Sunday, April30, 2017 L-36.com


Marine Weather and Tides
Whitemarsh Island, GA

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 6:36AMSunset 8:06PM Sunday April 30, 2017 10:47 AM EDT (14:47 UTC) Moonrise 9:32AMMoonset 11:45PM Illumination 21% Phase: Waxing Crescent; Moon at 5 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
AMZ354 Waters From Savannah Ga To Altamaha Sound Ga Out 20 Nm...including Grays Reef National Marine Sanctuary- 941 Am Edt Sun Apr 30 2017
.small craft advisory in effect from Monday morning through Monday evening...
Today..SE winds 10 kt...increasing to 15 kt. Seas 2 to 3 ft...building to 3 to 4 ft.
Tonight..SE winds 15 kt with gusts to 20 kt. Seas 4 to 5 ft.
Mon..S winds 15 to 20 kt...increasing to 20 to 25 kt in the afternoon. Seas 4 to 6 ft. A slight chance of showers and Thunderstorms in the afternoon.
Mon night..S winds 20 to 25 kt with gusts to 30 kt... Becoming W 15 kt after midnight. Seas 4 to 6 ft...subsiding to 3 to 4 ft after midnight. Showers likely with a slight chance of Thunderstorms.
Tue..NW winds 5 to 10 kt...becoming S in the afternoon. Seas 3 to 4 ft. A chance of showers with a slight chance of Thunderstorms in the morning.
Tue night..S winds 5 to 10 kt...becoming sw after midnight. Seas 2 ft.
Wed..NE winds 5 to 10 kt. Seas 2 ft.
Wed night..SE winds 10 to 15 kt. Seas 2 to 3 ft. A slight chance of showers and Thunderstorms.
Thu..S winds 15 to 20 kt. Seas 4 to 5 ft. A chance of showers and Thunderstorms.
Thu night..S winds 15 to 20 kt. Seas 4 to 6 ft. A chance of showers and Thunderstorms. Mariners are reminded that winds and seas can be higher in and near tstms.
AMZ300 941 Am Edt Sun Apr 30 2017
Synopsis for the coastal waters of south coastal south carolina and north coastal georgia.. Atlantic high pressure will give way to a cold front which will move through Monday night into Tuesday. High pressure will then bring dry weather through Wednesday night before rain chances return late in the week as a stronger storm system affects the area. Drier high pressure should then return by the end of the weekend.

7 Day Forecast for Marine Location Near Whitemarsh Island, GA
   Hourly   EDIT   Help
location: 32.08, -81.03     debug


Area Discussion for - Charleston, SC
      (on/off)   Help   NOTE: mouseover dotted underlined text for definition
Fxus62 kchs 301328
afdchs
area forecast discussion
national weather service charleston sc
928 am edt Sun apr 30 2017

Synopsis
Atlantic high pressure will give way to a cold front which will move
through Monday night into Tuesday. High pressure will then bring dry
weather through Wednesday night before rain chances return late in
the week as a stronger storm system affects the area. Drier high
pressure should then return by the end of the weekend.

Near term /until 6 pm this evening/
Isolated showers have recently developing in the rbw-nbc
corridor within an area of weak surface moisture convergence.

This band should quickly break down over the next hour or two
as the sea breeze circulation begins to form. Modified sounding
do not support much in the way of meaningful instability this
afternoon with pronounced mid-level capping noted. There are no
plans to introduce mentionable pops this cycle given the
current activity is expected to dissipate soon. Highs from the
upper 80s inland to the upper 70s at the beaches look on track.

Overall, only minor changes were made for the late morning
update.

Short term /6 pm this evening through Wednesday/
Tonight: a cold front is timed to push east of the mississippi
river by late tonight. The pressure gradient between the
approaching front from the west and high pressure over the
atlantic will result in steady south winds over land, with
increasing flow across the marine zones. A fairly wide band of
showers and thunderstorms is expected to persist along and ahead
of the cold front. A few weak showers may reach inland ga by
sunrise Monday, highlighted with schc pops. Temps should cool
generally to around 70 tonight.

Monday through Wednesday: a cold front will approach from the
west Monday, but should be weakening as it does so as the main
upper low moves north into the great lakes. Still think there is
a good chance for showers and thunderstorms, especially inland
and during the afternoon. There could be a few severe storms,
mainly late in the afternoon west of i- 95. Also, it will be
quite breezy as the pressure gradient and low- level jet
increase. Gusts to 30-35 mph are expected, especially near
charleston. A lake wind advisory is possible for lake moultrie.

