textproduct: Columbia

WHAT HAS CHANGED

Heat and humidly return with isolated diurnal convection continuing. Aviation discussion updated for 12z TAFs.

KEY MESSAGES

- 1. Hot and humid conditions return, with chances for diurnal showers and thunderstorms each day.

DISCUSSION

- 1. Hot and humid conditions return, with chances for diurnal showers and thunderstorms each day.

The mid/upper level low will continue to weaken and become absorbed into the broader trough as it lifts northeastward away from the region, resulting in a gradual reduction in its influence. Heights will rise through the remainder of the week supporting a slow warming trend with increasing afternoon temperatures. Meanwhile, PWAT values will steadily increase as the drier mid-level air is replaced by a more moist subtropical airmass. Although the trough is expected to weaken, the return of 1.8-2" PWATs will support continued daily convection. Pops will trend closer to climatological normals, with diurnally driven pulse convection expected to develop each afternoon and evening. Coverage should remain more isolated compared to the widespread activity over the past several days. The severe component should also decrease as DCAPE lowers and shear weakens, although a marginally severe microburst cannot be ruled out each day.

Convective temperatures are forecast to range from 88-93F, which should be reached relatively easily given the warm and humid boundary layer. With oppressive low-level moisture, weak mid/upper-level flow, and minimal large-scale forcing in place, the region will settle into a typical summertime pattern.

AVIATION /12Z WEDNESDAY THROUGH SUNDAY/

Restrictions this morning through 14z, then improving back to vfr outside of any shower activity the remainder of the period..

Showers are well east of taf sites this morning, and guidance not showing any shower development until after 18z. Bigger issue this morning will be the lifr ceilings and visibility restrictions that both satellite and surface observations are indicating across portions of the forecast area. Satellite showing cloud cover more widespread across the Midlands sites of cae/cub/ogb, and still developing south and east of the CSRA sites of ags/dnl. Do still expect some lower ceilings to develop towards sunrise in the CSRA. In addition, can not rule out periods of lifr visibility through 14z. After 14z, conditions should begin improving back towards vfr at all sites as low clouds break up and scatter out more. Vfr conditions then expected for the remainder of the taf period, although once again can not rule out another period of ceiling and visibility restrictions late tonight and into Thursday. With the potential afternoon showers and thunderstorms, PROB30 groups remain in all tafs through sunset, similar to previous days. Winds generally light overnight, then more out of the southeast through the day.

EXTENDED AVIATION OUTLOOK...Diurnal thunderstorms expected this week with early morning restrictions possible.

CAE WATCHES/WARNINGS/ADVISORIES

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