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. Privacy and Cookie policy

AMZ354 Waters From Savannah Ga To Altamaha Sound Ga Out 20 Nm, Including Grays Reef National Marine Sanctuary- 659 Pm Est Sat Dec 9 2023
.gale watch in effect from Sunday evening through late Sunday night...
Tonight..SE winds 10 kt, becoming S late. Seas 2 to 3 ft.
Sun..S winds 10 to 15 kt. Seas 2 to 3 ft, building to 3 to 4 ft in the afternoon. Showers likely with a chance of tstms in the afternoon.
Sun night..SW winds 25 to 30 kt with gusts to 35 kt, becoming nw after midnight. Seas 4 to 6 ft. Showers with a chance of tstms in the evening, then a chance of showers after midnight.
Mon..NW winds 15 to 20 kt with gusts to 25 kt, diminishing to 10 to 15 kt in the afternoon. Seas 3 to 4 ft, subsiding to 2 to 3 ft in the afternoon.
Mon night..N winds 10 to 15 kt. Seas 2 to 3 ft.
Tue..NE winds 15 to 20 kt. Seas 3 to 4 ft.
Tue night..NE winds 15 to 20 kt with gusts to 25 kt. Seas 4 ft.
Wed..NE winds 20 kt. Seas 4 to 5 ft.
Wed night..NE winds 20 to 25 kt. Seas 4 to 6 ft.
Thu..NE winds 20 to 25 kt. Seas 5 to 7 ft.
Thu night..NE winds 20 to 25 kt. Seas 5 to 7 ft. A slight chance of showers.
winds and seas higher in and near tstms.

AMZ300 659 Pm Est Sat Dec 9 2023
Synopsis for the coastal waters of south coastal south carolina and north coastal georgia.. A strong cold front will cross the area Sunday evening, followed by high pressure through late next week.

FXUS62 KCHS 100013 AFDCHS

Area Forecast Discussion National Weather Service Charleston SC 713 PM EST Sat Dec 9 2023

SYNOPSIS
A strong cold front will cross the area Sunday evening, followed by high pressure through late next week.

NEAR TERM /UNTIL 6 AM SUNDAY MORNING/
Early this evening: Overall, a quiet night is expected ahead of an approaching cold front. The forecast area will remain in the warm sector through the night, resulting in a very mild night.
In fact, lows are only expected to fall into the low 60s, which is only a couple of degrees below typical high temperatures for this time of year. There is good model consensus that land areas will remain dry tonight, with the best chance for noctural showers across the coastal waters and just off the Charleston County coast. It is possible that a few showers could brush or even move inland around McClellanville and Awendaw, but otherwise most places will remain dry.

SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/
Sunday: The forecast philosophy has not changed significantly from the previous forecast cycle. A sharp upper trough will dig across the lower Mississippi Valley Sunday then become negatively tilted as it pivots across the Southeast U.S. Sunday evening, helping to drive a strong cold front through the local area and into the coastal waters Sunday night. A corridor of intense upper forcing ahead of the upper trough comprised of strong DCVA, modest warm air advection and a well-defined window of 250 hPa difluence will support several large areas of widespread showers with isolated to scattered embedded tstms.
This activity is currently timed to reach far interior areas of Southeast Georgia by late morning, then spread across the remainder of Southeast South Carolina and Southeast Georgia through the afternoon before most of the activity exits off the coast during the mid-late evening hours. While the surface front should clear the coast roughly in the 11/01-04z timeframe, the anafrontal nature of the frontal surface suggests some degree of shower activity will likely linger for several hours after FROPA. However, expect a quick end to the rain and the onset of rapid clearing during the early morning Monday as high pressure and an expansive region of mid-level dry air begin to build into the area from the west. Categorical pops near 100% look on target for all areas into Sunday evening with rain chances ending from west-east as the night progresses. Highs will warm into the lower-mid 70s with temperatures with lows Monday morning dropping into the lower-mid 30s over far interior Southeast Georgia to the lower-mid 40s at the beaches.

