Sunrise 6:17 AM   Sunset 8:15 PM Moonrise 2:54 PM   Moonset 2:35 AM

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AMZ330 Charleston Harbor- 316 Am Edt Sat May 18 2024
Today - S winds 10 to 15 kt. Showers likely with a chance of tstms this afternoon, mainly late morning and this afternoon.Tonight - SW winds 5 to 10 kt. A chance of showers and tstms. Sun - NW winds 5 to 10 kt. Showers likely with a chance of tstms. Sun night - NE winds 10 kt. A chance of showers and tstms, mainly in the evening. Mon - NE winds 10 to 15 kt. A slight chance of showers and tstms in the morning. Mon night - NE winds 10 kt. Tue - NE winds 10 kt. Tue night - E winds 5 to 10 kt. Wed - E winds 5 to 10 kt. Wed night - S winds 5 to 10 kt.
winds and waves higher in and near tstms.
unless otherwise noted, waves 1 foot or less.
charleston harbor water temperature 77 degrees.

AMZ300 316 Am Edt Sat May 18 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 180827 AFDCHS

Area Forecast Discussion National Weather Service Charleston SC 427 AM EDT Sat May 18 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 THIS MORNING/
Overnight composite analysis reveals a short-wave trough axis extending from Kansas down through central Texas with a couple of embedded circulations; one over Arkansas, a second in eastern Texas and possibly a third near the Louisiana/Mississippi coastal region. A corridor of stronger low-mid level flow/moist advection ahead of the trough in tandem with short-wave forcing has kicked off several clusters of thunderstorms overnight from the Louisiana Gulf Coast up through central/southern Alabama and about to expand into western Georgia while spottier shower activity stretches through central Georgia. Meanwhile, a secondary plume of low level moisture is in place across the central Gulf into northern Florida where convection has persisted overnight in the northern Florida Panhandle region.

Convective evolution and risk for strong/severe storms later this morning is the main forecast concern.

An overall convoluted and active pattern is emerging across the region. Short-wave trough will advance along the northern Gulf/Deep South region through today. With associated forcing and deep layer moisture transport, ongoing convection from the Louisiana Gulf Coast into Alabama is likely to continue expanding through Georgia this morning and into parts of southeast South Carolina late morning and into the afternoon, possibly congealing with another line of convection that may develop across the Florida Panhandle over the next several hours. Additional shower/thunderstorm development might also occur further north across northern Georgia into South Carolina in response to daytime heating and increased forcing for ascent. Upshot; we have increased precip chances across the forecast area with the highest chances and higher impact anticipated across southeast Georgia later this morning and into the afternoon hours.

Severe weather potential: Strongest convection and greater severe weather threat is likely to occur across southern Georgia and the Florida Panhandle region where the greatest instability will be located. A lower severe weather risk is anticipated further north, although strong mid level and respectable 0-6km shear values in excess of 40 knots into the afternoon will support storm organization and a risk for severe storms with the primary threat damaging winds and highest risk across southeast Georgia where better instability will be found. Heavy rainfall is also possible given PWAT values increasing to around 2 inches. Given the anticipated convection developing across the Florida Panhandle, the heaviest rainfall potential appears to be across southeast Georgia and a bit further south than previous forecast. Rainfall amounts have been adjusted accordingly.

Tonight: Upper level trough settles into the region. The bulk of showers/storms is looking to diminish and move off the Atlantic Coast later in the afternoon into this evening, but there may be some additional sub-severe convection that percolates through the region through the course of the night as the upper trough settles in.

SHORT TERM /6 AM THIS MORNING THROUGH MONDAY/
Sunday: A positively tilted mid-level trough will be over the Southeast U.S. in the morning. It'll slowly shift offshore into the evening and overnight. Meanwhile, a ridge will build in from the west. A cold front will be located just offshore in the morning, and moving away as time progresses. Surface troughing is expected to move over our region in the afternoon, then shift offshore into the overnight. Deep moisture will remain in place across the region with PWATs in the 1.5-2.0" range. These values are above the 90% mark per SPC sounding climatology for CHS. They're also about 2 standard deviations above normal per NAEFS. With all of the moisture and lift in place, models are in good agreement indicating scattered showers in the morning increasing to numerous or widespread showers by the afternoon. Temperatures should peak in the upper 70s or lower 80s, limited by the aforementioned showers. This will also limit instability. MLCAPE should peak around 1,500 J/kg, mainly across our GA counties. Lapse rates won't be that steep and 0-6 km bulk shear may only peak in the 15-25 kt range, which is not that strong. So while there should be some thunderstorms, the overall severe risk is low. Locally heavy rainfall will be a bigger concern given the high PWATs and slower storm motions. A relatively quick 0.5-1.0" is possible, so we can't rule out flooding in some areas. This could be exasperated if soils are saturated from Saturday's rainfall. Showers will decrease in coverage and intensity from west to east during the evening and overnight hours. Most locations should be dry by daybreak Sunday, except maybe the immediate coast. Lows should range from the upper 50s to the mid 60s.

