Thursday, January21, 2021
Privacy Policy
L-36.com

Marine Weather and Tides
Mount Pleasant, SC

Version 3.4
NOTICE
8/26/2020 The 7 day forecast is taking about 5 seconds to load but it will eventually load. NOAA is still working on it.
8/18/2020 NOAA continues to have trouble. Wind guest will occasionally be left off graphs. I am working with NOAA to resolve the issue.
12/16/2019 NOAA is having trouble with requests that include wind gusts. I am posting graphs without wind gusts until it gets fixed.
10/9/2019 Updated the Marine Zones.
9/4/2019 Fixed the weather maps due to NOAA moving them.
7/25/2019 New feature in the Airports section gives a link to 5 minute updates for data reports.

Sunrise 7:18AMSunset 5:43PM Thursday January 21, 2021 10:22 PM EST (03:22 UTC) Moonrise 12:21PMMoonset 12:59AM Illumination 63% Phase: Waxing Gibbous; Moon at 9 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
AMZ330 Charleston Harbor- 948 Pm Est Thu Jan 21 2021
Tonight..W winds 10 kt, becoming nw late. A slight chance of rain this evening, then rain likely after midnight.
Fri..NW winds 5 to 10 kt, becoming W in the afternoon. Rain.
Fri night..NW winds 5 to 10 kt. A chance of showers in the evening.
Sat..NE winds 10 to 15 kt.
Sat night..NE winds 10 kt.
Sun..E winds 5 to 10 kt.
Sun night..SE winds 5 to 10 kt, becoming S after midnight. A chance of showers after midnight.
Mon..SW winds 10 to 15 kt. A chance of showers.
Mon night..SW winds 15 to 20 kt. Waves 1 to 2 ft. A chance of showers.
Tue..W winds 10 to 15 kt. A chance of showers.
Tue night..N winds 10 to 15 kt. Unless otherwise noted, waves 1 foot or less. Charleston harbor water temperature 53 degrees.
AMZ300 948 Pm Est Thu Jan 21 2021
Synopsis for the coastal waters of south coastal south carolina and north coastal georgia.. A cold front will advance quickly through the area overnight. Then, high pressure will return for the weekend. Another cold front is expected to affect the area early next week.


7 Day Forecast for Marine Location Near Mount Pleasant, SC
   Hourly   EDIT   Help
location: 32.93, -79.83     debug


Area Discussion for - Charleston, SC
      (on/off)   Help   NOTE: mouseover dotted underlined text for definition
FXUS62 KCHS 220319 AFDCHS

Area Forecast Discussion National Weather Service Charleston SC 1019 PM EST Thu Jan 21 2021

SYNOPSIS. A cold front will advance quickly through the area overnight. Then, high pressure will return for the weekend. Another cold front is expected to affect the area early next week.

NEAR TERM /UNTIL 6 AM FRIDAY MORNING/. As of late Thursday evening, the cold front was starting to slip into locations west of US-301 across far inland areas. In association with this front there have been pockets of light rain and/or drizzle. Temperatures across the local counties are much warmer than 24 hours ago, running on average 10-15F warmer. Dew points are similarly considerably higher than last night, and only a few degrees below the temperatures.

The front will reach roughly along a northeast to southwest oriented line from Charleston to Springfield to Reidsville by 2 AM, then to Beaufort, Savannah and Ludowici around 5 AM.

A potent upper jet of 1501-60 knots will prevail from the Ohio Valley to Mid-Atlantic states through the night, with the local region to lie near the right entrance region of that jet. While the flow aloft is mainly zonal, there are subtle impulses that pass through, along with hints that a wave low pressure will trek along the cold front over southeast Georgia overnight. Frontogenesis will increase as a result, mainly late, and it is during that time that we anticipate a rapid rise in the coverage of rainfall.

We have change to precipitation type to stratiform rains through the night, backing off somewhat on the coverage early on, but then raising PoP to 80-100% across southeast Georgia and the southern South Carolina zones by 5 or 6 AM. Further north, which generally includes the Charleston quad-county district and Allendale County we have 50-70% PoP.