Most showers should be offshore shortly after midnight Tuesday
with drier air moving into the area and persisting through
Wednesday. Temperatures should stay near to above normal through
the period.

Long term /Wednesday night through Saturday/
Mainly dry through Wednesday night before rain chances return with
the approach of a stronger storm system toward the end of the week.

Although there is a bit better agreement between the GFS and ecmwf
than 24 hours ago, there are still some timing differences so
forecast confidence is lower than normal. Conditions look at least
marginally favorable though for some stronger storms Thursday. Rain
chances should diminish by Friday night but we kept small rain
chances into Saturday given the uncertainty regarding the . Timing
of the cold front and strength/timing of the upper trough.

Temperatures should be near or above normal through at least
Thursday night before likely dropping below normal Friday through
the weekend.

Aviation /13z Sunday through Thursday/
Nam forecast soundings show thickening of low level saturated
layer after sunrise, generally agreeing with the 10z lamp. In
fact, recently IR satellite detected a band of MVFR ceilings
pushing rapidly east over the midlands at 1125z. I will include
a tempo group at kchs and ksav from 12z- 15z for bkn015 ovc025.

As the mixed layer deepens by late morning, momentum transfer
should yield south wind gusts from 23 kts to 28 kts through the
afternoon. Winds are forecast to decouple by 2z. Steady return
flow ahead of an approaching cold front will maintain dewpoints
around 70. Near term guidance indicates that stratus will
gradually increase across the terminals during the pre dawn
hours. However, if thick debris cirrus streams over the region
then the potential for MVFR stratus will decrease.

Extended aviation outlook: ceiling and/or visibility
restrictions are likely Monday into Monday night due to low
clouds, showers and thunderstorms, then again Thursday/Thursday
night, possibly lasting into Friday. Breezy/gusty conditions
also expected Monday, Thursday and Friday afternoons.

Marine
A cold front will sweep across the mississippi river by this
evening and tonight. Sse winds will become gusty today, reaching
just short of small craft advisory levels over the chs harbor
this afternoon. However, wave heights of six feet will spread
west into amz374 by this evening, reaching the near shore sc
waters following midnight. Wave heights and gusty winds will
spread across all marine zones, including the chs harbor by
sunrise Monday.

Monday through Friday: advisory conditions expected Monday into
Monday night when winds could gust near 30 kt and seas could build
to 8 ft near the gulf stream. Could see an advisory linger Tuesday
morning, mainly across the offshore ga waters, but otherwise no
significant issues until Thursday when another cold front
approaches. Much uncertainty regarding the timing of the frontal
passage but conditions look poor either way through Friday.

Climate
Observed minimums this morning indicate all three climate sites
should break the record high minimums for today.

Record high minimums for 30 april:
kchs: 69/2014 and previous years.

Kcxm: 73/1912.

Ksav: 72/1953 and previous years.

Chs watches/warnings/advisories
Marine... Small craft advisory from 8 am Monday to midnight edt Monday
night for amz330-354.

Small craft advisory from midnight tonight to noon edt Tuesday
for amz350-352.

Small craft advisory from 5 pm this afternoon to noon edt
Tuesday for amz374.



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
FPKG1 - 8670870 - Fort Pulaski, GA 7 mi47 min S 8 G 12 79°F 77°F1021.7 hPa (+0.7)
41033 36 mi39 min SSE 7.8 G 12 75°F 74°F1021.8 hPa
ACXS1 - ACE Basin Reserve, SC 45 mi62 min SSE 2.9 77°F 1022 hPa73°F
SAXG1 - Sapelo Island Reserve, GA 48 mi47 min SSE 14 80°F 1020 hPa (+0.0)72°F
41008 - GRAYS REEF - 40 NM Southeast of Savannah, GA 48 mi117 min SSE 7.8 G 9.7 75°F 74°F4 ft1021 hPa (+0.6)71°F

