textproduct: Columbia

WHAT HAS CHANGED

Current conditions have been updated based on latest observations. Aviation discussion updated for 18z TAFs.

KEY MESSAGES

- 1. Hot conditions continue across the area, with chances for thunderstorms the next couple of days. Higher chances of rain return this weekend with a slow moving front.

DISCUSSION

Key Message 1: Hot conditions continue across the area, with chances for thunderstorms the next couple of days. Higher chances of rain return this weekend with a slow moving front.

Forecast guidance has struggled significantly over the past few days in resolving convective coverage, consistently underestimating the extent of development. Despite this, the overall pattern/signal today remains the same, with most guidance continuing to suggest lower coverage than what may actually occur. The environment this afternoon closely resembles yesterday's setup, with temps in the lower 90s, PWATs over 2 inches, SBCAPE of 2500-3500 J/kg, DCAPE of 700-800 J/kg, and TEI ~25. Additionally, a few residual outflow boundaries from yesterdays activity may still be present across the area and could locally enhance convection. Cumulus development is already underway with spotty showers popping up in the northern and eastern portions of our CWA as the atmosphere destabilizes. Coverage will likely be somewhat lower than yesterday as mid- level heights slowly rise and subsidence increases. However, given the current environment, strong to severe thunderstorms remain possible.

Upper-level ridging over the western Atlantic near FL will build northward, shifting the focus of diurnal convection farther west through the week. Mid-level heights will continue to rise into Wed/Thu, resulting in a gradual decrease in convection. A few embedded shortwaves within a weak upper trough moving across the Carolina's on Thursday could support an uptick in showers/thunderstorms, though confidence remains low. Flow will become more zonal ahead of an approaching front this weekend, bribing another increase in shower and thunderstorm chances across the area.

As has been emphasized over the past week, the ongoing heat remains a concern, particularly for locations that receive limited relief from the afternoon convection. Temperatures are expected to remain 3-6 degrees above normal through Saturday, with height indices reaching the low to mid-100s. Most locations should remain below Heat Advisory criteria (108F), so no Heat Advisories are anticipated at this time. Continue to practice heat safety, especially with prolonged heat expected to persist. Please remain diligent if you have outdoor activities planned.

AVIATION /18Z TUESDAY THROUGH SUNDAY/

VFR conditions generally expected through the TAF period with brief restrictions in afternoon TSRA/SHRA.

Regional radar showing scattered convection has develop over the eastern portions of the Central Midlands early this afternoon. Some drier air is pushing in from the west, and as this moves in it should help to move the convection further east as the afternoon progresses. North and East is also where the deeper moisture and better instability is located too.

With low rain chances over the CSRA, have elected to leave out mention of any rainfall at this time through the forecast period at ags/dnl/aik. Further east at cae/cub/ogb, will have a brief 2 hour tempo window for a few showers and thunderstorms remaining close to those locations before the activity moves further east, then after 20z leave mention of any precip out for the remainder of the period.

Outside of any showers, vfr conditions are expected to prevail. If a shower does impact a site, brief mvfr visibilities and gusty winds may occur.

Winds will be west to southwesterly between 5-10 knots each day, while diminishing to less than 5 knots during the overnight hours.

EXTENDED AVIATION OUTLOOK...Daily rain chances and possible restrictions continue through at least midweek.

CAE WATCHES/WARNINGS/ADVISORIES

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