Sunday, August20, 2017 L-36.com


Marine Weather and Tides
Hardeeville, SC

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 6:52AMSunset 8:04PM Sunday August 20, 2017 11:26 AM EDT (15:26 UTC) Moonrise 4:31AMMoonset 6:24PM Illumination 3% Phase: Waning Crescent; Moon at 28 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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AMZ352 Waters From Edisto Beach Sc To Savannah Ga Out 20 Nm- 1023 Am Edt Sun Aug 20 2017
Rest of today..SE winds 5 to 10 kt. Seas 2 ft.
Tonight..SE winds 5 to 10 kt. Seas 2 to 3 ft. A slight chance of showers and tstms after midnight.
Mon..SE winds 5 to 10 kt. Seas 2 ft. A chance of showers and tstms.
Mon night..SE winds 5 to 10 kt. Seas 2 ft. A slight chance of showers and tstms.
Tue..S winds 5 to 10 kt. Seas 2 ft. A slight chance of showers and tstms.
Tue night..S winds 10 kt. Seas 3 ft. A slight chance of showers and tstms.
Wed..SW winds 5 to 10 kt. Seas 3 ft. A chance of showers and tstms.
Wed night..SW winds 10 kt. Seas 3 ft. A chance of showers and tstms.
Thu..SW winds 5 to 10 kt. Seas 2 to 3 ft. A chance of showers and tstms.
Thu night..SW winds 5 to 10 kt. Seas 2 ft. A chance of showers and tstms. Mariners are reminded that winds and seas higher in and near tstms.
AMZ300 1023 Am Edt Sun Aug 20 2017
Synopsis for the coastal waters of south coastal south carolina and north coastal georgia.. A weak stationary front will gradually dissipate across the region early this week. A stronger cold front is expected to pass over the region on Thursday. Slightly cooler and drier conditions are expected through the rest of the week into next weekend.

7 Day Forecast for Marine Location Near Hardeeville, SC
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location: 32.3, -81.12     debug


Area Discussion for - Charleston, SC
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Fxus62 kchs 201459
afdchs
area forecast discussion
national weather service charleston sc
1059 am edt Sun aug 20 2017

Synopsis
A weak stationary front will gradually dissipate across the
region early this week. A stronger cold front is expected to
pass over the region on Thursday. Slightly cooler and drier
conditions are expected through the rest of the week into next
weekend.

Near term through tonight
A few minor adjustments to the forecast:
1. Showers have dissipated across the coastal waters, mainly
along charleston county. While another shower could briefly pop
up over the next hour or two, the probabilities are so low that
we opted to lower pops and remove mention of precipitation for
the rest of this morning.

2. Adjusted the sky cover in these same areas to match the
visible satellite imagery and expected forecast into this
afternoon.

3. Bumped up the rip current risk to moderate (see the marine
section below).

Otherwise, everything else is generally on track.

Rest of today: a tutt low will continue to slowly progress w-nw
through the gulf of mexico, allowing for an expansion of strong
sub-tropical ridging to spread across the local area, keeping
short wave energy off to the n. A weak stationary front located
not too far to the n-nw of the cwfa will meander nearby
throughout the day, as atlantic high pressure starts to build
in. At this time, the synoptic flow backs around to the se,
causing even higher pwats to arrive from the atlantic. The sea
breeze and the proximity to the front looks to be the main focus
for convection during the afternoon, with coverage similar to
yesterday (mainly in the 20-30% range). We're not too concerned
with any severe potential due to warm mid levels, but dry air
in roughly the 750-450 mb layer will cause dcape values to peak
around 1,000-1,200 j kg, enough for locally gusty winds. Pwats
around 110-120% of normal and weak steering flow will cause a
few of the storms to produce heavy downpours with minor
flooding concerns.

The onshore trajectories and an early start to the sea breeze
will keep our coastal counties no higher than 90-94f, but still
into the middle 90s further inland. Heat indices will peak at
100-105f, maybe briefly a little higher near the us-17 corridor
if dew points can climb above 80f.

