Marine Weather and Tide Forecast for Irmo, SC

KEY MESSAGES
- 1. Areas of fog this morning and possible once again tonight.

- 2. Well above normal temperatures the remainder of the week with rain chances possible late in the week and this weekend.

DISCUSSION
KEY MESSAGE #1: Areas of fog this morning and possible once again tonight.

Fog has developed early this morning in portions of the area, although it has been patchy to this point. More widespread fog visible on satellite in the Coastal Plain with hi-res guidance indicating it will shift into the forecast area over the next several hours. Potential for fog to become dense with visibilities a quarter mile or less, especially in the southeastern forecast area but will continue to monitor for the need for a Dense Fog Advisory. Lingering low level moisture tonight will lead to the potential for additional fog, although there is a bit more uncertainty with a stronger low level jet developing which may favor more stratus versus fog.

KEY MESSAGE #2: Well above normal temperatures the remainder of the week with rain chances possible late in the week and this weekend.

Warming trend continues through the end of the week with strong upper ridging developing and surface high pressure offshore reinforcing an anomalously warm and moist air mass. Little change in the overall thinking with ensemble means continuing to favor 500mb heights between 1 to 2 standard deviations above normal through the end of the week and into the weekend leading to anomalous warmth persisting into early next week with relatively high confidence in temperature forecast based on the limited spread of blended model guidance. Pops will be limited through Saturday but there will be a slight chance beginning Friday and a bit higher Saturday, generally favoring diurnal showers with high moisture with ensemble probabilities greater than 80% of PWATs rising to above an inch. Ensemble means generally favor a bit of flattening of the ridging late weekend into early next week and while above average temperatures are expected to continue, this will lead to increasing chances for showers and possibly an isolated thunderstorm.

AVIATION /12Z WEDNESDAY THROUGH SUNDAY/
Visibility restrictions due to fog expected early this morning.

Satellite showing a good mixture of stratus and fog across the region. Fog is confined to more of the eastern and southern portions of the forecast area, while stratus is more across the upstate of SC/GA. Meanwhile the central Midlands around cae/cub is currently fog free with only some thin cirrus. Guidance does show the potential for ags/dnl to get squeezed with fog/stratus the next few hours prior to better mixing taking hold, and have leaned more in that direction there. Ogb is right on the edge of the fog deck, and expect that ifr visibilities will be encountered through 14z before mixing begins to improve conditions there. For cae/cub, guidance seems more bullish on keeping either vfr, or brief mvfr conditions through 14z or so.
All sites really have a good bit of uncertainty this morning, and this is a low confidence forecast due to this. Higher confidence late morning into the afternoon with vfr conditions at all sites. For tonight another round of fog/stratus with ifr/lifr conditions could occur, but not expected until after 08z. Winds will be light this morning, then increase out of the south around 5 knots with mixing. A return to light and variable to calm should occur after sunset.

EXTENDED AVIATION OUTLOOK...There is potential for additional morning stratus or fog into the latter half of the week along with increased shower chances for the weekend.

CAE WATCHES/WARNINGS/ADVISORIES
SC...None.
GA...None.