textproduct: Columbia

WHAT HAS CHANGED

Minimal change to Key Messages. Aviation discussion updated for 18Z 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 continues to not be 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. Temperatures will be about 3 to 8 degrees above normal for much of the forecast period, with heat indices approaching the triple digits but still cooler than the first week of September.

AVIATION /00Z FRIDAY THROUGH TUESDAY/

VFR conditions continue through this evening. Brief restrictions possible Friday morning.

A few showers have developed this evening across the western and central parts of the forecast area, with brief restrictions in vis down to 2SM noted at CAE with a passing shower, but probabilities for any continuing impacts through the next 2-3 hours at any of the terminals is rather low as they diminish. Light winds and VFR conditions likely continue this evening and tonight, though southwesterly flow should continue to advect moisture into the region. Chances are low for brief restrictions early Friday due to stratus and/or fog, mainly near the southeastern Midlands and OGB. Probabilities for ceiling restrictions across guidance remain low (20-40%), and have kept out mention of MVFR or IFR ceilings. Any patchy restrictions should clear by late morning (13-15z) Friday with light winds turning out of the southwest. Chances for potential restrictions will increase with isolated to scattered showers and thunderstorms developing by early to mid-afternoon across the forecast area, with greater coverage favored across the CSRA for the AGS, DNL, and AIK terminals.

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.