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Marine Weather and Tides
Version 3.4 |
3/3/2018 - There is a new GOES Satellite for the east coast that required rewriting that part of the code. Please report any issues. 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. |
Sunrise 6:38AM | Sunset 7:57PM | Monday April 23, 2018 5:36 AM EDT (09:36 UTC) | Moonrise 12:36PM | Moonset 1:44AM | Illumination 56% | ![]() |
Marine Forecasts
EDIT (on/off)  HelpAMZ330 Charleston Harbor- 318 Am Edt Mon Apr 23 2018 .small craft advisory in effect through late tonight... Today..E winds 15 kt with gusts to 20 kt, increasing to 20 to 25 kt with gusts to 30 kt late this morning. Waves building to 2 to 3 ft. Showers this morning, then showers with a slight chance of tstms this afternoon. Locally heavy rainfall possible this afternoon. Tonight..SE winds 15 to 20 kt with gusts to 30 kt. Waves 1 to 2 ft. A slight chance of tstms. Showers. Locally heavy rainfall possible in the evening. Tue..S winds 10 to 15 kt. A chance of showers with a slight chance of tstms in the morning, then a slight chance of showers in the afternoon. Tue night..SW winds 5 to 10 kt. Wed..SW winds 5 to 10 kt. Wed night..W winds 5 to 10 kt. Thu..SW winds 5 kt. A slight chance of showers. Thu night..SW winds 5 kt. A chance of showers. Fri..W winds 5 to 10 kt. Fri night..SW winds 5 to 10 kt. Mariners are reminded that winds and waves higher in and near tstms. Unless otherwise noted, waves 1 foot or less. Charleston harbor water temperature 65 degrees. | AMZ300 318 Am Edt Mon Apr 23 2018 Synopsis for the coastal waters of south coastal south carolina and north coastal georgia.. Low pressure will approach from the west today, then slowly move up the east coast through mid week. An upper disturbance will move over the area Thursday, followed by a cold front late week. High pressure will return over the weekend. |
7 Day Forecast for Marine Location Near Hanahan, SC
Hourly EDIT Helplocation: 32.91, -79.94 debug
Area Discussion for - Charleston, SC
  (on/off)  Help NOTE: mouseover dotted underlined text for definitionFxus62 kchs 230821 afdchs area forecast discussion national weather service charleston sc 421 am edt Mon apr 23 2018 Synopsis Low pressure will approach from the west today, then slowly move up the east coast through mid week. An upper disturbance will move over the area Thursday, followed by a cold front late week. High pressure will return over the weekend. Near term through tonight Today: a vertically stacked cyclone both surface and aloft will spiral through the tennessee valley today into tonight. The occluded front extended from the surface low to the SE will link up with a secondary but weaker low that forms near the georgia alabama line this afternoon. Strong high pressure near long island and southern new england will be reluctant to move much to the east, blocked by a slow moving trough in the nw atlantic. This in turn prevents the warm front over southern georgia from making too much progress n-ne until this afternoon and tonight, as it moves into the forecast zones. Rainfall: although for the past 5-7 days the models have been locked into the synoptic situation for today and tonight, it has taken until yesterday or even now until it has a grasp on where the heaviest rainfall will occur. While we are still forecasting around 1.5 to 2.5 inches of rain, with the potential for locally higher amounts, the highest amounts are in the charleston tri-county district. There are various mid level perturbations that pass through today into tonight, and with strong low level convergence off the atlantic and plenty of upper difluence and divergence with the lfq of the upper jet. Combined with strong QG forcing and a 40-50 kt low level jet there is considerable upward vertical velocities that will transpire. The air mass is about as moist as it can be for late april, with pwat approaching 150-175% of normal. This would be a major concern if we weren't in a rainfall deficit for the year, which is around 4-7 inches below normal and a d2 or severe drought going into this rain event. So the overall flooding risk is low since the progression of the surface and upper low is slow. But, if there is any back- building that is able to develop, or there are persistent convergent bands that set up. Although tides are forecast to be around 3 4 to 1 foot mllw below levels where typical coastal flooding occurs, with the potential for heavy rains around the time of the mid afternoon high tide, there could be concerns along the coast and in downtown charleston, beaufort and