Minimum temperatures tonight will be at their warmest in about 3 weeks.

Previous discussion . The early evening update required only minor changes, mainly to show completely overcast skies tonight and to adjust for latest trends. The biggest change was to include mention of fog, especially from Savannah south and southwest to the Altamaha River after 4 or 5 am. This is probably due more to low stratus rather than fog, but visibilities will nevertheless be down to 2-3 miles.

SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/. Friday: As a cold front lingers just south of the area on Friday, deep moisture will remain throughout the day. There will be plenty of shortwave energy embedded within the boundary that numerous to widespread showers are likely. PWATs will generally remain between 1.0-1.5 inches for much of the day. With instability low, thunderstorms are not expected at this time. Subsidence/dry air will be gradually pushing into the area from the north, depleting showers first across the Charleston Tri-county area by late afternoon. Then, for the rest of the evening, showers will gradually decrease north to south as high pressure pushes the deeper moisture offshore. Rainfall totals will not be overly impressive with 0.25-0.5 inches expected, with the greater amounts falling across SE GA. Temperatures could be tricky on Friday depending on the exact timing on the front as the 12Z GFS/NAM have the cold front moving through a bit quicker than previously. Though, should see high temperatures in the mid 50s inland and upper 50s to low 60s along the coast. Lows should be in the upper 30s to low 40s inland and mid 40s along the coast. There could be a larger temperature spread if clouds clear out sooner than expected Friday night, especially across the Charleston Tri-county area.

Saturday and Sunday: High pressure will prevail across the region on Saturday and Sunday. As a second cold front shifts across/just north of the area, any lingering moisture will dissipate and clouds will clear, leaving Saturday mostly sunny. A coastal trough looks to develop late Saturday/early Sunday and moisture will gradually increase. Though, have left the onshore forecast dry and added a sliver of slight chance POPs in the outer Georgia waters on Sunday morning. If showers do form, they should be light. High temperatures both days will be in the mid to upper 50s and low 60s mainly across SE GA. Lows on Saturday will be in the mid to upper 30s inland and low 40s along the coast.

LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/. Surface high pressure will be positioned over the Southern/Central Atlantic Ocean Monday and ridging will gradually decline over the area. Relatively zonal flow through a redeveloping jet streak over the Mid-Atlantic states through the period will cause showers to develop nearly daily due to continuous upper forcing mechanisms present. A cold front is forecast to approach the area Monday where showers will likely develop over the region Monday through Tuesday before dissipating by Tuesday night. Additional showers are expected as a secondary system is forecast to pass over the forecast area Wednesday afternoon into Thursday. Above normal temperatures are expected Monday and Tuesday as WAA ramps up ahead of the front. By Wednesday temperatures should return to near normal for the remainder of the period.

AVIATION /03Z FRIDAY THROUGH TUESDAY/. As a backdoor cold front drops into the area overnight, light rain will further develop, increasing in coverage as low level moisture will drastically increase.

The early wind shear has ended now that the 35-45 kt low level jet is pulling away.

Progressively deteriorating flight conditions will occur this evening through the overnight hours with IFR or even LIFR likely by late tonight into Friday. Poor conditions likely to persist through much of Friday with widespread light to moderate rain, IFR or LIFR ceilings, and visibility occasionally reduced to IFR.

Extended Aviation Outlook: Flight restrictions are expected through Friday evening due to numerous showers affecting the terminals. VFR will return for the weekend. Another storm system could bring flight restrictions to the terminals early next week.

MARINE. As the 35-45 kt low level jet moves over the northern South Carolina waters, there will still be frequent enough gusts at or greater than 25 kt to keep the Small Craft Advisory in effect for AMZ350 through 1 AM. Guidance still implies that at lest patchy fog will develop late tonight and last through at least Friday morning across AMZ352, AMZ354 and into or near the Port of Savannah. Visibility could get down to 1 or 2 nm, but locally dense fog is possible.

