Sunrise 6:25 AM   Sunset 8:21 PM Moonrise 2:07 PM   Moonset 2:19 AM

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AMZ354 Waters From Savannah Ga To Altamaha Sound Ga Out 20 Nm, Including Grays Reef National Marine Sanctuary- 624 Pm Edt Fri May 17 2024
Tonight - SE winds 5 to 10 kt, becoming S 10 to 15 kt with gusts to 20 kt late this evening. Seas 2 ft. Wave detail: S 2 ft at 4 seconds and se 1 foot at 8 seconds. Showers likely with a chance of tstms late this evening. A slight chance of showers and tstms late. Sat - SW winds 10 to 15 kt. Seas 2 ft. Wave detail: S 2 ft at 4 seconds and E 1 foot at 9 seconds. A chance of showers and tstms in the morning, then showers and tstms likely in the afternoon. Sat night - SW winds 10 kt. Seas 2 ft. Wave detail: S 2 ft at 4 seconds and E 1 foot at 9 seconds. Showers with tstms likely in the evening, then showers likely with a chance of tstms after midnight. Sun - W winds 10 kt. Seas 2 to 3 ft. Wave detail: sw 2 ft at 5 seconds and E 1 foot at 8 seconds. A chance of tstms. A chance of showers in the morning, then showers likely in the afternoon. Sun night - NW winds 10 kt, becoming N after midnight. Seas 2 to 3 ft. Wave detail: S 2 ft at 5 seconds and E 2 ft at 8 seconds. A chance of tstms. Showers likely, mainly in the evening. Mon - NE winds 10 to 15 kt. Seas 3 to 4 ft. Wave detail: ne 3 ft at 5 seconds and S 2 ft at 4 seconds. A chance of tstms in the morning. A slight chance of showers. Mon night - NE winds 10 to 15 kt. Seas 2 to 3 ft.Tue - NE winds 10 kt. Seas 2 to 3 ft. Tue night - E winds 5 to 10 kt. Seas 2 to 3 ft. Wed - E winds 5 to 10 kt. Seas 2 to 3 ft. Wed night - S winds 10 kt. Seas 2 ft.
winds and seas higher in and near tstms.

AMZ300 624 Pm Edt Fri May 17 2024
Synopsis for the coastal waters of south coastal south carolina and north coastal georgia - A storm system will bring impacts to our area this weekend. High pressure returns to our region next week.

FXUS62 KCHS 172241 AFDCHS

Area Forecast Discussion National Weather Service Charleston SC 641 PM EDT Fri May 17 2024

SYNOPSIS
A storm system will bring impacts to our area this weekend.
High pressure returns to our region next week.

NEAR TERM /UNTIL 6 AM SATURDAY MORNING/
Poor lapse rates, a Normalized CAPE less than 1 unit, and limited MLCAPE have kept convection in check, with mainly just isolated to scattered showers. The closest t-storms as of early evening are in southwest Georgia. As the evening progresses, mid level lapse rates get a little better, MLCAPE increases to as much as 500-1000 J/kg, and with deep shear of 40-50 kt, there will be an increase in convection. Recent HRRR guidance does show some potential fro strong or severe t-storms over Long and McIntosh County during the mid and late evening. But the Warn on Forecast (WoF) keeps the better chances to the south of the Altamaha River. Due to Supercell Composite values as high as 2-4, we'll maintain mention of isolated severe storms with maybe a tornado in the Hazardous Weather Outlook for Long and McIntosh County.

There are indications that additional activity could attempt to move in from the west and southwest closer to daybreak. But this scenario will be re-evaluated with the next update.

Depending upon how much rain occurs, there could be some stratus developing and building down late, as per the LAMP and to some extent the HRRR. Even so, geostrophic winds look a little too high for any serious fog concerns.

Low temperatures will be well above normal given the elevated dew points and extensive cloud cover.

SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/
Much of this period is expected to be the most active for the entire forecast period through the next work week. Models show an upper level trough over the lower MS River Valley early Saturday, moving eastward toward the forecast area through Sunday. Conditions look the most favorable for showers/thunderstorms later Saturday afternoon through Sunday. Peak values of CAPE and bulk shear will be later Saturday afternoon and Saturday evening, which is the main time frame that the SPC has our entire region in a SLT Risk for severe storms. Have kept high likely/low end categorical PoPs for much of the area on Saturday and Saturday evening, chance Saturday night, and then likely again Sunday. The threat for any severe storms looks too low to mention for Sunday due to a significant decrease in CAPE, despite the passage of a surface cold front and the presence of the upper level trough. By later Sunday night and Monday, the upper trough axis will move offshore, allowing a cold front to push south of the area. High pressure builds in from the northwest Sunday night and Monday, which will bring slightly cooler and drier conditions.