savannah. Severe thunderstorms: there is a little elevated instability this morning, but with extensive cloud cover and the widespread rains (100% pop), there ins't much chance for any surface based convection to develop. That could change this afternoon into this evening, especially over georgia where the best heating will occur. It is in these locations where the steeper lapse rates will occur in tandem with MUCAPE of near 1000 j kg, based of course on our MAX temp forecast. This along with shear of 40-45 kt in the veering wind profiles with generate decent srh values. The lifting condensation levels (lcl's) come down, and with the northward advancing warm front we will need to maintain a close watch for isolated supercells near this boundary. Spc has the area in a "marginal risk" of severe weather, mainly for potential damaging winds and maybe an isolated tornado. Winds: we raised a lake wind advisory where our confidence is high on winds reaching 20-25 kt late this morning through sunset. Regarding any potential wind advisory our confidence is much lower, since we're not certain on how high we're able to tap into the robust 40-50 kt winds in the lower levels. For now we have winds capped at no more than 30 or 35 mph in gusts, highest along the coast and in charleston county. We will issue a special weather statement to address travel concerns due to the winds on the bridges of charleston county and tidal berkeley. Even with winds not technically at the advisory thresholds of at least 30 mph sustained and or 40 mph in gusts, given the saturated grounds, these winds could still bring down some weaker trees and tree limbs, with maybe a risk of isolated power outages. Temperatures: cloud cover and the widespread rains will limit max temps in sc to no warmer than upper 60s and lower 70s, but there could be a few breaks over georgia this afternoon to get temps into the mid or upper 70s. Deep moisture will begin to strip out during tonight and rain chances steadily diminish from s-sw to n-ne through the night. The heaviest and steadiest of the rains will be mainly over the charleston tri-county district early tonight where we still have categorical pop. Isolated thunderstorms are still in the forecast all locations early, then mainly east of i-95 overnight. Lows tonight mainly 60-65f. Short term Tuesday through Thursday At the start of the period, an area of low pressure will be stretched from tennessee into central sc and ga. Through the day, the low will slowly start to lift northeastward. As this occurs, the flow will turn more westerly and drier air will begin to work into the forecast area. Southern zones should have a precip-free day, but couldn't rule out some isolated showers and maybe a rumble of thunder or two in the north with the upper low nearby. Models are showing little to no QPF so rain chances will be capped at 20-30%. Temperatures will return closer to normal. The surface low will continue to lift away from the area on Wednesday. Meanwhile aloft, the main shortwave will also exit the area allowing the flow to become more zonal. Mostly sunny skies expected although could see some cumulus pop up in the afternoon. High temperatures will peak near 80 across most locations inland of the beaches. Temperatures Wednesday night will be mild, with lows in the ranging from mid 50s inland to around 60 at the coast. On Thursday, a strong shortwave will drop into the gulf coast states and head towards the local area. This will bring our next chance of |
rain. There are still discrepancies between models on the timing of this feature, which in turn has implications on rain chances. GFS is the slower of the global models, with rain mostly holding off until the next period, and ECMWF canadian is a bit faster. Took a blend of models and the current forecast features 30% chances. Highs will be in the mid 70s. Long term Thursday night through Sunday Forecast confidence in the extended period continues to be low given large spread in model guidance. General consensus is that a cold front will cross the area late week early weekend. Given the uncertainty on details, have kept pops pretty low until trends become clearer. Models come into better agreement on Sunday with a return to high pressure. Temperatures through the period will generally be near normal, perhaps slightly cooler on Saturday. Aviation 08z Monday through Friday Kchs:VFR conditions will remain in place before morning with -shra and breezy E winds of around 10-20 kt to occur. Conditions will then deteriorate later this morning into tonight as moderate convective