textproduct: Columbia

WHAT HAS CHANGED

A Heat Advisory remains in effect through 8pm Friday evening. It remains unclear if heat products will be needed this weekend. Aviation discussion updated for 12z TAFs.

KEY MESSAGES

- 1. A Heat Advisory remains in effect through 8pm Friday evening with heat Indices between 105-110F expected.

- 2. Rain chances are lower today but increase again this weekend and into next week.

DISCUSSION

- 1. A Heat Advisory remains in effect through 8pm Friday evening with heat Indices between 105-110F expected.

The upper ridge axis centered to the west is expected to be strongest today, breaking down and flattening this weekend. This should limit convective activity today and result in warmer daytime temperatures. The combination of highs in the mid to upper 90s and high dewpoints should result in peak heat index values between 105 and 110 today. A Heat Advisory remains in effect until 8pm this evening. With the weakening ridge, it remains unclear if the advisory will be extended again for Saturday. The latest guidance shows another day of heat index values near criteria and any extension will likely be coordinated later today when the latest guidance comes in.

- 2. Rain chances are lower today but increase again this weekend and into next week.

As mentioned, the ridge should result in decreased convective development across the FA today, with the highest probabilities currently anticipated in the CSRA. Having said that, the atmosphere remains very moist therefore an isolated shower or thunderstorm cannot be ruled out anywhere today.

As the ridge weakens this weekend, a more typical August pattern should return with daily convective chances. With high PWATs expected and an inverted-V in modeled soundings, any robust thunderstorms could produce localized flash flooding and damaging wind gusts. There is also a signal that a trough could develop over the eastern CONUS towards the middle portion of next week resulting in a wetter pattern and near to below normal temperatures.

AVIATION /12Z FRIDAY THROUGH TUESDAY/

VFR conditions likely outside of scattered convection Friday afternoon and evening.

Some shallow sunrise stratus-fog is possible through 13-14z this morning, but no restrictions expected in the TAFs at this time; mentioned MIFG with no restrictions at AGS, CAE, and AIK through 13z this morning. For the rest of Friday, a typical summer day is expected with cu around 5k feet developing and late afternoon & evening scattered thunderstorms. Prob30 group included for all TAF sites for tsra this afternoon- evening. Winds throughout the day will be west- southwest, with some gusts periodically up to 10 knots outside of any convection.

EXTENDED AVIATION OUTLOOK...Diurnal chances for thunderstorms continue each day through the weekend.

CAE WATCHES/WARNINGS/ADVISORIES

SC...Heat Advisory until 8 PM EDT this evening for SCZ016-018- 020>022-025>031-035-037-038-041-115-116-135>137. GA...Heat Advisory until 8 PM EDT this evening for GAZ040-063>065- 077.