Charleston Harbor Marine Forecast
| This Afternoon...Se Winds 10 Kt. A Chance Of Showers. |
| Tonight...S Winds 10 To 15 Kt, Increasing To 15 To 20 Kt After Midnight. Waves 1 To 2 Ft. A Chance Of Showers. |
| Sun...Sw Winds 20 To 25 Kt With Gusts To 40 Kt. Waves 2 To 3 Ft. A Slight Chance Of Tstms. Showers. |
| Sun Night...Nw Winds 15 Kt With Gusts To 30 Kt. |
| Mon...N Winds 5 To 10 Kt. |
| Mon Night...N Winds 5 Kt. |
| Tue...Ne Winds 5 To 10 Kt. |
| Tue Night...E Winds 10 Kt. A Slight Chance Of Showers. |
| Wed...E Winds 10 To 15 Kt. Showers. |
| Wed Night...N Winds 10 To 15 Kt. Showers Likely. Winds And Waves Higher In And Near Tstms. Unless Otherwise Noted, Waves 1 Foot Or Less. Charleston Harbor Water Temperature 55 Degrees. |
|
Area Forecast Discussion National Weather Service Charleston SC 428pm EST Sat Feb 15 2025 Synopsis A strong cold front will impact the area Sunday, followed by high pressure for Monday and Tuesday. A low pressure system will move across the region during the middle of next week. High pressure will then return late next week. Near Term - Until 6am Sunday Morning This Afternoon: Latest surface analysis shows the coastal trough well inland with temperatures warming into the 70s across the region. The isentropic upglide has also continued to ramp up this afternoon with shower coverage rapidly expanding near the Savannah river and north. These weak showers and upglide will persist through the afternoon with temperatures holding near 70 degrees. Tonight: A potent mid-level wave will approach the area from the west tonight with the WAA (Warm Air Advection - the movement of warm air) wing/ isentropic upglide translating east. This means that the showers from this afternoon will also advect northeast. However, another weak pocket of PVA in the southwest flow is already causing further development over northern FL, and this will likely translate across GA through the evening hours. After midnight, the precipitation will come to an end for most of the region with southerly winds increasing. Short Term - 6am Sunday Morning Through Tuesday Sunday: A potent upper level wave will advect east Sunday morning with a seasonably strong 250 mb jet streak approaching the area (140 - 150 kt). At 500 mb, the mid-level wave will be over the southern Ohio River Valley around sunrise with 200 m height falls approaching. The wave will then begin to take on a negative tilt as it ejects northeast with the core of the DCVA and height falls moving along the spine of the Appalachians. Across SC/ GA 80/100 m height falls will still move east over the region. At 850/ 925 mb, the PGF is forecast to tighten through the morning period with the LLJ peaking at 50 to 60 kt overhead. At the surface, a cold front and associated line of showers (with a rumble of thunder possible) will be approaching the western zones between 6 and 8 am. Timing-- Severe Weather Line: * I-95 between 9 - 11am * The GA/ SC coast between 11am - 1 PM. Sunday Severe Threat: The main concern for Sunday will be the chance for severe weather/ strong to locally damaging wind gusts. Cloud bearing shear values are around 50 kt along the line, however instability is extremely limited (only around 100 J/kg of MU CAPE). As mentioned above though, 50 - 60 kt of wind is forecast to be in the 925/850 mb layer and with any downward momentum transfer, locally damaging wind gusts will be possible. The greatest instability, is towards southern GA and therefore Storm Prediction Center has introduced a slight risk for severe weather across GA, and continued a marginal risk for SC. Wind Threat: A wind advisory is also in effect for all zones from 5am through 6pm Sunday. Ahead of the cold front, winds will start to approach wind advisory criteria and remain gusty after the line passes and a cold front sweeps across the region. Latest forecast soundings show wind gusts behind the cold front around 30 kt (via momentum transfer techniques), or just shy of wind advisory criteria. Given the strong Cold Air Advection though, have opted to keep the wind advisory until 6pm Sunday. Monday and Tuesday: Surface high pressure will build over the region for Monday and Tuesday. Quiet and dry weather is expected. There will be plenty of sunshine, although cloud cover will be on the increase during the latter half of the day Tuesday. Seasonally cool temperatures mainly in the mid 50s on Monday will moderate closer to normal for Tuesday. Lows Monday night will range from the low 30s inland to upper 30s/around 40 closer to the coast. Long Term - Tuesday Night Through Saturday Focus for the extended period will be on mid-week as the next weather system impacts the region. Surface low pressure is expected to develop over the northern Gulf and then lift northeast, passing near/along the Southeast coast Wednesday into Wednesday night. Ample forcing for ascent along with PWATs (Precipitable Waters) rising to well over an inch will result in a fairly wet day with widespread showers currently forecast. This system has the potential to bring 1-2 inches of rain to the area. Instability progs are pretty meager, so no thunder is mentioned in the forecast at this time. Rain chances should decrease Wednesday night. The aforementioned low will lift away from the area on Thursday, allowing chilly and dry high pressure to build for late week. Temperatures will be notably cooler, with lows dipping well into the 20s. Will need to monitor the potential for a Cold Weather Advisory (wind chill 20F or colder) Thursday night. Marine This afternoon: The coastal trough has moved onshore, with seas generally 3 to 5 ft. Showers will also continue to expand in coverage this afternoon and translate to our northeastern zones with the best isentropic upglide. Tonight: Winds and seas will start to increase as the PGF rapidly begins to tighten with 850/925 mb winds approaching 40 kt. At the surface, expect wind gusts up to 30 kt with seas building 5 to 7 ft. Sunday: A cold front will be approaching the waters from the west and sweep across the marine zones in the early afternoon. Out ahead of the cold front, the core of the 60 kt jet will be just off the SC coast. Some high res guidance is indicating the possibility of storm force gusts, but given the temperatures of the shelf waters have opted for a Gale Warning with gusts peaking at 45 kt. Seas will also be dangerous Sunday and peak 8 to 12 ft. A high surf advisory was considered, but we opted to hold for now given the coastline parallel wave energy. However this might need to be re-evaluated. Monday through Thursday: Marine conditions will subside on Monday as high pressure expands across the area and the pressure gradient relaxes. Winds will turn northerly and eventually more northeasterly with no concerns through Tuesday. A low pressure system is expected to impact the region Wednesday into Wednesday night which will bring the next chance for Small Craft Advisories. Winds could stay elevated on Thursday behind the system as high pressure builds into the area. NOAA Charleston SC Office: Watches - Warnings - Advisories GA...Wind Advisory from 5am to 6pm EST Sunday for GAZ087-088- 099>101-114>119-137>141. SC...Wind Advisory from 5am to 6pm EST Sunday for SCZ040-042>045- 047>052. Marine Small Craft Advisory from 11pm this evening to 7am EST Sunday for AMZ330. Gale Warning from 7am to 3pm EST Sunday for AMZ330. Small Craft Advisory from 7pm this evening to 7am EST Sunday for AMZ350-352-354. Gale Warning from 7am to 6pm EST Sunday for AMZ350-352-354- 374. Small Craft Advisory until 7am EST Sunday for AMZ374. |
Charleston SC Radar
Southeast Radar