Monday: The mid-levels will consist of a positively tilted trough just off the Southeast U.S. coast in the morning, and a ridge just to our west. The ridge will slowly build into our area as time progresses. At the surface, High pressure centered well to our north will build down the coast, with it's southern periphery making its way into our area. The High will bring drier conditions with skies becoming mostly sunny/clear. Low-level thickness values support temperatures in the middle 80s. But we went a little below this due to the northeasterly surface winds and the expectation that surface evaporation should limit temperatures. Highs should peak in the lower 80s. Lows should range from the upper 50s far inland to the mid 60s closer to the coast.

Tuesday: A positively tilted mid-level trough will be just off the Southeast U.S. coast in the morning, while a ridge will prevail over the Southeast U.S. High pressure centered just to our north in the morning will shift off the Mid-Atlantic Coast as the day progresses.
Though, it's southern periphery will continue to dominate our weather. Subsidence will yield dry conditions with mostly sunny skies. Temperatures should rise to near normal.

LONG TERM /MONDAY NIGHT THROUGH FRIDAY/
Mid-level ridging will be over our region through Wednesday, followed by southwest flow on Thursday. A weak trough may pass to our north on Friday. Broad surface High pressure will stretch from just to our north into the Atlantic Tuesday night into Wednesday.
It's expected to shift offshore later Thursday. A cold front could approach from the northwest later Friday, possibly bringing showers and thunderstorms. Temperatures will be trending higher, reaching into the 90s by Thursday.

AVIATION /06Z SATURDAY THROUGH WEDNESDAY/
KCHS/KJZI/SAV: Precip has largely exited the region for the moment.
There may be some isolated/scattered showers that move through the KCHS/KJZI terminals through early morning although overall chances are too low to include in the forecast. We are maintaining overall VFR conditions overnight, although some lower stratus development and reduced vsbys remain a possibility.

On Saturday: Increasing favorable chances for showers and some thunderstorms to roll through the region Saturday morning and into the afternoon hours, with the greater impact likely to occur at the KSAV terminal. We have a period of flight restrictions at all three terminals between roughly 14Z and 20Z with further timing refinements highly likely. Bulk of showers/thunder will exit the region Saturday evening.

Extended Aviation Outlook: A departing storm system could bring periodic flight restrictions on Sunday. VFR returns on Monday.

MARINE
A weak surface pressure pattern will maintain overall lighter winds (10 to 15 kt) and seas 2 to 4 ft across the coastal waters through tonight. That said, a period of showers and thunderstorms is anticipated later this morning and through the afternoon hours. Some strong storms will be possible which may produce locally strong winds and higher seas.

Extended Marine: Westerly flow early Sunday will turn to the NE and increase Sunday night. Wind gusts could briefly approach 25 kt late Sunday night into Monday morning, mainly over the Charleston County nearshore waters. But no Small Craft Advisories are anticipated. Winds should gradually ease later Monday. High pressure will continue to bring NE or E winds through Tuesday. Winds should then shift to the SE on Wednesday.
Seas will remain in the 2-4 ft range.

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

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Clouter Creek
Click for Map
Sat -- 03:35 AM EDT     Moonset
Sat -- 05:38 AM EDT     4.91 feet High Tide
Sat -- 06:18 AM EDT     Sunrise
Sat -- 11:43 AM EDT     0.73 feet Low Tide
Sat -- 03:53 PM EDT     Moonrise
Sat -- 06:21 PM EDT     5.26 feet High Tide
Sat -- 08:14 PM EDT     Sunset
Tide / Current data from XTide NOT FOR NAVIGATION

Clouter Creek, north entrance, Cooper River, South Carolina, Tide feet

Charleston Harbor Entrance
Click for Map
Sat -- 01:34 AM EDT     1.07 knots Max Flood
Sat -- 03:35 AM EDT     Moonset
Sat -- 05:04 AM EDT     -0.00 knots Slack
Sat -- 06:18 AM EDT     Sunrise
Sat -- 08:41 AM EDT     -1.63 knots Max Ebb
Sat -- 11:49 AM EDT     0.00 knots Slack
Sat -- 02:07 PM EDT     1.27 knots Max Flood
Sat -- 03:53 PM EDT     Moonrise
Sat -- 05:57 PM EDT     -0.00 knots Slack
Sat -- 08:13 PM EDT     Sunset
Sat -- 09:18 PM EDT     -1.86 knots Max Ebb
Tide / Current data from XTide NOT FOR NAVIGATION

Charleston Harbor Entrance, South Carolina Current, knots

Full Color Weather Map

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