Thursday, July20, 2017 L-36.com


Marine Weather and Tides
Groton, CT

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 5:31AMSunset 8:17PM Thursday July 20, 2017 6:30 PM EDT (22:30 UTC) Moonrise 2:45AMMoonset 5:34PM Illumination 8% 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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ANZ330 Long Island Sound East Of New Haven Ct/port Jefferson Ny- 518 Pm Edt Thu Jul 20 2017
Tonight..SW winds 10 to 15 kt, becoming W 5 to 10 kt late this evening and overnight. Seas 1 ft or less. Slight chance of showers and tstms early this evening, then showers and tstms likely late this evening. Chance of showers and tstms after midnight.
Fri..W winds 5 to 10 kt. Seas 1 ft or less.
Fri night..NW winds 5 to 10 kt. Seas 1 ft or less.
Sat..NW winds around 5 kt, becoming sw in the afternoon. Seas 1 ft or less.
Sat night..SW winds 5 to 10 kt, becoming se 10 to 15 kt with gusts up to 20 kt after midnight. Seas 1 ft or less. Chance of showers after midnight.
Sun..NE winds 5 to 10 kt, becoming S in the afternoon. Seas 1 ft or less. Chance of showers. Chance of tstms in the afternoon.
Sun night..E winds 5 to 10 kt. Seas 1 ft or less. Chance of showers.
Mon..N winds around 5 kt, becoming se in the afternoon and evening, then becoming ne after midnight. Seas 1 ft or less. Chance of showers. Chance of tstms.
Tue..NE winds 5 to 10 kt. Seas 1 ft or less. Chance of showers and tstms. Winds and seas higher in and near tstms.
ANZ300 518 Pm Edt Thu Jul 20 2017
Synopsis for the long island waters and new york harbor.. A cold front will pass across the coastal waters tonight and settle south of the area by Friday night. The front will remain stationary through the day on Saturday before returning north as a warm front Saturday night into Sunday. Multiple waves of low pressure move through the area through early next week, followed by building high pressure for the mid to late week.

7 Day Forecast for Marine Location Near Groton city, CT
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location: 41.3, -72.08     debug


Area Discussion for - New York City/Upton, NY
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Fxus61 kokx 202226
afdokx
area forecast discussion
national weather service new york ny
626 pm edt Thu jul 20 2017

Synopsis
A complex of showers and thunderstorms will move through early
tonight. Dry conditions are expected for Friday in the wake of a
cold front, however, hot and humid weather will continue. A
warm front will approach late Saturday and lift north across the
area into Sunday morning. Multiple waves of low pressure move
through the area through early next week, followed by building
high pressure for the mid to late week.

Near term until 6 am Friday morning
Cluster of storms moves through western locales this evening.

Damaging winds and heavy downpours likely for portions of the
area. This moves through by late evening.

The heat was on across the tri-state areas as of midday with the
temperature reaching into the 90s at central park for the 9th
time this year and tying june 13th for the hottest day of the
year so far with the high up to 94 degrees as of writing. See
the climate section below for more heat facts for 2017. The
heat advisory remains in effect through this evening where it is
out due to the combination of hot temperatures and high
humidity values. Via mixing, dew points have since dropped
across the area with a peak value of 77 degrees noted at jfk
which is up there climatologically for this part of the world.

In summary:
* a complex of thunderstorms will approach the area this evening
from the west and move east, possibly weakening as it moves
toward the immediate coast.

* some strong to severe thunderstorms are likely, with gusty
winds over 50 mph possible along with possible hail.

* downpours producing rainfall rates in excess of one inch per
hour may occur in any heavier thunderstorms that could result
in poor drainage flooding, especially in more urbanized areas.

* those outdoors with plans this evening should watch the sky
and be aware for any alerts. Travel may be impacted by low
visibility, ponding of water poor drainage flooding and gusty
winds that blow any objects over or around especially during
the evening commute.

In the wake of activity, patchy fog may form in areas that get
heavier rain briefly and temps cool to near the dewpoint. This
is mostly likely in orange county this evening for a bit.

The actual "cold" front will lag a bit behind the convection.

Based on progged theta-e from the GFS (which sometimes is the
best indicator of front locations in subtle temperature
gradient situations) shows a packing of contours around 3 am to
6 am across the area, indicative of the front's location.