rains develop as low pressure approaches from the west. Currently expecting conditions down into the MVFR category from 14-20z, then down to the ifr range thereafter. SE winds will become even stronger, averaging a solid 20-30 kt through the bulk of the day, dropping off to 15-20 kt tonight. There is a risk for tsra, mainly near the approaching warm front during the late afternoon and evening. Probabilities are too low to include mention at this time. Ksav: we begin the TAF set withVFR conditions in -shra, but that will change this morning and today as low pressure approaches from the west and a warm front lifts into the area from the sw. Expecting flight restrictions mainly in the MVFR range, but possibly down into the ifr range after 09z as shra impacts the terminal, before tapering off this evening. There is a chance for tsra during the afternoon near the warm front, and we will address this concern in later tafs. A tight e-se gradient will boost winds into the 15-25 kt range, maybe even occasionally higher. Extended aviation outlook:VFR is expected to return by Tuesday afternoon. Flight restrictions possible in showers late Thursday early Friday. Marine Today and tonight: poor to hazardous marine conditions will impact all waters, with a tight pinching of the gradient between strong high pressure off new england and low pressure spinning in the tennessee valley. With as much as a 4-5 mb spread across the waters, solid small craft advisories are in place for all marine zones for e-se winds reaching 20-30 kt today, dropping around 5 kt tonight as the gradient slackens a little. Where the best pressure packing occurs we have raised a gale warning on the charleston county atlantic waters beginning at 11 am and continuing through late tonight. Winds will peak at 35 kt or higher during this time. There has been several days of onshore winds and with it continuing today, seas will easily reach 5-10 ft, highest on the outer georgia waters and the 0-20 nm off charleston county. Mariners should also be prepared for reduced visibility in heavy rains at times, plus the risk for afternoon and night time t-storms. A few of these could be strong or severe with damaging winds and maybe an isolated waterspout. Tuesday through Saturday: marine conditions will continue to improve on Tuesday as low pressure lifts northeast away from the area. Small craft advisories will gradually drop as seas fall below 6 feet, first in the southern two coastal zones early Tuesday afternoon then charleston county waters and outer ga waters Wednesday morning. Low confidence in forecast late week given model discrepancies, but it appears conditions will remain below any headline criteria. A cold front could drop through the waters early in the weekend, then high pressure will return for the remainder of the weekend. High surf: with strong e-se winds, our local wave breaking matrices show around 5 foot breakers will impact the beaches of charleston county this afternoon into tonight. That along with seas building to 8-10 ft on the waters within 20 nm of the coast suggests that a high surf advisory is necessary. In addition areas of beach erosion can occur, especially near the time of the 330-400 pm high tide. Rip currents: the large surf and strong e-se winds will produce a high risk of rip currents on the charleston county beaches today. A moderate risk is forecast on the lower south carolina and georgia beaches, but if swells are greater than we now indicate, a high risk would be required on the other beaches as well. Chs watches warnings advisories Ga... None. Sc... Lake wind advisory from 11 am this morning to 8 pm edt this evening for scz045. High rip current risk from 8 am edt this morning through this evening for scz050. High surf advisory from 11 am this morning to 5 am edt Tuesday for scz050. Marine... Small craft advisory until 2 pm edt Tuesday for amz352-354. Small craft advisory until 11 am edt this morning for amz350. Gale warning from 11 am this morning to 2 am edt Tuesday for amz350. Small craft advisory until 8 am edt Wednesday for amz374. Small craft advisory until 2 am edt Tuesday for amz330. Near term... short term... Ect long term... Ect aviation... marine... |
Weather Reporting Stations
EDIT (on/off)  Help NOTE: Click on distance to see the station location on a mapStations | Dist | Age | Wind | Air Temp | Water Temp | Waves | Pressure | DewPt |
CHTS1 | 9 mi | 49 min | E 14 G 17 | |||||
41029 - Capers Nearshore (CAP 2) | 18 mi | 89 min | E 14 G 18 | 65°F | 64°F | 1021.3 hPa | ||
ACXS1 - ACE Basin Reserve, SC | 36 mi | 112 min | N 5.1 | 64°F | 61°F | |||