Temperatures above normal Saturday, near normal Sunday and possibly a tad below normal behind the cold front on Monday.

Heavy Rainfall Potential: Blended models solutions continue to point toward later Saturday afternoon and evening for the most likely window for locally heavy rainfall. The area with the highest chance for heavy rainfall appears to be our coastal counties, especially from the Charleston Tri-county region, southward to the Savannah River. However, there continues to be uncertainty in the exact placement of the heavy rainfall, since localized boundaries produced by convection/thunderstorms will likely dictate where the heaviest rainfall occurs. Thunderstorm induced boundaries could collide with a weak seabreeze close to the coast Saturday afternoon, which is why we are leaning toward higher chances for the heaviest rainfall to be over our coastal counties.

LONG TERM /MONDAY NIGHT THROUGH FRIDAY/
This period looks to be much quieter, with little/no chances for any significant rainfall and temperatures above normal. Another cold front may impact the area later Thursday and Friday with at least slight chances for showers/thunderstorms. However, the timing of this front and whether or not there will be sufficient deep layer moisture to support precipitation remains uncertain. Temperatures expected to be above normal during this period, especially by Thursday and Friday as a deep layer ridge builds to the south- southwest of the area, keeping our region under low level west- southwest flow.

AVIATION /23Z SATURDAY THROUGH WEDNESDAY/
Prior to the 18Z TAFs, KCLX detected scattered showers streaming across SE GA, with showers passing over and near KSAV.
Showers and thunderstorms should gradually increase across SE GA through mid-evening. The KSAV TAF will feature a TEMPO between 0-3Z for VRB10G15kt during TSRA. KCHS and KJZI may see passing showers this evening into the late night hours. MOS and forecast soundings indicate that MVFR ceilings are expected to develop over the terminals late tonight remaining into mid Saturday morning. Conditions are expected to become VFR by 14Z Saturday.

Extended Aviation Outlook: Saturday through Sunday: Periods of showers and thunderstorms are expected with brief flight restrictions possible, especially later Saturday afternoon and evening. Isolated to scattered strong to severe storms will be possible Saturday afternoon and evening.

Sunday night through Wednesday: VFR expected to prevail.

MARINE
The surface pattern will support south winds between 10 to 15 kts, with gusts around 20 kts 15 nm and beyond. Wave heights are forecast to gradually build to 2-3 ft by late tonight. A cluster of strong thunderstorms may push off the Georgia coast late this evening. It is possible that a Special Marine Warning or Marine Weather Statement could be issued later tonight.

No highlights are expected through the period. The waters will remain under the influence of a ridge of high pressure well to the southeast and lower pressure well inland, to the northwest. This will keep southwest winds of 15 knots or less and seas generally 2 to 4 feet through Sunday. A cold front is expected to push through the waters during the day on Sunday. Behind this front, winds will veer to north-northwest and increase to 15 to 20 knots. Seas building to 3 to 5 feet. The increased winds/seas are not expected to persist long. They should begin to subside a bit by later Monday as winds become more northeast at 15 knots or less, with seas 2 to 4 feet Monday night through Wednesday.

CHS WATCHES/WARNINGS/ADVISORIES
GA...None.
SC...None.
MARINE...None.

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Purrysburg Landing
Click for Map
Fri -- 01:38 AM EDT     0.61 feet Low Tide
Fri -- 03:16 AM EDT     Moonset
Fri -- 06:18 AM EDT     2.83 feet High Tide
Fri -- 06:24 AM EDT     Sunrise
Fri -- 02:04 PM EDT     0.47 feet Low Tide
Fri -- 03:04 PM EDT     Moonrise
Fri -- 07:01 PM EDT     2.83 feet High Tide
Fri -- 08:17 PM EDT     Sunset
Tide / Current data from XTide NOT FOR NAVIGATION

Purrysburg Landing, Savannah River, South Carolina, Tide feet

S.C.L. RR. bridge
Click for Map
Fri -- 01:09 AM EDT     1.23 feet Low Tide
Fri -- 03:16 AM EDT     Moonset
Fri -- 05:54 AM EDT     5.88 feet High Tide
Fri -- 06:25 AM EDT     Sunrise
Fri -- 01:35 PM EDT     0.95 feet Low Tide
Fri -- 03:04 PM EDT     Moonrise
Fri -- 06:37 PM EDT     5.88 feet High Tide
Fri -- 08:17 PM EDT     Sunset
Tide / Current data from XTide NOT FOR NAVIGATION

S.C.L. RR. bridge, Savannah River, Georgia, Tide feet

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