The combination of widespread rain and extensive cloud cover will tend to limit net instability across the area ahead of the cold front. However, the lack of instability will likely be overcome by the intense, deep-layered forcing noted on model cross sections. This coupled with 0-6km bulk shear of 45-50 kt and some MLCAPE as high as 500 J/kg could support an isolated damaging wind event or two, or even an isolated, brief tornado in a classic high shear/low CAPE environment. There are some indications that pockets of higher instability could occur across parts of the Charleston Tri-County where widespread rains will arrive the latest. If this is realized, a slight uptick in the severe weather potential could occur, but it does appear that any meaningful higher risk for severe tstm development will likely occur up to the north into northeast South Carolina and eastern North Carolina.

Breezy to windy conditions will occur Sunday afternoon into Sunday evening the the period of highest winds likely occurring just prior to and after FROPA. Gusts 25-35 mph will be common late afternoon into mid-evening with a potential for gusts as high as 40 mph, especially along the lower South Carolina coast when the low-level jet is at its most intense prior to FROPA.
Wind gusts could be higher over the elevated bridges across the Charleston and Savannah Metro Areas as well as the exposed bridges heading out to the various barrier islands. These winds could pose a hazard to high- profile vehicles. A Lake Wind Advisory will be needed for Lake Moultrie, although winds speeds may be subdued somewhat in the warm sector by the poor mixing profiles due to chilly water temperatures in the upper 50s. The better potential for higher lake winds will hold off until cold air advection kicks in after FROPA. A short-fuse Wind Advisory may be needed as wind trends become more apparent, especially for the lower South Carolina coastal counties.

Monday and Tuesday: Quiet and cooler weather will prevail as high pressure dominates. Highs Monday will only warm into the lower-mid 50s then warm into the mid-upper 50s for Tuesday. Lows Tuesday morning will drop to around 30 for areas adjacent to the CSRA and Southern Midlands to the mid 40s at the beaches.

LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/
Mainly quiet conditions will prevail through much of next week with high pressure centered to the north. A subtle coastal trough could develop off the coast by mid-week, but any associated shower activity should remain offshore. Rain chances could start to increase by Friday as a storm system begins to organize over the Gulf of Mexico. Details of this system and how it could impact Southeast South Carolina and Southeast Georgia are highly uncertain this far out.

AVIATION /00Z SUNDAY THROUGH THURSDAY/
KCHS and KJZI: Through the overnight, the main concern will be the potential for IFR ceilings to develop and impact the terminals for short periods of time. Satellite imagery and the KJZI observation actually showed that a small patch of IFR ceilings developed just before 00z, but this has since moved inland. Model guidance favors KCHS for the best chance of brief IFR ceilings, so we have introduced a TEMPO group there.
Attention then turns to strengthening winds and increasing shower and thunderstorm coverage on Sunday. Winds will pick up by mid morning, and gusts will increase right on through the end of the 00z TAF period. Frequent gusts up to and just over 25 knots can be expected in the afternoon and evening. The morning should mostly be dry, with increasing showers in the afternoon and then the potential for thunderstorms in the late afternoon and early evening. Since thunderstorms are most likely near the end of the TAF period, we did not explicitly include thunder, but it is certainly something to keep an eye on.

KSAV: There continues to be a chance for low stratus development in the early morning hours, but confidence isn't particularly high. For now, we have kept the forecast VFR but amendments could be needed if IFR ceilings develop near the terminal. Attention then turns to strengthening winds and increasing shower and thunderstorm coverage on Sunday. Winds will pick up by mid morning, and gusts will increase right on through the end of the 00z TAF period. Frequent gusts up to 25 knots can be expected in the afternoon and evening. The morning should mostly be dry, with increasing showers in the early afternoon and then the potential for thunderstorms in the mid to late afternoon. Since thunderstorms are most likely in the latter part of the TAF period, we did not explicitly include thunder, but it is certainly something to keep an eye on.

Extended Aviation Outlook: Widespread rain with vsby and cig restrictions will occur through Sunday evening with conditions improving early Monday. Gusty winds and possible low-level shear are possible at all three terminals. Tstm probabilities are still fairly low, although rumbles can not be ruled out. VFR will prevail Monday through much of next week.

