Sunrise 6:21 AM   Sunset 8:19 PM Moonrise 4:49 PM   Moonset 3:30 AM

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AMZ354 Waters From Savannah Ga To Altamaha Sound Ga Out 20 Nm, Including Grays Reef National Marine Sanctuary- 601 Pm Edt Mon May 20 2024
Tonight - NE winds 15 kt. Seas 4 to 5 ft, subsiding to 3 to 4 ft after midnight. Wave detail: E 4 ft at 7 seconds. Tue - NE winds 10 to 15 kt with gusts to 20 kt. Seas 3 to 4 ft. Wave detail: E 4 ft at 7 seconds. Tue night - E winds 5 to 10 kt. Seas 2 to 3 ft. Wave detail: E 3 ft at 7 seconds. Wed - NE winds 5 to 10 kt. Seas 2 ft. Wave detail: E 2 ft at 7 seconds and se 1 foot at 10 seconds. Wed night - SE winds 5 to 10 kt. Seas 2 ft. Wave detail: E 2 ft at 7 seconds and se 1 foot at 10 seconds. Thu - S winds 5 to 10 kt. Seas 2 ft. Wave detail: E 2 ft at 8 seconds. Thu night - S winds 10 kt. Seas 2 to 3 ft. Fri - S winds 5 to 10 kt. Seas 2 ft. Fri night - S winds 10 kt. Seas 2 ft. Sat - SW winds 10 kt. Seas 2 ft. A slight chance of showers and tstms. Sat night - S winds 10 kt. Seas 2 to 3 ft. A slight chance of showers and tstms.
winds and seas higher in and near tstms.

AMZ300 601 Pm Edt Mon May 20 2024
Synopsis for the coastal waters of south coastal south carolina and north coastal georgia - High pressure will persist for most of this week. A series of upper level disturbances should impact our area this weekend.

FXUS62 KCHS 202251 AFDCHS

Area Forecast Discussion National Weather Service Charleston SC 651 PM EDT Mon May 20 2024

SYNOPSIS
High pressure will persist for most of this week. A series of upper level disturbances should impact our area this weekend.

NEAR TERM /UNTIL 6 AM TUESDAY MORNING/
Diurnally driven cumulus/stratocumulus will continue to diminish and eventually dissipate by around 9-10 pm, leaving us with generally clear skies the rest of the night. As winds go light or calm away form the coast, radiational cooling will allow for late night lows to get down to the the upper 50s and lower 60s inland from US-17, mid and upper 60s closer to the coast, and in downtown Charleston and downtown Savannah.

We already had mention of patchy fog well inland late, and with simulated satellite images and some of the guidance indicating it can happen (albeit not a very high probability), we maintained mention in the forecast. Mainly light fog is expected, but with the lowering subsidence inversion through the night, there could be enough moisture concentrated into the boundary layer for some patchy fog.

SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/
High pressure will prevail both at the surface and aloft through the middle portion of the week. With a weak subsidence inversion around 850 mb, PWat down near the 10-25 percentile, and the lack of any forcing mechanisms, it'll be a quiet weather pattern. We aren't going as warm as the low level thickness would on Tuesday and Wednesday given an onshore flow. We have lower-middle 80-s inland from the coast Tuesday, then add a few degrees for highs Wednesday. The synoptic flow turns to the south-southwest on Thursday, and that'll be the warmest day of the short term period. Highs will be more in line with the 1000-850 mb thickness; pushing 90F most places inland from US-17.

Excellent radiational cooling both Tuesday and Wednesday night, prompting us to go a bit below the consensus of guidance, especially in the typically cooler rural locations. Conditions could favor some fog Tuesday night and early Wednesday morning.
But given the time of year when it's difficult to get fog, we refrained from including it in the forecast at this time.

LONG TERM /THURSDAY NIGHT THROUGH MONDAY/
A cold front drops into the Southeast by Friday, although it never gets into the local region. Instead it lifts back north as a warm front over the weekend. We then lie near the western edge of Atlantic high pressure into early next week. Any forcing will occur from a series of short waves that traverse the area within a westerly flow aloft. Moisture is more plentiful during this time, so we do expect some convection to occur, most especially Saturday through Monday. We prefer not to show anything more than scattered activity this far out, which is in line with the NBM and GEFS guidance. Due to 850 mb temperatures as warm as 17-19C, which is near or above the 90th percentile, it appears that each day will be 90F or warmer away from the coast. Night time lows will also be quite a bit warmer with a noticeable increase in dew points.