Dewpoints may drop a hair with the front's passage.

Lows tonight will still be in the upper 60s in the coolest
spots well north and west of the city with readings in the mid
to upper 70s in more urban areas. Some spots may actually set a
calendar day low during any heavier convection this evening as
rain cooled air drops toward the surface in convective
downbursts.

Short term 6 am Friday morning through Saturday night
West to northwest flow aloft sets up for Friday as the front
drifts on south and stalls toward the DELMARVA peninsula. Drier
air aloft should mix down a bit as the flow aloft remains
offshore to 925 mb. However, this flow aloft is light (10 kts or
less) that the seabreeze will likely return in the afternoon
which would bring dewpoints at the surface back up. With the
offshore, flow I have favored the warmer end of guidance and
gone with the higher end of mos. This will push temps to near 90
over well inland areas and into the low to mid 90s along the
coast and in and around immediate nyc and urbanized areas in
north jersey. Thus the heat advisory was extended for most areas
today except for rockland, westchester, western bergen and
southern fairfield counties which look to fall just short of
criteria.

Although moisture and some instability lingers I have kept the
forecast dry as the presence of a lee-side surface pressure
trough and seabreeze do not look to be enough to pop any lid to
trigger convection tomorrow.

Dry for Friday night with west northwest flow aloft holding
firm. Lows should be a little cooler, with readings in the low
to mid 60s well north and west of the city to the mid 70s in nyc
and hudson county, nj.

I'm not enthused much for convection during the day on Saturday.

Westerly flow aloft sets up and a surface stationary front is
well to our south. Again, the only triggers will be the lee side
surface pressure trough and the sea breeze. I left in a low end
slight chance of a shower or thunderstorm along the sea breeze
on long island and over interior areas where differential
heating of the hilly terrain may set off something. Highs will
be a bit cooler and many spots will only be in the 80s for a
high. However, humidity will still be enough to make it a sticky
Saturday.

The warm front should start to lift back north Saturday night
and return the potential for showers and thunderstorms from the
south and west. Models show a spread in timing, so i
broadbrushed in pops for this time frame. The better chance
should be closer to sunrise on Sunday as a low-level jet of
40 kts+ moves from the jersey shore toward long island. With
high pwat values approaching 2 inches per the gfs, the threat
for heavy rain will be there Saturday night along with gusty
winds in any more potent convection. Lows will be a little
warmer due to the increase in clouds and warm front lifting
north.

Long term Sunday through Thursday
Much of the extended will be dominated by an unseasonably south
latitude polar jet orientation, with multiple short waves moving
through the northeast in northwest flow, which is typically a
pattern that offers very little predictability.

Despite considerable uncertainty for the extended period, the
pattern remains favorable for periods of heavy rainfall and
thunderstorms as multiple mesoscale convective systems move through
the area in northwest flow. The greatest complexity with the
forecast remains on where any frontal boundaries stall, which have
impacts on temperature, wind, instability, cloud cover, etc, but
most importantly on where exactly these systems will track. The
forecast will need to be monitored over the next few days for any
heavy rainfall flooding and severe potential.

By mid week, a brief respite in the active wet pattern may come as
ridging builds aloft and confluent flow allows a surface high to
strengthen. At least briefly, dew points and subsequently relative
humidity values will finally fall to more comfortable thresholds.

However, this may be short lived as the overall pattern still looks
to be active.

Aviation 22z Thursday through Tuesday
Convective complex to impact terminals this evening...

a convective complex will cross the nyc terminals early this
evening through about 02z. There is some uncertainty as to how
much of the complex stays together, but it seems likely that it
will have an impact on most of the terminals, especially from
nyc and points north and west. Gusty winds to 35 kt and very
heavy rain are possible with this activity.

For the most part, outside of the convection,VFR conditions
will prevail through Monday.

W-sw flow this evening around 10 kt, with some occasional gusts
up to 25 kt in the vicinty of any thunderstorms. Winds will
become northerly behind the complex this evening, then w-nw
overnight into Friday morning.