Previous discussion . Data from the radiosonde instrument released at KCHS this evening reveals winds of 35-45 kt in the lowest few thousand feet. While not all of this will mix down, it does indicate that we will achieve Small Craft Advisory conditions over the Charleston County Atlantic waters where the core of these winds pass over. We'll need to carefully monitor winds in Charleston Harbor, as they might need a short duration advisory as well.

Late tonight and into Friday morning, various guidance showing the potential for fog, mainly over the nearshore waters from Edisto Beach south to the Altamaha River and out about 20 nm. This includes at least parts of the region in or near the Port of Savannah. It initially looks to be due to low stratus, but as winds turn N-NE and light behind the front, it could become more of "pure" sea fog, especially on the Georgia waters. There is some concern for dense fog and greater coverage to the fog, and this will be re-evaluated in later updates.

Previous discussion . A low-level jet will pass over the northern SC waters this afternoon and evening, potentially producing some 25 kt gusts over outer portions of the Charleston waters. We have a Small Craft Advisory for this zone until 1 am. Wind speeds will diminish overnight as a front drops into the waters and a weak gradient results.

After the passage of the cold front on Friday, 10-15 kt WNW winds will prevail through Saturday. The pressure gradient will tighten on Saturday and winds will shift NE at 15-20 kt. For now, have kept winds below SCA criteria but could see occasional gusts to 25 kt. By Sunday, winds will subside to 10- 15 kt. Ahead of an approaching cold front on Monday/Tuesday, another surge in winds is expected and Small Craft Advisories could be needed mainly for winds but could see seas approach 6 ft.

CHS WATCHES/WARNINGS/ADVISORIES. GA . None. SC . None. MARINE . Small Craft Advisory until 1 AM EST Friday for AMZ350.



NEAR TERM . SHORT TERM . RAD LONG TERM . BRM AVIATION . MARINE .


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
CHTS1 11 mi82 min SW 6 G 8 59°F 53°F1012.3 hPa (-0.4)
FBIS1 - Folly Island, SC 17 mi82 min SW 7 G 8.9 56°F 1012.9 hPa (-0.0)
ACXS1 - ACE Basin Reserve, SC 42 mi97 min SW 2.9 61°F 1013 hPa56°F
NIWS1 - North Inlet-Winyah Bay Reserve, SC 45 mi97 min SW 6 56°F 1011 hPa49°F
41004 - EDISTO - 41 NM Southeast of Charleston, SC 49 mi62 min WSW 23 G 29 64°F 62°F1012.4 hPa56°F

Wind History for Charleston, SC
(wind in knots)    EDIT      (on/off)   Help
11
PM
12
AM
1
AM
2
AM
3
AM
4
AM
5
AM
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
Last
24hr
W3
W4
W4
G7
W4
SW3
SW5
SW5
SW5
SW5
SW5
W7
G10
W5
G10
SW3
G6
SW4
SW7
G10
SW7
G10
SW6
G9
SW7
G10
SW7
G12
SW4
G9
SW5
G8
SW4
SW6
SW4
G9
1 day
ago
SW5
SW7
G11
SW6
G9
SW6
G10
SW4
SW4
G7
SW4
G8
SW6
G9
W8
G12
W8
G13
W6
G11
W10
G16
W7
G12
W7
G13
NW8
G12
W8
G12
NW8
G14
NW5
G11
NW4
G11
W3
G6
W2
G5
SW4
W4
W3
2 days
ago
W4
G7
W5
W4
G7
W6
W4
G8
W2
W3
W1
G4
NW2
NW2
NW1
NE2
SE2
SE3
S7
S7
S9
S6
G11
SW7
G10
SW6
G9
SW4
G7
SW5
SW5
G8
SW6
G9

Airport Reports
    EDIT      (on/off)   Help   Click EDIT to display multiple airports. Follow links for more data.
AirportDistAgeWind ktVisibilitySky/WeatherTempDewPtHumidityPressure
Mount Pleasant Regional-Faison Field, SC3 mi27 minSW 6 G 1110.00 miOvercast59°F55°F88%1011.8 hPa
Charleston, Charleston Air Force Base, SC11 mi26 minWSW 710.00 miOvercast59°F53°F81%1012 hPa
Charleston Executive Airport, SC18 mi27 minSW 7 G 129.00 miOvercast61°F55°F83%1012.2 hPa
Moncks Corner Berkeley County, SC21 mi27 minN 07.00 miOvercast55°F55°F100%1012.2 hPa

