textproduct: Columbia

WHAT HAS CHANGED

Early morning showers and storms should diminish over the next few hours. Heat and humidity continue, with diurnal chances for showers/thunderstorms this afternoon and evening. Aviation discussion updated for 06z TAFs.

KEY MESSAGES

- 1. Diurnal showers and storms each day through the period.

DISCUSSION

- 1. Diurnal showers and storms each day through the period.

Rounds of showers and thunderstorms continue to move through the area from the west along remnant outflow boundaries. However, convection has started to weaken, especially as it approaches the I-20 corridor. Any lingering activity should dissipate into the early morning hours.

Little change has been made in the overall forecast. The weak upper level low that has been spinning over the southern Appalachians is finally being absorbed into a digging longwave trough extending south from the Great Lakes. In its wake, guidance remains in good agreement that a low-amplitude, seasonably strong ridge centered just to our south will build in by the weekend. Deep-layer southwesterly flow will maintain elevated PWATs through the end of the week. A classic summertime pattern will persist as 500mb heights climb to around the 90th percentile for early August. Highs will remain in the low to mid 90s with daily afternoon and evening showers/thunderstorms. With PWATs generally between 1.8-2", expect typical summertime convection. While a few stronger storms cannot be ruled out, widespread severe weather is not expected. However, efficient rainfall rates and slow storm motions may result in localized flash flooding.

AVIATION /06Z THURSDAY THROUGH MONDAY/

Ceiling and visibility restrictions possible once again through sunrise this morning. Otherwise expecting VFR conditions to be likely outside of isolated storms.

Another round of nighttime showers and thunderstorms across the region will bring some restrictions within that activity as it moves across any taf location. Outside of the rainfall overnight, may see some periods of vfr, but once again towards morning expecting to see mvfr/ifr ceilings and visibilities to develop due to plentiful low- level moisture in place. The potential for widespread dense fog and extremely low cigs appears lower that previous morning, but still may see some patchy lifr conditions through 14z again.

For much of the daytime hours after 14z, ceilings should lift back to VFR with cumulus returning for most of the day. Similar coverage of isolated afternoon and evening showers/thunderstorms is expected, with current probabilities supporting a PROB30 group, consistent with previous days lasting into the evening hours.

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

CAE WATCHES/WARNINGS/ADVISORIES

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