Ny metro enhanced aviation weather support...

detailed information, including hourly TAF wind component forecasts,
can be found at: http:

Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
LDLC3 - New London Ledge CT - Ledge Light Weather 0 mi31 min SSW 14 G 14 77°F 1010.4 hPa (-1.6)71°F
NLNC3 - 8461490 - New London, CT 4 mi43 min S 8 G 9.9 84°F 69°F1010.8 hPa
44039 - Central Long Island Sound 32 mi61 min SSW 7.8 G 9.7 85°F 77°F
QPTR1 - 8454049 - Quonset Point, RI 41 mi43 min SSW 9.9 G 12 1011.2 hPa
44017 - 23 Nautical Miles Southwest of Montauk Point, NY 42 mi41 min 78°F 77°F2 ft1012.1 hPa (-1.1)78°F
NWPR1 - 8452660 - Newport, RI 42 mi43 min SSW 9.9 G 12 75°F 71°F1011.2 hPa
NWHC3 - 8465705 - New Haven, CT 44 mi43 min SSW 5.1 G 6 82°F 81°F1011.3 hPa
NAXR1 - Narragansett Bay Reserve, RI 46 mi106 min SW 5.1 85°F 1011 hPa70°F
PTCR1 - 8452951 - Potter Cove, Prudence Island, RI 46 mi43 min SW 4.1 G 8.9 1010.6 hPa
PRUR1 46 mi43 min 77°F 69°F
CPTR1 - 8452944 - Conimicut Light, RI 48 mi43 min S 16 G 18 81°F 75°F1010.5 hPa

Wind History for New London, CT
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Groton / New London, Groton / New London Airport, CT3 mi35 minSSW 67.00 miFair77°F71°F82%1010.7 hPa
Westerly, Westerly State Airport, RI15 mi38 minSW 78.00 miFair84°F73°F70%1011.3 hPa
Montauk, Montauk Airport, NY17 mi37 minSSW 6 mi81°F75°F82%1011.9 hPa
Chester, Chester Airport, CT23 mi36 minSSW 410.00 miFair86°F69°F59%1011.5 hPa

Wind History from GON (wind in knots)
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Last 24hrSW8SW9SW5W4SW3W5CalmCalmCalmCalmCalmCalmCalmCalmS4S6SW5SW6SW8SW7S6S7S6SW6
1 day agoS8S6CalmS7S3S4S4S3CalmS3CalmCalmCalmCalmSW6SW5S6S7S7S7S6SW9SW9SW7
2 days agoS4SE5SE6SE5SE3E5S3CalmCalmSE4CalmCalmCalmCalmCalmS5S6S7S7S6S7S10S9S9

Tide / Current Tables for Silver Eel Pond, Fishers Island, N.Y.
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Silver Eel Pond
Click for Map
Thu -- 01:22 AM EDT     0.02 feet Low Tide
Thu -- 02:45 AM EDT     Moonrise
Thu -- 05:32 AM EDT     Sunrise
Thu -- 06:54 AM EDT     2.34 feet High Tide
Thu -- 01:23 PM EDT     0.15 feet Low Tide
Thu -- 05:33 PM EDT     Moonset
Thu -- 07:16 PM EDT     3.22 feet High Tide
Thu -- 08:15 PM EDT     Sunset
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
0.400.10.61.31.82.22.32.21.81.30.90.50.20.20.81.62.42.93.23.12.72.11.5

Tide / Current Tables for The Race, Long Island Sound, New York Current
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The Race
Click for Map
Thu -- 02:45 AM EDT     Moonrise
Thu -- 03:19 AM EDT     0.00 knots Slack
Thu -- 05:32 AM EDT     Sunrise
Thu -- 06:06 AM EDT     2.90 knots Max Flood
Thu -- 09:24 AM EDT     -0.00 knots Slack
Thu -- 12:21 PM EDT     -3.16 knots Max Ebb
Thu -- 03:26 PM EDT     0.00 knots Slack
Thu -- 05:33 PM EDT     Moonset
Thu -- 06:25 PM EDT     3.32 knots Max Flood
Thu -- 08:16 PM EDT     Sunset
Thu -- 09:44 PM EDT     -0.00 knots Slack
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
-3.6-3.1-2-0.51.12.42.92.61.80.6-0.9-2.3-3.1-3-2.1-0.70.92.43.23.22.41.2-0.4-2.2

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 New York City/Upton, NY (18,4,5,8)
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Ground Weather Radar Station Boston, MA
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weather_mapweather_map weather_map

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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.