AVIATION /00Z TUESDAY THROUGH SATURDAY/
KCHS/KJZI/KSAV: Mainly VFR prevails through 00Z Wednesday. For late tonight and early Tuesday, clear skies and light to calm winds will allow for efficient radiational cooling, and shallow/light fog could develop. The greatest chance is at KCHS.

Extended Aviation Outlook: Maybe a little ground fog late Tuesday night into early Wednesday, otherwise VFR will prevail.

MARINE
Ridging inland builds stronger over the waters this evening with troughing persisting well offshore. The gradient will continue to very slowly weaken, with breezy (15-25 kt) NE winds this evening trending more moderate (10-15 kt) by the early morning hours.

Seas remain elevated in mainly northerly windswell, but slowly diminish overnight as well. 3 to 5 ft seas prevail, with some 6 ft seas beyond 30 nm offshore/near the western wall of Gulf Stream this evening. Seas fall below 6 ft offshore late tonight, with to SCA for the offshore Georgia waters expiring accordingly. 2-4 ft seas prevail through the early morning hours, with some 5 ft seas beyond 30 nm.

Extended Marine: Tuesday and Tuesday night: High pressure centered to the north and northeast will extend across the immediate waters, resulting in NE and E winds as high as 10 or 15 kt during the day, and 10 kt or less at night. Seas that are 3-5 feet Tuesday drop about a foot or so Tuesday night.

Wednesday through Saturday night: High pressure remains the main feature during mid and late week, although a cold front does get a bit closer as it drops into the Southeast Friday. No significant marine concerns, even with some afternoon/evening enhancement from the sea breeze in Charleston Harbor and near the coast. However, there does appear to be at least some potential for t-storms late in the period.

Rip Currents: With the Full Moon is approaching, it won't take more than a small swell to lead to enhance of rip currents at the local beaches. Since there is some uncertainty regarding the amount of swell energy, we are showing a low risk of rip currents at areas beaches Tuesday and Wednesday, and an adjust later if necessary.

TIDES/COASTAL FLOODING
The combination of rising astronomical tides with the upcoming Full Moon and onshore winds will cause tides to be elevated through the middle of this week. Minor flooding is possible with the evening high tides again Tuesday and Wednesday along coastal Charleston and coastal Colleton. There are no concerns at this time along the remainder of our coast.

CHS WATCHES/WARNINGS/ADVISORIES
GA...None.
SC...Coastal Flood Advisory until 8 PM EDT this evening for SCZ049- 050.
MARINE...Small Craft Advisory until 11 PM EDT this evening for AMZ374.

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Florida Passage
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Mon -- 01:30 AM EDT     0.73 feet Low Tide
Mon -- 04:29 AM EDT     Moonset
Mon -- 06:24 AM EDT     Sunrise
Mon -- 07:06 AM EDT     6.64 feet High Tide
Mon -- 01:29 PM EDT     0.50 feet Low Tide
Mon -- 05:48 PM EDT     Moonrise
Mon -- 07:40 PM EDT     7.61 feet High Tide
Mon -- 08:18 PM EDT     Sunset
Tide / Current data from XTide NOT FOR NAVIGATION

Florida Passage, Ogeechee River, Georgia, Tide feet

Savannah River Entrance
Click for Map
Mon -- 01:39 AM EDT     0.00 knots Slack
Mon -- 04:07 AM EDT     1.70 knots Max Flood
Mon -- 04:28 AM EDT     Moonset
Mon -- 06:22 AM EDT     Sunrise
Mon -- 07:33 AM EDT     -0.00 knots Slack
Mon -- 10:28 AM EDT     -1.51 knots Max Ebb
Mon -- 01:33 PM EDT     0.00 knots Slack
Mon -- 04:16 PM EDT     1.93 knots Max Flood
Mon -- 05:47 PM EDT     Moonrise
Mon -- 08:00 PM EDT     -0.00 knots Slack
Mon -- 08:17 PM EDT     Sunset
Mon -- 11:35 PM EDT     -1.91 knots Max Ebb
Tide / Current data from XTide NOT FOR NAVIGATION

Savannah River Entrance, Georgia Current, knots

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