Link to 5 minute data for KLRO

Wind History from LRO (wind in knots)
11
PM
-12
PM
1
AM
2
AM
3
AM
4
AM
5
AM
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
Last 24hr--------CalmCalmCalmCalmCalmCalmCalmCalmCalmSW3SW10SW11SW10SW9SW7SW8SW7SW8
G13
SW6SW6
1 day agoSW6S4
G10
SW7SW8CalmSW6SW7SW56
G11
CalmW7W9
G14
------------------------
2 days agoCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmCalmS8
G13
S8S9
G14
S8S6S5CalmS5S6

Tide / Current Tables for Cainhoy, Wando River, South Carolina
   EDIT   Weekend mode (on/off)   (on/off)   Help   One Week of Data
Cainhoy
Click for Map
Thu -- 12:59 AM EST     Moonset
Thu -- 02:33 AM EST     5.32 feet High Tide
Thu -- 07:20 AM EST     Sunrise
Thu -- 08:30 AM EST     0.96 feet Low Tide
Thu -- 12:21 PM EST     Moonrise
Thu -- 02:53 PM EST     4.86 feet High Tide
Thu -- 05:41 PM EST     Sunset
Thu -- 08:49 PM EST     0.51 feet Low Tide
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.

12
am
1
am
2
am
3
am
4
am
5
am
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
3.94.85.25.34.73.72.61.6111.62.53.44.24.74.94.53.72.61.50.80.511.9

Tide / Current Tables for Charleston Harbor Entrance, South Carolina Current
   EDIT      (on/off)   Help   One Week of Data
Charleston Harbor Entrance
Click for Map
Thu -- 12:59 AM EST     Moonset
Thu -- 02:06 AM EST     -0.00 knots Slack
Thu -- 05:33 AM EST     -1.49 knots Max Ebb
Thu -- 07:20 AM EST     Sunrise
Thu -- 08:46 AM EST     0.00 knots Slack
Thu -- 10:52 AM EST     1.10 knots Max Flood
Thu -- 12:21 PM EST     Moonrise
Thu -- 02:12 PM EST     -0.00 knots Slack
Thu -- 05:42 PM EST     Sunset
Thu -- 05:48 PM EST     -1.46 knots Max Ebb
Thu -- 08:58 PM EST     0.00 knots Slack
Thu -- 11:19 PM EST     1.29 knots Max Flood
Tide / Current data from XTide NOT FOR NAVIGATION
Sorry tide depth graphs only, please select another station.

12
am
1
am
2
am
3
am
4
am
5
am
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
0.90.60.1-0.6-1.1-1.4-1.5-1.1-0.50.20.91.10.80.50.1-0.5-1-1.4-1.5-1.2-0.600.81.3

Weather Map
       (on/off)   Help Weather Map
wmap_A
GEOS Local Image of    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.
Link to Loop

Other links: Northern Pacific     Contential US     Full GOES-East
Ground Weather Radar Station




Cookie Policy:
This website uses cookies to save your settings. No personal information is saved. I do not collect statistics on your visit. You can disable cookies in your browser if you like but it is not recommended for this site. I do not sell cookies. Go to a bakery for that. In fact I do not sell anything. To disable cookies from L-36.com, please refer to the Help button in your browser.
Privacy Policy:
I do not sell or share any user data or anything else for that matter. The only personal information I save is in the site log which has a line for each page view which includes the IP address your browser sends in the header as well as which page you requested. I use this to block hackers and other bad actors. I do not use this raw data to create profiles on users. I periodically delete the log files. Google supplies the ads on this site. Because I do not track who you are, I cannot customize how these ads are served. They may be personalized to improve the ad experience. If you do not want personalized ads, please adjust the settings on the Google site HERE. NOTE: The best I can determine, this site is not subject to CCPA but I am doing my best to comply anyway.
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 numerous 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.