textproduct: Columbia

WHAT HAS CHANGED

Aviation discussion updated for 00z TAFs.

KEY MESSAGES

- 1. Unsettled weather returns for the rest of the work week.

DISCUSSION

Key Message 1: Unsettled weather returns for the rest of the work week. Unsettled weather is expected to return for the remainder of the week as the frontal boundary lingers across the southeast and multiple shortwaves move over the region. This pattern will help expand shower and thunderstorm coverage into the forecast area, particularly as a weak surface low attempts to develop along the stalled boundary Tuesday morning. The latest guidance trends keep the highest moisture transport and PWATs generally south of the area for much of the week, keeping the highest PoPs in the southern portions of the forecast area and locations south. Periods of scattered showers and storms are expected Tuesday and Wednesday as a summer-like pattern returns. Instability appears relatively weak, so widespread severe weather is not anticipated at this time, but given the time of year, a strong storm is capable of producing gusty winds.

Looking further, most deterministic guidance remain in good agreement regarding a vigorous shortwave trough diving into the Upper Midwest while a weak tropical disturbance drifts across the western Gulf. The associated low is expected to lift into the northeast along the boundary, helping to maintain a stalled front across the Deep South. Temperatures should gradually warm back to near-normal by midweek, while increased moisture chances return after Thursday. Forecast confidence decreases late in the week as model solutions diverge on the evolution of the low in the Gulf as it tracks inland along the frontal zone across the Southeast. The ECMWF continues to depict a stronger and slower- moving system, while the GFS remains faster with the wave reaching the area by Thursday. Regardless, increasing rain chances appear likely late in the week as upper level winds will pull moisture from the system to the North and East. A heavy rainfall threat and isolated severe weather could be possible, but confidence remains too low for greater detail at this time. By the weekend, drier air should return as the upper trough shifts eastward.

AVIATION /00Z TUESDAY THROUGH SATURDAY/

VFR conditions generally expected through the TAF period.

Mid to high level clouds are starting to stream over the area from the southwest. Expect cloud cover through the TAF period, with ceilings gradually lowering. Ceilings are likely to remain VFR, however. Winds become light and variable to calm overnight, increasing out of the WSW after about 13z. Winds shift to more southwesterly after 18z, with gusts in the 15 to 20 kts. Guidance continues to indicate the potential for shower activity near AGS, DNL, AIK, and OGB through the day, but probabilities are low that showers affect those terminals until after 18z, when the potential for tsra exists. Chances remain too low to include any mention of activity at CAE or CUB at this time, but can't rule out a shower or storm late in the period there.

EXTENDED AVIATION OUTLOOK...Diurnally favored convection possible each afternoon mid week with possible morning fog/stratus bringing restrictions. Breezy conditions expected Thu/Fri.

CAE WATCHES/WARNINGS/ADVISORIES

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