Charleston Harbor Marine Forecast
|Tonight...S Winds 5 To 10 Kt, Becoming Sw 5 Kt. A Chance Of Showers And Tstms, Mainly This Evening.|
|Mon...Sw Winds 5 To 10 Kt, Becoming S 10 To 15 Kt With Gusts To 20 Kt In The Afternoon. A Chance Of Showers And Tstms.|
|Mon Night...Sw Winds 10 To 15 Kt With Gusts To 20 Kt, Diminishing To 5 To 10 Kt After Midnight. Showers And Tstms Likely, Mainly In The Evening.|
|Tue...Se Winds 5 To 10 Kt. A Slight Chance Of Showers And Tstms In The Morning, Then A Chance Of Showers And Tstms In The Afternoon.|
|Tue Night...Se Winds 10 Kt With Gusts To 20 Kt. A Chance Of Showers And Tstms, Mainly In The Evening.|
|Wed...Se Winds 5 To 10 Kt. A Slight Chance Of Showers And Tstms.|
|Wed Night...S Winds 10 Kt. A Slight Chance Of Showers And Tstms In The Evening.|
|Thu...S Winds 10 To 15 Kt. A Chance Of Showers With A Slight Chance Of Tstms.|
|Thu Night...S Winds 10 To 15 Kt. A Chance Of Showers With A Slight Chance Of Tstms.|
|Fri...Sw Winds 10 To 15 Kt. A Chance Of Showers With A Slight Chance Of Tstms.|
|Fri Night...Sw Winds 5 To 10 Kt. A Chance Of Showers With A Slight Chance Of Tstms. Winds And Waves Higher In And Near Tstms. Unless Otherwise Noted, Waves 1 Foot Or Less. Charleston Harbor Water Temperature 79 Degrees.|
| Area Forecast Discussion|
National Weather Service Charleston SC
934pm EDT Sunday May 22 2022
Warm and humid conditions in place, along with a few weather systems moving through, will maintain unsettled weather across the area through much of the week. Drier conditions could return next weekend behind a cold front.
Near Term - Until 6am Monday Morning
Today was yet another reminder that summer is essentially here with several pulse severe tstms occurring and locally heavy rainfall with minor flooding being observed in a few spots. Between the convective system that pushed through this morning and the numerous convective clusters that fired this afternoon and evening, some solid rains have finally fallen in areas that desperately needed it.
Convection is slowly waning across the area this evening as instability diminishes and the deepest updrafts shift off the Georgia and far southern South Carolina coasts. Pockets of heavy rainfall will linger along the Georgia coast for the next hour or so, but the risk for flooding and severe weather is quickly ending. Late evening probability of precipitation were adjusted to shift the axis of heaviest rains offshore with a slight increase in probability of precipitation across the Charleston Tri-County where approaching shower activity could drop a few hundredths. Convection continues to fire across far Southeast Georgia south of the Altamaha, but that region is still somewhat unstable. North of the Altamaha, the atmosphere is sufficiently overturned with deep convection unlikely to regenerate as the night progresses.
Lows from the upper 60s inland to the mid 70s along the coast still look on track.
Short Term - 6am Monday Morning Through Wednesday
Pattern Synopsis/Forecast: Low amplitude short-wave trough progressing through the northern Great Lakes today, will exit into the north Atlantic tonight, while another piece of strong Pacific energy digs into the central CONUS and closes off by midweek. Larger scale ridging, warm and somewhat humid conditions will remain in place across the SE CONUS and Gulf Coast region, although there will be a weakening boundary attempting to sag down into the Carolinas into Monday, which is looking to stall out before getting this far south.
Meanwhile, some semblance of a disorganized tropical low is over the central Gulf region, pinwheeling bouts of tropical moisture, showers and thunderstorms across the Gulf Coast region and into our area. That feature will be a player for our weather for the next couple of days.
Details: A period of active weather will persist across the forecast area for the first part of the week, although with a good amount of uncertainty in regard to timing/placement of precipitation chances. As mentioned, stalling boundary is looking to lay out W-E across North Carolina on Monday, never getting this far southward. However, one or more surges of tropical moisture, associated with the loosely organized low in the Gulf, will be spreading north-northeastward up through Georgia and the Carolinas Monday into Monday night. With daytime heating and influences from the loosely organized wave in the Gulf (possibly another small tropical MCV pressing N/NE up through Georgia and the Carolinas), shower and thunderstorm chances should increase across the region later in the morning and through the afternoon/evening timeframe. Again, exact timing and placement carries a lot of uncertainty. But I feel that at least likely probability of precipitation are warranted at this juncture for most of the forecast area.
Like the last few days, an organized widespread severe weather threat appears low. But a few strong, possibly severe storms are likely, producing hail and strong winds. Heavy rainfall/localized flooding is also possible and we are in a marginal excessive rainfall risk for Monday.
It may quiet down some for Tuesday and Wednesday, at least in terms of convection coverage, as the tropical feature in the Gulf becomes absorbed by increasing larger scale flow. But, given the persistent warm/moist airmass, shower and thunderstorm chances will continue right through midweek.
Long Term - Wednesday Night Through Sunday
A cold front will be situated to the west of the region on Thursday. Then on Friday, the cold front will move through the area before stalling offshore overnight. High pressure will then build into the region on Saturday and Sunday. In regards to rain chances, decent moisture and isentropic lift will be in place so expect isolated to scattered showers/thunderstorms on Thursday and Friday. As the front stalls offshore, there could be enough lingering moisture/forcing to support isolated showers on Saturday and Sunday. High temperatures will be in the 80s to low 90s with lows in the 60s to 70s.
Overnight: Southerly winds will prevail through night with speeds generally less than 15 kt outside of convection. An outflow boundary moving off the Savannah River Entrance is bringing winds around the northwest in its wake. This boundary will gradually mix out and winds will eventually turn more southerly as the night progresses. Seas will average 2-3 ft.
Monday through Friday: Conditions will remain below Small Craft Advisory levels through midweek, although locally higher winds and waves will occur with any storms. A bit stronger southeasterly winds and higher seas develop through the coastal waters late in the week as a strong cold front approaches from the west. However, at this juncture, winds and seas are still expected to remain below headline criteria.
NOAA Charleston SC Office: Watches - Warnings - Advisories