
area forecast discussion
national weather service taunton ma
721 pm edt Tue aug 22 2017

Synopsis
A cold front will bring the potential for scattered showers and
thunderstorms late tonight, which may persist into Wednesday
morning along the coastal plain. High pressure brings dry
weather with very comfortable humidity levels Thursday through
early next week.

Near term until 6 am Wednesday morning
* severe thunderstorm watch remains in effect for western ma
until midnight
7pm update...

convection across ny pa attempting to form qlcs within a
corridor of enhanced shear along a 45-50 kt ssw-nne oriented llj
and pre-frontal trof. Overall, trend has actually been for this
convection to wane somewhat as it approaches, likely given it is
entering an area where moisture is lacking (over us here in s
new england) as k-indices remain between 26-28. However, the
moisture plume is advecting E with the LLJ and could allow for
the maintenance of at least some mu CAPE values near 1000j kg
during the late overnight hours. Pops were timed using a blend
of WRF and hrrr data which are currently handling the situation
relatively well from a timing standpoint.

The lackluster mid lvl lapse rates will remain, and this could
prove a convective mitigation factor to consider as the storms
approach, but given the ongoing severe watch and very strong
forcing llj, even in a more stable environment storms could
retain a risk for strong winds.

Previous discussion follows...

tricky forecast tonight. The high heat and humidity resulted in
very high CAPE values for our region. Most unstable CAPE values
were between 2,500-3,000 j kg, with mixed layer CAPE values
between 1,500-2,000 j kg. Despite this, our region remains
fairly capped this afternoon due to poor mid level lapse rates
and low shear.

The complication in the forecast tonight will be how quickly the
cape values drop after sunset, and how quickly stronger shear
arrives. It will be delicate balance. At this time, thinking
strong convection may arrive east of the berkshires between 8
and 10 pm, then weaken as it moves east from there. Helicity
values in the 0-1km agl layer range between 150-300 m2 s2. This
would mean at least a very low risk for a tornado as these
storms move across our region overnight.

The other risks from any strong thunderstorms tonight will be
gusty winds and locally heavy rainfall. Thinking any flooding
risk tonight will be very localized as storms should be moving
rather quickly. Training storms also appear to be unlikely.

Well above normal temperatures continue tonight.

Short term 6 am Wednesday morning through Wednesday night
The threat for scattered showers and thunderstorms may persist
into Wednesday morning across the coastal plain, and perhaps
even into early afternoon across the CAPE and islands. Much
drier air will arrive behind a cold front, which should move
offshore by late afternoon. Near normal temperatures expected
through this period.

Long term Thursday through Tuesday
Overview and model preferences...

22.12z model guidance suite continues the trend of a mainly dry
forecast through early next week. Synoptically, there remains
good agreement, and this is in spite of a fairly amplified
pattern across the N CONUS and canada, something long range
guidance typically struggles with. Reinforcement of an alaskan
vortex is the catalyst for building a highly amplified ridge
across central canada, and although not a true block, leads to
enough downstream trof digging to reinforce the trof upstream of
new england. In spite of the cyclonic curvature, flow aloft is
confluent predominantly, shifting the mean jet over new england
rather than in the typical ageostrophic lift region of the mean
jet. This coincides with an area of subsidence in development of
reasonably strong high pres which will generally define the
sensible wx across new england through early next week. Thermal
profiles are supported by drier cooler flow within the upstream
trof out of central canada, supporting the previous
forecaster's thinking that a break from the summer heat humidity
can be expected.

Details...

thu...

front shifts further offshore allowing deeper column drying and
cold advection aloft. Dewpoints drop into the 50s and h85 temps
drop to +10c to +12c, which should keep highs mainly slightly
below normal, or in the mid-upper 70s with a few spots around
80. Subsidence maintains a dry forecast outside of cu
development.

Fri...

vigorous shortwave will rotate through during the daytime fri.

Lapse rates are reasonably steep given the cold advection
leading the wave aloft, nearing 6.0c km across much of the
region. A slight spike in moisture possible as well as pwats
shift closer to the 1.00 inch mark according to some soundings.

Although some convective feedback QPF is noted, but likely not
well progged, will feature diurnally timed increase in pops to
at least slight chance during the afternoon and early evening
hours Fri with this wave passage. Shower, or even a very
isolated thunderstorm not out of the question. Otherwise, highs
once again slightly below normal, mainly in the mid-upper 70s.

This weekend...

high pres crests over the region through the period as the base
of the longwave trof also shifts w-e across new england.

Soundings continue to be mostly dry, suggesting the risk for
even any showers remains quite low, especially given the lack of
strong forcing. Will continue to feature a mainly dry forecast
with nil pops. Highs in the 70s predominantly, with comfortable
overnights dipping into the 50s thanks to dewpoints in the upper
40s and 50s as well.

Early next week...

low lvl ridging is reinforced by the influence of the stronger
synoptic ridge shifting E in new england as the longwave moves e
of new england. In fact, already noting that high pres will
approach 1030+ hpa. Dry weather looks likely to continue, along
with comfortable dewpoints.

Aviation 00z Wednesday through Sunday
Forecaster confidence levels...

low - less than 30 percent.

Moderate - 30 to 60 percent.

High - greater than 60 percent.

Short term through Wednesday night ...

tonight... Moderate confidence.