Tonight: a short wave located near the northern bahamas from
this morning will lift n-nw with a weakness in the sub-tropical
ridge, bringing with it a further increase in moisture from the
ocean. A deepening SE flow that extends through about 500 mb,
better isentropic ascent and larger scale forcing for ascent
with the short wave will produce an increasing chance of showers
and t-storms arriving overnight, probably after 2 or 3 am. By
daybreak Monday at least widely scattered to scattered activity
will be encompassing the coastal counties. Although the steering
flow is more progressive, given the abundance of moisture there
will be a heavy rain and localized flooding threat. Temps will
remain well above average for this time of year, which has been
the case most nights this month. Not completely convinced of
fog late at night since SREF probabilities are low and we may
not reach our cross-over temps. But MOS guidance is showing fog
along the NW tier of counties after 09z, so will make
adjustments in later forecasts if necessary.

Short term Monday through Wednesday
Monday: short range guidance shows a broad mid level low will track
across the western gulf of mexico as the center of ridge shifts near
the sc coast during the daylight hours Monday. A weak mid level
inverted trough is expected to run between the gulf low NE across fl
off the ga coast. GFS and ECMWF indicate that a band of enhanced
cloud cover will develop within the region of the weak mid level
trough. Simulated IR from the GFS indicates that the cloud cover
associated with the h5 trough will expand between the southeast
coast and bermuda between 15z through 0z today. It will be very
interesting to observe later today if the mid and high cloud cover
develops as guidance suggests. Otherwise, Mon will be a day where pw
values increase to around 2 inches with tall and thin instability.

This environment should support a healthy CU field with some degree
of cirrus level moisture. Overall, cloud cover and deep convection
will be a factor across the forecast area during the solar eclipse.

However, several gaps in the cloud cover should occur, more common
north of the edisto river basin. Scattered thunderstorms are
forecast across SE ga and west of i-95. Elsewhere, isolated
thunderstorms are possible. Guidance supports high temperatures
ranging from the low 90s across the mid savannah river valley to the
upper 80s near the beaches.

Tuesday and Wednesday: mid level ridge is forecast to remain
centered over the forecast area on Tuesday and will gradually weaken
as trough ripples over the mid west on Wednesday. Forecast soundings
show an inversion at h75 Tuesday afternoon, decreasing on Wednesday.

I will indicate low chc pops across the land zones on Tuesday,
increase to solid chc pops on Wednesday. High temperatures are
forecast to peak across the inland savannah river valley weds
afternoon, reaching the mid to upper 90s.

Long term Wednesday night through Saturday
A cold front should push across the forecast area on Thursday,
likely supporting a band of thunderstorms. Pops on Thursday have
been increase into the likely range across most of the forecast
area. High pressure sourced from canada will remain centered
well north of the region through the rest of the week.

Confidence in the day 5 through 7 forecast is low. Medium range
guidance indicates that the sfc high center will shift over new
england, ridging SW across the carolinas and ga. In addition,
both the GFS and ECMWF show a coastal low developing off the
ga sc coast by late this week. Guidance supports prolonged ne
winds, yielding afternoon dewpoints in the upper 60s inland by
the weekend. I will favor the marine and near shore zones for
chc pops through much of the day 5 through 7 period.

Aviation 15z Sunday through Thursday
Vfr through 12z Monday. Their is a risk of shra tsra directly
impacting the airports from roughly 18-22z. However, the
probabilities are currently too low to include mention in the
current tafs.

Extended aviation outlook: thunderstorms may result in short periods
of flight restrictions, greatest potential during the afternoon and
early evening. Patchy fog is possible over wet soil Wednesday
morning.

Marine
Today: a stationary front will meander inland over the se, as
high pressure becomes more dominate from the e. The result is
for winds backing around from SW to SE through the day at no
higher than 10 or 15 kt. Even with a small ~9 second swell,
combined seas will be no more than 2 or 3 ft.

Tonight: the stationary front becomes ill-defined as sub-
tropical high pressure continues to expand west, producing se
and S winds around 10 kt. Little change in seas.

Monday through Friday: western atlantic high pressure will yield a
weak pressure gradient over the coastal waters through mid week. A
cold front should sweep across the forecast area on Thursday. Sfc
winds are forecast to remain light from the SE through Tuesday, then
veering from the south-southwest Wednesday and Thursday. Wave
heights are expected to generally range between 2-3 feet Monday
through Thursday. Large high pressure centered over the great lakes
will build over the region on Friday. In addition, a coastal low may
develop off the ga and sc coast late Friday. Winds should shift from
the ne, increasing to around 10 kts by Friday afternoon. Four foot
wave are forecast across portions of amz350 and possibly beyond 20
nm offshore.

