textproduct: Columbia

WHAT HAS CHANGED

Fog is developing in portions of the area but remains patchy. Additional fog development possible tonight. Aviation discussion updated for 06z TAFs.

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 hires 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 /06Z WEDNESDAY THROUGH SUNDAY/

Visibility restrictions due to fog expected early this morning.

Satellite showing a few areas of broken mvfr stratus forming across the central Midlands and upstate of SC due to weak upslope flow off the surface. This should mainly impact cae/cub with mvfr ceilings the next few hours, then skies should become more scattered. Meanwhile, ags/dnl/ogb will have mvfr impacts due to visibility restrictions becoming possible through 09z. After 09z, all sites forecast to have a higher probability of visibility restrictions due to the formation of fog. Highest probability appears to be across the CSRA and eastern Midlands, with visibilities there dropping below ifr at times through 13z. Central Midlands sites of cae/cub may be more on the edge of the fog bank according to some guidance, but still appears as if some impacts with brief ifr visibilities will be possible through sunrise. Trends will have to be watched at all sites overnight. Vfr conditions then expected to prevail after 14z at all locations. Winds mainly calm to light and variable through the period.

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.