MARINE
Tonight: Tonight, wind are expected to increase to 10-15 kts, with gusts around 20 kts across portions of AMZ350 and 374 late tonight/early Sunday morning. As dew points surge into the 60s tonight and PWATs increase to around 1.4 inches scattered to numerous showers and possibly a thunderstorm are expected over the marine waters.

Sunday through Thursday: Southerly winds will begin to ramp up Sunday ahead of an approaching cold front. Winds in the warm air advection regime atop the chilly shelf waters will tend to temper speeds a bit, but frequent gusts to 25 kt appear likely over the South Santee-Edisto Beach nearshore and Georgia offshore legs by afternoon. Similar conditions are expected in Charleston Harbor where land heating influences will be greater.
A Small Craft Advisory has been posted for these areas.
Widespread will move across the marine area Sunday afternoon/evening, ending from west- east early Monday. A few heavier tstms could produce convective wind gusts in excess of 35 kt or even an isolated waterspout. A few Special Marine Warnings may be need. Offshore winds will increase quickly after the passage of the cold front with the risk for gales increasing in the post-frontal cold air advection regime.
Frequent gusts to 35 kt appears likely for all legs out of the Charleston Harbor from roughly Sunday evening through early Monday. Gale Watches have been posted for all legs to account for this, excluding Charleston Harbor (although it may be close). Gale Warnings will likely be issued with the early Sunday morning update. Seas will peak 4-7 ft nearshore waters with 5-9 ft over the Georgia offshore leg and the outer portion of the South Santee-Edisto Beach nearshore waters. The next chance for Small Craft Advisory conditions could come as early as Wednesday as both winds and seas build in response to a tightening pressure gradient with the development of a coastal trough offshore.

EQUIPMENT
KCLX remains operational, but level 2 data is not being distributed to external users due to an internal hardware failure. We are still awaiting the arrival of new parts to resolve this problem. Until then, level 2 data will not be available. Radar data is available for all connected AWIPS users. Level 3 data is also available for some external users.

CHS WATCHES/WARNINGS/ADVISORIES
GA...None.
SC...None.
MARINE...Small Craft Advisory from noon Sunday to 6 AM EST Monday for AMZ330.
Small Craft Advisory from noon to 6 PM EST Sunday for AMZ350- 374.
Gale Watch from Sunday evening through late Sunday night for AMZ350-352-354.
Gale Watch from Sunday evening through late Sunday night for AMZ374.

toggle option: (graph/table)

Coffee Bluff
Click for Map
Sat -- 03:48 AM EST     Moonrise
Sat -- 06:02 AM EST     7.49 feet High Tide
Sat -- 07:13 AM EST     Sunrise
Sat -- 12:03 PM EST     1.00 feet Low Tide
Sat -- 02:53 PM EST     Moonset
Sat -- 05:20 PM EST     Sunset
Sat -- 06:13 PM EST     6.94 feet High Tide
Tide / Current data from XTide NOT FOR NAVIGATION

Coffee Bluff, Forest River, Georgia, Tide feet

Savannah River Entrance
Click for Map
Sat -- 02:11 AM EST     1.95 knots Max Flood
Sat -- 03:47 AM EST     Moonrise
Sat -- 05:53 AM EST     -0.00 knots Slack
Sat -- 07:12 AM EST     Sunrise
Sat -- 09:13 AM EST     -1.83 knots Max Ebb
Sat -- 12:20 PM EST     0.00 knots Slack
Sat -- 02:47 PM EST     1.77 knots Max Flood
Sat -- 02:52 PM EST     Moonset
Sat -- 05:19 PM EST     Sunset
Sat -- 06:11 PM EST     -0.00 knots Slack
Sat -- 08:51 PM EST     -1.62 knots Max Ebb
Tide / Current data from XTide NOT FOR NAVIGATION

Savannah River Entrance, Georgia Current, knots

Full Color Weather Map

Link to Loop


Other links: GEOS-West     Contential US     Full GOES-East

Charleston, SC,