Wind History for Fort Pulaski, GA
(wind in knots)    EDIT      (on/off)   Help
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
3
AM
4
AM
5
AM
6
AM
7
AM
8
AM
9
AM
Last
24hr
S6
G11
S8
G13
S7
G10
SW9
G13
S7
G11
S8
G14
S8
G12
S7
G12
S6
G10
SE4
G10
SE4
G8
SE5
G9
SE6
G9
SE5
G8
SE4
SE3
SE5
S6
G10
SE5
G8
S7
G10
SE6
G9
SE6
G9
S5
G8
S7
G10
1 day
ago
S5
G9
SW6
G9
S6
S6
G9
S6
G11
S7
G13
S8
G12
S7
G10
S7
G12
S7
G10
S7
G10
S6
G10
S6
G10
S6
G11
S5
G8
S6
G10
S5
G8
S6
G10
S5
G9
S5
G11
S4
G8
S3
S5
S6
G10
2 days
ago
S7
G13
S8
G15
S8
G15
S11
G19
SW13
G18
S8
G15
S7
G12
S7
G11
S10
G14
S8
G13
S6
G11
S7
G12
SW13
G16
SW7
G11
SW10
G16
S11
G16
SW7
G12
SW4
S2
S2
S4
S2
S4
SW5

Airport Reports
    EDIT      (on/off)   Help   Click EDIT to display multiple airports
AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Hunter U. S. Army Airfield, GA7 mi49 minSSE 10 G 1910.00 miA Few Clouds79°F74°F86%1020.6 hPa
Savannah, Savannah International Airport, GA10 mi54 minS 1510.00 miMostly Cloudy84°F66°F55%1021 hPa
Hilton Head Island, Hilton Head Airport, SC20 mi57 minSSE 810.00 miPartly Cloudy77°F73°F89%1021.7 hPa

Wind History from SVN (wind in knots)
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
3
AM
4
AM
5
AM
6
AM
7
AM
8
AM
9
AM
10
AM
Last 24hrS8S8
G15
S8
G17
S8SE7S9
G15
SE11
G15
SE8S10
G15
SE6SE4SE6SE6SE4SE4SE5CalmSE4SE7S3CalmCalmS7
G15
S10
G19
1 day agoSE5S5S6S4SE8SE5SE7S4SE7SE4S6S5S5S6S7S8
G14
S6
G15
S8S7S6S7S4S8S3
2 days agoS8S9S12
G18
S10
G17
S14
G21
S11
G17
S11
G20
S7S4S5S5S6S6S6S4CalmCalmCalmCalmCalmCalmCalmCalmCalm

Tide / Current Tables for Fort Jackson, Savannah River, Georgia
   EDIT   RT Ports Option   Weekend mode (on/off)   (on/off)   Help   One Week of Data
Fort Jackson
Click for Map
Sun -- 12:07 AM EDT     8.64 feet High Tide
Sun -- 06:38 AM EDT     Sunrise
Sun -- 06:58 AM EDT     -0.54 feet Low Tide
Sun -- 10:32 AM EDT     Moonrise
Sun -- 12:52 PM EDT     7.34 feet High Tide
Sun -- 07:11 PM EDT     -0.52 feet Low Tide
Sun -- 08:04 PM EDT     Sunset
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
8.68.47.55.93.91.80.1-0.50.32.24.46.17.17.375.94.12.10.4-0.501.94.36.5

Tide / Current Tables for Savannah River Entrance, Georgia Current
   EDIT      (on/off)   Help   One Week of Data
Savannah River Entrance
Click for Map
Sun -- 12:56 AM EDT     -0.00 knots Slack
Sun -- 04:07 AM EDT     -2.60 knots Max Ebb
Sun -- 06:38 AM EDT     Sunrise
Sun -- 07:10 AM EDT     0.00 knots Slack
Sun -- 09:37 AM EDT     2.19 knots Max Flood
Sun -- 10:31 AM EDT     Moonrise
Sun -- 01:22 PM EDT     -0.00 knots Slack
Sun -- 04:30 PM EDT     -2.32 knots Max Ebb
Sun -- 07:21 PM EDT     0.00 knots Slack
Sun -- 08:03 PM EDT     Sunset
Sun -- 10:02 PM EDT     2.66 knots Max Flood
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.
12am1am2am3am4am5am6am7am8am9am10am11am12pm1pm2pm3pm4pm5pm6pm7pm8pm9pm10pm11pm
1.1-0.1-1.4-2.3-2.6-2.4-1.7-0.31.222.11.81.20.4-0.7-1.8-2.3-2.3-1.8-0.612.22.72.4

Weather Map and Satellite Images
       (on/off)   Help
Weather Map
wmap_A
IR Satellite Image from GEOS
east_satellite

GOES Local Image of Southeast    EDIT
Geos

Wind Forecast for Charleston, SC (10,2,3,4)
      (on/off)   Help

Ground Weather Radar Station Charleston, SC
   (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.