Sct shra tsra should move east of the berkshires between 01z-
04z. Storms are expected to weaken as they shift east with time,
but a few stronger storms cannot be ruled out. This line weakens
for a bit early in the morning, but then another round of
showers and storms could impact mainly southeastern ma after
10z. Mix of mainlyVFR with occasional MVFR ifr in
showers storms, low confidence in ifr lifr stratus mainly cape
cod and the islands. Winds gusting 20-30 kt at times, with llws
given 40-45 kt at around 2kft.

Wednesday... High confidence in trends, but lower confidence in
overall timing. Sct shra tsra may persist near and especially
southeast ma into early Wednesday afternoon. Improvement toVFR
conditions expected from west to east, but timing somewhat
uncertain.

Wednesday night... High confidence.VFR.

Kbos terminal... High confidence in TAF trends. Moderate
confidence in timing.

Kbdl terminal... High confidence in TAF trends. Moderate
confidence in timing.

Outlook Thursday through Sunday ...

mainlyVFR. Mainly w-nw flow with sea breezes by day.

Marine
Forecaster confidence levels...

low - less than 30 percent.

Moderate - 30 to 60 percent.

High - greater than 60 percent.

Short term through Wednesday night ... High confidence.

Strong southwest low level jet moves across the waters tonight
into Wednesday morning. Gusty southwest winds ahead of an
approaching cold front. Some risk for thunderstorms, but showers
more likely. Will continue small craft advisory headlines, but
did tweak times.

Winds and seas diminish Wednesday afternoon, with more tranquil
boating conditions starting Wednesday night.

Outlook Thursday through Sunday ...

generally quiet boating weather. NW winds dominate, with gusts
peaking only around 15 kt at any given time. Seas waves remain
below 4 ft.

Box watches warnings advisories
Ct... None.

Ma... None.

Ri... None.

Marine... Small craft advisory until noon edt Wednesday for anz231>234-
250.

Small craft advisory until 2 am edt Wednesday for anz230-236.

Small craft advisory until 2 pm edt Wednesday for anz235-237.

Small craft advisory until 8 am edt Wednesday for anz251.

Small craft advisory until 4 pm edt Wednesday for anz254>256.

Synopsis... Belk doody
near term... Belk doody
short term... Belk
long term... Doody
aviation... Belk doody
marine... Belk doody


Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
44090 17 mi44 min 68°F2 ft
44020 - NANTUCKET SOUND 34 mi58 min SSW 19 G 23 72°F 72°F2 ft1010.5 hPa (-1.5)72°F
WAXM3 - Waquoit Bay Reserve, MA 35 mi63 min 5.1 76°F 1011 hPa72°F
NTKM3 - 8449130 - Nantucket Island, MA 44 mi48 min SSW 12 G 14 1011.5 hPa (-1.4)
BZBM3 - 8447930 - Woods Hole, MA 44 mi48 min 74°F 73°F1010.2 hPa (-1.5)
44013 - BOSTON 16 NM East of Boston, MA 44 mi58 min S 18 G 19 72°F 67°F3 ft1007.6 hPa (-1.3)

Wind History for Nantucket Island, MA
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Provincetown Municipal Airport, MA11 mi52 minSSW 1410.00 miA Few Clouds73°F71°F94%0 hPa
Chatham, Chatham Municipal Airport, MA15 mi56 minSSW 11 G 197.00 miOvercast73°F73°F100%1011.2 hPa
Hyannis, Barnstable Municipal-Boardman Airport, MA21 mi52 minSW 15 G 269.00 miA Few Clouds75°F73°F94%1010.1 hPa

Wind History from PVC (wind in knots)
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1 day agoNW4SW4W6SW4W6W5W5W6W6SW3W5W4W7W6W7W7SW4SW8S6S9S8SW13SW11S8
2 days agoSW8SW7SW7SW7SW6SW5S6SW7S5SW5W7W7W7NW10W9NW8NW7NW8NW6N5N5N5NW4N4

Tide / Current Tables for Wellfleet, Massachusetts
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Wellfleet
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Tue -- 12:00 AM EDT     12.21 feet High Tide
Tue -- 05:55 AM EDT     Sunrise
Tue -- 06:35 AM EDT     -1.29 feet Low Tide
Tue -- 06:43 AM EDT     Moonrise
Tue -- 12:34 PM EDT     11.21 feet High Tide
Tue -- 06:52 PM EDT     -0.66 feet Low Tide
Tue -- 07:29 PM EDT     Sunset
Tue -- 08:11 PM EDT     Moonset
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
12.211.59.77.141-1-1.10.42.96.19.110.911.1107.95.22.30-0.60.52.969.2

Tide / Current Tables for Cape Cod Lighthouse, SE of, Cape Cod, Massachusetts
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Cape Cod Lighthouse
Click for Map
Tue -- 05:55 AM EDT     Sunrise
Tue -- 06:16 AM EDT     -0.98 feet Low Tide
Tue -- 06:43 AM EDT     Moonrise
Tue -- 12:32 PM EDT     8.54 feet High Tide
Tue -- 06:33 PM EDT     -0.50 feet Low Tide
Tue -- 07:29 PM EDT     Sunset
Tue -- 08:11 PM EDT     Moonset
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
9.38.77.252.50.3-0.9-0.60.72.757.28.48.47.55.73.51.2-0.3-0.40.82.757.3

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 (20,4,5,8)
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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.