Rip currents... The 10 am NOAA buoys are now reporting a 2.0-2.5
ft swell around 9 seconds. Even though it may decay to 1.5 ft
by the time it reaches the beaches, the combination of it with
the onshore flow and astronomical influences should lead to an
environment more favorable for rip currents, which would be more
impactful given the influx of people to the area. We bumped up
the risk of rip currents to moderate through this evening.

Tides coastal flooding
Astronomical influences will continue to produce elevated tides
through Tuesday. Only small tidal departures are necessary and
we could approach shallow coastal flooding levels with the
evening high tides along parts of the sc coast. Coastal flood
advisories might be needed.

Climate
Record high minimums for august 20...

kchs... 78 set in 2010 and previous.

Kcxm... 80 set in 2009 and previous.

Ksav... 82 set in 1878.

Equipment
The temperature and dew point sensors at the downtown charleston
observation site (kcxm) could periodically fail. Technicians
plan on fixing the problem.

Chs watches warnings advisories
Ga... None.

Sc... None.

Marine... None.

Near term...

short term...

long term...

aviation...

marine...

tides coastal flooding...

climate...

equipment...



Weather Reporting Stations
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Stations Dist Age Wind Air TempWater Temp WavesPressureDewPt
FPKG1 - 8670870 - Fort Pulaski, GA 22 mi39 min SSW 2.9 G 5.1 86°F 87°F1018.7 hPa
41033 38 mi19 min SSW 5.8 G 7.8 85°F 1018.1 hPa
ACXS1 - ACE Basin Reserve, SC 40 mi102 min Calm 82°F 1018 hPa78°F
SAXG1 - Sapelo Island Reserve, GA 62 mi87 min S 1 86°F 1017 hPa (+0.0)76°F

Wind History for Fort Pulaski, GA
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Airport Reports
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AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Savannah-Hilton Head International Airport, GA12 mi34 minno data10.00 miPartly Cloudy89°F75°F63%1018.2 hPa
Hunter U. S. Army Airfield, GA19 mi89 minN 010.00 miFair86°F74°F69%1017.5 hPa
Hilton Head Island, Hilton Head Airport, SC23 mi37 minS 510.00 miPartly Cloudy86°F78°F79%1018.6 hPa

Wind History from SAV (wind in knots)
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Last 24hrCalmNW5W8S5W6SW7SW3S10S6S9S5SW3CalmCalmCalmSW5S3CalmS4SE4S4S5E3SE6
1 day agoW5W7W8W4W4W6SW6S15S11S9SW7SW5S8SW8SW7SW5SW4SW4W4SW3SW4W4W4Calm
2 days ago5NW5SW13
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Tide / Current Tables for Purrysburg Landing, Savannah River, South Carolina
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Purrysburg Landing
Click for Map
Sun -- 05:11 AM EDT     -0.07 feet Low Tide
Sun -- 05:31 AM EDT     Moonrise
Sun -- 06:52 AM EDT     Sunrise
Sun -- 09:48 AM EDT     3.12 feet High Tide
Sun -- 05:25 PM EDT     -0.31 feet Low Tide
Sun -- 07:24 PM EDT     Moonset
Sun -- 08:02 PM EDT     Sunset
Sun -- 10:12 PM EDT     3.57 feet High Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
2.72.11.40.80.2-0.10.21.22.333.132.621.40.70.1-0.3-0.10.82.13.13.63.5

Tide / Current Tables for Savannah River Entrance, Georgia Current
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Savannah River Entrance
Click for Map
Sun -- 02:35 AM EDT     0.00 knots Slack
Sun -- 05:08 AM EDT     1.88 knots Max Flood
Sun -- 05:31 AM EDT     Moonrise
Sun -- 06:51 AM EDT     Sunrise
Sun -- 08:45 AM EDT     -0.00 knots Slack
Sun -- 12:15 PM EDT     -2.33 knots Max Ebb
Sun -- 02:44 PM EDT     0.01 knots Slack
Sun -- 05:29 PM EDT     2.51 knots Max Flood
Sun -- 07:22 PM EDT     Moonset
Sun -- 08:01 PM EDT     Sunset
Sun -- 09:15 PM EDT     -0.00 knots Slack
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
-2.4-2-0.80.51.51.91.81.50.8-0.3-1.3-2-2.3-2.1-1.10.41.82.42.52.11.50.3-0.9-1.9

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

GOES Local Image of Southeast    EDIT
Geos

Wind Forecast for Charleston, SC (11,2,3,4)
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Ground Weather Radar Station Charleston, SC
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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.