NIWS1 - North Inlet-Winyah Bay Reserve, SC | 50 mi | 112 min | E 12 | 64°F | 1023 hPa | 58°F |
Wind History for Charleston, SC
(wind in knots) EDIT (on/off)  Help6 AM | 7 AM | 8 AM | 9 AM | 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 | |
Last 24hr | NE G11 | NE | NE G11 | NE G16 | E | E | E | E | E | E | E G17 | NE | NE G17 | NE G17 | NE G17 | NE G20 | NE G22 | NE G22 | NE | E G19 | E G17 | E | E | E G17 |
1 day ago | W G4 | NW G5 | NW G5 | NW G5 | SW G7 | N G8 | N G8 | NW G9 | NW G7 | NW G6 | NW G9 | NE G21 | NE | NE | NE | NE G13 | NE | NE G16 | NE G15 | NE G16 | NE G16 | NE | NE | NE G12 |
2 days ago | N G20 | N G21 | N G21 | N | N G23 | N G16 | N G13 | NE G16 | E G16 | E G15 | E G14 | E | E | E G10 | E | NE | NE | NE | NE | NE | NE | NE | NW | N G4 |
Airport Reports
EDIT (on/off)  Help Click EDIT to display multiple airportsAirport | Dist | Age | Wind kt | Visibility | Sky/Weather | Temp | DewPt | Humidity | Pressure |
Charleston, Charleston Air Force Base, SC | 5 mi | 41 min | ESE 11 | 8.00 mi | Light Rain | 65°F | 59°F | 81% | 1020.4 hPa |
Mount Pleasant Regional-Faison Field, SC | 8 mi | 62 min | E 6 | 7.00 mi | Mostly Cloudy | 64°F | 60°F | 88% | 1021.3 hPa |
Charleston Executive Airport, SC | 15 mi | 42 min | E 13 | 5.00 mi | Fog/Mist | 64°F | 60°F | 88% | 1020 hPa |
Moncks Corner Berkeley County, SC | 20 mi | 42 min | ESE 4 | 7.00 mi | Mostly Cloudy | 59°F | 55°F | 88% | 1021.3 hPa |
Summerville Airport, SC | 21 mi | 42 min | E 3 | 10.00 mi | Mostly Cloudy | 61°F | 57°F | 88% | 1020.7 hPa |
Wind History from CHS (wind in knots)
6 AM | 7 AM | 8 AM | 9 AM | 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 | |
Last 24hr | NE | E | E | E | E G17 | E | E | SE G20 | SE G20 | E | E G21 | E G19 | E | E | E | E G21 | E | E G21 | E | E G22 | E G21 | SE G19 | SE | E |
1 day ago | NE | NE | NE | NE | NE | E | E G21 | E | E | E | E | E | E | E | E | NE | NE | NE | E | E | E | NE | NE | E |
2 days ago | NE G21 | NE G18 | NE G21 | N G22 | NE | E G18 | NE G17 | NE | NE | E | E | E | SE | SE | SE | E | Calm | Calm | E | NE | E | NE | NE |
Tide / Current Tables for Clouter Creek, north entrance, Cooper River, South Carolina
EDIT RT Ports Option Weekend mode (on/off) (on/off)  Help One Week of DataClouter Creek Click for Map Mon -- 02:43 AM EDT Moonset Mon -- 03:37 AM EDT 6.00 feet High Tide Mon -- 06:40 AM EDT Sunrise Mon -- 09:49 AM EDT 0.38 feet Low Tide Mon -- 01:35 PM EDT Moonrise Mon -- 04:19 PM EDT 5.20 feet High Tide Mon -- 07:55 PM EDT Sunset Mon -- 10:08 PM EDT 0.32 feet Low Tide Tide / Current data from XTide NOT FOR NAVIGATION |
12am | 1am | 2am | 3am | 4am | 5am | 6am | 7am | 8am | 9am | 10am | 11am | 12pm | 1pm | 2pm | 3pm | 4pm | 5pm | 6pm | 7pm | 8pm | 9pm | 10pm | 11pm |
3 | 4.3 | 5.3 | 5.9 | 5.9 | 5.3 | 4.2 | 2.8 | 1.6 | 0.7 | 0.4 | 0.8 | 1.8 | 2.9 | 3.9 | 4.7 | 5.2 | 5 | 4.3 | 3.1 | 1.9 | 0.8 | 0.3 | 0.6 |
Tide / Current Tables for Charleston Harbor Entrance, South Carolina Current
EDIT (on/off)  Help One Week of DataCharleston Harbor Entrance Click for Map Mon -- 02:42 AM EDT Moonset Mon -- 03:21 AM EDT -0.00 knots Slack Mon -- 06:39 AM EDT -2.38 knots Max Ebb Mon -- 06:40 AM EDT Sunrise Mon -- 09:52 AM EDT 0.00 knots Slack Mon -- 12:01 PM EDT 1.39 knots Max Flood Mon -- 01:35 PM EDT Moonrise Mon -- 03:51 PM EDT -0.00 knots Slack Mon -- 07:07 PM EDT -2.13 knots Max Ebb Mon -- 07:55 PM EDT Sunset Mon -- 10:09 PM EDT 0.00 knots Slack Tide / Current data from XTide NOT FOR NAVIGATION |
12am | 1am | 2am | 3am | 4am | 5am | 6am | 7am | 8am | 9am | 10am | 11am | 12pm | 1pm | 2pm | 3pm | 4pm | 5pm | 6pm | 7pm | 8pm | 9pm | 10pm | 11pm |
1.6 | 1.3 | 0.9 | 0.3 | -0.7 | -1.6 | -2.2 | -2.3 | -1.8 | -0.9 | 0.1 | 1 | 1.4 | 1.2 | 1 | 0.6 | -0.1 | -1 | -1.8 | -2.1 | -1.9 | -1.1 | -0.2 | 0.8 |
Weather Map and Satellite Images
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GOES Local Image of Southeast EDIT
NOTE: East coast views moved to GEOS-16. They are experimental and not well supported by NOAA so they may not be correct so be warned. This change required redoing a large amount of the GOES code. If the image you are expecting is not showing, please let me know. You may need to use the EDIT function to update your location.
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Other links: Northern Pacific Contential US Full GOES-East
Wind Forecast for Charleston, SC (5,6,7,8)
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Ground Weather Radar Station Charleston, SC
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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. |