textproduct: Columbia

WHAT HAS CHANGED

Aviation discussion updated for 12Z TAF issuance.

KEY MESSAGES

- 1. Above normal temperatures with increasing chances for showers and storms late week into the weekend.

DISCUSSION

KEY MESSAGE 1: Above normal temperatures with increasing chances for showers and storms late week into the weekend.

Little has changed to the forecast through early next week. Global ensembles continue to favor ridging to our east through the weekend with a stronger ridge developing over the Southeast for next week. This pattern will support southerly flow through the weekend and deep moisture over the Southeast with PWAT values near or above 2 inches. This setup tends to give the forecast area scattered, diurnal thunderstorms. Convective coverage may be a little higher on Saturday with some potential shortwave energy set to ride up over the ridge into the southern Appalachians. Widespread severe weather is generally not expected but the biggest threats being isolated downburst winds and locally heavy rain. Height rises early next week should work to suppress convective coverage with just isolated to widely scattered thunderstorms each afternoon next week. Temperatures will be about 3 to 8 degrees above normal for much of the forecast period, but still cooler than the first week of September.

AVIATION /10Z THURSDAY THROUGH MONDAY/

Brief restrictions possible through 14Z.

The primary concern through the next few hours will be low clouds and patchy fog developing at all terminals. Guidance has backed off on potential impacts, especially regarding conditions at CAE/CUB/AIK but brief MVFR/IFR ceilings around daybreak are still possible. Any low stratus or fog should dissipate and transition to SCT cumulus by midday as southerly winds increase to around 5 knots. Diurnal convection chances return later today, but confidence remains too low for inclusion at the terminals except at OGB where a PROB30 was maintained. Passing high clouds and light winds are then expected to develop after sunset and continue through the remainder of the TAF period. However a 10 to 20 kt LLJ should hinder fog development tonight.

EXTENDED AVIATION OUTLOOK...Rain chances increase into the weekend along with a higher probability for morning fog/stratus concerns due to higher atmospheric moisture.

CAE WATCHES/WARNINGS/ADVISORIES

SC...None. GA...None.